CASE SELECTION FOR HIGH-ENERGY TRANSURETHRAL MICROWAVE THERMOTHERAPY

Transurethral microwave thermotherapy (TUMT) is a minimally invasive o utpatient procedure for the treatment of benign prostatic hyperplasia (BPH). Different devices and operating software have been used in vari ous clinical trials. The objective of this study was to identify the p ossible baseline parameters that could be used to identify the best re sponders to different microwave devices and treatment programs. Data o n three different high-energy thermotherapy devices (Urowave, Prostalu nd, and Prostatron) were collected and analyzed. At 1 year of follow-u p, 166 patients were available for the Prostatron system. In all, 52 h ad a greater than or equal to 50% change in both symptom score and pea k flow rate, whereas 114 patients were considered nonresponders. Respo nders were characterized at baseline by a lower peak flow rate (8.80 v ersus 10.48 m/s, P less than or equal to 0.0001) and a larger degree o f outlet obstruction as measured by the URA parameter (45.33 versus 36 .70 cmH(2)O, P less than or equal to 0.0300); a larger energy dose was delivered to this group during treatment (173.36 versus 156.40 kJ, P less than or equal to 0.0258). A total of 19 patients were available f rom the Prostalund cohort. No significant difference was found in the values recorded for baseline parameters between responders (5 patients ) and nonresponders (14 patients). Stratification of 143 patients trea ted with the Urowave resulted in 29 responders (greater than or equal to 50% improvement in both Q(max) and AUA score) at 6 months of follow -up, with a significant difference being found in the baseline value r ecorded for peak flow rate (7.0 versus 8.0 ml/s, P less than or equal to 0.026). At 12 months, however, this significance difference could n o longer be found. In conclusion, baseline parameters with significant predictive value for a clinical response could be identified for the Prostatron device only. The results of this study further confirm the importance of ail extensive laboratory and clinical research program f or a fuller understanding of the clinical response obtained with a cer tain microwave device and a particular treatment software and for prov ision of the greatest possible advantage from these new alternative tr eatments. Further exploratory work is required for a better understand ing of the role of other parameters such as prostate tissue architectu re and vascularity, the microwave frequency, the applicator design, th e intraprostatic temperature, and the treatment duration in the clinic al response to microwave thermotherapy.