Transurethral microwave thermotherapy for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia

Juan VA Franco; Luis Garegnani; Camila Micaela Escobar Liquitay; Michael Borofsky; Philipp Dahm

doi:10.1002/14651858.CD004135.pub4

Termoterapia transuretral con microondas para el tratamiento de los síntomas urinarios bajos en hombres con hiperplasia prostática benigna

Declaraciones de intereses de los autores

Versión publicada: 28 junio 2021 Historial de versiones

https://doi.org/10.1002/14651858.CD004135.pub4

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Resumen

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Antecedentes

La resección transuretral de la próstata (RTUP) ha sido el tratamiento de referencia para aliviar los síntomas urinarios y mejorar el flujo urinario en los hombres con hiperplasia benigna de la próstata (HBP) sintomática. Sin embargo, la morbilidad de la RTUP es de cerca de un 20% y se han desarrollado técnicas menos invasivas para tratar la HBP. La termoterapia transuretral con microondas (TTUM) es un tratamiento alternativo mínimamente invasivo que suministra energía de microondas para producir necrosis por coagulación en el tejido prostático. Esta es una actualización de una revisión publicada por última vez en 2012.

Objetivos

Evaluar los efectos de la termoterapia transuretral con microondas para el tratamiento de los síntomas urinarios bajos en hombres con hiperplasia prostática benigna.

Métodos de búsqueda

Se realizó una búsqueda exhaustiva en varias bases de datos (la Biblioteca Cochrane, MEDLINE, Embase, Scopus, Web of Science y LILACS), registros de ensayos, otras fuentes de literatura gris y resúmenes de congresos publicados hasta el 31 de mayo de 2021, sin restricciones por idioma ni por estado de publicación.

Criterios de selección

Se incluyeron ensayos controlados aleatorizados (ECA) y ECA por conglomerados de participantes con HBP que recibieron TTUM.

Obtención y análisis de los datos

Dos autores de la revisión, de forma independiente, evaluaron los estudios para inclusión en cada etapa, y realizaron la extracción de los datos y las evaluaciones del riesgo de sesgo y de GRADE de la certeza de la evidencia (CdE). Los desenlaces de la revisión medidos hasta los 12 meses después de la asignación al azar se consideraron como a corto plazo y los medidos después de los 12 meses como a largo plazo. Los desenlaces principales fueron: puntuaciones de síntomas urológicos, calidad de vida, eventos adversos graves, necesidad de un nuevo tratamiento, y función eyaculatoria y eréctil.

Resultados principales

En esta actualización no se identificaron nuevos ECA, pero se incluyeron datos de estudios excluidos en la versión anterior de la revisión. Se incluyeron 16 ensayos con 1919 participantes con una mediana de edad de 69 años y síntomas urinarios bajos moderados. La certeza de la evidencia para la mayoría de las comparaciones fue moderada a baja, debido a un alto riesgo general de sesgo en los estudios y a la imprecisión (escasos participantes y pocos eventos).

TTUM versus RTUP

Según los datos de cuatro estudios con 306 participantes, en comparación con la RTUP, la TTUM probablemente suponga poca o ninguna diferencia en las puntuaciones, en el seguimiento a corto plazo, de los síntomas urológicos medidas con la International Prostatic Symptom Score (IPSS) en una escala de 0 a 35, donde las puntuaciones más altas indican peores síntomas (diferencia de medias [DM] 1,00; intervalo de confianza [IC] del 95%: ‐0,03 a 2,03; certeza moderada). Es probable que la diferencia en la calidad de vida sea escasa o nula (DM ‐0,10; IC del 95%: ‐0,67 a 0,47; un estudio; 136 participantes; certeza moderada). Es probable que la TTUM produzca menos eventos adversos graves (RR 0,20; IC del 95%: 0,09 a 0,43; seis estudios, 525 participantes; certeza moderada); sobre la base de 168 casos por 1000 hombres del grupo de RTUP, que se corresponde con 135 menos (153 a 96 menos) por cada 1000 hombres del grupo de TTUM. No obstante, es probable que la TTUM dé lugar a un gran aumento en la necesidad de un nuevo tratamiento (razón de riesgos [RR] 7,07; IC del 95%: 1,94 a 25,82; cinco estudios, 337 participantes; certeza moderada) (a menudo repetición de la TTUM o la RTUP); sobre la base de cero casos por 1000 hombres del grupo de RTUP, que se corresponde con 90 más (40 a 150 más) por 1000 hombres del grupo de TTUM. Podría haber poca o ninguna diferencia entre las intervenciones en la función eréctil (RR 0,63; IC del 95%: 0,24 a 1,63; cinco estudios, 337 participantes; certeza baja). Sin embargo, la TTUM podría dar lugar a menos casos de disfunción eyaculatoria en comparación con la RTUP (RR 0,36; IC del 95%: 0,24 a 0,53; cuatro estudios; 241 participantes; certeza baja).

TTUM versus tratamiento simulado

A partir de los datos de cuatro estudios con 483 participantes, se encontró que, en comparación con el tratamiento simulado, la TTUM probablemente reduce las puntuaciones de los síntomas urológicos medidas con la IPSS en el seguimiento a corto plazo (DM ‐5,40; IC del 95%: ‐6,97 a ‐3,84; certeza moderada). La TTUM podría conllevar poca o ninguna diferencia en la calidad de vida (DM ‐0,95; IC del 95%: ‐1,14 a ‐0,77; dos estudios, 347 participantes; certeza baja) medida según la pregunta de calidad de vida de la IPSS en una escala de 0 a 6, donde puntuaciones más altas indican una peor calidad de vida. Existe muy poca seguridad en la evidencia acerca de los efectos sobre los eventos adversos graves, puesto que la mayoría de estudios no informaron eventos ni lesiones aisladas del tracto urinario. La TTUM también podría reducir la necesidad de un nuevo tratamiento en comparación con el tratamiento simulado (RR 0,27; IC del 95%: 0,08 a 0,88; dos estudios, 82 participantes; certeza baja); sobre la base de 194 nuevos tratamientos por 1000 hombres del grupo de tratamiento simulado, que se corresponde con 141 menos (178 a 23 menos) por 1000 hombres del grupo de TTUM. Existe muy poca seguridad sobre los efectos en la función eréctil y eyaculatoria (certeza muy baja), ya que se encontraron informes aislados de impotencia y trastornos eyaculatorios (aneyaculación y hematospermia).

No hubo datos disponibles para las comparaciones de la TTUM versus la terapia térmica de vapor de agua por radiofrecuencia convectiva, la elevación de la uretra prostática, la embolización arterial prostática o el dispositivo de nitinol implantable temporal.

Conclusiones de los autores

La TTUM proporciona una reducción similar de los síntomas urinarios en comparación con el tratamiento estándar (RTUP), con menos eventos adversos graves y menos casos de disfunción eyaculatoria en el seguimiento a corto plazo. Sin embargo, es probable que la TTUM dé lugar a un gran aumento en las tasas de nuevos tratamientos. Las limitaciones y la imprecisión de los estudios redujeron la confianza que se puede depositar en los resultados. Además, la mayoría de los estudios se realizaron hace más de 20 años. Dada la aparición de nuevos tratamientos mínimamente invasivos, se necesitan ensayos de alta calidad de comparación directa con un seguimiento más prolongado para aclarar su efectividad relativa. Los valores y preferencias de los pacientes, sus comorbilidades y los efectos de otros procedimientos mínimamente invasivos disponibles, entre otros factores, pueden orientar a los profesionales clínicos a la hora de elegir el tratamiento óptimo para esta afección.

PICO

Population

Intervention

Comparison

Outcome

El uso y la enseñanza del modelo PICO están muy extendidos en el ámbito de la atención sanitaria basada en la evidencia para formular preguntas y estrategias de búsqueda y para caracterizar estudios o metanálisis clínicos. PICO son las siglas en inglés de cuatro posibles componentes de una pregunta de investigación: paciente, población o problema; intervención; comparación; desenlace (outcome).

Para saber más sobre el uso del modelo PICO, puede consultar el Manual Cochrane.

Resumen en términos sencillos

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Termoterapia transuretral con microondas para los síntomas urinarios bajos en hombres con hiperplasia prostática benigna

Pregunta de la revisión

¿La termoterapia transuretral con microondas (TTUM) mejora los síntomas urinarios molestos sin efectos secundarios indeseables en hombres con próstata agrandada?

Antecedentes

La hipertrofia prostática puede causar síntomas molestos de las vías urinarias, como el aumento de la necesidad de orinar durante el día o la noche, un chorro débil y la sensación de falta de vaciamiento de la vejiga. Cuando los cambios en el estilo de vida (como beber menos líquidos) o los medicamentos no surten efecto, los hombres pueden optar por la cirugía, como la resección transuretral de la próstata. Sin embargo, esta intervención podría causar efectos indeseables, como problemas de erección y eyaculación, o requerir un nuevo tratamiento. Esta revisión observa los resultados de la termoterapia transuretral con microondas (TTUM), que es una intervención alternativa, menos invasiva, que utiliza energía de microondas para reducir el tejido prostático.

Características de los estudios
No se encontraron estudios que compararan la termoterapia transuretral con microondas con otros tratamientos más nuevos y menos invasivos para esta afección.

Se encontraron 16 estudios con 1919 hombres que compararon la termoterapia transuretral con microondas con una intervención simulada (a los participantes se les hace creer que reciben el tratamiento, cuando en realidad no es así) o con cirugía tradicional (resección transuretral de la próstata [RTUP]). La media de edad de los participantes fue de 69 años, y la mayoría presentaba un grado moderado de síntomas urinarios molestos.

Resultados clave

En comparación con la cirugía tradicional, la termoterapia transuretral con microondas probablemente produce poca o ninguna diferencia en los síntomas urinarios a corto plazo, pero no existe seguridad sobre sus efectos a largo plazo. Podría haber poca o ninguna diferencia en la calidad de vida o en los problemas de erección entre estas intervenciones, tanto a corto como a largo plazo. Es probable que esta intervención produzca menos efectos secundarios graves y problemas de eyaculación en comparación con la cirugía. Sin embargo, es probable que dé lugar a un aumento en la necesidad de un nuevo tratamiento (incluida la cirugía).

En comparación con una intervención simulada, es probable que la termoterapia transuretral con microondas mejore los síntomas urinarios y la necesidad de un nuevo tratamiento a corto plazo (menos de 12 meses). Este tratamiento podría dar lugar a poca o ninguna diferencia en la calidad de vida. No existe seguridad en cuanto a si los efectos secundarios graves indeseables, incluidos los problemas de erección y eyaculación, son más frecuentes o no.

Los resultados de esta revisión están actualizados hasta el 31 de mayo de 2021.

Certeza de la evidencia

La certeza de la evidencia para los desenlaces varió en su mayoría de moderada a baja debido al pequeño tamaño de los estudios y a deficiencias en cómo se realizaron. Esto significa que la confianza en los resultados es moderada o limitada.

Authors' conclusions

Implications for practice

TUMT provides a similar reduction in urinary symptoms compared to the standard treatment (TURP), with fewer major adverse events and fewer cases of ejaculatory dysfunction at short‐term follow‐up. However, TUMT probably results in a large increase in retreatment rates. Most of the evidence is short‐term and from studies with a high risk of bias. Patients' values and preferences, their comorbidities and the effects of other available minimally‐invasive procedures, among other factors, can guide clinicians when choosing the optimal treatment for this condition.

Implications for research

Relatively few patients have been studied in controlled clinical trials of TUMT, and there is a paucity of research on this procedure in the last 20 years. Further studies with better reporting, using randomized treatment allocation, larger sample sizes, and comprehensive measures of relevant outcomes, including adverse events, are still needed to better define the role of TUMT techniques for treating lower urinary tract symptoms in men with benign prostatic hyperplasia. With the emergence of newer minimally‐invasive treatments, head‐to‐head comparisons between them could clarify their relative effectiveness.

