Prognostic Value of PSMA PET-Derived Tumor Burden Stratification in Metastatic Hormone-Sensitive Prostate Cancer

The addition of prostate-specific membrane antigen (PSMA) PET to conventional imaging (CI) leads to both downstaging and upstaging in a substantial proportion of patients with metastatic hormone-sensitive prostate cancer (mHSPC) when applying CHAARTED criteria to both modalities. In this cohort of 42 patients with mHSPC (median follow-up time, 39 mo), PET-derived tumor burden (high-volume, low-volume, and local disease) was more strongly associated with overall survival than was CI-derived tumor burden. Also, the correlation of PET-assessed volumes of disease with progression-free survival exhibited a trend toward improved prognostic performance compared with CI-derived tumor burden (high- and low-volume disease). Stratifying patients by whole-body PSMA PET tumor volume did not yield significant differences. These findings support the implementation of PSMA PET alongside CI into major clinical trials to validate the potential prognostic superiority of PSMA PET-defined tumor burden in patients with mHSPC.