ESTRO 2024 - Abstract Book

S2486

Clinical - Urology

ESTRO 2024

1 Ghent University, Human structure and Repair, Ghent, Belgium. 2 Iridium network, Radiation oncology, Antwerp, Belgium. 3 Epworth Healthcare, Radiation oncology, Melbourne, Australia. 4 Sir Peter MacCallum, oncology, Melbourne, Australia. 5 Oslo university hospital, Radiation oncology, Oslo, Norway. 6 AZ Groeninge, Radiation oncology, Kortrijk, Belgium. 7 Jules Bordet Institute, Radiation oncology, Brussels, Belgium. 8 Hospital Universitario Cruces, Radiation oncology, Barakaldo, Belgium. 9 University Hospitals Leuven, Urology, Leuven, Belgium. 10 University Leuven, Department of cellular and Molecular Medicine, Leuven, Belgium. 11 Bern University Hospital, Radiation oncology, Bern, Switzerland. 12 Hospital Universitari i Politècnic la Fe, Radiation oncology, Valencia, Spain. 13 Hospital Universitario Ramón y Cajal, Radiation oncology, Madrid, Spain. 14 Universitätsspital Basel, Radiation oncology, Basel, Switzerland. 15 University Hospital Zurich, Radiation oncology, Zurich, Switzerland. 16 Humanitas Clinical and Research Hospital, Radiation oncology, Rozzano, Italy. 17 University Hospital La Princesa, Radiation oncology, Madrid, Spain. 18 Complejo Hospitalario de Navarra, Radiation oncology, Navarra, Spain. 19 17. Instituto Oncólogico Clinica Universitaria IMQ, Radiation oncology, Bilbao, Spain. 20 University Hospital Quironsalud, Radiation oncology, Madrid, Belgium. 21 Napoli Istituto Nazionale Tumori IRCCS Fondazione Pascale, Radiation oncology, Napoli, Belgium. 22 AZ St Lucas, Radiation oncology, Ghent, Belgium. 23 Geneva University Hospital, Oncology, Geneva, Switzerland. 24 Ghent University Hospital, Radiation oncology, Ghent, Belgium. 25 Ghent University, Department of Applied Mathematics, Ghent, Belgium. 26 Oncology Institute of Southern Switzerland, oncology, Bellinzona, Belgium. 27 University of Melbourne,, Urology, Melbourne, Australia

Purpose/Objective:

Pelvic nodal recurrences are being increasingly diagnosed in prostate cancer (PCa) patients with the introduction of new molecular imaging techniques, like PSMA PET-CT. There are no specific treatment recommendations for patients with these recurrences and different locoregional treatment approaches are currently being used. Here we report the first oncological outcomes of metastasis directed therapy (MDT) versus elective nodal pelvic radiotherapy (ENRT).

Material/Methods:

STORM is an international, phase II, open-label, randomised, superiority trial. Patients diagnosed with PET-detected pelvic nodal oligorecurrence (≤5 nodes) following radical local treatment for PCa, were randomized in a 1:1 ratio between arm A: MDT and 6 months of ADT, or arm B: ENRT (25x1.8Gy) with MDT and 6 months of ADT. In case of radiotherapy, SBRT (3x10Gy) was used for arm A, with a simultaneous integrated boost in arm B. The primary endpoint is metastasis-free survival (MFS) and here we report the secondary endpoint biochemical relapse-free survival (bRFS), regional relapse-free survival (rRFS). The log-rank test was used to compare endpoints between treatment arms. This study is registered on ClinicalTrials.gov Identifier: NCT03569241

Results:

Between June 2018 and April 2021, 196 patients were randomly assigned to MDT (n=99) or ENRT (n=97). The PET tracer was choline in 32 (17%) patients and PSMA in 157 (83%) patients. Patients were diagnosed with a single node, 2 nodes or 3-5 nodes in 110 (58%), 49 (26%), 28 (15%) patients (missing information for 2 patients). Surgery was the MDT type of choice in only 11 patients (6%). The median follow-up for the entire group is 34 months. The 3-year