Summary of findings

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Summary of findings 1. Transurethral microwave thermotherapy compared to transurethral resection of the prostate for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia

Outcomes	№ of participants (studies) Follow up	Certainty of the evidence (GRADE)	Relative effect (95% CI)	*Anticipated absolute effects^ (95% CI)**
Transurethral microwave thermotherapy compared to transurethral resection of the prostate for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia
Patient or population: men with lower urinary tract symptoms due to benign prostatic hyperplasia Setting: outpatient (TUMT) / inpatient (TURP) ‐ UK, Netherlands, Scandinavia, USA Intervention: Transurethral microwave thermotherapy (TUMT) Comparison: Transurethral resection of the prostate (TURP)
Outcomes	№ of participants (studies) Follow up	Certainty of the evidence (GRADE)	Relative effect (95% CI)	Risk with transurethral resection of the prostate (TURP)	Risk difference with Transurethral microwave thermotherapy
Urologic symptom scores Assessed with: IPSS Scale from 0 (best: not at all) to 35 (worst: almost always) Follow‐up: 6 ‐ 12 months	306 (4 RCTs)	⊕⊕⊕⊝ MODERATE^a	‐	The mean urologic symptoms score (IPSS) was 5.63	MD 1 higher (0.03 lower to 2.03 higher)
Quality of life Assessed with: IPSS‐QoL Scale from 0 (best: delighted) to 6 (worst: terrible) Follow‐up: 12 months	136 (1 RCT)	⊕⊕⊕⊝ MODERATE^a	‐	The mean quality of life was 1.5	MD 0.10 lower (0.67 lower to 0.47 higher)
Major adverse events Assessed with: Clavien‐Dindo classification system (Grade III, IV and V complications) Follow‐up: 6 ‐ 12 months	525 (6 RCTs)	⊕⊕⊕⊝ MODERATE^a	RR 0.20 (0.09 to 0.43)	Study population
	525 (6 RCTs)	⊕⊕⊕⊝ MODERATE^a	RR 0.20 (0.09 to 0.43)	168 per 1000	135 fewer per 1000 (153 fewer to 96 fewer)
Retreatment Participants requiring additional procedures or surgery Follow‐up: 6 ‐ 12 months	463 (5 RCTs)	⊕⊕⊕⊝ MODERATE^a,b	RR 7.07 (1.94 to 25.82)	Study population
	463 (5 RCTs)	⊕⊕⊕⊝ MODERATE^a,b	RR 7.07 (1.94 to 25.82)	0 per 1000	90 more per 1000 (40 more to 150 more)
Erectile function (sexually‐active men only) Assessed with: issues related to erectile function Follow‐up: 6 ‐ 12 months	337 (5 RCTs)	⊕⊕⊝⊝ LOW^a,c	RR 0.63 (0.24 to 1.63)	Study population
	337 (5 RCTs)	⊕⊕⊝⊝ LOW^a,c	RR 0.63 (0.24 to 1.63)	129 per 1000	48 fewer per 1000 (98 fewer to 82 more)
Ejaculatory function (sexually‐active men only) Assessed with: issues related to ejaculatory function Follow‐up: 6 ‐ 12 months	241 (4 RCTs)	⊕⊕⊝⊝ LOW^a,c	RR 0.36 (0.24 to 0.53)	Study population
	241 (4 RCTs)	⊕⊕⊝⊝ LOW^a,c	RR 0.36 (0.24 to 0.53)	523 per 1000	335 fewer per 1000 (397 fewer to 246 fewer)
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; MD: mean difference; RCT: randomized controlled trial; RR: Risk ratio.
GRADE Working Group grades of evidence High certainty: We are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect. Very low certainty: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect.
^aDowngraded by one level for study limitations: studies at an overall high risk of bias. ^bWe did not downgrade for imprecision since we used a minimally conceptualized approach: although the confidence interval is wide, there are no concerns about whether the effect results in a moderate to a large increase in the retreatment rate. ^cDowngraded by one level for imprecision: the incidence is mostly reported in a subset of sexually‐active participants.

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Summary of findings 2. Transurethral microwave thermotherapy compared to sham treatment for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia

Outcomes	№ of participants (studies) Follow up	Certainty of the evidence (GRADE)	Relative effect (95% CI)	*Anticipated absolute effects^ (95% CI)**
Transurethral microwave thermotherapy compared to sham treatment for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia
Patient or population: men with lower urinary tract symptoms due to benign prostatic hyperplasia Setting: outpatient ‐ France, USA, UK, Sweden, Netherlands Intervention: Transurethral microwave thermotherapy Comparison: Sham treatment
Outcomes	№ of participants (studies) Follow up	Certainty of the evidence (GRADE)	Relative effect (95% CI)	Risk with sham treatment	Risk difference with Transurethral microwave thermotherapy
Urologic symptom scores Assessed with: IPSS Scale from 0 (best: not at all) to 35 (worst: almost always) Follow‐up: 3 ‐ 6 months	483 (4 RCTs)	⊕⊕⊕⊝ MODERATE^a	‐	The mean urologic symptom scores was 16.2	MD 5.40 lower (6.97 lower to 3.84 lower)
Quality of life Assessed with: IPSS‐QoL Scale from 0 (best: delighted) to 6 (worst: terrible) Follow‐up: 6 months	347 (2 RCTs)	⊕⊕⊝⊝ LOW^a,b	‐	The mean quality of life score was 3.05	MD 0.95 lower (1.14 lower to 0.77 lower)
Major adverse events Assessed with: Clavien‐Dindo classification system (Grade III, IV and V complications) Follow‐up: 6 ‐ 12 months	924 (8 RCTs)	⊕⊝⊝⊝ VERY LOW^a,c	‐	Six studies reported that there were no major adverse events. The two remaining studies reported four isolated cases of lesions of the urinary tract related to the procedure in both groups.
Retreatment Participants requiring additional procedures or surgery Follow‐up: 6 ‐ 12 months	82 (2 RCTs)	⊕⊕⊝⊝ LOW^a,d	RR 0.27 (0.08 to 0.88)	Study population
	82 (2 RCTs)	⊕⊕⊝⊝ LOW^a,d	RR 0.27 (0.08 to 0.88)	194 per 1000	141 fewer per 1000 (178 fewer to 23 fewer)
Erectile function (sexually‐active men only) Assessed with: issues related to erectile function Follow‐up: 6 ‐ 12 months	375 (3 RCTs)	⊕⊝⊝⊝ VERY LOW^a,c	‐	Two studies reported normal erections. One study reported one case of impotence.
Ejaculatory function (sexually‐active men only) Assessed with: issues related to ejaculatory function Follow‐up: 6‐12 months	727 (5 RCTs)	⊕⊝⊝⊝ VERY LOW^a,c	‐	Three studies reported no issues related to ejaculatory function. The two remaining studies reported isolated cases of loss of ejaculate and hematospermia.
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; MD: mean difference; RCT: randomized controlled trial; RR: Risk ratio.
GRADE Working Group grades of evidence High certainty: We are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect. Very low certainty: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect.
^aDowngraded by one level for study limitations: studies at an overall high risk of bias. ^bDowngraded by one level for imprecision: confidence interval crosses assumed threshold of minimal clinically important difference. ^cDowngraded by two levels for imprecision: very few events (isolated reports). ^dDowngraded by one level for imprecision: few events.

Background

Description of the condition

The prostate gland is an organ approximately the size of a walnut located below the urinary bladder encircling the urethra (Leissner 1979). Benign prostatic hyperplasia (BPH) is a histological diagnosis defined as an increased number of epithelial and stromal cells in the prostate; this may cause prostatic enlargement and subsequently compression of the urethra and obstruction (Roehrborn 2008). BPH may therefore develop with or without lower urinary tract symptoms (LUTS) in men aged over 40 years (Dunphy 2015). BPH acquires clinical significance when associated with bothersome LUTS (Roehrborn 2008). 'Symptom bother' typically correlates with the increased number and severity of symptoms, which relate to both the quality‐of‐life impairment and treatment‐seeking (Agarwal 2014). Self‐administered questionnaires, (e.g. the International Prostate Symptom Score (IPSS)), include the quality‐of‐life domain to evaluate the relative degree of bother across all LUTS (Barry 1995). Chapple 2017 reported that increasing LUTS severity was associated with worsening men's overall distress using the patient perception of bladder condition, which is a single‐item global question (ranging from 1 (causes no problems at all) to 6 (causes severe problems)). In this Cochrane Review, we consider the term BPH as prostatic enlargement with LUTS to define the disease condition and potential need for intervention.

BPH can progress and cause serious consequences such as acute urinary retention, urinary tract infection, and upper urinary tract deterioration. BPH also negatively impacts public health and a reduction in a person's quality of life (Kozminski 2015; Martin 2014). In Europe, 30% of men over 50 years of age, equivalent to 26 million men, are affected by bothersome LUTS, including storage symptoms (such as urinary frequency, urgency, and nocturia) or voiding symptoms (such as urinary hesitancy, weak urinary stream, straining to void, and prolonged voiding), or both. The yearly reported associated number of medical prescriptions is estimated to be around 11.6 million for 74 million people at risk from 2004 to 2008 (Cornu 2010). According to an international study involving 7588 men, the prevalence of LUTS was 18% in 40‐year‐olds, 29% in the 50s, 40% in the 60s, and 56% in the 70s (Homma 1997). In the USA, an estimated eight million men over 50 years of age have BPH (Roehrborn 2008). More recent data show that the lifetime prevalence of BPH was 26.2% (95% confidence interval 22.8 to 29.6%) (Lee 2017).

Diagnosis

Initial evaluation of LUTS suggestive of BPH includes patient history, physical examination including a digital rectal examination, urinalysis, prostate‐specific antigen (PSA) blood test, voiding diary, and IPSS (EAU 2021; McVary 2011). A digital rectal examination is performed to assess the prostate for size and any lesions suspicious of cancer. PSA is secreted by the prostate gland and is found to be abnormally elevated in conditions such as prostate cancer, BPH, infection, or inflammation of the prostate (EAU 2021; McVary 2011). The IPSS is used to assess urinary symptom severity and quality of life. It is also used to document subjective responses to treatment (Barry 1992; EAU 2021; McVary 2011). Measurements of maximum flow rate (Q_max) and postvoid residual (PVR) are also often used in diagnosis and treatment decisions (EAU 2021; McVary 2011). A low Q_max and a large PVR predict an increased risk of symptom progression (Crawford 2006). Other tests include radiological imaging, urodynamic evaluation, and cystoscopy to determine appropriate treatment and predict treatment response (Egan 2016; McVary 2011).

Treatment

Treatment decisions are based on symptoms and the degree of bother noted by the patient. Initial treatment options for BPH include conservative management (watchful waiting and lifestyle modification) and medication (alpha‐blockers and 5‐alpha reductase inhibitors) (EAU 2021; McVary 2011). If patients have been refractory to conservative and medical treatment, and BPH causes subsequent complications, such as acute urinary retention, recurrent urinary tract infection, bladder stones or diverticula, hematuria, or renal insufficiency, surgical options are considered (EAU 2021; McVary 2011). Until the 1970s, the only option available to treat this condition and relieve LUTS was an open or endoscopic surgery to remove or resect prostatic tissue to open up the blocked urethra (Pariser 2015). Clinical guidelines recommend monopolar or bipolar transurethral resection of the prostate (TURP) as a standard treatment modality for subjective symptom relief and objective improvements in urinary flow (EAU 2021; McVary 2011), but this procedure is also associated with significant morbidity and long‐term complications, including hematuria requiring blood transfusion, urethral stricture, recurrent urinary tract infection, and urinary incontinence. Moreover, men may experience ejaculatory (65%) and erectile dysfunction (10%) related to TURP (AUA 2003). Furthermore, BPH is a disease common in elderly men who have an increased risk of complications for general anesthesia and the surgery itself (Dunphy 2015; Yoo 2012). Some alternatives to TURP include laser enucleation, vaporization, and Aquablation, but they all require spinal anesthesia (EAU 2021). In recent years, the number of men undergoing TURP has steadily declined due to increasing pharmacologic treatments (alpha‐blockers and 5‐alpha‐reductase inhibitors) and minimally‐invasive treatments that are usually performed under local anesthesia (Dahm 2021), such as convective radiofrequency water vapor therapy (Hwang 2019), prostatic urethral lift (Jung 2019), prostatic arterial embolization (Jung 2020) which are covered in current evidence‐based guidelines (Parsons 2020).

Description of the intervention

Transurethral microwave thermotherapy (TUMT) uses microwave‐induced heat to ablate prostatic tissue and is designed to have fewer major complications than TURP (Walmsley 2004). The patient is treated in an outpatient setting. Once the patient's bladder is emptied by straight catheterization, a local lidocaine gel is inserted for local anesthesia. The treatment catheter is then placed within the urethra, confirmed by the return of sterile water and transabdominal or transrectal ultrasound, and the balloon is inflated. The catheter is composed of a curved tip, a temperature sensor and a microwave unit. The distal port contains the bladder balloon, allowing for urine drainage and cooling. A rectal probe may be inserted to monitor the rectal temperature (Rubeinstein 2003).

TUMT has evolved over the past decades. Initial systems worked at lower energy or heat settings, and treatment would take around an hour with minimal discomfort, but results were disappointing. Subsequent systems incorporated catheters that provided urethral cooling, thus allowing higher energy delivery. These advances reduced the procedure time to around 30 minutes and improved outcomes, but the higher energy leads to more significant discomfort during the procedure, in which patients often require sedation and analgesia, with continued risk of urinary retention (Walmsley 2004).

While TUMT was once the most widely‐used procedure for minimally‐invasive surgical therapies among the USA's Medicare population (Yu 2008), its use has declined since its peak in 2006 (Malaeb 2012). A recent study in Australia highlighted that TUMT currently constitutes only 0.26% of all procedures performed for BPH (Morton 2020).

How the intervention might work

TUMT uses a special transurethral catheter that transmits heat into the prostate using microwaves' electromagnetic radiation, penetrating water‐rich tissue. The energy transferred by the microwave to the tissue in the form of heat‐induces coagulation necrosis, reducing prostatic volume. This mechanism may also cause denervation of receptors, decreasing smooth muscle tone of the prostatic urethra (Walmsley 2004). Temperatures lower than 45 ºC seemed ineffective in producing this effect, so higher‐energy devices were developed to reach more than 70 ºC, causing thermoablation of the prostatic tissue (Aoun 2015).

Why it is important to do this review

A review was published in 2012 (Hoffman 2012). The Cochrane Urology Review Group commissioned a network meta‐analysis of minimally‐invasive treatments for lower urinary tract symptoms (Franco 2020) that draws its evidence from individual reviews of these interventions. It therefore became necessary to update the previous version of the review in search of the latest evidence and using the latest Cochrane guidance and methodological standards. This review in its updated format intends to guide clinicians, patients, and guideline developers when assessing the available options for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia, especially considering the critical outcomes of the summary of findings table, which are now comparable with other reviews on this topic published by the Cochrane Urology Group (Hwang 2019; Jung 2019; Jung 2020; Kang 2020).

