Primary Score as a Predictive Marker in Intermediate-Risk Prostate Cancer: Insights from PSMA PET/CT Imaging.

Area of Science:

• Oncology
• Radiology
• Nuclear Medicine

Background:

• Intermediate-risk prostate cancer (PCa) requires accurate staging to guide treatment decisions.
• Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) is an advanced imaging technique for evaluating PCa.
• Predictive markers for adverse pathology and prognosis are crucial for optimizing patient outcomes.

Purpose of the Study:

• To evaluate the predictive capability of the PRIMARY score derived from PSMA PET/CT for adverse pathology and prognosis in intermediate-risk PCa.
• To assess the correlation between PRIMARY scores and Gleason score changes.
• To determine the utility of PRIMARY score in predicting biochemical recurrence.

Main Methods:

• Retrospective, multicenter analysis of 78 intermediate-risk PCa patients.
• Staging performed using multiparametric magnetic resonance imaging (mpMRI) and PSMA PET/CT ([68Ga]Ga-PSMA-11 or [18F]F-PSMA1007).
• Quantitative analysis using PI-RADS v2.1 for mpMRI and PRIMARY score for PSMA PET/CT.

Main Results:

• PRIMARY scores >3 were observed in 62% of favorable-risk and 71% of unfavorable-risk cases.
• Gleason score changes occurred in 20% of favorable-risk patients, with 90% having a PRIMARY score >3.
• Biochemical recurrence (PSA >0.2 ng/ml) was seen in 17% of patients, primarily in favorable-risk cases with Gleason score changes and PRIMARY score >3.

Conclusions:

• The PRIMARY score demonstrates significant predictive value for Gleason score changes in intermediate-risk PCa.
• PSMA PET/CT PRIMARY scoring can aid in identifying patients at higher risk for adverse pathology.
• This imaging metric may assist in refining prognostic assessments and treatment strategies for PCa.