Larson 1998.

Study characteristics
Methods	Study design: prospective, randomized parallel study Study dates: September 1994 to June 1996 Setting: outpatient, multicenter, national Country: USA
Participants	Inclusion criteria: men with: 45 – 85 years old Symptomatic BPH confirmed by digital rectal examination (DRE) and transrectal ultrasound (TRUS) Qmax ≤ 12 mL/s with voided volume ≥ 125 mL on at least 2 clinic visits within 30 days of study enrollment AUA (American Urological Association) symptom score ≥ 9 3–5‐cm preprostatic urethral length as determined by cystoscopy or TRUS No disproportionately enlarged or prominent prostatic median lobe on cystoscopy Life expectancy ≥ 1 year Informed written consent Exclusion criteria: men with: UTI within 1 week of study enrollment as diagnosed by positive urine culture Gross hematuria not due to BPH Acute urinary retention Prostate weight > 100 g Use of alpha‐antagonists within 4 wks or antiandrogens within 3 months of study enrollment Concomitant medications that could affect study outcome measures Co‐existing disease that could mimic obstructive bladder neck syndrome Co‐existing illness or specific obstructive symptoms caused by neurogenic bladder; bladder stones; renal failure; cardiac failure; prostate cancer; urethral stricture (i.e. inability to pass 22F urethroscope easily); severe bladder neck contracture; bladder cancer; urinary sphincter abnormalities; prostatitis; or hepatic failure Continuous or intermittent urinary catheterization within 2 weeks of the study procedure Previous prostate surgery or nonmedical treatment for BPH other than balloon dilation ≤ 12 mo before study entry Penile implant or artificial urinary sphincter Previous pelvic or rectal surgery that would increase participant risk or render study procedures more difficult Metallic implants in the pelvic area Cardiac pacemaker Desire for future offspring Likely noncompliance with study follow‐up evaluation requirements Total number of participants randomized: 169 Group 1: n = 125 transurethral microwave thermotherapy (TUMT) Age, mean (95% CI): 66.0 (64.7 – 67.4) years. Prostate volume (cc), mean (95% CI): 38.1 (35.1 – 41.2) PSA (ng/mL), mean (95% CI): 3.4 (2.7 – 4.1) AUA score, Mean (95% CI): 20.8 (19.8 – 21.9) Qmax (mL/s), Mean (95% CI): 7.8 (7.4 – 8.2) Group 2: n = 44 Sham Age, mean (95% CI): 65.9 (63.4 – 68.3) years. Prostate volume (cc), mean (95% CI): 44.7 (38.8 – 50.5) PSA (ng/mL), mean (95% CI): 3.6 (2.2 – 5.1) AUA score, Mean (95% CI): 21.3 (19.3 – 23.3) Qmax (mL/s), Mean (95% CI): 7.8 (7.00 – 8.6)
Interventions	Group 1 (n = 125): TUMT Power was applied with a Targis device in increments to achieve a target urethral temperature of 40 ± 1 °C with measurement by the catheter’s fibreoptic thermo sensor. Microwave treatment was administered continuously for 1 hour, with the circulation of coolant at 8 °C Group 2 (n = 44): Sham The same procedure as TUMT group, with the exception that microwave power was not applied, and coolant temperature was increased in increments from 8 °C to 20 °C over the same time period as microwave power was increased in the microwave group. It was not feasible to increase the urethral temperature further in the sham group because the Targis cooling system is not designed or equipped to provide active heating of coolant other than that occurring as the result of the application of microwave energy. The sham‐group participants experienced rising urethral temperatures rather than unchanging low temperatures Co‐interventions: All participants underwent insertion of a Targis (formerly T3) transurethral thermoablation system treatment catheter (Urologix, Inc., Minneapolis, Minn). It is a compact and portable unit equipped with a 21F silicone treatment catheter containing a helical dipole microwave antenna operating in the range 902 to 928 MHz. This provides urethral cooling via circumferential cooling compartments and also includes a urine drainage canal and a fibreoptic thermo sensor for monitoring urethral catheter interface temperatures. The thermoablation system automatically interrupts microwave power if urethral temperatures reach 44.5 °C or higher or rectal temperatures reach 42.5 °C or higher. Catheterization was carried out under topical lidocaine anesthesia. The positioning of the catheter balloon and antenna was confirmed by TRUS. The catheter was then secured in the proper spatial orientation with respect to the posteroanterior prostatic axis. A rectal thermal unit equipped with 5 thermocouples was used to monitor rectal temperatures. All participants received a 3‐day prescription of prophylactic oral antibiotics and catheterization for 36 to 60 hours
