COMBINED EXTERNAL-BEAM IRRADIATION AND EXTERNAL REGIONAL HYPERTHERMIAFOR LOCALLY ADVANCED ADENOCARCINOMA OF THE PROSTATE

Purpose: To determine the safety and efficacy of combined external bea m irradiation and external regional hyperthermia in the treatment of a denocarcinoma of the prostate. Methods and Materials: From 1987 to 199 4, 30 patients received combined external beam irradiation and externa l regional hyperthermia for locally advanced prostate cancer. The resu lts of the 21 patients with newly diagnosed (n = 18) or locally recurr ent (n = 3) adenocarcinoma are reported herein. No patient had evidenc e of distant metastases. Total radiotherapy doses of 65-70 Gy to the p rostate were planned using a four-field box technique. Hyperthermia tr eatments were delivered using an annular phased array microwave device , The treatment goal was to achieve temperatures greater than or equal to 42 degrees C in all measured points within the prostate. Results: Of the newly diagnosed patients, 16 out of 18 (89%) had T3 or T4 tumor s, 11 out of 18 (61%) had Gleason scores of 7-9, and the mean pretreat ment Prostate Specific Antigen (PSA) was 69 ng/ml. The median follow-u p of all 21 patients was 36 months, None of the patients achieved the treatment goal of all intratumoral temperatures greater than or equal to 42 degrees C. The mean CEM 43 T90 was 2.34 min. The disease-free su rvival at 36 months is 25%; 12 out of 18 (67%) of the patients have re lapsed. The only significant predictor of relapse was pretreatment PSA . There were no complications > Grade 3. Conclusions: In spite of the inability to achieve high tumor temperatures, the relapse-free surviva l rate in this population of patients with very advanced localized pro state cancer treated with radiation therapy plus hyperthermia compares favorably with most series using radiation therapy alone. Further stu dies aimed at improving the ability to deliver hyperthermia to the pro state are warranted. (C) 1997 Elsevier Science Inc.