An Innovative Approach with [⁶⁸Ga]Ga-PSMA PET/CT: The Relationship Between PRIMARY Scores and Clinical and...

Area of Science:

• Nuclear Medicine
• Oncology
• Radiology

Background:

• Prostate cancer aggressiveness varies significantly, impacting treatment decisions.
• Accurate staging and risk stratification are crucial for optimal patient management.
• The PRIMARY score from [68Ga]Ga-PSMA PET/CT is a novel imaging biomarker for prostate cancer.

Purpose of the Study:

• To investigate the correlation between the PRIMARY score and prostate cancer aggressiveness parameters.
• To assess the interobserver agreement of the PRIMARY score in clinical practice.
• To evaluate the utility of the PRIMARY score in routine prostate cancer staging.

Main Methods:

• Retrospective analysis of 51 patients with biopsy-proven prostate cancer undergoing [68Ga]Ga-PSMA PET/CT.
• PRIMARY scores assigned based on intraprostatic uptake, intensity, and localization.
• Comparison of PRIMARY scores with PSA levels, ISUP Grade Group, D'Amico risk, and histopathological features.

Main Results:

• Significant associations found between PRIMARY scores and PSA, ISUP Grade Group, and D'Amico risk.
• PRIMARY 5 was linked to ISUP GG 5 and high-risk D'Amico classification.
• Excellent interobserver agreement (κ = 0.833) for the PRIMARY score was observed.

Conclusions:

• The PRIMARY score is reproducible and clinically relevant for stratifying prostate cancer aggressiveness.
• Binary classification limitations exist, particularly for PRIMARY Score 2, which may indicate high-grade disease.
• Integrating imaging scores with clinical and pathological data is vital for accurate staging and treatment decisions.