Objectives

To assess the effects of transurethral microwave thermotherapy for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia.

Methods

Criteria for considering studies for this review

Types of studies

The methods for this update have been extensively modified since its last publication to meet current methodological expectations; please refer to the Differences between protocol and review section. We included parallel‐group RCTs and cluster‐RCTs. We excluded cross‐over trials, as these study designs are not relevant in this setting. We did not include single‐armed studies. We included studies regardless of their publication status or language.

Types of participants

We defined the eligible participant population as men over the age of 40 years with a prostate volume of 20 mL or greater (as assessed by ultrasound or cross‐sectional imaging), with lower urinary tract symptoms (LUTS) as determined by International Prostate Symptom Scores (IPSS) of eight or over, and a maximum flow rate (Q_max) of less than 15 mL/second, as measured by non‐invasive uroflowmetry, invasive pressure flow studies, or both (Dunphy 2015; EAU 2021; McNicholas 2016; McVary 2011). We based the age limit on the fact that the prevalence of BPH increases in middle‐aged and older men and is infrequent in younger men (Barry 1997; EAU 2021; Egan 2016). We included studies in which only a subset of participants was relevant to this review (i.e. studies with more than 75% of participants only as relevant to the review) if data were available separately for the relevant subset.

We excluded studies of men with active urinary tract infection, bacterial prostatitis, chronic renal failure, untreated bladder calculi or large diverticula, prostate cancer, and urethral stricture disease, as well as those who had undergone prior prostate, bladder neck, or urethral surgery. We also excluded studies of people with other conditions that affect urinary symptoms, such as neurogenic bladder due to spinal cord injury, multiple sclerosis, or central nervous system disease.

Types of interventions

Experimental intervention

Transurethral microwave thermotherapy (TUMT)

Comparator interventions

Sham control (or no intervention)
Transurethral resection of the prostate (TURP) (monopolar or bipolar)
Minimally‐invasive therapies: convective radiofrequency water vapor thermal therapy (CRFWVT, also known as Rezum); prostatic urethral lift (PUL), prostatic arterial embolization (PAE), temporary implantable nitinol device (TIND)

We planned to investigate the following comparisons of experimental intervention versus comparator interventions. Concomitant interventions must be the same in the experimental and comparator groups to establish fair comparisons.

Comparisons

TUMT versus TURP
TUMT versus sham control (or no intervention)
TUMT versus CRFWVT
TUMT versus PUL
TUMT versus PAE
TUMT versus TIND

Types of outcome measures

We did not use the measurement of the outcomes assessed in this review as an eligibility criterion.

Primary outcomes

Urologic symptom scores (continuous outcome)
Quality of life (continuous outcome)
Major adverse events (dichotomous outcome)

Secondary outcomes

Retreatment (dichotomous outcome)
Erectile function (continuous outcome)
Ejaculatory function (continuous outcome)
Minor adverse events (dichotomous outcome)
Acute urinary retention (dichotomous outcome)
Indwelling urinary catheter (continuous outcome)

Method and timing of outcome measurement

We considered the clinically important differences for the review outcome measures to rate the overall certainty of evidence in the summary of findings Table 1 and summary of findings Table 2 (Jaeschke 1989; Johnston 2013).

Urologic symptom scores

Mean change from baseline or final mean value, measured using a validated scale (such as IPSS)
We considered the improvement of an IPSS score of three points as the minimal clinically important difference (MCID) to assess the efficacy and comparative effectiveness (Barry 1995). If possible, we used different thresholds of MCID based on the severity of IPSS, with a threshold of three points for men with mild LUTS, five for moderate LUTS, and eight for severe LUTS (Barry 1995).

Quality of life

Mean change from baseline or final mean value measured as a validated scale (such as IPSS‐quality of life or BPH Impact Index)
A BPH Impact Index score of one as an MCID was used to indicate improvement (Barry 2013; Rees 2015).

Major adverse events

Example: postoperative hemorrhage requiring admission or intervention
We used the Clavien‐Dindo classification system to assess surgical complications (Dindo 2004), and categorized grade III, IV and V complications as major adverse events. If the study authors of eligible studies did not use the Clavien‐Dindo system, we judged the adverse events by severity using the available information described in the studies.

Retreatment

Events requiring other surgical treatment modalities (e.g. TURP) after the intervention.

Erectile function

Mean change from baseline or final mean value measured as a total score on the International Index of Erectile Function (IIEF)‐5 questionnaire, also known as Sexual Health Inventory for Men (Rosen 1997)
We considered the MCID an erectile function domain score of four on the IIEF (Rosen 2011). If possible, we used different thresholds of MCID based on the severity of erectile dysfunction, with a threshold of two for men with mild erectile dysfunction, five for moderate erectile dysfunction, and seven for men with severe erectile dysfunction (Rosen 2011). We considered a difference in IIEF‐5 score of over five points as the MCID (Spaliviero 2010).

Ejaculatory function

Mean change from baseline or final mean value measured using the Male Sexual Health Questionnaire for Ejaculatory Dysfunction (MSHQ‐EjD) or the four‐item version of the MSHQ‐EjD (Rosen 2004; Rosen 2007)
We considered the MCID as an ejaculatory function domain score of two on the MSHQ or a four‐item version of the MSHQ‐EjD (Rosen 2004; Rosen 2007).

Minor adverse events

Example: postoperative fever or pain requiring medication
We used the Clavien‐Dindo classification system to assess surgical complications (Dindo 2004) and categorized grade I and II complications as minor adverse events. If the authors of eligible studies did not use the Clavien‐Dindo system, we judged the severity of adverse events using the available information described in these studies.

Acute urinary retention

Events requiring catheterization after the intervention

Indwelling urinary catheter

Measured in hours from intervention to urinary catheter removal (as a continuous outcome) or the need for urinary catheterization (as a dichotomous outcome)

Hospital stay

Measured in days from admission to discharge

There were no reported thresholds in adverse events, retreatment, acute urinary retention, indwelling urinary catheter, or hospital stay. We considered a clinically important difference for adverse events, retreatment, acute urinary retention, and indwelling catheter as risk ratio reductions of at least 25% (Guyatt 2011a). We used a MCID of one day (24 hours) to assess the efficacy and comparative effectiveness for indwelling urinary catheter and hospital stay.

We considered outcomes measured up to and including 12 months after randomization as short‐term, and later than 12 months as long‐term, for urologic symptom scores, quality of life, major adverse events, retreatment, erectile function, ejaculatory function, minor adverse events, and acute urinary retention. We assessed retreatment, indwelling urinary catheter and hospital stay as short‐term only.

Search methods for identification of studies

We performed a comprehensive search with no restrictions by date, by language of publication or publication status.

Electronic searches

We searched the following sources from the inception of each database to the date of search, and placed no restrictions on the language of publication:

CENTRAL (Cochrane Central Register of Controlled Trials) searched 31 May 2021;
MEDLINE (Ovid) searched 31 May 2021;
Embase (Elsevier) searched 31 May 2021;
LILACS ( Bireme) searched 31 May 2021;
Scopus searched 31 May 2021;
Web of Science (Clarivate analytics) searched 31 May 2021;
ClinicalTrials.gov (www.ClinicalTrials.gov) searched 31 May 2021;
World Health Organization International Clinical Trials Registry Platform (ICTRP; www.who.int/trialsearch/) searched 31 May 2021.

For detailed search strategies, see Appendix 1.

Searching other resources

We tried to identify other potentially eligible studies or ancillary publications by searching the reference lists of included studies, reviews, meta‐analyses, and health technology assessment reports. We also contacted the authors of the included studies to identify any further studies that we may have missed. We contacted drug/device manufacturers for ongoing or unpublished studies. We searched only the published abstract proceedings of relevant meetings of the American Urological Association, European Association of Urology, and International Continence Society for the last three years (2018 to 2020) for unpublished studies (see Appendix 2).

Data collection and analysis

Selection of studies

We used Covidence software to identify and remove potential duplicate records. Two review authors (JVAF, LIG) independently scanned abstracts and titles to determine which studies should be assessed further. Two review authors categorized all potentially relevant records as full‐text or mapped records to studies, and classified studies as included studies, excluded studies, studies awaiting classification, or ongoing studies, following the criteria in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2021). We resolved any disagreements between the two review authors through consensus or by recourse to a third review author (PD). If a resolution was not possible, we designated the corresponding study as 'awaiting classification'. We documented reasons for the exclusion of studies in the Characteristics of excluded studies table. We presented a PRISMA 2020 flow diagram showing the process of study selection (Page 2020).

Data extraction and management

We developed a dedicated data extraction form that we pilot‐tested ahead of time.

For studies that fulfilled our inclusion criteria, two review authors (JVAF and LIG) independently abstracted the following information, which we provide in the Characteristics of included studies table.

Study design
Study dates (if dates are not available, then this was reported as such)
Study settings and country
Participant inclusion and exclusion criteria (e.g. age, baseline IPSS, medical pretreatment)
Participant details, baseline demographics (e.g. age, prostate size, IPSS)
The number of participants by study and by study arm
Details of relevant experimental intervention, such as delivery devices (e.g. size of cystoscope) for the intervention and comparator (e.g. monopolar versus bipolar energy, type of laser)
Definitions of relevant outcomes, and method (e.g. type of instrument, such as IPSS) and timing of outcome measurement (e.g. in months) as well as any relevant subgroups (e.g. based on age, prostate volume, the severity of LUTS)
Study funding sources
Declarations of interest by primary investigators

We extracted outcome data relevant to this Cochrane Review as needed to calculate summary statistics and measures of variance. For dichotomous outcomes, we attempted to obtain numbers of events and totals for the study population in a 2 x 2 table, as well as summary statistics with corresponding measures of variance. We attempted to obtain means and standard deviations or other data necessary to calculate this information for continuous outcomes.

We resolved any disagreements by discussion, or if required by consultation with a third review author (PD).

We have provided information, including study identifiers, about potentially relevant ongoing studies in the Characteristics of ongoing studies table.

We contacted the authors of included studies to obtain key missing data as needed.

Dealing with duplicate and companion publications

In the event of duplicate publications, companion documents or multiple reports relating to a primary study, we maximized the yield of information by mapping all publications to unique studies and collating all available data. We used the most complete data set aggregated across all known publications. In case of doubt, we gave priority to publications reporting the longest follow‐ups associated with our primary or secondary outcomes.

Assessment of risk of bias in included studies

Two review authors (JVAF and LIG) independently assessed the risks of bias of each included study. We resolved disagreements by consensus, or by consultation with a third review author (PD). We have presented a risk of bias summary figure to illustrate these findings. We further summarize the risk of bias across the studies and domains for each outcome in each included study, in accordance with the approach for the summary assessments of the risk of bias presented in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2021).

We assessed risk of bias using Cochrane's risk of bias assessment tool (Higgins 2021). We assessed the following domains.

Random sequence generation (selection bias)
Allocation concealment (selection bias)
Blinding of participants and personnel (performance bias)
Blinding of outcome assessment (detection bias)
Incomplete outcome data (attrition bias)
Selective reporting (reporting bias)
Other potential sources of bias

We judged risk of bias domains as 'low risk', 'high risk' or 'unclear risk' and evaluated individual bias items as described in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011).

For selection bias (random sequence generation and allocation concealment), we evaluated risk of bias at study level. For performance bias (blinding of participants and personnel), we considered all outcomes as similarly susceptible to performance bias. For detection bias (blinding of outcome assessment), we grouped outcomes as susceptible to detection bias (subjective) or not susceptible to detection bias (objective).

We defined the following outcomes as subjective outcomes.

Urologic symptom scores
Quality of life
Erectile function
Ejaculatory function
Minor adverse events

We defined the following outcomes as objective outcomes.

Major adverse events
Retreatment
Acute urinary retention
Indwelling urinary catheter

We also assessed attrition bias (incomplete outcome data) on an outcome‐specific basis and present the judgment for each outcome separately when reporting our findings in the risk of bias tables.

For reporting bias (selective reporting), we evaluated the risk of bias at the study level.

Measures of treatment effect

We expressed dichotomous data as risk ratios (RRs) with 95% confidence intervals (CIs). We expressed continuous data as mean differences (MDs) with 95% CIs, unless different studies used different measures to assess the same outcome, in which case we re‐expressed the data as standardized mean differences (SMDs) with 95% CIs.

Unit of analysis issues

The unit of analysis was each individual participant. We planned to take into account the level at which randomization occurred, such as cluster‐randomized trials, and multiple observations of the same outcome. If more than one comparison from the same study was eligible for inclusion in the same meta‐analysis, we either combined study groups to create a single pairwise comparison or appropriately reduced the sample size so that the same participants did not contribute multiple times (if possible, splitting the 'shared' group into two or more groups). While the latter approach offers some solution to adjust the precision of the comparison, it does not account for correlations arising from the same set of participants being in multiple comparisons (Deeks 2021).

Dealing with missing data

We obtained missing data from corresponding study authors, if feasible, and performed intention‐to‐treat analyses if data were available. Otherwise, we performed available‐case analyses. We investigated attrition rates (e.g. dropouts, losses to follow‐up, and withdrawals), and critically appraised issues of missing data. We did not impute missing data.

