The role of external beam radiotherapy with I-125/Pd-103 brachytherapy forprostate carcinoma

Background and purpose: To compare the biochemical outcomes of patients tre ated with Pd-103/I-125 brachytherapy alone vs. brachytherapy combined with external beam radiotherapy for early stage prostate carcinoma. Methods: Brachytherapy monotherapy was used in 403 patients. Brachytherapy was combined with 45 Gy of external beam radiotherapy in 231 patients. Medi an follow-up was 58 months. To compare the biochemical outcomes of these tw o treatment approaches, patients were stratified into three relative risk g roups: low risk, T-1-T-2, Gleason 2-6/10, PSA less than or equal to 10.0; i ntermediate risk, T-3, Gleason 7-10/10, PSA > 10.0 tone factor); high risk, T3. Gleason 7-10/10, PSA > 10.0 (two factors). Results: The actuarial biochemical progression-free rate (bNED) for the ent ire 634 patients was 85% at 10 years. The bNED outcomes by risk group for m onotherapy vs, combined therapy respectively were: low risk, 94 vs. 87%; in termediate risk, 84 vs. 85%; high risk, 54 vs. 62%. These differences did n ot reach statistical significance for any risk group. Rectal morbidity was slightly greater in the combined treatment patients. Conclusion: Although the addition of external beam irradiation to brachythe rapy is conceptually appealing for patients with higher risk prostate carci noma, we were unable to demonstrate a benefit. Whether this is because of p atient selection biases within the risk groupings, an artefact of retrospec tive review, or because external radiotherapy does not offer additional ben efit is uncertain. (C) 2000 Elsevier Science Ireland Ltd. All rights reserv ed.