The prognostic role of staging [18F]PSMA-1007 PET/CT volumetric and dissemination features in prostate cancer.

Abstract

Background: This study aimed the role of volumetric and dissemination features of staging [18F]PSMA-1007 PET/CT in predicting progression-free survival (PFS) in patients with prostate cancer (PCa) and their relationship with the main clinical data (ISUP grade groups, number of lesions, PSA).

Methods: We included 164 patients with high-risk PCa who underwent baseline [18F]PSMA-1007 PET/CT. With the help of LIFEx version 7.7, the main volumetric and dissemination PET parameters were semi-automatically extracted: PSMA-prostate tumor volume (PSMA-TV), PSMA-prostate total lesion (PSMA-TL), PSMA total TV (PSMA-TTV), PSMA total TL (PSMA-TTL) and Dmax corrected for body-surface-area (Dmax_bsa). Spearman rank correlations between semiquantitative PET features and the clinical variables were analyzed. PFS estimates were plotted with the Kaplan-Meier method.

Results: A high correlation was seen between the number of lesions and both PSMA-TTL (r 0.725), and Dmaxbsa (r 0.935). A moderate correlation was registered between PSA and PSMA-TTV (r 0.333), PSMA-TTL (r 0.441), Dmax_bsa (r 0.333), as well as between number of lesions and PSMA-TTV (r 0.342). After a median follow-up of 17 months (range 2-45), relapse/progression happened in 17 patients (10%). PSA level, presence of distant metastases at staging, PSMA-TV, PSMA-TL, PSMA-TTL and Dmax_bsa were significantly associated with PFS at univariate analysis, but only the presence of distant metastases, PSMA-TTL and Dmax_bsa were confirmed to be independent prognostic factors.

Conclusion: Volumetric and dissemination features derived by staging [18F]PSMA-1007 PET/CT were significantly correlated with PSA and number of lesions. The combination of PSMA-TTL and Dmax_bsa was the best predictor of PFS and may help to better stratify PCa patients.