This study aims to evaluate the association of the maximum standardized uptake value (SUVmax) in positron-emission tomography targeting prostate-specific membrane antigen (PSMA-PET) prior to salvage radiotherapy (sRT) on biochemical recurrence free survival (BRFS) in a large multicenter cohort.
Patients who underwent 68 Ga-PSMA11-PET prior to sRT were enrolled in four high-volume centers in this retrospective multicenter study. Only patients with PET-positive local recurrence (LR) and/or nodal recurrence (NR) within the pelvis were included. Patients were treated with intensity-modulated-sRT to the prostatic fossa and elective lymphatics in case of nodal disease. Dose escalation was delivered to PET-positive LR and NR. Androgen deprivation therapy was administered at the discretion of the treating physician. LR and NR were manually delineated and SUVmax was extracted for LR and NR. Cox-regression was performed to analyze the impact of clinical parameters and the SUVmax-derived values on BRFS.
Two hundred thirty-five patients with a median follow-up (FU) of 24 months were included in the final cohort. Two-year and 4-year BRFS for all patients were 68% and 56%. The presence of LR was associated with favorable BRFS (p = 0.016). Presence of NR was associated with unfavorable BRFS (p = 0.007). While there was a trend for SUVmax values ≥ median (p = 0.071), SUVmax values ≥ 75% quartile in LR were significantly associated with unfavorable BRFS (p = 0.022, HR: 2.1, 95%CI 1.1-4.6). SUVmax value in NR was not significantly associated with BRFS. SUVmax in LR stayed significant in multivariate analysis (p = 0.030). Sensitivity analysis with patients for who had a FU of > 12 months (n = 197) confirmed these results.
The non-invasive biomarker SUVmax can prognosticate outcome in patients undergoing sRT and recurrence confined to the prostatic fossa in PSMA-PET. Its addition might contribute to improve risk stratification of patients with recurrent PCa and to guide personalized treatment decisions in terms of treatment intensification or de-intensification. This article is part of the Topical Collection on Oncology-Genitourinary.
European journal of nuclear medicine and molecular imaging. 2022 Aug 19 [Epub ahead of print]
Simon K B Spohn, Andrea Farolfi, Sarah Schandeler, Marco M E Vogel, Juri Ruf, Michael Mix, Simon Kirste, Francesco Ceci, Stefano Fanti, Helena Lanzafame, Francesca Serani, Christian Gratzke, August Sigle, Stephanie E Combs, Denise Bernhardt, Juergen E Gschwend, Josef A Buchner, Christian Trapp, Claus Belka, Peter Bartenstein, Lena Unterrainer, Marcus Unterrainer, Matthias Eiber, Stephan G Nekolla, Kilian Schiller, Anca L Grosu, Nina-Sophie Schmidt-Hegemann, Constantinos Zamboglou, Jan C Peeken
Department of Radiation Oncology, University Medical Center Freiburg, Faculty of Medicine, University of Freiburg, Robert-Koch-Straße 3, 79106, Freiburg, Germany. ., Nuclear Medicine, IRCCS Azienda Ospedaliero-Universitaria Di Bologna, Bologna, Italy., Department of Radiation Oncology, University Medical Center Freiburg, Faculty of Medicine, University of Freiburg, Robert-Koch-Straße 3, 79106, Freiburg, Germany., Department of Radiation Oncology, Klinikum Rechts Der Isar, Technical University of Munich, Munich, Germany., Department of Nuclear Medicine, Faculty of Medicine, Medical Center, University of Freiburg, Freiburg, Germany., Division of Nuclear Medicine, IEO European Institute of Oncology Scientific IRCCS, Milan, Italy., Department of Urology, University Medical Center Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany., Department of Urology, Klinikum Rechts Der Isar, Technical University of Munich, Munich, Germany., German Cancer Consortium (DKTK), Partner Site Munich, Munich, Germany., Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany., Department of Nuclear Medicine, Klinikum Rechts Der Isar, Technical University of Munich, Munich, Germany.