Enhanced Metastatic Detection With PSMA PET: Implications for Prognostic Classification in mCSPC

Current volume (CHAARTED) and risk (LATITUDE) criteria have long guided treatment decisions for patients with metastatic castration-sensitive prostate cancer (mCSPC). However, the introduction of advanced imaging techniques such as PSMA PET, which offers greater accuracy and earlier detection of metastatic disease, raises questions about the continued relevance of these criteria.

At the American Society of Clinical Oncology 2025 Genitourinary Cancers Symposium, results of a retrospective, single-center study were presented, which compared patients with metastatic mCSPC staged with PSMA PET after curative therapy or de novo metastatic disease. Patients with stage IVA disease, such as N1, were also included.

A total of 48 patients were grouped based on the presence of high- and low-volume disease and risk, with the aim of comparing these prognostic factors with overall survival outcomes. Gleason scores of 8 to 10 were found in 81.3% of patients, 57% had T classification of T3 or greater, and 32% had N1 lesions based on conventional examinations.

Based on PSMA PET results, 40% of patients had de novo metastatic disease, with the most common disease sites including bones (M1b, 52%), nonpelvic lymph nodes (M1a, 21%), pelvic lymph nodes (N1, 17%), and viscera (M1c, 10%). Of these patients, 71% had low-volume disease and 75% were at low risk.

The median follow-up was 37.5 months. At 36 months, seven deaths had occurred. A total of 64.6% of the patients with high-volume disease remained alive, compared with 96.6% of patients with low-volume  disease (P=.054). A total of 77.8% of high-risk patients were alive compared with 89.9% of low-risk patients (P=.739).

A 67% increase in distant metastasis detection was observed. When compared with findings from bone scintigraphy, there was a 78.9% discrepancy in the number and/or location of bone lesions. In 53.3% of cases, PSMA PET positively identified bone disease despite negative findings on bone scintigraphy.

When applied to volume curves, PSMA PET appears to provide prognostic value, but this does not hold for risk classification. Beyond improving metastatic disease detection compared with conventional imaging, PSMA PET also demonstrates greater accuracy in identifying bone disease compared with bone scintigraphy.