Development and validation of a multi-institutional nomogram of outcomes for PSMA-PET–based salvage radiotherapy in recurrent prostate cancer

Autor: Constantinos Zamboglou, Armelle Arnoux, Ali Janbain, Iosif Strouthos, Andrea Farolfi, Stefan Koerber, Jan Peeken, Marco Vogel, Konstantinos Ferentinos, Mohamed Shelan, Anca L. Grosu, Stephanie Kroeze, Matthias Guckenberger, Stefano Fanti, George Hruby, Sophia Scharl, Thomas Wiegel, Christoph Henkeberens, Louise Emmett, Nina-Sophie Hegemann
Rok vydání: 2023
Předmět:
Zdroj: Journal of Clinical Oncology. 41:355-355
ISSN: 1527-7755
0732-183X
Popis: 355 Background: We aimed to develop and to validate a multi-institutional nomogram of outcomes for PSMA-PET based salvage radiotherapy (sRT) following radical prostatectomy (RP) for patients with recurrent or persistent prostate cancer (PCa). Methods: Data from patients with a detectable post-RP prostate-specific antigen (PSA) treated with sRT with or without concurrent androgen-deprivation therapy (ADT) were obtained from 11 academic institutions from 5 countries. All patients had a PSMA-PET scan prior sRT and patients with distant metastases on PET were excluded from this analysis. The freedom from biochemical failure (FFBF) rate was estimated, and a predictive nomogram was generated and validated. Biochemical relapse (BR) was defined as PSA nadir +0.2 ng/ml after sRT. Results: Overall, 1029 patients (training set n=821, external validation set n=208) with a median follow-up of 33 months were included. On PSMA-PET, 427 (42%) and 313 (30%) patients had local and nodal recurrences, respectively. Elective pelvic lymphatics were irradiated in 368 (36%) patients. All patients received sRT to the prostatic fossa receiving a dose of 70 Gy in 103 (10%), 551 (54%) and 375 (36%) patients, respectively. Androgen deprivation therapy (ADT) was given in 325 (32%) patients. On multivariable Cox regression analysis, pre-SRT PSA, ISUP grade, pT stage, surgical margins, ADT use, sRT dose and nodal recurrence on PSMA PET were associated with FFBF. The nomogram concordance index was 0.7 for FFBF in external validation. Conclusions: We present an externally validated contemporary nomogram which can estimate individual patient outcomes after PSMA-PET guided sRT. Positive lymph nodes on PSMA-PET seem to be a new risk factor for BR after sRT.
Databáze: OpenAIRE
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