Assessment of heterogeneity

We planned to assess heterogeneity. We identified heterogeneity (inconsistency) through visual inspection of the forest plots to assess the amount of overlap of CIs, and by using the I² statistic, which quantifies inconsistency across studies to assess the impact of heterogeneity on the meta‐analysis (Higgins 2002; Higgins 2003). We would have interpreted the I² statistic as follows (Deeks 2021).

0% to 40%: may not be important
30% to 60%: may indicate moderate heterogeneity
50% to 90%: may indicate substantial heterogeneity
75% to 100%: considerable heterogeneity

When we identified heterogeneity, we attempted to determine possible reasons by examining individual study and subgroup characteristics.

Assessment of reporting biases

We tried to obtain study protocols to assess selective outcome reporting.

We could not use funnel plots to assess small‐study effects due to the few number of participants in each comparison. If we had included 10 or more studies in a meta‐analysis, we would have used funnel plots to assess small‐study effects (Page 2021). Several explanations can be offered for the asymmetry of a funnel plot, including true heterogeneity of effect with respect to study size, poor methodological design (and hence bias of small studies), and publication bias. We would therefore have interpreted results cautiously.

Data synthesis

Unless there was good evidence for homogeneous effects across studies, we summarized data using a random‐effects model. We interpreted random‐effects meta‐analyses with due consideration of the whole distribution of effects. We also performed statistical analyses according to the statistical guidelines contained in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2021). For dichotomous outcomes, we used the Mantel‐Haenszel method. For continuous outcomes, we used the inverse variance method. We used Review Manager 5 (RevMan 2020) software to perform analyses.

Subgroup analysis and investigation of heterogeneity

We expected the following characteristics to potentially introduce clinical heterogeneity, and carried out subgroup analyses to investigate interactions.

Participant age (less than 65 years versus 65 years or more)
Prostate volume (less than 50 mL versus 50 mL or more)
Severity of LUTS based on IPSS (score less than or equal to 19 (moderately symptomatic) versus greater than 19 (severely symptomatic))

These subgroup analyses are based on the following observations.

Age is a well‐known risk factor of BPH surgery. Older men have a higher rate of postoperative complications compared with younger men (Bhojani 2014; Pariser 2015). The age cut‐off is based on the World Health Organization (WHO) definition of old age (WHO 2012).
The outcomes and complications of minimally‐invasive procedures, such as TURP, correlate with prostate volume (Reich 2008). We adjusted the prostate volume to 50 mL based on the available evidence.
The relationship between changes in IPSS scores and patient global ratings of improvement is influenced by the baseline scores (Barry 1995).

We planned to limit subgroup analyses to the primary outcomes only.

Sensitivity analysis

We performed sensitivity analyses limited to the primary outcomes to explore the influence of the following factors (when applicable) on effect size.

Restricting the analysis to RCTs by considering risk of bias, excluding studies with at least one domain at 'high risk' or 'unclear risk' of bias for the analyzed outcome.
Restricting the analysis to RCTs with adequately‐described inclusion criteria (prostate size, age, IPSS value, and Q_max).

Summary of findings and assessment of the certainty of the evidence

We presented the overall certainty of the evidence for each outcome according to the GRADE approach (Guyatt 2008). For each comparison, two review authors (JVAF and LIG) independently rated the certainty of the evidence for each outcome as 'high', 'moderate', 'low', or 'very low', using the GRADEpro Guideline Development Tool (GRADEpro GDT). We resolved any discrepancies by consensus or if needed by arbitration from a third review author (PD). For each comparison, we presented a summary of the evidence for the main outcomes in the summary of findings table, which provides key information about the best estimate of the magnitude of effect in relative terms and absolute differences for each relevant comparison of alternative management strategies; numbers of participants and studies addressing each important outcome; and the rating of our overall confidence in the effect estimates for each outcome (Guyatt 2011b; Schünemann 2021). We considered five criteria, not only related to internal validity (risk of bias, inconsistency, imprecision, and publication bias), but also external validity (directness of results), for downgrading the certainty of the evidence for a specific outcome (Schünemann 2021). We included the following outcomes:

Urologic symptom scores
Quality of life
Major adverse events
Retreatment
Erectile function
Ejaculatory function

Results

Description of studies

Details of included studies are presented elsewhere (see Table 1 and Characteristics of included studies).

Open in table viewer

Table 1. Characteristics of included studies

Study name	Trial period	Setting/country	Description of participants	Duration of follow‐up	Intervention and comparator	Age (mean ± SD)*	IPSS (mean ± SD)*	Prostate volume (mean ± SD)*
Abbou 1995	N/A	France	Men ≥ 50 years with symptoms > 3 months, prostate 30 ‐ 80 g, PFR < 15 mL/s, PVR < 300 mL	12 months	TUMT (Thermex II, Prostcare, BSD‐50)	65 ± 8	N/A	45 ± 15 g
Abbou 1995	N/A	France		12 months	Sham	66 ± 7	N/A	44 ± 11 g
Ahmed 1997	N/A	UK	Men ≥ 55 years with AUA score > 12 > 1 year, prostate 25 ‐ 100 mL, PFR < 15 mL/s and a PVR < 300 mL	6 months	TUMT (Prostatron)	69.36	18.5	36.6 mL
Ahmed 1997	N/A	UK		6 months	TURP	69.45	18.4	46.1 mL
Albala 2002	N/A	USA	Men 50 ‐ 80 years, AUA index > 13 and a bother score > 11, PFR < 12 mL/sec and PVR > 125 mL; prostate 30 ‐ 100 mL without a significant intravesical middle lobe	12 months	TUMT (TMx‐2000)	65.2 ± 7.3	22.2 ± 5.0	50.5 ± 18.6 mL
Albala 2002	N/A	USA		12 months	Sham	64.6 ± 7.1	22.7 ± 5.7	47.1 ± 17.9 mL
Bdesha 1994	N/A	UK	Men with prostatism (WHO score > 14), PVR > 50 mL, PFR < 15 mL/s	3 months	TUMT (LEO Microthermer)	63.7	19.2	N/A
Bdesha 1994	N/A	UK		3 months	Sham	62.6	18.8	N/A
Blute 1996	N/A	USA	Men suffering from urinary symptoms (Madsen Symptom score > 8), PVR 10000 mL, PFR < 10 mL/s, prostate length 30 ‐ 50 mm	12 months	TUMT (Prostatron)	66.9 ± 7.8	19.9 ± 7.2	37.4 ± 14.2 mL
Blute 1996	N/A	USA		12 months	Sham	66.9 ± 7.1	20.8 ± 6.7	36.1 ± 13.4 mL
Brehmer 1999	N/A	Sweden	Men suffering from lower urinary tract symptoms and with an enlarged prostate	12 months	TUMT (30' ‐ 60' ‐ ECP system)	70.4	N/A	N/A
Brehmer 1999	N/A	Sweden		12 months	Sham	70.4	N/A	N/A
D'Ancona 1998	1994 ‐ 1995	Netherlands	Men ≥ 45 years with Madsen score > 8 months, prostate 2.5 ‐ 5 cm/30 ‐ 100 mL, PFR < 15 mL/s PRV < 350 mL	24 months	TUMT (Prostatron)	69.6 ± 8.5	16.7 ± 5.6	45 ± 15 mL
D'Ancona 1998	1994 ‐ 1995	Netherlands		24 months	TURP	69.3 ± 5.9	18.3 ± 6.3	43 ± 12 mL
Dahlstrand 1995	N/A	Sweden	Men ≥ 45 years with Madsen score > 8 months, prostate 3.5 ‐ 5 cm, PFR < 15 mL/s PRV > 150 mL	24 months	TUMT (Prostatron)	68	N/A	33 mL
Dahlstrand 1995	N/A	Sweden		24 months	TURP	79	N/A	37 mL
De Wildt 1996	1991 ‐ 1992	Netherlands/UK	Men ≥ 45 years with Madsen score > 8 months, PFR < 15 mL/s PRV > 150 mL	12 months	TUMT (Prostatron)	63.3 ± 8.1	N/A	48.6 ± 16.6 mL
De Wildt 1996	1991 ‐ 1992	Netherlands/UK		12 months	Sham	66.9 ± 6.0	N/A	49.0 ± 20.0 mL
Floratos 2001	1996 ‐ 1997	Netherlands	Men ≥ 45 years, prostate ≥ 30 cm³, prostatic urethral length ≥ 25 mm, a Madsen symptom score ≥ 8, PFR ≤ 15 mL/s, PVR ≤ 350 mL	36 months	TUMT (Prostatron)	68	21	42 mL
Floratos 2001	1996 ‐ 1997	Netherlands		36 months	TURP	66	20	48 mL
Larson 1998	1994 ‐ 1996	USA	Men ≥ 45 years with AUA score > 9, enlarged prostate (3 ‐ 5 cm TRUS), PFR < 12 mL/s without a significantly enlarged middle lobe	12 months	TUMT (Targis)	66	20.8	38.1 mL
Larson 1998	1994 ‐ 1996	USA		12 months	Sham	65.9	21.3	44.7 mL
Nawrocki 1997	N/A	UK	Men with a Madsen symptom score ≥ 8, PFR ≤ 15 mL/s, PVR > 150 mL, detrusor pressure > 70 cm H2O	6 months	TUMT (Prostatron)	70 (56 ‐ 80)	19 (7 ‐ 31)	41.2 ± 14.6 mL
Nawrocki 1997	N/A	UK		6 months	Sham	70 (56 ‐ 80)	17.5 (7 ‐ 28)	46.7 ± 16.8 mL
Nørby 2002a	1996 ‐ 1997	Denmark	Men ≥ 50 years, IPSS ≥ 7, PFR ≤ 12 mL/s	6 months	TUMT (Prostatron)	66 ± 7	20.5 ± 5.7	43 (35 – 79) mL
Nørby 2002a	1996 ‐ 1997	Denmark	Men ≥ 50 years, IPSS ≥ 7, PFR ≤ 12 mL/s	6 months	TURP/TUIP	68 ± 7	21.3 ± 6.6	44 (35 – 50) mL
Roehrborn 1998	N/A	USA	Men ≥ 55 years, AUA‐SI ≥ 13, PFR ≤ 12 mL/s, prostate volume 25 ‐ 100 mL	6 months	TUMT (Dornier)	66.3 ± 6.5	23.6 ± 5.6	48.1 ± 16.2 mL
Roehrborn 1998	N/A	USA		6 months	Sham	66.0 ± 5.8	23.9 ± 5.6	50.5 ± 18.1 mL
Venn 1995	N/A	UK	Men with a Madsen symptom score ≥ 8, PVR < 250 mL	6 months	TUMT (Microwave Engineering Designs)	70.5	19.2	40.4 mL
Venn 1995	N/A	UK	Men with a Madsen symptom score ≥ 8, PVR < 250 mL	6 months	Sham	68	20.1	40.6 mL
Wagrell 2002	1998 ‐ 1999	Scandinavia/USA	Men IPSS ≥ 13, PFR ≤ 13 mL/s, prostate volume 30 ‐ 100 mL	5 years	TUMT (ProstaLund Feedback)	67 ± 8	21.0 ± 5.4	48.9 ± 15.8 mL
Wagrell 2002	1998 ‐ 1999	Scandinavia/USA	Men IPSS ≥ 13, PFR ≤ 13 mL/s, prostate volume 30 ‐ 100 mL	5 years	TURP	69 ± 8	20.4 ± 5.9	52.7 ± 17.3 mL

TUMT: transurethral microwave thermotherapy; TURP: transurethral resection of the prostate; IPSS: International Prostate Symptom Score; SD: standard deviation; N/A: not available. (*) SD when available.

Results of the search

We identified 3635 records from electronic databases, including 445 records from trial registers. We found no relevant records in the grey literature repository. After removing duplicates, we screened the titles and abstracts of the remaining 1995 records, 1935 of which we excluded. We assessed 60 full‐text articles: we were unable to find six full‐text articles (see Characteristics of studies awaiting classification) and we excluded 22 studies (23 records) for various reasons (see Excluded studies). Finally, we included 16 studies (37 reports) in this review. There were no ongoing studies that met the inclusion criteria or were relevant to the review question. We have shown the flow of literature through the assessment process in the PRISMA 2020 flowchart (Figure 1).

Figure 1

PRISMA 2020 flow diagram.

Included studies

Study design and settings

We included 16 randomized controlled trials. The median sample size was 117 (range 40 to 220). The studies were mostly performed in Europe and the USA: one in France (Abbou 1995), four in the USA (Albala 2002; Blute 1996; Larson 1998; Roehrborn 1998), two in the Netherlands (D'Ancona 1998; Floratos 2001) four in the United Kingdom (Ahmed 1997; Bdesha 1994; Nawrocki 1997; Venn 1995), three in Scandinavian countries (Brehmer 1999; Dahlstrand 1995; Nørby 2002a) and two international studies (De Wildt 1996; Wagrell 2002).

Participants

The included studies randomized 1919 participants with a median age of 69 years. All studies included participants with moderate symptoms, with a median IPSS score of 21 points (range 17 to 29 points); however, four studies did not provide a baseline IPSS score (Abbou 1995; Brehmer 1999; Dahlstrand 1995; De Wildt 1996). The median prostate size was 45 mL (range 33 to 53 mL), but two studies did not provide a baseline prostate size (Bdesha 1994; Brehmer 1999).

Major exclusion criteria relevant to all trials were urethra (e.g. urethral stricture) or bladder disorders (e.g. neurogenic bladder, bladder calculi or diverticula), renal failure, history of prostate, bladder neck, or urethral surgery, and suspected prostate cancer.

