Early Toxicity of a Phase 2 Trial of Combined Salvage Radiation Therapy and Hormone Therapy in Oligometastatic Pelvic Node Relapses of Prostate Cancer (OLIGOPELVIS GETUG P07)

Abstract

Limited pelvic nodal relapse of prostatic cancer is a paramount challenge for locoregional salvage treatments. Salvage whole pelvis radiation therapy as considered in the BLINDED trial is an attractive option, but there are concerns about its toxicity. This article describes early toxicity with the technique. BLINDED was a prospective multicenter phase 2 trial investigating high-dose salvage pelvic irradiation with an additional dose to the fluorocholine-based positron emission tomography-positive pelvic lymph nodes, combined with 6-month androgen blockade. The prescribed dose was 54Gy in 1.8Gy fractions with up to 66Gy in 2.2Gy fractions to the pathologic pelvic lymph nodes. Early toxicity was defined as toxicity until 1year after radiation therapy. Patients quality of life was assessed using the European Organisation for Research and Treatment of Cancer questionnaires (QLQ-C30 and QLQ-PR25). Seventy-four patients were recruited in 15 French radiation oncology departments between August 2014 and July 2016. Seven were excluded before treatment because of violation of the inclusion criteria. The intention-to-treat analysis therefore included 67 patients. Half had received prior prostatic irradiation. Median age was 67.7±6.5years. Grade 2 acute urinary toxicity was observed in 9 of 67 patients (13.4%), and grade 2 1-year toxicity occurred in 4 of 67 patients (6%). Three patients (4.4%) had grade 3 urinary toxicity. Grade 2 acute digestive toxicity was observed in 10 of 67 patients (14.9%), and grade 2 1-year toxicity occurred in 4 of 67 patients (6%). Patients with prior prostate bed irradiation did not exhibit increased urinary or digestive toxicity. The European Organisation for Research and Treatment of Cancer questionnaire scores at 1year did not worsen significantly. The acute and 1-year toxicity of the BLINDED protocol was satisfactory, even in patients with a history of prostatic irradiation.