Clinical response to transurethral microwave thermotherapy is thermal dose dependent.

Transurethral microwave thermotherapy of the prostate was used to treat men with symptomatic benign prostatic hypertrophy. Three treatment protocols delivering increasing thermal doses (Prostasoft T-A > Prostasoft II > Prostasoft I) were evaluated. The results show a dose-dependent response. Histological changes induced by microwave heating were dependent on the temperature achieved in the tissue. Thermocoagulation is obtained above 45 degrees C and thermoablation above 60 degrees C. Using Prostasoft II in a long-term follow-up study, the Madsen symptom score decreased by 66% and peak flow rates increased by 41% over a period of more than 18 months. Using Prostasoft T-A (thermoablation) in 28 patients, a cavity was obtained inside the prostate without major complication. The symptoms and obstruction caused by benign prostatic hypertrophy can be treated by transurethral thermotherapy in a single, anesthesia-free 1-hour session on an ambulatory basis.