Interventions and comparisons

All TUMT procedures were performed in an outpatient setting under local anesthesia. Each device's software and programs varied (most studies used the Prostatron device with the Prostasoft v2.0); however, they delivered a temperature between 45 ºC and 55 ºC in a 60‐ to 90‐minute session through a urethral catheter. The temperature was monitored through the urethral catheter with a rectal probe that triggered a power cut‐off when it reached a certain temperature (usually 42.5 ºC in the rectum). Some studies routinely catheterized participants for two to four days, whereas others only when the participants presented with voiding difficulties or acute urinary retention. Antibiotic prophylaxis across studies was poorly described.

The comparators included:

Sham: the participants were catheterized with the TUMT system, but a sham procedure took place with activation of the monitors in a simulated program. Furthermore, sometimes heat was externally irradiated to the perineum to maintain blinding of participants.
TURP: this was poorly described throughout studies; however, most studies reported that senior surgeons performed this surgery under spinal anesthesia. Participants were usually routinely catheterized for some days.

Ten studies with 1287 randomized participants compared TUMT with sham. The devices used to deliver TUMT by these studies included:

Thermex II (Abbou 1995)
LEO Microthermer (Bdesha 1994)
Prostatron (Blute 1996; De Wildt 1996; Nawrocki 1997)
TherMatrx TMx‐2000 (Albala 2002)
ECP system (Brehmer 1999)
Targis Microwave (Larson 1998)
Dornier Urowave (Roehrborn 1998)
Microwave Engineering Designs (Venn 1995)

Six studies with 632 randomized participants compared TUMT with TURP. The devices used to deliver TUMT by these studies included:

Prostatron (Ahmed 1997; D'Ancona 1998; Dahlstrand 1995; Floratos 2001; Nørby 2002a)
ProstaLund Feedback (Wagrell 2002)

Outcomes

Most studies reported urologic symptom scores and quality of life by IPSS and IPSS‐quality of life, respectively. Adverse events were poorly reported, and in many cases we had to infer whether they were minor or major according to the Clavien‐Dindo classification system. None of the studies reported sexual function as we had predefined, so we extracted data on adverse sexual function instead (i.e. impotence and retrograde ejaculation). Moreover, this information was usually reported in the subset of sexually‐active participants. The reporting of indwelling catheter duration was very scarce across studies and influenced by routine versus selective catheterization during the procedure. Data on acute urinary retention were extracted from data on adverse events. Finally, information on the retreatment rates was scattered, and we had to infer it from the sections reporting the flow of participants or accompanying adverse events.

All studies reported short‐term follow‐up outcomes and only four studies in the TUMT versus TURP comparison reported long‐term outcomes (D'Ancona 1998; Dahlstrand 1995; Floratos 2001; Wagrell 2002). In many cases, long‐term outcomes were only reported in one arm of the study and without sufficient statistical details.

Funding sources

Most studies did not report their funding sources. Three studies were funded by their manufacturers (Larson 1998; Roehrborn 1998; Wagrell 2002), two by public institutions (Nawrocki 1997; Nørby 2002a) and one by a combination of manufacturers and public funders (Abbou 1995).

Excluded studies

We excluded 22 studies (23 records) for the following reasons:

Two studies addressed transrectal thermotherapy (Zerbib 1992; Zerbib 1994; Albala 2000)
Three studies provided economic data on published trials (Kobelt 2004; Norby 2002b; Waldén 1998)
Cross‐over studies with insufficient data (Albala 2000; Tan 2005)
Observational studies and other non‐randomized comparisons (Arai 2000; D'Ancona 1997; Hahn 2000; Hansen 1998; Mulvin 1994; Ohigashi 2007; Servadio 1987; Trock 2004; Vesely 2006)
Review articles identified through full‐text assessment (Dahlstrand 2003; Nørby 2004)
Ineligible comparison (Djavan 1999; Schelin 2006; Shore 2010)
Terminated study (ISRCTN23921450)

Risk of bias in included studies

The summary of the risks of bias by study and domain is available in Figure 2.

Figure 2

Allocation

Random sequence generation

Only five studies reported adequately how the random sequence was generated (Abbou 1995; Blute 1996; Nawrocki 1997; Roehrborn 1998; Venn 1995). The other studies did not provide sufficient information for this domain.

Allocation concealment

Only two studies reported an adequate method for allocation concealment (Blute 1996; Roehrborn 1998). One study used an inadequate method to conceal the allocation (Nawrocki 1997). The other studies did not provide sufficient information for this domain.

Blinding

Blinding of participants and personnel

For the TUMT versus sham comparison, we rated most studies as low risk of bias, since they used an adequate method for blinding (Abbou 1995; Bdesha 1994; Blute 1996; De Wildt 1996; Larson 1998; Nawrocki 1997; Roehrborn 1998). However, three studies did not specify whether personnel were blinded (Albala 2002; Brehmer 1999; Venn 1995), and are rated at unclear risk.

For the TUMT versus TURP comparison, we rated all studies at high risk of bias since blinding was not possible (Ahmed 1997; D'Ancona 1998; Dahlstrand 1995; Floratos 2001; Nørby 2002a; Wagrell 2002).

Blinding of outcome assessment

Subjective outcomes (urologic symptom scores, quality of life, major adverse events, erectile function, ejaculatory function, and minor adverse events): we judged all unblinded studies for the TUMT versus TURP comparison as high risk of bias.
Objective outcomes (retreatment, acute urinary retention, and indwelling urinary catheter): we rated all studies as low risk of bias for these outcomes that are not likely to be affected by lack of blinding.

Incomplete outcome data

We rated four studies (Abbou 1995; Blute 1996; D'Ancona 1998; Larson 1998) as high risk of bias due to high and unbalanced attrition affecting all outcomes. Three studies did not provide details on outcome data lost at follow‐up (Ahmed 1997; Brehmer 1999; Roehrborn 1998). The rest of the studies were rated as low risk of bias.

Selective reporting

We rated all studies at unclear risk of bias, given the lack of available protocols. Two studies were reported as high risk of bias since they selectively reported outcomes for one of the arms of the study or only graphically (Albala 2002; Blute 1996).

Other potential sources of bias

We rated all studies at low risk of bias; no other sources of bias were identified.

Effects of interventions

See: Summary of findings 1 Transurethral microwave thermotherapy compared to transurethral resection of the prostate for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia; Summary of findings 2 Transurethral microwave thermotherapy compared to sham treatment for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia

1. TUMT versus TURP

Six studies (Ahmed 1997; D'Ancona 1998; Dahlstrand 1995; Floratos 2001; Nørby 2002a; Wagrell 2002) with 632 randomized participants were included under this comparison. See Table 1 for a summary of the characteristics of participants, interventions and comparisons. See summary of findings Table 1.

1.1. Urologic symptom scores

Based on four studies (Ahmed 1997; D'Ancona 1998; Nørby 2002a; Wagrell 2002) with 306 participants, TUMT probably results in little to no difference in urologic symptom scores measured by IPSS scores when compared to TURP at 6 to 12 months follow‐up (mean difference (MD) 1.00, 95% confidence interval (CI) −0.03 to 2.03; Analysis 1.1). In two studies (D'Ancona 1998; Dahlstrand 1995) with 108 participants that assessed this outcome with the Madsen‐Iversen score (range 0 to 28) a small difference was found favoring TURP (MD 1.59, 95% CI 0.69 to 2.48; 2 studies, 108 participants; I² = 0%, Analysis 1.2). The certainty of the evidence is moderate, due to an overall high risk of bias.

Long‐term data

Three studies (D'Ancona 1998; Dahlstrand 1995; Wagrell 2002) with 187 participants reported long‐term data. We are uncertain of the effect of TUMT on urologic symptom scores when compared to TURP at 2‐ to 5‐year follow‐up (SMD 0.32, 95% CI 0.03 to 0.62; I² = 0%; Analysis 1.3). Another study with 155 participants (Floratos 2001) was not incorporated in meta‐analysis due to missing data. It reported that the TUMT group had a reduction in IPSS scores from 20 to 12 at three years, whereas the TURP group had a reduction from 20 to 3 in the same period (P < 0.001). The certainty of the evidence is very low due to an overall high risk of bias (severe attrition at long‐term follow‐up) and imprecision.

Subgroup analysis

Since heterogeneity was extremely low, subgroup analysis by baseline severities found no significant differences across subgroups.

1.2. Quality of life

Based on one study with 136 participants (Wagrell 2002), TUMT likely results in little to no difference in the quality of life when compared to TURP at 12 month follow‐up (MD −0.10, 95% CI −0.67 to 0.47; Analysis 1.5). Another study (Nørby 2002a) with 66 participants reported similar scores in quality of life in the TUMT group (median 2, IQR 1 to 3) and in the TURP group (median 1, IQR 1 ‐ 2) at six‐month follow‐up (P = 0.64 from a three‐arm comparison with interstitial laser coagulation). The certainty of the evidence is moderate, due to an overall high risk of bias.

Long‐term data

Long‐term data from Wagrell 2002 indicated that TUMT may result in little to no difference in the quality of life when compared to TURP at 60‐month follow‐up (MD 0.00, 95% CI −0.46 to 0.46; Analysis 1.6). Floratos 2001 (155 participants) reported that quality‐of‐life scores decreased from 4 to 2 at three years in the TUMT group and from 4 to 1 in the TURP group (P < 0.001).

1.3. Major adverse events

Based on six studies (Ahmed 1997; D'Ancona 1998; Dahlstrand 1995; Floratos 2001; Nørby 2002a; Wagrell 2002) with 525 participants, TUMT probably results in significantly fewer major adverse events when compared to TURP at 6‐ to 12‐month follow‐up (RR 0.20, 95% CI 0.09 to 0.43; I² = 0%; Analysis 1.7). Based on 168 cases per 1000 men in the TURP group, this corresponds to 135 fewer (153 to 96 fewer) per 1000 men in the TUMT group. These events primarily included: hospitalization due to bleeding, clot retention, serious infection, TURP syndrome, and urethral stricture (requiring another surgical intervention). The certainty of the evidence is moderate, due to an overall high risk of bias.

Subgroup analysis

Since heterogeneity was extremely low, subgroup analysis by baseline severities found no significant differences across subgroups.

1.4. Retreatment

Based on five studies (D'Ancona 1998; Dahlstrand 1995; Floratos 2001; Nørby 2002a; Wagrell 2002) with 463 participants, TUMT probably results in a large increase in the need for retreatment at 6‐ to 36‐month follow‐up (RR 7.07, 95% CI 1.94 to 25.82; I² = 0%; Analysis 1.9). Retreatment was usually TURP, TUMT, or TUMT and then TURP. Based on no cases per 1000 men in the TURP group, this corresponds to 90 more (40 to 150 more) per 1000 men in the TUMT group. The certainty of the evidence is moderate, due to an overall high risk of bias.

1.5. Erectile function

Based on five studies (Ahmed 1997; Dahlstrand 1995; Floratos 2001; Nørby 2002a; Wagrell 2002) with 337 participants, TUMT may result in little or no difference in erectile function when compared to TURP at 6‐ to 12‐month follow‐up (RR 0.63, 95% CI 0.24 to 1.63; I² = 35%; Analysis 1.10). The certainty of the evidence is low due to an overall high risk of bias and imprecision (the incidence is mostly reported in a subset of sexually‐active participants).

Long‐term data

One study (Wagrell 2002) reported five‐year data on erectile dysfunction with an incidence of 7.5% in the TUMT group and 15.4% in the TURP group (data were available for 119/154 randomized participants). The certainty of the evidence is very low due to an overall high risk of bias and imprecision (the incidence is mostly reported in a subset of sexually‐active participants with high attrition).

1.6. Ejaculatory function

Based on four studies (Ahmed 1997; Dahlstrand 1995; Floratos 2001; Nørby 2002a) with 241 participants, TUMT may result in fewer cases of retrograde ejaculation when compared to TURP at 6‐ to 12‐month follow‐up (RR 0.36, 95% CI 0.24 to 0.53; I² = 0%, Analysis 1.11). The certainty of the evidence is low, due to an overall high risk of bias and imprecision (the incidence mostly reported in a subset of sexually‐active participants).

1.7. Minor adverse events

Based on five studies (Ahmed 1997; D'Ancona 1998; Dahlstrand 1995; Nørby 2002a; Wagrell 2002) with 397 participants, TUMT may result in little to no difference in the incidence of minor adverse events when compared to TURP at 6‐ to 12‐month follow‐up (RR 1.27, 95% CI 0.75 to 2.15; I² = 0%, Analysis 1.12). These events primarily included urinary tract infection. The certainty of the evidence is low due to an overall high risk of bias and imprecision.

1.8. Acute urinary retention

Based on four studies (Ahmed 1997; D'Ancona 1998; Nørby 2002a; Wagrell 2002) with 343 participants, TUMT may result in an increased incidence of acute urinary retention when compared to TURP at 6‐ to 12‐month follow‐up (RR 2.61, 95% CI 1.05 to 6.47; I² = 40%; Analysis 1.13). The certainty of the evidence is low due to an overall high risk of bias and imprecision (the incidence mostly reported in a subset of sexually‐active participants). In many cases, we highlight that participants undergoing TURP were routinely catheterized after surgery and for shorter periods of time than TUMT (see below).

