Conformal radiotherapy plus local hyperthermia in patients affected by locally advanced high risk prostate cancer: preliminary results of a prospective phase II study.

PURPOSE Hyperthermia has been used in several trials to treat pelvic cancers without excessive toxicity and with positive results. The aim of this study was to evaluate feasibility and results in terms of biochemical recurrence-free, disease-free survival, overall survival, and treatment toxicity profile of hyperthermia combined with radiotherapy in locally advanced high risk prostate cancer. PATIENTS AND METHODS From November 1998 to December 2004, 144 patients with locally advanced prostate cancer (LAPC) were enrolled in a phase II study. They were treated using conformal radiotherapy (CRT) plus local hyperthermia (LHT) and androgen suppression therapy (AST). Treatment modalities consisted of: 1) CRT with a mean dose of 74 Gy (2 Gy/fraction/5 fractions per week); 2) LHT: one session per week during the first, second, third, and fourth week of the radiotherapy course; 3) AST was administered as neo-adjuvant and adjuvant therapy in more than 60% of patients. RESULTS The median follow-up time was 51.7 months. Four patients were lost at follow-up. Of 140 evaluated patients, four died because of intercurrent diseases and 12 because of progression of disease. Patients were evaluated in terms of five-year overall survival (87%), and five-year biochemical progression-free survival (49%). No significant side effects, except symptoms related to AST have been reported. No late grade 3 toxicity occurred. CONCLUSIONS In advanced high risk prostatic cancer, hyperthermia is feasible and well tolerated. It may be useful to enhance the radiotherapy efficacy at intermediate dose in order to avoid higher doses of irradiation which increases acute and late sequelae. The advantage of LHT combined with CRT should be confirmed by a randomized phase III trial, comparing irradiation plus AST with or without hyperthermia.