Maximizing diagnostic yield: A systematic review and deep dive into PSMA PET scan protocol variations for prostate...

Area of Science:

• Nuclear Medicine
• Oncology
• Radiology

Background:

• Prostate-specific membrane antigen (PSMA) PET is a key imaging tool for prostate cancer (PCa).
• Standard PSMA PET protocols show variability, with unclear clinical value of non-standard approaches.
• Optimizing PSMA PET protocols is crucial for improving diagnostic accuracy in PCa management.

Purpose of the Study:

• To systematically review and compare various PSMA PET protocols in PCa patients.
• To evaluate the detection rates and potential advantages of non-standard PSMA PET imaging techniques.
• To assess the clinical utility of modified PSMA PET protocols beyond standard acquisition times.

Main Methods:

• Systematic literature review of PubMed and Scopus databases up to August 2025.
• Inclusion of original research studies comparing PSMA PET protocols (early, delayed, diuretic-aided, hybrid/multiphasic) with standard imaging.
• Analysis of 97 studies involving 8,428 PCa patients.

Main Results:

• Early imaging improved visualization and detection of local recurrence (9-12%) with enhanced tumor-to-background ratios.
• Late imaging (2-4h post-injection) increased lesion contrast, detected more lesions (up to 38.5%), and altered staging (up to 66.7%).
• Diuretic-aided protocols reduced artifacts and improved confidence (63-91%); hybrid/multiphasic protocols offered context-dependent gains.

Conclusions:

• Additional PSMA PET acquisitions offer scenario-specific advantages, especially in low PSA biochemical recurrence and equivocal findings.
• Judicious use of modified protocols can enhance diagnostic confidence and detection rates in specific clinical contexts.
• While offering complementary benefits, the overall incremental value of additional PSMA PET acquisitions is modest and requires careful consideration.