1.9. Indwelling urinary catheter

The evidence is very uncertain about the effect of TUMT on the duration of catheterization when compared to TURP. This outcome was not adequately reported across the included studies. Furthermore, one study (Floratos 2001) reported that per‐protocol all participants were catheterized for 2 to 4 days. Most of the information we found was narrative:

Ahmed 1997 reported that three participants required an indwelling catheter for 10 days to six weeks in the TUMT group and two participants for four weeks in the TURP group.
D'Ancona 1998 reported that the mean days of catheterization were 12.7 (range 6 to 35) in the TUMT group and 4.1 (range 4 to 5) in the TURP group.
Dahlstrand 1995 reported that eight participants required catheterization for less than one week in the TUMT group and two participants in the TURP group required prolonged catheterization.
Nørby 2002a reported that the median catheterization time in the TUMT group was seven days for those treated with Prostasoft v2.0 and 14 in those with Prostasoft v2.5, whereas the median in the TURP group was two days.
Wagrell 2002 reported that the mean catheterization time was 14 days (SD 8) after TUMT and 3 days (SD 4) after TURP.

The certainty of the evidence is very low, due to an overall high risk of bias, inconsistency and imprecision.

2. TUMT versus sham

Ten studies with 1287 randomized participants were included under this comparison (Abbou 1995; Albala 2002; Bdesha 1994; Blute 1996; Brehmer 1999; De Wildt 1996; Larson 1998; Nawrocki 1997; Roehrborn 1998; Venn 1995). See Table 1 for a summary of the characteristics of participants, interventions and comparisons. Refer to the summary of findings Table 2 for the main outcomes.

2.1. Urologic symptom scores

Based on four studies (Bdesha 1994; Blute 1996; Larson 1998; Roehrborn 1998) with 483 participants, TUMT probably reduces urologic symptom scores measured by IPSS at three to six months when compared to sham (MD −5.40, 95% CI −6.97 to −3.84; I² = 45%; Analysis 2.1). Similar results were obtained in two studies (Blute 1996; De Wildt 1996) with 196 participants that used the Madsen‐Iversen score (range 0 to 28) (MD −5.10, 95% CI −6.42 to −3.79; I² = 0%; Analysis 2.2). The certainty of the evidence is moderate, due to an overall high risk of bias.

Responder rate

Based on four studies (Abbou 1995; Bdesha 1994; De Wildt 1996; Venn 1995) with 322 participants, TUMT may cause little to no difference in the responder rate, defined as a large decrease in symptom scores at three months (RR 2.50, 95% CI 0.57 to 10.86; Analysis 2.4.1), but it may increase the responder rate at 12 months (RR 3.10, 95% CI 1.34 to 7.17, see Analysis 2.4.2). The certainty of the evidence is low, due to imprecision (few events) and overall high risk of bias.

Two studies were not included in the meta‐analysis, since they did not report standard deviations or exact P values:

Albala 2002 with 183 participants reported that the mean AUA score in the active treatment group was 12.4 and 17 in the control group ("statistically significant", P value not available).
Nawrocki 1997 with 78 participants reported that the mean score in the TUMT group was 9.5 (range 1 to 27) and 9.5 (range 0 to 30) in the sham group (P = 0.81).

2.2. Quality of life

Based on two studies (Larson 1998; Roehrborn 1998) with 347 participants, TUMT may result in little to no difference in quality of life at six months as measured by IPSS subscore (MD −0.95, 95% CI −1.14 to −0.77; I² = 25%; Analysis 2.5). The certainty of the evidence is low, due to an overall high risk of bias and imprecision.

2.3. Major adverse events

The evidence is very uncertain about the effect of TUMT on adverse events.

Most studies did not comprehensively report adverse events during their 6‐ to 12‐month follow‐up. Six studies (Abbou 1995; Albala 2002; Bdesha 1994; Brehmer 1999; Nawrocki 1997; Roehrborn 1998) with 662 participants reported that all adverse events were minor, but one participant in one study (Bdesha 1994) underwent TURP after persistent acute urinary retention. One multicenter study (De Wildt 1996) with 93 participants did not adequately describe major adverse events, but one of the reports of a single centre of the same study (n = 40) reported that one participant in the TUMT group received TURP due to persistent urinary tract retention and one participant in the sham group received TUMT due to a lesion in the verumontanum. Another study (Larson 1998) with 169 participants reported that two participants were hospitalized after TUMT due to urethral stricture and urinary tract infection. The remaining two studies (Blute 1996; Venn 1995) did not report the incidence of adverse events.

The certainty of the evidence is very low due to an overall high risk of bias and severe imprecision.

2.4. Retreatment

Based on two studies (Bdesha 1994; Brehmer 1999) with 82 participants, TUMT may reduce the incidence of retreatment at 6 to 12 months (RR 0.27, 95% CI 0.08 to 0.88; I² = 0%; Analysis 2.6). Based on 194 retreatments per 1000 men in the sham group, this corresponds to 141 fewer (178 to 23 fewer) per 1000 men in the TUMT group. The certainty of the evidence is low, due to an overall high risk of bias and imprecision (few events).

One study (Abbou 1995) reported that 9/66 (14%) in the TUMT group, 6/31 (19%) in the sham group withdrew due to lack of improvement to seek other treatments, but they comprised either medical or surgical treatment. Another study (Larson 1998) reported that 7/42 (17%) participants in the sham group and 2/125 (2%) in the TUMT group required a subsequent therapeutic procedure or medication.

2.5. Erectile function

The evidence is very uncertain about the effect of TUMT on erectile function at 6 to 12 months.

Three studies (Bdesha 1994; Blute 1996; Roehrborn 1998) with 375 participants reported this outcome within the description of adverse events. Bdesha 1994 and Blute 1996 reported that there were normal erections and no report of sexual dysfunction respectively. Roehrborn 1998 reported that 44 (28.9%) participants in the TUMT group and one (1.4%) in the sham group suffered sexual dysfunction, including one case of impotence due to corporeal fibrosis.

The certainty of the evidence is very low, due to an overall high risk of bias and severe imprecision.

2.6. Ejaculatory function

The evidence is very uncertain about the effect of TUMT on ejaculatory function at 6 to 12 months.

Five studies (Albala 2002; Bdesha 1994; Blute 1996; Larson 1998; Roehrborn 1998) with 727 participants reported this outcome within the description of adverse events. Albala 2002, Bdesha 1994, and Blute 1996 reported that there were normal erections and no report of sexual dysfunction. Roehrborn 1998 reported that 44 (28.9%) participants in the TUMT group and one (1.4%) in the sham group suffered sexual dysfunction, including mostly participants with hematospermia and other ejaculatory abnormalities. Larson 1998 reported that five participants (4%) had a loss of ejaculate after TUMT and no cases in the sham group.

The certainty of the evidence is very low, due to an overall high risk of bias and severe imprecision.

2.7. Minor adverse events

Most studies did not comprehensively report adverse events during their 6‐ to 12‐month follow‐up. Based on three studies (Abbou 1995; Blute 1996; Larson 1998) with 378 participants, TUMT may increase the incidence of minor adverse events compared to sham (RR 1.42, 95% CI 1.00 to 2.01; I² = 31%; Analysis 2.7). The most commonly‐described adverse events were: hematuria, urethral bleeding, acute urinary retention and urinary tract infection. Six studies were not included in the meta‐analysis, since they did not report the global incidence of minor adverse events, but the narrative description of the findings are similar to the main analysis of this outcome.

Albala 2002 (200 participants) reported that both the active treatment arm (6.6%) and the sham arm (4.8%) suffered from dysuria. Gross hematuria (9.1%) and bladder spasm (4.1%) were only reported in the active treatment arm.
Bdesha 1994 (40 participants) reported that 65% of the active treatment and 60% of the sham‐treated participants experienced bladder spasm, while 82% and 83% respectively reported mild or moderate discomfort during treatment. Thirty percent of all participants reported transient dysuria, urgency, frequency or bloodstained urethral discharge lasting up to 48 hours (no disaggregated data).
Brehmer 1999 (44 participants) reported that two participants contracted bacterial cystitis (no disaggregated data).
De Wildt 1996 (93 participants) reported that most participants had some hematuria for up to three days. However, one of the reports of a single centre of the same study (n = 40) said that five participants required treatment for urinary tract infection in the TUMT group and one in the sham group.
Nawrocki 1997(120 participants) reported that all participants treated by standard or simulated TUMT experienced some hematuria and dysuria following treatment, and that these symptoms were self‐limiting and none required specific treatment.
Roehrborn 1998 (220 participants) reported that the main difference in minor adverse events was pain on the day of the treatment (87.8% of the actively treated and 65.8% of sham‐treated participants). Others included: bladder spasms, urethral bleeding, and hematuria and other transient adverse events that were distributed similarly across groups.

The remaining study (Venn 1995) did not report the incidence of adverse events. The certainty of the evidence is low, due to an overall high risk of bias and imprecision.

2.8. Acute urinary retention

Based on eight studies (Abbou 1995; Albala 2002; Bdesha 1994; Blute 1996; De Wildt 1996; Larson 1998; Nawrocki 1997; Roehrborn 1998) with 995 participants, TUMT probably results in a large increase in the incidence of acute urinary retention at 6‐ to 12‐month follow‐up (RR 9.02, 95% CI 3.31 to 24.63; I² = 0%; Analysis 2.8). Based on six cases per 1000 men in the sham group, this corresponds to 54 more (20 to 148 more) per 1000 men in the TUMT group. The certainty of the evidence is moderate, due to high risk of bias.

2.9. Indwelling urinary catheter

This outcome was not adequately reported across the included studies. Four studies reported that participants that suffered from acute urinary retention (see section above) were catheterized for one to six weeks (Abbou 1995; Bdesha 1994; De Wildt 1996; Nawrocki 1997). In some studies (Albala 2002; Larson 1998; Roehrborn 1998), catheterization after each procedure was routinely maintained for two to four days. One study (Brehmer 1999) reported that four participants were catheterized for four days (no disaggregated data by group).

Secondary analyses

Subgroup analysis based on age

We were unable to conduct this analysis due to the lack of data.

Subgroup analysis based on prostate volume

We were unable to conduct this analysis due to the lack of data.

Subgroup analysis based on baseline severity of LUTS

Our predefined subgroup analysis suggests that participants with more severe symptoms (MD −5.07, 95% CI −5.97 to −4.18) may experience less symptom improvement compared to those with moderate symptoms at baseline (MD −9.10, 95% CI −12.83 to −5.37, test for subgroup differences: P = 0.04, I² = 76.4%; Analysis 2.3). There were insufficient data to perform these subgroup analyses on other primary outcomes.

3. Other comparisons

We found no trials for the following comparisons:

TUMT versus CRFWVT
TUMT versus PUL
TUMT versus PAE
TUMT versus TIND

Discussion

Summary of main results

We found evidence for our two main comparisons.

TUMT versus TURP

Based on data from six studies with 414 participants, when compared to TURP, TUMT probably results in little to no difference in urologic symptom scores in the short term, but due to the lack of any eligible study with follow‐up longer than 12 months, we are uncertain about the long‐term effects. There may be little to no difference in minor adverse events, quality of life or erectile function between these interventions. TUMT likely results in significantly fewer major adverse events and less ejaculatory dysfunction compared to TURP. TUMT, however, likely results in a large increase in the need for retreatment (usually by repeated TUMT or TURP) and acute urinary retention. The duration of indwelling catheterization was not adequately reported across studies.

TUMT versus sham

Based on data from 10 studies with 679 participants, we found that, compared to sham, TUMT probably reduces urologic symptoms scores at short‐term follow‐up and may result in a higher responder rate at long‐term follow‐up. TUMT may also reduce the need for retreatment, but it may cause little to no difference in the quality of life. We are very uncertain of the effects on major adverse events, or on erectile and ejaculatory functions. TUMT probably results in a large increase in the incidence of acute urinary retention. The incidence of minor adverse events and the duration of indwelling catheterization was not adequately reported across studies.

Overall completeness and applicability of evidence

The studies did not consistently define or report on adverse events, particularly dysuria, hematuria, and sexual dysfunction, and our estimates for these complications may be unreliable. Few studies evaluated the quality of life. Although studies usually reported the occurrence of urinary retention, they did not consistently or uniformly indicate its duration or the use of catheterization. One important complication that was not reported in the clinical trial literature was thermal injury. On 11 October 2000, the United States Food and Drug Administration (FDA) published a Public Health Notification because they had received 16 reports of severe thermal injury associated with TUMT, including 10 resulting in fistula formation and six resulting in tissue damage to the penis or urethra (Henney 2000). The FDA noted that the injuries could take hours or days to develop. Although the FDA recommended several corrective measures for physicians, they considered TUMT to be safe and effective based on the performance of over 25,000 procedures.

The current American Urological Association guidelines for the management of LUTS considered TUMT to be an appropriate alternative for treating men with lower urinary tract symptoms with small‐ to average‐size prostate (Parsons 2020), with the warning that patients should be advised that surgical retreatment rates are higher compared to TURP, which corresponds with the findings of our review. The Canadian guidelines considered TUMT an optional treatment for men with moderate symptoms, with similar considerations about retreatment (Nickel 2018). The European Association of Urology does not list TUMT as one of their alternatives for managing LUTS (EAU 2021).

Quality of the evidence

The certainty of the evidence was primarily affected by:

High risk of bias across studies: most studies did not report the randomization process adequately, and for the TUMT versus TURP comparison none of the included studies was blinded.
Imprecision: details on ejaculatory and erectile function were only reported as binary outcomes in a subset of sexually‐active participants.

