Intraprostatic temperature monitoring during transurethral microwave thermotherapy for the treatment of benign prostatic hyperplasia.

PURPOSE

We evaluated whether the results of transurethral microwave thermotherapy improve using high intraprostatic temperatures of 55C or greater.

MATERIALS AND METHODS

We accrued 30 men 58 to 85 years old (mean age 69) from the waiting list for transurethral prostatic resection in whom maximum urinary flow was less than 13 ml. per second and Madsen score was greater than 8. According to the Abrams-Griffith nomogram all but 1 patient had obstruction. Before treatment 3 thin temperature probes, each containing 5 sensors in a row, were introduced into the prostate from the perineum and positioned using transurethral ultrasound guidance. The microwave power of the transurethral microwave thermotherapy equipment was set based on the actual temperature in the prostatic tissue. A temperature of at least 55C and often more than 60C was reached at the hottest spot. Treatment duration was 1 hour. Postoperatively an indwelling catheter remained in place for 2 weeks. Patients were followed for 6 months with the first followup after 3 months.

RESULTS

At the 3-month followup mean maximum urinary flow had increased from 7.4 to 12.5 ml. per second and the mean Madsen score had decreased from 12.6 to 2.9. At the 6-month followup mean maximum urinary flow was 12.2 ml. per second and the mean Madsen score was 3.4. Using pressure-flow data we divided the patients into responders and nonresponders. In the 18 responders maximum urinary flow had increased from 7.2 to 14.6 ml. per second (103%), the Madsen score had decreased from 12.5 to 1.4 (89%) and detrusor pressure had decreased from 9.2 to 6 kPa. (35%).

CONCLUSIONS

High energy transurethral microwave thermotherapy relieved bladder outlet obstruction in 60% of the patients and had a good effect on symptoms. Compared with a previous multicenter study with 40% responders, using the same criteria there were 60% responders in our series. Our results indicate that better control of intraprostatic temperature provides better results, approaching those after transurethral prostatic resection.