Transurethral microwave hyperthermia for benign prostatic hyperplasia: the Leuven clinical experience.

Local microwave hyperthermia, delivered transurethrally or transrectally, is a new treatment modality for benign prostatic hyperplasia. We started transurethral application, delivering 915-MHz microwaves at the prostatic urethra using a helical microwave antenna incorporated in a Foley catheter. This hyperthermia was given without a urethral surface cooling system. Thermophysical testing of the applicator proved therapeutic efficacy in vitro and in vivo. Pathologic studies demonstrated hyperthermia-induced lesions in the periurethral prostatic tissues and permitted us to hypothesize a working mechanism of transurethral hyperthermia. Clinical Phase I and II studies showed clinical efficacy in patients with urinary retention or prostatism secondary to benign hyperplasia, especially in bilobar or trilobar prostatic configurations. While awaiting results of further pathologic and thermophysical experimental work and ongoing Phase II and III studies, we consider transurethral hyperthermia an investigational but promising conservative treatment modality for benign prostatic hyperplasia.