Furthermore, our interpretation of the retreatment data was cautious, since this was not consistently reported across studies. In some cases, it was described in the initial flow of participants across the studies, in some studies as a comment about follow‐up, and in other cases within adverse events. The urinary catheterization data were inconsistently reported, since some studies included them as a standard procedure, and some measured them selectively.

Potential biases in the review process

This update changed the original protocol and replaced it with current methods applied to a suite of other reviews by the Urology Review Group on lower urinary tract symptoms due to benign prostatic hyperplasia (Hwang 2019; Jung 2019; Jung 2020; Kang 2020). This allowed us to secure comparability across interventions and to include the findings of this review in our upcoming network meta‐analysis (Franco 2020).

Considering that review methods have improved over time, including the details of the search strategy, we decided to run our searches from inception using the original inclusion criteria but excluding the comparison to alpha‐blockers. While our search identified more references for the included studies in the previous review, it failed to identify the included studies Abbou 1995 and Brehmer 1999. Furthermore, we identified the citations of some additional reports of the included studies, including long‐term data on one of the studies, but we were unable to retrieve the full text through different means, including the use of Task Exchange (Albala 2000a; Dahlstrand 1994; Dahlstrand 1997; Dahlstrand 1998; Roehrborn 1997). We also identified another randomized study that was cited in the Background of the included studies (Devonec 1994) but again we were unable to retrieve the full text.

Finally, reporting on some of the outcomes was scattered and not thoroughly detailed. For some outcomes, including adverse events, retreatment, acute urinary retention, ejaculatory and erectile function, we had to interpret the data available in the flow of participants and in the section describing “complications.” It is unclear whether the studies reported all events or only those they considered relevant, especially with a lack of a prespecified protocol.

Agreements and disagreements with other studies or reviews

The previous version of this Cochrane Review yielded similar results for the global effects of TUMT in relation to sham and TURP (Hoffman 2012). The main difference from the previous version of the review is that we pooled the data for more outcomes in each comparison, with additional critical outcomes in the summary of findings tables. This provided us with a greater understanding of the differences between TURP and TUMT. In this version, we favor an interpretation of similar urinary symptoms scores at short‐term follow‐up, considering that long‐term data from selected studies provided very low‐certainty evidence to highlight substantial differences between these interventions. We also found important differences in the incidence of major adverse events and the incidence of retrograde ejaculation between these interventions, favoring TUMT.

We found a few additional systematic reviews on this topic. A health technology assessment from Sweden assessed the average IPSS score, and concluded that TUMT was inferior to TURP in the improvement of symptoms, which does not take into account the confidence interval and minimally important differences (SBU 2011). Furthermore, the authors stated that they could not determine the differences in major adverse events, as we found in our review, which could be explained by the lack of grouping of serious events. Nevertheless, the findings related to retreatment were similar. Another systematic review reported similar results for urinary symptoms and retreatment, but highlighted the lower incidence of serious adverse events with TURP than with TUMT (Barry Delongchamps 2012). They state that the rate of retreatment for TUMT may vary from 20% to 80% (focusing on observational data), but at the same time highlight that the rate of retreatment is lower in long‐term randomized trials such as the one included in our review (Wagrell 2002). Finally, two systematic reviews focusing on sexual outcomes reported a lower incidence of sexual adverse events (especially retrograde ejaculation) for men undergoing TUMT compared to TURP, which agrees with our findings (Frieben 2010; Marra 2016). None of these studies followed Cochrane methods for high‐quality reviews.

Figure 1

PRISMA 2020 flow diagram.

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Figure 2

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Analysis 1.1

Comparison 1: Transurethral microwave thermotherapy versus transurethral resection of the prostate (TURP), Outcome 1: Urologic symptoms score (IPSS)

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Analysis 1.2

Comparison 1: Transurethral microwave thermotherapy versus transurethral resection of the prostate (TURP), Outcome 2: Urologic symptoms score (Madsen‐Iversen)

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Analysis 1.3

Comparison 1: Transurethral microwave thermotherapy versus transurethral resection of the prostate (TURP), Outcome 3: Urologic symptoms score (SMD) ‐ long‐term

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Analysis 1.4

Comparison 1: Transurethral microwave thermotherapy versus transurethral resection of the prostate (TURP), Outcome 4: Urologic symptoms score (IPSS) ‐ subgroup analysis (severity)

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Analysis 1.5

Comparison 1: Transurethral microwave thermotherapy versus transurethral resection of the prostate (TURP), Outcome 5: Quality of life

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Analysis 1.6

Comparison 1: Transurethral microwave thermotherapy versus transurethral resection of the prostate (TURP), Outcome 6: Quality of life ‐ long term

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Analysis 1.7

Comparison 1: Transurethral microwave thermotherapy versus transurethral resection of the prostate (TURP), Outcome 7: Major adverse events

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Analysis 1.8

Comparison 1: Transurethral microwave thermotherapy versus transurethral resection of the prostate (TURP), Outcome 8: Major adverse events ‐ subgroup analysis (severity)

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Analysis 1.9

Comparison 1: Transurethral microwave thermotherapy versus transurethral resection of the prostate (TURP), Outcome 9: Retreatment

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Analysis 1.10

Comparison 1: Transurethral microwave thermotherapy versus transurethral resection of the prostate (TURP), Outcome 10: Erectile function

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Analysis 1.11

Comparison 1: Transurethral microwave thermotherapy versus transurethral resection of the prostate (TURP), Outcome 11: Ejaculatory function

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Analysis 1.12

Comparison 1: Transurethral microwave thermotherapy versus transurethral resection of the prostate (TURP), Outcome 12: Minor adverse events

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Analysis 1.13

Comparison 1: Transurethral microwave thermotherapy versus transurethral resection of the prostate (TURP), Outcome 13: Acute urinary retention

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Analysis 2.1

Comparison 2: Transurethral microwave thermotherapy versus sham treatment, Outcome 1: Urologic symptom scores (IPSS/AUA)

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Analysis 2.2

Comparison 2: Transurethral microwave thermotherapy versus sham treatment, Outcome 2: Urologic symptom scores (Madsen score)

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Analysis 2.3

Comparison 2: Transurethral microwave thermotherapy versus sham treatment, Outcome 3: Urologic symptom scores (IPSS/AUA) ‐ subgroup (severity)

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Analysis 2.4

Comparison 2: Transurethral microwave thermotherapy versus sham treatment, Outcome 4: Urologic symptom score (responder analysis)

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Analysis 2.5

Comparison 2: Transurethral microwave thermotherapy versus sham treatment, Outcome 5: Quality of Life

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Analysis 2.6

Comparison 2: Transurethral microwave thermotherapy versus sham treatment, Outcome 6: Retreatment

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Analysis 2.7

Comparison 2: Transurethral microwave thermotherapy versus sham treatment, Outcome 7: Minor adverse events

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Analysis 2.8

Comparison 2: Transurethral microwave thermotherapy versus sham treatment, Outcome 8: Acute urinary retention

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Outcomes	№ of participants (studies) Follow up	Certainty of the evidence (GRADE)	Relative effect (95% CI)	*Anticipated absolute effects^ (95% CI)**
Transurethral microwave thermotherapy compared to transurethral resection of the prostate for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia
Patient or population: men with lower urinary tract symptoms due to benign prostatic hyperplasia Setting: outpatient (TUMT) / inpatient (TURP) ‐ UK, Netherlands, Scandinavia, USA Intervention: Transurethral microwave thermotherapy (TUMT) Comparison: Transurethral resection of the prostate (TURP)
Outcomes	№ of participants (studies) Follow up	Certainty of the evidence (GRADE)	Relative effect (95% CI)	Risk with transurethral resection of the prostate (TURP)	Risk difference with Transurethral microwave thermotherapy
Urologic symptom scores Assessed with: IPSS Scale from 0 (best: not at all) to 35 (worst: almost always) Follow‐up: 6 ‐ 12 months	306 (4 RCTs)	⊕⊕⊕⊝ MODERATE^a	‐	The mean urologic symptoms score (IPSS) was 5.63	MD 1 higher (0.03 lower to 2.03 higher)
Quality of life Assessed with: IPSS‐QoL Scale from 0 (best: delighted) to 6 (worst: terrible) Follow‐up: 12 months	136 (1 RCT)	⊕⊕⊕⊝ MODERATE^a	‐	The mean quality of life was 1.5	MD 0.10 lower (0.67 lower to 0.47 higher)
Major adverse events Assessed with: Clavien‐Dindo classification system (Grade III, IV and V complications) Follow‐up: 6 ‐ 12 months	525 (6 RCTs)	⊕⊕⊕⊝ MODERATE^a	RR 0.20 (0.09 to 0.43)	Study population
	525 (6 RCTs)	⊕⊕⊕⊝ MODERATE^a	RR 0.20 (0.09 to 0.43)	168 per 1000	135 fewer per 1000 (153 fewer to 96 fewer)
Retreatment Participants requiring additional procedures or surgery Follow‐up: 6 ‐ 12 months	463 (5 RCTs)	⊕⊕⊕⊝ MODERATE^a,b	RR 7.07 (1.94 to 25.82)	Study population
	463 (5 RCTs)	⊕⊕⊕⊝ MODERATE^a,b	RR 7.07 (1.94 to 25.82)	0 per 1000	90 more per 1000 (40 more to 150 more)
Erectile function (sexually‐active men only) Assessed with: issues related to erectile function Follow‐up: 6 ‐ 12 months	337 (5 RCTs)	⊕⊕⊝⊝ LOW^a,c	RR 0.63 (0.24 to 1.63)	Study population
	337 (5 RCTs)	⊕⊕⊝⊝ LOW^a,c	RR 0.63 (0.24 to 1.63)	129 per 1000	48 fewer per 1000 (98 fewer to 82 more)
Ejaculatory function (sexually‐active men only) Assessed with: issues related to ejaculatory function Follow‐up: 6 ‐ 12 months	241 (4 RCTs)	⊕⊕⊝⊝ LOW^a,c	RR 0.36 (0.24 to 0.53)	Study population
	241 (4 RCTs)	⊕⊕⊝⊝ LOW^a,c	RR 0.36 (0.24 to 0.53)	523 per 1000	335 fewer per 1000 (397 fewer to 246 fewer)
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; MD: mean difference; RCT: randomized controlled trial; RR: Risk ratio.
GRADE Working Group grades of evidence High certainty: We are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect. Very low certainty: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect.
^aDowngraded by one level for study limitations: studies at an overall high risk of bias. ^bWe did not downgrade for imprecision since we used a minimally conceptualized approach: although the confidence interval is wide, there are no concerns about whether the effect results in a moderate to a large increase in the retreatment rate. ^cDowngraded by one level for imprecision: the incidence is mostly reported in a subset of sexually‐active participants.

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Summary of findings 2. Transurethral microwave thermotherapy compared to sham treatment for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia

Outcomes	№ of participants (studies) Follow up	Certainty of the evidence (GRADE)	Relative effect (95% CI)	*Anticipated absolute effects^ (95% CI)**
Transurethral microwave thermotherapy compared to sham treatment for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia
Patient or population: men with lower urinary tract symptoms due to benign prostatic hyperplasia Setting: outpatient ‐ France, USA, UK, Sweden, Netherlands Intervention: Transurethral microwave thermotherapy Comparison: Sham treatment
Outcomes	№ of participants (studies) Follow up	Certainty of the evidence (GRADE)	Relative effect (95% CI)	Risk with sham treatment	Risk difference with Transurethral microwave thermotherapy
Urologic symptom scores Assessed with: IPSS Scale from 0 (best: not at all) to 35 (worst: almost always) Follow‐up: 3 ‐ 6 months	483 (4 RCTs)	⊕⊕⊕⊝ MODERATE^a	‐	The mean urologic symptom scores was 16.2	MD 5.40 lower (6.97 lower to 3.84 lower)
Quality of life Assessed with: IPSS‐QoL Scale from 0 (best: delighted) to 6 (worst: terrible) Follow‐up: 6 months	347 (2 RCTs)	⊕⊕⊝⊝ LOW^a,b	‐	The mean quality of life score was 3.05	MD 0.95 lower (1.14 lower to 0.77 lower)
Major adverse events Assessed with: Clavien‐Dindo classification system (Grade III, IV and V complications) Follow‐up: 6 ‐ 12 months	924 (8 RCTs)	⊕⊝⊝⊝ VERY LOW^a,c	‐	Six studies reported that there were no major adverse events. The two remaining studies reported four isolated cases of lesions of the urinary tract related to the procedure in both groups.
Retreatment Participants requiring additional procedures or surgery Follow‐up: 6 ‐ 12 months	82 (2 RCTs)	⊕⊕⊝⊝ LOW^a,d	RR 0.27 (0.08 to 0.88)	Study population
	82 (2 RCTs)	⊕⊕⊝⊝ LOW^a,d	RR 0.27 (0.08 to 0.88)	194 per 1000	141 fewer per 1000 (178 fewer to 23 fewer)
Erectile function (sexually‐active men only) Assessed with: issues related to erectile function Follow‐up: 6 ‐ 12 months	375 (3 RCTs)	⊕⊝⊝⊝ VERY LOW^a,c	‐	Two studies reported normal erections. One study reported one case of impotence.
Ejaculatory function (sexually‐active men only) Assessed with: issues related to ejaculatory function Follow‐up: 6‐12 months	727 (5 RCTs)	⊕⊝⊝⊝ VERY LOW^a,c	‐	Three studies reported no issues related to ejaculatory function. The two remaining studies reported isolated cases of loss of ejaculate and hematospermia.
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; MD: mean difference; RCT: randomized controlled trial; RR: Risk ratio.
GRADE Working Group grades of evidence High certainty: We are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect. Very low certainty: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect.
^aDowngraded by one level for study limitations: studies at an overall high risk of bias. ^bDowngraded by one level for imprecision: confidence interval crosses assumed threshold of minimal clinically important difference. ^cDowngraded by two levels for imprecision: very few events (isolated reports). ^dDowngraded by one level for imprecision: few events.

