Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
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Randomized Controlled Trial Multicenter Study Comparative Study
20 Gy versus 44 Gy supplemental beam radiation with Pd-103 prostate brachytherapy: preliminary biochemical outcomes from a prospective randomized multi-center trial.
While favorable results are achieved with combined modality irradiation, there has never been a rigorous study of the need for supplemental beam. The study reported here compares clinical outcomes with substantially different external beam radiation doses. Similar to classic randomized Wilm's tumor studies from the 1980s, the intention of the trial design was to decrementally test the need for beam radiation. ⋯ The randomized data presented here suggests that the likelihood of biochemical cure is similar with standard (44 Gy) or lower dose (20 Gy) supplemental beam radiation. Since the biological effect of 20 Gy external beam radiation is likely to be small, we interpret these preliminary results to suggest that supplemental beam radiation is unnecessary, in the setting of a high degree of prostate coverage by the brachytherapy prescription dose. With closure of this study, we have begun treating intermediate and high risk patients on a prospective randomized comparison of Pd-103 with 20 versus 0 Gy supplemental beam radiation.