Transurethral microwave thermotherapy in the armamentarium of therapeutic modalities for benign prostatic hyperplasia

Transurethral microwave thermotherapy (TUMT) has gained a firm place in the spectrum of therapeutic modalities for management of patients with lower urinary tract symptoms suggestive of bladder outflow obstruction. To achieve optimum results following TUMT, intense research focuses on appropriate patient selection, heat-tissue interactions, and modification of technical specifications. Results of TUMT are good to excellent for the majority of patients, but there is a non-negligible number of patients who respond poorly. The selection of favorable candidates for TUMT aims to improve the therapeutic results, and both clinical baseline parameters and intrinsic characteristics of the prostate (histologic composition and vasculature) may influence treatment outcome. TUMT achieves therapeutic response through coagulative necrosis of the hyperplastic tissue, but additional theories have been proposed recently, suggesting that TUMT may cause neural destruction and induce apoptosis. Individualization of the treatment is expected to offer the best results, and because the temperature achieved inside the prostate determines the actual parenchymal necrosis, thermal monitoring during treatment will permit application of microwave energy in a feedback mode. Various microwave devices differ in technical specifications (operating frequency, design of antenna, cooling system), and recently introduced software programs (high-energy protocols, heat-shock strategy, short-duration protocols) aim at better efficacy, providing a more patient-friendly procedure. TUMT has survived the "test of time" that other, initially promising, modalities have failed. What remains to be determined is the maximum benefit that patients and health systems can gain from such a technique.