ESTRO 2023 - Abstract Book

S1189

Digital Posters

ESTRO 2023

Conclusion This is the first study reporting oncological outcomes of oligometastatic PCa M1c patients, specifically with lung metastases treated with SBRT. We showed that SBRT in this setting is a good option without severe toxicities. Because of the lack of specific data on oligometastatic M1c patients, it seems essential to include these patients in prospective studies.

PO-1467 Split-course hypofractionated radiotherapy for bladder cancer in elderly patients

F. Mignot 1 , E. Fabiano 2 , A. Alati 2 , C. Durdux 2 , C. Hennequin 1 , L. Quero 3

1 Saint Louis hospital, Department of radiation oncology, Paris, France; 2 European Georges Pompidou hospital, Department of radiation oncology, Paris, France; 3 Saint Louis hospital, Department of radiation oncology, Saint Louis hospital, France Purpose or Objective to investigate the feasibility, efficacy, and safety of trimodal therapy (TMT) using a bifractionated split-course hypofractionated radiation therapy for nonmetastatic muscle-invasive bladder (MIBC) cancer in elderly patients. Materials and Methods we retrospectively reviewed the characteristics and outcomes of patients over 75 years old with nonmetastatic MIBC suitable or not for radical cystectomy (RC) and treated with transurethral resection of bladder tumor followed by concomitant radiochemotherapy (platinum salt and 5-fluorouracil) at two institutions (XXX and YYY) between 1990 and 2021. Radiation therapy consisted of an adapted bifractionated split-course hypofractionated radiation therapy. Acute toxicities were reported according to CTCAE v5.0 and late toxicities were reported according to the RTOG/EORTC late radiation morbidity scoring schema. Results 122 patients were identified, with a median follow-up of 51.1 months (range: 0.5–210.8). 83.5 % of patients completed radiochemotherapy. In multivariate analysis, the completion of radiation therapy and concomitant chemotherapy were significantly associated with better overall survival and specific survival. For patients fit to receive RC, a complete histologic response was achieved for 77 patients (91.7 %) with radiochemotherapy and the bladder conservation rate was 90.5 %. Acute and late grade 3 or higher toxicities were below 5%. Conclusion bifractionated split-course hypofractionated radiation therapy with concomitant chemotherapy regimen appears to be well tolerated and effective. Trimodal treatment seems to be a curative option for elderly patients unfit for radical surgery compared with palliative care and may contribute to improved survival in these patients. I.S. Knudtsen 1 , B.S. Abrahamsen 2 , K.M. Selnæs 3 , M. Elschot 1,3 , S. Langørgen 3 , T.M. Keil 3 , H. Johansen 3 , H. Bertilsson 4,5 , T. Tandstad 6,5 , T.F. Bathen 1,3 1 Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway; 2 Department of Circulation and Medical Imaging , Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway; 3 Department of Radiology and Nuclear Medicine, St. Olavs hospital, Trondheim University Hospital, Trondheim, Norway; 4 Department of Urology, St. Olavs hospital, Trondheim University Hospital, Trondheim, Norway; 5 Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway; 6 The Cancer clinic, St. Olavs hospital, Trondheim University Hospital, Trondheim, Norway Purpose or Objective PSMA-PET is becoming part of clinical practice for detection of recurrent prostate cancer, but is a resource-demanding examination limited by decreasing detections rates at lower PSA levels.We have investigated how a combined PSMA PET/MRI/CT-protocol affected treatment of patients referred to our hospital as candidates for salvage radiotherapy (RT) after biochemical recurrence (BCR). PO-1468 Influence of PSMA-PET on treatment of prostate cancer patients with biochemical recurrence