The external radiotherapy with three-dimensional conformal boost after theneoadjuvant androgen suppression for patients with locally advanced prostatic carcinoma

Purpose: To analyze the results in patients with locally advanced prostatic carcinoma treated by hormonal therapy followed by external radiotherapy us ing three-dimensional conformal radiation therapy (3D-CRT) boost. Methods and Materials: From 1987 to 1995, 46 patients with histologically p roven locally advanced adenocarcinoma of the prostate were treated with 3D- CRT at the National Cancer Center Hospital, Tokyo. The neoadjuvant androgen suppression started immediately after the diagnosis followed by radical ra diation therapy, according to the prospective protocol. They were treated w ith photons of 6-14 MV for wide fields and the boost, of which a multiple-l eaf collimator of 2-cm width was available. The boosted dose was delivered with the rotational SD-CRT, after the delivery of whole pelvis 4-field box from a dose of 40-46 Gy up to 66 Gy, The planning target volume encompassed 1 cm outside throughout the clinical target volume, and the prostate and t he seminal vesicles were included in the boost field. Results: The 3D-CRT boost treatment completed as planned in all 46 patients , The median follow-up for all the patients was 60 months (range, 5-120 mon ths). Nineteen of 46 patients died, Of these, 11 patients died of the inter current diseases. For all 46 patients, the 5- and 8-year overall survival r ates were 61.3% and 42.4%, and the 5- and 8-year cause-specific survival ra tes were 82.4% and 64,4%, respectively, The prostate-specific antigen (PSA) relapse-free rates for 5- and 8-year were 64.6% and 52.5%, and the clinica l local control rates for 5 and 8 years were 75.3% and 69.9%, respectively. The preradiation therapy PSA and the Gleason score were the factors that s ignificantly associated with PSA relapse-free survival. Sixteen of 46 patie nts (35%) showed at least one form of late toxicities. Of these, 3 patients experienced late complications of Grade 3 (urinary, 2, proctitis, 1). Conclusion: The treatment results were fairly good and were consistent with those in Western countries, indicating that this study shows the prelimina ry status of 3D-CRT for the locally advanced prostate cancer in Japan, Prer adiation therapy PSA seems to be a significant predictor of PSA relapse-fre e survival (p = 0.004) after neoadjuvant androgen suppression. (C) 2000 Els evier Science Inc.