Early toxicity of a phase II trial of combined salvage radiotherapy and hormone therapy in oligometastatic pelvic node relapses of prostate cancer (OLIGOPELVIS GETUG P07)

Abstract : PURPOSE: Limited pelvic nodal relapse of prostatic cancer is a paramount challenge for locoregional salvage treatments. Salvage whole pelvis radiotherapy as considered in the BLINDED trial, is an attractive option but with concerns about its toxicity. This article describes early toxicity with the technique. METHODS AND MATERIALS: BLINDED was a prospective multi-center phase II trial investigating high-dose salvage pelvic irradiation with an additional dose to the fluorocholine-based positron-emission-tomography (FCH-PET)-positive pelvic lymph nodes (PLN), combined with six-month androgen blockade. The prescribed dose was 54 Gy in 1.8 Gy fractions with up to 66 Gy in 2.2 Gy fractions to the pathological PLN. Early toxicity was defined until one year after radiotherapy. Patients quality of life was assessed using the EORTC questionnaires (QLQ-C30 and QLQ-PR25). RESULTS: Seventy-four patients were recruited in fifteen 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 sixty-seven patients. Half of them had received prior prostatic irradiation. Median age was 67.7 ± 6.5 years. Grade 2 acute urinary toxicity was observed in 9/67 patients (13.4%) and grade 2 one-year toxicity in 4/67 patients (6%). Three patients (4.4%) had grade 3 urinary toxicity. Grade 2 acute digestive toxicity was observed in 10/67 patients (14.9%) and grade 2 one-year toxicity in 4/67 patients (6%). Patients with prior prostate bed irradiation did not exhibit increased urinary or digestive toxicity. EORTC questionnaire scores at one year did not worsen significantly. CONCLUSIONS: The acute and one-year toxicity of the BLINDED protocol was satisfactory, even in patients with a past history of prostatic irradiation.