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. 2021 Jul 15;2021(7):CD013656. doi: 10.1002/14651858.CD013656.pub2

Blute 1996.

Study characteristics
Methods Study design: parallel group randomized trial
Study dates: study dates not available
Setting: outpatient
Country: USA
Participants Inclusion criteria: men suffering from urinary symptoms (Madsen Symptom score > 8), PVR between 100 and 200 mL, PFR < 10 mL/s, prostate length between 35 and 50 mm on ultrasound examination.
Exclusion criteria: men receiving medication for said symptoms, metallic implants, conditions suggesting neuropathic bladder, evidence of prostate cancer previous surgery (rectal or transurethral), antiandrogen therapy, serum creatinine > 2 mg/dL, urinary retention, bladder stones, uncontrolled dysrhythmias or cardiac pacemakers, and asymmetric median lobe enlargement.
Total number of participantsrandomized: 115
Group 1 (n = 78) TUMT
  • AUA score, mean (SD): 19.9 (7.2)

  • Age, mean (SD): 66.9 (7.8) years

  • Prostate volume, mean (SD): 37.4 (14.2) mL

  • Qmax, mean (SD): 1.3 (1.6) mL/s


Group 2 (n = 37) sham
  • AUA score, mean (SD): 20.8 (6.7)

  • Age, mean (SD): 66.9 (7.1) years

  • Prostate volume, mean (SD): 36.1 (13.4) mL

  • Qmax, mean (SD): 7.4 (1.7) mL/s

Interventions Group 1 (n = 78): TUMT
Prostatron device is inserted by a 20F transurethral applicator (with 2 cooling channels) catheter and a rectal probe confirmed by ultrasonography. The specially designed transurethral catheter is comprised of a microwave antenna that allows. The treatment catheter emits a radiofrequency of 1,296 MHz. The treatment consists of three stages: 1) cooling (to 27 ºC), 2) microwave emission to a threshold of 42.5 ºC rectal temperature, 3) progressive cooling.
(Details provided in the report of a previous non‐randomized study Blute 1996)
Group 2 (n = 37): Sham
This consisted of circulation of urethral coolant without application of microwave power while a sham treatment was displayed on the computer monitor and the program run for 60 minutes.
Co‐interventions: Patients were given anti‐inflammatory agents and prophylactic antibiotics before and after (7 days) the procedure. If the patient experiences difficulties, a Foley catheter is inserted. Sedation was used at discretion in (no sedation in 89% of TUMT sessions, and 100% of sham sessions).
Outcomes Urologic symptom scores
How measured: Madsen Symptom score / AUA symptom score
Time points measured: baseline, 6 weeks, 3, 6, and 12 months
Time points reported: baseline, 6 weeks, 3, 6, and 12 months (mostly graphically; comparative outcome data was only available at 3 months)
Minor adverse events (including erectile/ejaculatory function)
How measured: narratively including sexual adverse events
Time points measured: at complete follow‐up (12 months)
Time points reported: at complete follow‐up (12 months)
Acute urinary retention
How measured: narratively
Time points measured: at complete follow‐up (12 months)
Time points reported: at complete follow‐up (12 months)
Relevant outcomes not reported in this study:
  • Quality of life

  • Retreatment

  • Major adverse events

  • Indwelling urinary catheter

Funding sources Not available
Declarations of interest Not available
Notes Randomization ratio 2:1
Whereas the blinding lasted for 3 months, the follow‐up time was 12 months.
The reporting of outcomes was not disaggregated by group (intervention vs. sham, but for the entire population) for most outcomes and time points.
Protocol: not available
Language of publication: English
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Low risk Quote: “The patients were randomized to TUMT or sham treatment in a 2:1 ratio based on a permuted‐blocks procedure.”
Allocation concealment (selection bias) Low risk Quote: “Randomization assignments were distributed in sealed envelopes identified only by a unique patient number. The treating physician opened the envelope after completing all screening tests just prior to treatment.”
Blinding of participants and personnel (performance bias)
Subjective outcomes Low risk Quote: “The evaluating physician was not the treating physician and was not allowed to enter the room. The study nurse who administered symptom score tests and supervised uroflowmetry was also blinded to the randomization scheme”
There was also “blinding verification” at 1 week after procedure: “When patients were queried about the treatment they had received, only half of the TUMT patients (51.3%; 40 of 78) guessed correctly, and in the sham‐treatment group, less than half of the patients (44.4%; 16 of 36) guessed correctly (Table 8).”
Blinding of outcome assessment (detection bias)
Subjective outcomes Low risk Double blind study ‐ see above.
Blinding of outcome assessment (detection bias)
Objective outcomes Low risk Double blind study ‐ see above.
Incomplete outcome data (attrition bias)
Urologic symptom scores/Quality of life High risk “Of the 150 patients treated 118 had Madsen symptom score data at 12 months, since 11 discontinued the study or were lost to follow‐up, 16 were re‐treated with the Prostatron unit, 4 received alternative therapy (3 underwent transurethral procedures, and 1 received terazosin) and 1 was missing a Madsen score at follow‐up.”
Incomplete outcome data (attrition bias)
Major adverse events/minor adverse events Unclear risk No information on missing data for other outcomes beyond urinary symptoms.
Incomplete outcome data (attrition bias)
Erectile function Unclear risk No information on missing data for other outcomes beyond urinary symptoms.
Incomplete outcome data (attrition bias)
Ejaculatory function Unclear risk No information on missing data for other outcomes beyond urinary symptoms.
Incomplete outcome data (attrition bias)
Acute urinary retention Unclear risk No information on missing data for other outcomes beyond urinary symptoms.
Selective reporting (reporting bias) High risk No protocol available. Data was presented graphically for most time points. Comparative outcome data was only available at 3 month‐follow‐up for some outcomes.
Other bias Low risk No other sources of bias were detected.