Can histopathology predict treatment outcome following high-energy transurethral microwave thermotherapy of the prostate? Results of a biopsy study

BACKGROUND. Despite good results of high-energy transurethral microwave the rmotherapy (TUMT) in the treatment of benign prostatic hyperplasia, it is s till difficult to predict the response to treatment on an individual basis. Besides clinical baseline parameters, intrinsic histological parameters ar e suggested to play a role in the response variance after TUMT. In this stu dy we analyzed histological parameters (vessel density and epithelium-strom a (E/S) ratio) in patients who were selected for high-energy TUMT and relat ed these parameters to clinical outcome. METHODS. We treated 42 patients with high-energy TUMT, who prier to treatme nt agreed upon ultrasonographic investigation of the prostate in combinatio n with biopsies of the peripheral and transitional zones of the prostate. F or all separate biopsy locations, the histological stained prostate slides were morphometrically quantified with computer assistance and analyzed for E/S ratio and vessel density. Response to treatment was measured by using s tandardized response evaluation criteria and was correlated with histologic al outcome. RESULTS. The E/S ratio in the inner gland biopsies tended to be higher in t he good response group compared to the very poor responders. Furthermore, a clear trend was seen towards a lower vessel density in good responders. La rge prostates and prostates with a high E/S ratio responded well to the hig h-energy thermotherapy. CONCLUSIONS. Histopathological parameters of the prostate tend to be modera tely predictive for clinical response in this research population. Poor res ponders appeared to have a somewhat higher vessel density in all prostate b iopsy sides, and there was also a trend towards a lower E/S ratio in these patients. (C) 1999 Wiley-Liss, Inc.