Microwave thermotherapy for benign prostatic hyperplasia

Transurethral resection of the prostate (TURP) has been the gold-standard treatment for alleviating urinary symptoms and improving urinary flow in men with symptomatic benign prostatic hyperplasia (BPH). However, the morbidity of TURP approaches 20%, and less invasive techniques have been developed for treating BPH. Preliminary data suggest that microwave thermotherapy, which delivers microwave energy to produce coagulation necrosis in prostatic tissue, is a safe, effective treatment for BPH.

To assess the therapeutic efficacy and safety of microwave thermotherapy techniques for treating men with symptomatic benign prostatic obstruction.

Randomized controlled trials were identified from the Cochrane Collaboration Library, MEDLINE, EMBASE, bibliographies of retrieved articles and reviews, and by contacting expert relevant trialists and microwave manufacturers.

All randomized controlled trials evaluating transurethral microwave thermotherapy (TUMT) for men with symptomatic BPH were eligible for this review. Comparison groups could include transurethral resection of the prostate, minimally invasive prostatectomy techniques, sham thermotherapy procedures, and medications. Outcome measures included urinary symptoms, urinary function, prostate volume, mortality, morbidity, and retreatment. Two reviewers independently identified potentially relevant abstracts and then assessed the full papers for inclusion.

Two reviewers independently abstracted study design, baseline characteristics and outcomes data and assessed methodological quality using a standard form. We attempted to obtain missing data from authors and/or sponsors.

Fourteen studies involving 1493 patients met inclusion criteria, including six comparisons of microwave thermotherapy with TURP, seven comparisons with sham thermotherapy procedures, and one comparison with an alpha blocker. Study durations ranged from 3 to 60 months. The mean age of subjects was 66.8 years, and the baseline symptom scores and urinary flow rates, which did not differ across treatment groups, demonstrated moderately severe lower urinary tract symptoms. The pooled mean urinary symptom scores decreased by 65% with TUMT and by 77% with TURP. The weighted mean difference (WMD) (95% confidence interval) for the symptom score was -1.36 (-2.25 to -0.46), favoring TURP. The pooled mean peak urinary flow increased by 70% with TUMT and by 119% with TURP. The WMD for peak urinary flow was 5.08 (3.88 to 6.28) mL/s, favoring TURP. Compared to TURP, TUMT was associated with decreased risks for retrograde ejaculation, treatment for strictures, hematuria, blood transfusions, and the transurethral resection syndrome, but increased risks for dysuria, urinary retention, and retreatment for BPH symptoms. Microwave thermotherapy improved symptom scores (IPSS WMD -4.75, 95% CI -3.89 to -5.60) and peak urinary flow (WMD 1.67 mL/s, 95% CI 0.99 to 2.34) compared with sham procedures. Microwave thermotherapy also improved symptom scores (IPSS WMD -4.20, 95% CI -3.15 to -5.25) and peak urinary flow (WMD 2.30 mL/s, 95% CI 1.47 to 3.13) in the one comparison with alpha blockers. No studies evaluated the effects of symptom duration, patient characteristics, prostate-specific antigen levels, or prostate volume on treatment response.

Microwave thermotherapy techniques are effective alternatives to TURP and alpha-blockers for treating symptomatic BPH for men with no history of urinary retention or previous prostate procedures and prostate volumes between 30 to 100 mL. However, TURP provided greater symptom score and urinary flow improvements and reduced the need for subsequent BPH treatments compared to TUMT. Small sample sizes and differences in study design limit comparison between devices with different designs and energy levels. The effects of symptom duration, patient characteristics, or prostate volume on treatment response are unknown.