Outcomes	Urologic symptom scores How measured: AUA score Time points measured: baseline, 6 weeks, 3 months and 6 months Time points reported: baseline, 6 weeks, 3 months and 6 months Subgroups: none Quality of life How measured: QOL score was evaluated by participant responses to the question of how they would feel if their current urinary symptoms were to continue indefinitely. Time points measured: Baseline and 6 months Time points reported: baseline, 6, 9 and 12 months follow‐up (these last 2 time points were not reported In group 2) Subgroups: none Minor and major adverse event (including ejaculatory function) How measured: number of participants with UTI confirmed by urine culture and resolved with antibiotics, among other adverse events Time points measured: not reported Time points reported: not reported Subgroups: none Retreatment How measured: number of participants requiring other treatment within the 6 months follow‐up Time points measured: 6 months Time points reported: 6 months Subgroups: none Acute urinary retention How measured: number of participants with urinary retention > 1 week after the procedure Time points measured: > 1 week Time points reported: > 1 week Subgroups: none Relevant outcomes not reported in this study Erectile function Indwelling urinary catheter (all participants were catheterized)
Funding sources	This study was supported by a grant from Urologix Inc
Declarations of interest	Not available
Notes	Blinding was broken after 6 months (we included data from the blinded phase in this review).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: “Patients were randomised in a 3:1 target ratio to the microwave (n = 125) or sham (n = 44) group.” Comment: Insufficient information about the sequence generation process to permit judgment of ‘Low risk’ or ‘High risk’.
Allocation concealment (selection bias)	Unclear risk	Quote: “Patients were randomised in a 3:1 target ratio to the microwave (n = 125) or sham (n = 44) group.” Comment: Insufficient information about the sequence generation process to permit judgment of ‘Low risk’ or ‘High risk’.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: “The study was double‐blind: Neither the patients nor any of the investigators and support staff involved in carrying out the study procedures had knowledge of group assignment (microwave versus sham).” Comment: Blinding of participants and key study personnel ensured, and unlikely that the blinding could have been broken.
Blinding of outcome assessment (detection bias) Objective outcomes	Low risk	Quote: “The study was double‐blind: Neither the patients nor any of the investigators and support staff involved in carrying out the study procedures had knowledge of group assignment (microwave versus sham).” Comment: Blinding of participants and key study personnel ensured, and unlikely that the blinding could have been broken.
Blinding of outcome assessment (detection bias) Subjective outcomes	Low risk	Quote: “The study was double‐blind: Neither the patients nor any of the investigators and support staff involved in carrying out the study procedures had knowledge of group assignment (microwave versus sham).” Comment: Blinding of participants and key study personnel ensured, and unlikely that the blinding could have been broken.
Incomplete outcome data (attrition bias) All outcomes	High risk	Quote: “Of the 169 patients enrolled, 155 were evaluable at the conclusion of the 6‐month blinded phase of the study (Table III) and 114 at the end of the full 12‐month follow‐up period. Analyses of efficacy results are presented for the 155 subjects evaluable at the conclusion of the blinded phase.” Comment: Unbalanced attrition at 6 months (20% vs 4%).
Selective reporting (reporting bias)	Unclear risk	No protocol available. Insufficient information to permit judgment of ‘Low risk’ or ‘High risk’.
Other bias	Low risk	No other sources of bias were identified.