Purpose: Prostate-specific membrane antigen positron emission tomography (PSMA-PET) is increasingly used to guide salvage radiation therapy (sRT) in patients with prostate cancer and biochemical recurrence/persistence after prostatectomy. This work examined (1) metastasis-free survival (MFS) after PSMA-PET guided sRT and (2) the metastatic patterns on PSMA-PET images after sRT.Methods and Materials: This retrospective, multicenter (9 centers, 5 countries) study included patients referred for PSMA-PET due to recurrent/persistent disease after prostatectomy. Patients with distant metastases (DM) on PSMA-PET before sRT were excluded. Cox regression was performed to assess the effect of clinical parameters on MFS. The distribution of PSMA-PET detected DM after sRT and their respective risk factors were analyzed.Results: All (n = 815) patients received intensity modulated RT to the prostatic fossa. In the case of PET-positive pelvic lymph nodes (PLN-PET) (n = 275, 34%), pelvic lymphatics had been irradiated. Androgen deprivation therapy had been given in 251 (31%) patients. The median follow-up after sRT was 36 months. The 2-/4-year MFS after sRT were 93%/81%. In multivariate analysis, the presence of PLN-PET was a strong predictor for MFS (hazard ratio, 2.39; P < .001). After sRT, DM were detected by PSMA-PET in 128/198 (65%) patients, and 2 metastatic patterns were observed: 43% had DM in sub-diaphragmatic para-aortic LNs (abdominal-lymphatic), 45% in bones, 9% in supra-diaphragmatic LNs, and 6% in visceral organs (distant). Two distinct signatures with risk factors for each pattern were identified.Conclusions: MFS in our study is lower compared with previous studies, obviously due to the higher detection rate of DM in PSMA-PET after sRT. Thus, it remains unclear whether MFS is a surrogate endpoint for overall survival in PSMA PET-staged patients in the post-sRT setting. PLN-PET may be proposed as a new surrogate parameter predictive of MFS. Analysis of recurrence patterns in PET after sRT revealed risk factor signatures for 2 metastatic patterns (abdominal-lymphatic and distant), which may allow individualized sRT concepts in the future.

Metastasis-free survival and patterns of distant metastatic disease after PSMA-PET-guided salvage radiotherapy in recurrent or persistent prostate cancer after prostatectomy / C. Zamboglou, I. Strouthos, J. Sahlmann, A. Farolfi, F. Serani, F. Medici, L. Cavallini, A.G. Morganti, C. Trapp, S.A. Koerber, J.C. Peeken, M.M.E. Vogel, K. Schiller, S.E. Combs, M. Eiber, A. Vrachimis, K. Ferentinos, S.K.B. Spohn, S. Kirste, C. Gratzke, J. Ruf, A.-. Grosu, F. Ceci, W.P. Fendler, J. Miksch, S. Kroeze, M. Guckenberger, H. Lanzafame, S. Fanti, G. Hruby, T. Wiegel, L. Emmett, N.S. Schmidt-Hegemann, C. Henkenberens. - In: INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS. - ISSN 0360-3016. - 113:5(2022 Aug 01), pp. 1015-1024. [10.1016/j.ijrobp.2022.04.048]

Metastasis-free survival and patterns of distant metastatic disease after PSMA-PET-guided salvage radiotherapy in recurrent or persistent prostate cancer after prostatectomy

F. Ceci;
2022

Abstract

Purpose: Prostate-specific membrane antigen positron emission tomography (PSMA-PET) is increasingly used to guide salvage radiation therapy (sRT) in patients with prostate cancer and biochemical recurrence/persistence after prostatectomy. This work examined (1) metastasis-free survival (MFS) after PSMA-PET guided sRT and (2) the metastatic patterns on PSMA-PET images after sRT.Methods and Materials: This retrospective, multicenter (9 centers, 5 countries) study included patients referred for PSMA-PET due to recurrent/persistent disease after prostatectomy. Patients with distant metastases (DM) on PSMA-PET before sRT were excluded. Cox regression was performed to assess the effect of clinical parameters on MFS. The distribution of PSMA-PET detected DM after sRT and their respective risk factors were analyzed.Results: All (n = 815) patients received intensity modulated RT to the prostatic fossa. In the case of PET-positive pelvic lymph nodes (PLN-PET) (n = 275, 34%), pelvic lymphatics had been irradiated. Androgen deprivation therapy had been given in 251 (31%) patients. The median follow-up after sRT was 36 months. The 2-/4-year MFS after sRT were 93%/81%. In multivariate analysis, the presence of PLN-PET was a strong predictor for MFS (hazard ratio, 2.39; P < .001). After sRT, DM were detected by PSMA-PET in 128/198 (65%) patients, and 2 metastatic patterns were observed: 43% had DM in sub-diaphragmatic para-aortic LNs (abdominal-lymphatic), 45% in bones, 9% in supra-diaphragmatic LNs, and 6% in visceral organs (distant). Two distinct signatures with risk factors for each pattern were identified.Conclusions: MFS in our study is lower compared with previous studies, obviously due to the higher detection rate of DM in PSMA-PET after sRT. Thus, it remains unclear whether MFS is a surrogate endpoint for overall survival in PSMA PET-staged patients in the post-sRT setting. PLN-PET may be proposed as a new surrogate parameter predictive of MFS. Analysis of recurrence patterns in PET after sRT revealed risk factor signatures for 2 metastatic patterns (abdominal-lymphatic and distant), which may allow individualized sRT concepts in the future.
Androgen Antagonists; Gallium Radioisotopes; Humans; Male; Neoplasm Recurrence, Local; Positron Emission Tomography Computed Tomography; Positron-Emission Tomography; Prostate; Prostatectomy; Retrospective Studies; Salvage Therapy; Prostatic Neoplasms
Settore MED/36 - Diagnostica per Immagini e Radioterapia
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/937951
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