ESTRO 2024 - Abstract Book

S2438

Clinical - Urology

ESTRO 2024

analysis. Biochemical recurrence-free survival (BRFS) defined as PSA < post-RT nadir + 0.2ng/ml, metastasis-free survival (MFS) and nodal recurrence-free survival (NRFS) were calculated using the Kaplan-Meier method and compared using the log rank test.

Results:

Median follow-up was 29 months. At time of the PSMA-PET/CT more than half of the patients had a PSA of > 1 ng/ml. More than 80% received an EQD2α/β=1.5 Gy of ≤ 50 Gy to the lymphatic pathways and more than 80% received boosts to PSMA-positive LN. 70% of the patients received concomitant ADT. There were no significant differences between both groups in BRFS (p = .97), MFS (p = .43) and NRFS (p = .43). After two years, BRFS, MFS and NRFS were 61%, 86% and 88% in the WPRT group and 57%, 90% and 82% in the HPRT group, respectively. Application of a LN boost, a higher RT dose to the lymphatic pathways (> 50 Gy EQD2α/β=1.5 Gy) and concomitant ADT were significantly associated with longer BRFS in uni- and multivariate analysis.

Conclusion:

Overall, the present analysis shows that HPRT results in a similar oncologic outcome compared with WPRT. A prospective evaluation of uni- vs. bilateral RT volumes could help to better understand the way of LN metastasizing and in which patient smaller pelvic lymphatic RT volumes are sufficient.

Keywords: Prostate Cancer, Lymph Node Recurrence

1444

Digital Poster

Diagnostic capacity of 18F-PSMA DCFPyL in biochemical relapse of prostate cancer with low PSA values

Francesco Amorelli 1 , Palmira Foro 1 , Jose M Torices 2 , Augusto O Natali 3 , Alvaro Martinez 1 , Javier Sanz 1 , Ismael Membrive 1 , Manuel Algara 1 , Pedro J Plaza 4 1 Hospital del Mar, Radiation Oncology, Barcelona, Spain. 2 Hospital Quiron Salud, Radiation Oncology, Barcelona, Spain. 3 Hospital Josep Trueta, Laboratory Medicine, Girona, Spain. 4 Hospital del Mar, Nuclear Medicine, Barcelona, Spain

Purpose/Objective:

To analyze the diagnostic capacity of PET-PSMA in patients with biochemical relapse of prostate cancer after primary treatment with radical intent who have PSA values less than 2 ng/ml.

To analyze the optimal cut-off, point of the PSA value (ng/ml) for greater diagnostic specificity and sensitivity.