Loading...
Fetching results...
0 items found

P047: Metastasis-free survival after salvage radiotherapy for post-operative prostate cancer patients in the PSMA PET/CT era – a multicenter analysis

Authors
Zamboglou C.1, Schmidt-Hegemann N.S.2, Emmett L.3, Strouthos I.4, Ferentinos K.5, Serani F.6, Farolfi A.6, Fanti S.7, Federica M.8, Lanzafame H.7, Kirste S.1, Ruf J.9, Vrachimis A.5, Ceci F.10, Grosu A.L.1, Henkenberens C.11
Institutions
1Medical Center - University of Freiburg, Dept. of Radiation Oncology, Freiburg, Germany, 2University of Munich (LMU), Dept. of Radiation Oncology, Munich, Germany, 3St Vincent's Hospital, Dept. of Nuclear Medicine and Theranostics, Sydney, Australia, 4German Oncology Center, European University, Radiation Oncology, Limassol, Cyprus, 5German Oncology Center, European University, Dept. of Radiation Oncology, Limassol, Cyprus, 6University of Bologna, Dept.of Nuclear Medicine , Bologna, Italy, 7University of Bologna, Dept.of Nuclear Medicine, Bologna, Italy, 8University of Bologna, Dept.of Radiation Oncology, Bologna, Italy, 9Medical Center - University of Freiburg, Dept. of Nuclear Medicine, Freiburg, Germany, 10Istituto Europeo di Oncologia, Divisione di Medicina Nucleare, Mailand, Italy, 11University of Hannover, Dept. of Radiation Oncology, Hannover, Germany
Event
13th European Multidisciplinary Congress on Urological Cancers
Date – Time - Location
25 November 2021, 00:00 - 00:00, PDF
Session
EMUC e-posters - e-posters
Topic
Prostate Cancer, Localised - Follow up, Clinical / Prognosis

Introduction & Objectives

Prostate specific membrane antigen positron emission tomography (PSMA-PET) has a high detection rate and influences therapeutic decision making in prostate cancer (PCa) patients with biochemical recurrence or persistence after primary prostatectomy. However, the outcome of PET-based salvage radiotherapy (sRT) in terms of metastasis-free survival (MFS) has not yet been extensively studied. MFS is associated with a significant risk of death from PCa and is a surrogate parameter for PCa specific survival. The purpose of this analysis was to assess MFS in the era of PSMA PET/CT which was used for sRT guidance and for restaging in terms of biochemical failure after sRT. Additionally the metastatic pattern on PSMA PET images after sRT was evaluated.

Materials & Methods

This multicenter (7 centers from 4 countries), retrospective analysis included patients referred for PSMA PET/CT after radical prostatectomy due to biochemically recurrent or persistent disease. Patients with distant metastases (lymph nodes above iliac bifurcation, bone/visceral metastases) in PSMA PET/CT prior to sRT were excluded. MFS was the primary study endpoint. Cox-regression analysis was performed to assess the impact of clinical parameters derived from the MSKCC nomogram as well as of positive findings in pre-sRT PET (recurrent disease in the prostatic fossa / positive lymph nodes in the pelvis) on MFS. Finally, the localization of the metastases in PSMA PET/CT after sRT was assessed.

Results

The final analysis included 502 patients. Nearly all patients (n=481, 96%) received intensity-modulated RT with a median dose of 70 Gy to the prostatic fossa. In case of PET positive lymph nodes (n=198, 39%), elective pelvic lymphatics were irradiated with a dose of 45-50 Gy including a boost to the PET positive regions (up to 60 Gy) in most of the cases. Androgen deprivation therapy was given in 160 (32%) patients. After a medium follow-up time of 40 months (IQR: 27-49), 187 (37.3%) and 113 (22.5%) patients had biochemical recurrent disease and distant metastatic disease, respectively. The 2- and 4-year MFS rates after sRT were 86% and 74%, respectively. In multivariate analysis PSA before sRT, pT stage, local recurrences in PET and pelvic lymph nodes in PET had significant (p<0.05) impact on MFS. The metastases after sRT were localized in subdiaphragmal paraaortic lymph nodes (44%), pelvic bones (23%), non-pelvic bones (19%), supradiaphragmal lymph nodes (9%) and visceral organs (5%).

Conclusions

This analysis on MFS showed promising results in terms of tumor control. Additionally, the present analysis confirmed the strong prognostic effect on MFS of known variables (e.g. PSA level prior to sRT) but also depicted the prognostic impact of PET-derived variables (local recurrences and pelvic lymph nodes metastases). Most of the metastases after sRT were located in abdominal lymph nodes.

Loading...
Fetching poster...
  • © 2022 European Association of Urology
  • Disclaimer