Summary of findings 2. Transurethral microwave thermotherapy compared to sham treatment for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia

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Table 1. Characteristics of included studies

Study name	Trial period	Setting/country	Description of participants	Duration of follow‐up	Intervention and comparator	Age (mean ± SD)*	IPSS (mean ± SD)*	Prostate volume (mean ± SD)*
Abbou 1995	N/A	France	Men ≥ 50 years with symptoms > 3 months, prostate 30 ‐ 80 g, PFR < 15 mL/s, PVR < 300 mL	12 months	TUMT (Thermex II, Prostcare, BSD‐50)	65 ± 8	N/A	45 ± 15 g
Abbou 1995	N/A	France		12 months	Sham	66 ± 7	N/A	44 ± 11 g
Ahmed 1997	N/A	UK	Men ≥ 55 years with AUA score > 12 > 1 year, prostate 25 ‐ 100 mL, PFR < 15 mL/s and a PVR < 300 mL	6 months	TUMT (Prostatron)	69.36	18.5	36.6 mL
Ahmed 1997	N/A	UK		6 months	TURP	69.45	18.4	46.1 mL
Albala 2002	N/A	USA	Men 50 ‐ 80 years, AUA index > 13 and a bother score > 11, PFR < 12 mL/sec and PVR > 125 mL; prostate 30 ‐ 100 mL without a significant intravesical middle lobe	12 months	TUMT (TMx‐2000)	65.2 ± 7.3	22.2 ± 5.0	50.5 ± 18.6 mL
Albala 2002	N/A	USA		12 months	Sham	64.6 ± 7.1	22.7 ± 5.7	47.1 ± 17.9 mL
Bdesha 1994	N/A	UK	Men with prostatism (WHO score > 14), PVR > 50 mL, PFR < 15 mL/s	3 months	TUMT (LEO Microthermer)	63.7	19.2	N/A
Bdesha 1994	N/A	UK		3 months	Sham	62.6	18.8	N/A
Blute 1996	N/A	USA	Men suffering from urinary symptoms (Madsen Symptom score > 8), PVR 10000 mL, PFR < 10 mL/s, prostate length 30 ‐ 50 mm	12 months	TUMT (Prostatron)	66.9 ± 7.8	19.9 ± 7.2	37.4 ± 14.2 mL
Blute 1996	N/A	USA		12 months	Sham	66.9 ± 7.1	20.8 ± 6.7	36.1 ± 13.4 mL
Brehmer 1999	N/A	Sweden	Men suffering from lower urinary tract symptoms and with an enlarged prostate	12 months	TUMT (30' ‐ 60' ‐ ECP system)	70.4	N/A	N/A
Brehmer 1999	N/A	Sweden		12 months	Sham	70.4	N/A	N/A
D'Ancona 1998	1994 ‐ 1995	Netherlands	Men ≥ 45 years with Madsen score > 8 months, prostate 2.5 ‐ 5 cm/30 ‐ 100 mL, PFR < 15 mL/s PRV < 350 mL	24 months	TUMT (Prostatron)	69.6 ± 8.5	16.7 ± 5.6	45 ± 15 mL
D'Ancona 1998	1994 ‐ 1995	Netherlands		24 months	TURP	69.3 ± 5.9	18.3 ± 6.3	43 ± 12 mL
Dahlstrand 1995	N/A	Sweden	Men ≥ 45 years with Madsen score > 8 months, prostate 3.5 ‐ 5 cm, PFR < 15 mL/s PRV > 150 mL	24 months	TUMT (Prostatron)	68	N/A	33 mL
Dahlstrand 1995	N/A	Sweden		24 months	TURP	79	N/A	37 mL
De Wildt 1996	1991 ‐ 1992	Netherlands/UK	Men ≥ 45 years with Madsen score > 8 months, PFR < 15 mL/s PRV > 150 mL	12 months	TUMT (Prostatron)	63.3 ± 8.1	N/A	48.6 ± 16.6 mL
De Wildt 1996	1991 ‐ 1992	Netherlands/UK		12 months	Sham	66.9 ± 6.0	N/A	49.0 ± 20.0 mL
Floratos 2001	1996 ‐ 1997	Netherlands	Men ≥ 45 years, prostate ≥ 30 cm³, prostatic urethral length ≥ 25 mm, a Madsen symptom score ≥ 8, PFR ≤ 15 mL/s, PVR ≤ 350 mL	36 months	TUMT (Prostatron)	68	21	42 mL
Floratos 2001	1996 ‐ 1997	Netherlands		36 months	TURP	66	20	48 mL
Larson 1998	1994 ‐ 1996	USA	Men ≥ 45 years with AUA score > 9, enlarged prostate (3 ‐ 5 cm TRUS), PFR < 12 mL/s without a significantly enlarged middle lobe	12 months	TUMT (Targis)	66	20.8	38.1 mL
Larson 1998	1994 ‐ 1996	USA		12 months	Sham	65.9	21.3	44.7 mL
Nawrocki 1997	N/A	UK	Men with a Madsen symptom score ≥ 8, PFR ≤ 15 mL/s, PVR > 150 mL, detrusor pressure > 70 cm H2O	6 months	TUMT (Prostatron)	70 (56 ‐ 80)	19 (7 ‐ 31)	41.2 ± 14.6 mL
Nawrocki 1997	N/A	UK		6 months	Sham	70 (56 ‐ 80)	17.5 (7 ‐ 28)	46.7 ± 16.8 mL
Nørby 2002a	1996 ‐ 1997	Denmark	Men ≥ 50 years, IPSS ≥ 7, PFR ≤ 12 mL/s	6 months	TUMT (Prostatron)	66 ± 7	20.5 ± 5.7	43 (35 – 79) mL
Nørby 2002a	1996 ‐ 1997	Denmark	Men ≥ 50 years, IPSS ≥ 7, PFR ≤ 12 mL/s	6 months	TURP/TUIP	68 ± 7	21.3 ± 6.6	44 (35 – 50) mL
Roehrborn 1998	N/A	USA	Men ≥ 55 years, AUA‐SI ≥ 13, PFR ≤ 12 mL/s, prostate volume 25 ‐ 100 mL	6 months	TUMT (Dornier)	66.3 ± 6.5	23.6 ± 5.6	48.1 ± 16.2 mL
Roehrborn 1998	N/A	USA		6 months	Sham	66.0 ± 5.8	23.9 ± 5.6	50.5 ± 18.1 mL
Venn 1995	N/A	UK	Men with a Madsen symptom score ≥ 8, PVR < 250 mL	6 months	TUMT (Microwave Engineering Designs)	70.5	19.2	40.4 mL
Venn 1995	N/A	UK	Men with a Madsen symptom score ≥ 8, PVR < 250 mL	6 months	Sham	68	20.1	40.6 mL
Wagrell 2002	1998 ‐ 1999	Scandinavia/USA	Men IPSS ≥ 13, PFR ≤ 13 mL/s, prostate volume 30 ‐ 100 mL	5 years	TUMT (ProstaLund Feedback)	67 ± 8	21.0 ± 5.4	48.9 ± 15.8 mL
Wagrell 2002	1998 ‐ 1999	Scandinavia/USA	Men IPSS ≥ 13, PFR ≤ 13 mL/s, prostate volume 30 ‐ 100 mL	5 years	TURP	69 ± 8	20.4 ± 5.9	52.7 ± 17.3 mL
TUMT: transurethral microwave thermotherapy; TURP: transurethral resection of the prostate; IPSS: International Prostate Symptom Score; SD: standard deviation; N/A: not available. (*) SD when available.

Table 1. Characteristics of included studies

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Comparison 1. Transurethral microwave thermotherapy versus transurethral resection of the prostate (TURP)

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1.1 Urologic symptoms score (IPSS) Show forest plot	4	306	Mean Difference (IV, Random, 95% CI)	1.00 [‐0.03, 2.03]

1.2 Urologic symptoms score (Madsen‐Iversen) Show forest plot	2	108	Mean Difference (IV, Random, 95% CI)	1.59 [0.69, 2.48]

1.3 Urologic symptoms score (SMD) ‐ long‐term Show forest plot	3	187	Std. Mean Difference (IV, Random, 95% CI)	0.32 [0.03, 0.62]

1.4 Urologic symptoms score (IPSS) ‐ subgroup analysis (severity) Show forest plot	4	306	Mean Difference (IV, Random, 95% CI)	1.00 [‐0.03, 2.03]

1.4.1 Baseline IPSS score < 19 points	2	104	Mean Difference (IV, Random, 95% CI)	0.95 [‐0.51, 2.40]
1.4.2 Baseline IPSS score > 19 points	2	202	Mean Difference (IV, Random, 95% CI)	1.17 [‐1.34, 3.68]
1.5 Quality of life Show forest plot	1	136	Mean Difference (IV, Random, 95% CI)	‐0.10 [‐0.67, 0.47]

1.6 Quality of life ‐ long term Show forest plot	1	97	Mean Difference (IV, Random, 95% CI)	0.00 [‐0.46, 0.46]

1.7 Major adverse events Show forest plot	6	525	Risk Ratio (M‐H, Random, 95% CI)	0.20 [0.09, 0.43]

1.8 Major adverse events ‐ subgroup analysis (severity) Show forest plot	5	456	Risk Ratio (M‐H, Random, 95% CI)	0.23 [0.10, 0.50]

1.8.1 Baseline IPSS score < 19 points	2	112	Risk Ratio (M‐H, Random, 95% CI)	0.12 [0.02, 0.61]
1.8.2 Baseline IPSS score > 19 points	3	344	Risk Ratio (M‐H, Random, 95% CI)	0.28 [0.10, 0.78]
1.9 Retreatment Show forest plot	5	463	Risk Ratio (M‐H, Random, 95% CI)	7.07 [1.94, 25.82]

1.10 Erectile function Show forest plot	5	337	Risk Ratio (M‐H, Random, 95% CI)	0.63 [0.24, 1.63]

1.11 Ejaculatory function Show forest plot	4	241	Risk Ratio (M‐H, Random, 95% CI)	0.36 [0.24, 0.53]

1.12 Minor adverse events Show forest plot	5	397	Risk Ratio (M‐H, Random, 95% CI)	1.27 [0.75, 2.15]

1.13 Acute urinary retention Show forest plot	4	343	Risk Ratio (M‐H, Random, 95% CI)	2.61 [1.05, 6.47]

Comparison 1. Transurethral microwave thermotherapy versus transurethral resection of the prostate (TURP)

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Comparison 2. Transurethral microwave thermotherapy versus sham treatment

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
2.1 Urologic symptom scores (IPSS/AUA) Show forest plot	4	483	Mean Difference (IV, Random, 95% CI)	‐5.40 [‐6.97, ‐3.84]

2.2 Urologic symptom scores (Madsen score) Show forest plot	2	196	Mean Difference (IV, Random, 95% CI)	‐5.10 [‐6.42, ‐3.79]

2.3 Urologic symptom scores (IPSS/AUA) ‐ subgroup (severity) Show forest plot	4	483	Mean Difference (IV, Random, 95% CI)	‐5.40 [‐6.97, ‐3.84]

2.3.1 Baseline IPSS score > 19 points	3	443	Mean Difference (IV, Random, 95% CI)	‐5.07 [‐5.97, ‐4.18]
2.3.2 Baseline IPSS score < 19 points	1	40	Mean Difference (IV, Random, 95% CI)	‐9.10 [‐12.83, ‐5.37]
2.4 Urologic symptom score (responder analysis) Show forest plot	4	322	Risk Ratio (M‐H, Random, 95% CI)	2.60 [0.82, 8.24]

2.4.1 3 to 6‐month follow‐up	3	225	Risk Ratio (M‐H, Random, 95% CI)	2.50 [0.57, 10.86]
2.4.2 12‐month follow‐up	1	97	Risk Ratio (M‐H, Random, 95% CI)	3.10 [1.34, 7.17]
2.5 Quality of Life Show forest plot	2	347	Mean Difference (IV, Fixed, 95% CI)	‐0.95 [‐1.14, ‐0.77]

2.6 Retreatment Show forest plot	2	82	Risk Ratio (M‐H, Random, 95% CI)	0.27 [0.08, 0.88]

2.7 Minor adverse events Show forest plot	3	378	Risk Ratio (M‐H, Random, 95% CI)	1.42 [1.00, 2.01]

2.8 Acute urinary retention Show forest plot	8	995	Risk Ratio (M‐H, Random, 95% CI)	9.02 [3.31, 24.63]

Comparison 2. Transurethral microwave thermotherapy versus sham treatment

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Resumen en términos sencillos

Termoterapia transuretral con microondas para los síntomas urinarios bajos en hombres con hiperplasia prostática benigna

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