Predictors of treatment outcome for high-energy transurethral microwave thermotherapy

Background and Purpose: Transurethral microwave thermotherapy (TUMT) is an innovative alternative to transurethral resection of the prostate (TURP) fo r the treatment of lower urinary tract symptoms (LUTS) suggestive of bladde r outflow obstruction (BOO), Although the results are satisfactory for the majority of the patients, a considerable number of patients have an unfavor able outcome, Thus, the identification of features able to predict efficacy of TUMT for individual candidates is an important issue, Materials and Methods: The available literature in MEDLINE covering the pre dictive role of various baseline measures for the outcome of high-energy TU MT was reviewed. Direct comparison among various studies was not possible b ecause of differences in thermotherapy devices, treatment protocols, and th e definition of a good response to treatment. Results: Predictive features have been detected only for the Prostatron dev ice. A small prostate volume, a low grade of BOG, and advanced age were ind ependent predictors of poor outcome, The strongest predictive feature was t he amount of energy delivered during treatment. Histologic characteristics (epithelial:stromal ratio and microvessel density) have not proved predicti ve for therapeutic outcome. The role of intraprostatic vascularization, as a regulator of the temperature during treatment, seems to be of the greates t importance, but results have not been presented yet. Conclusion: The value of baseline clinical measures for the selection of th e best candidates for TUMT is limited at best. Variations in the internal s tructure of the individual prostate seem to play the most important role in regulating the amount of energy absorbed during treatment, and further res earch must focus on this item.