PSMA PET Applications in Prostate Cancer Management

Scott T. Tagawa, MD, identified 3 primary clinical scenarios where PSMA PET scans have become the established standard for prostate cancer care. The first application is initial staging for patients with high risk disease, where the combination of MRI and PSMA PET provides superior localization compared to older methods. Second, PSMA PET is now considered the conventional choice for detecting biochemical relapse. While MRI remains useful for examining the prostate bed post radiation, PSMA PET has proven more effective than traditional CT and bone scans in these settings. This transition toward what Dr. Tagawa calls modern imaging is already changing clinical practice, even as researchers continue to study its long term impact on overall survival.

The third essential use involves assessing patient eligibility for PSMA targeted radionuclide therapy. Although a contrast CT remains helpful for identifying the 15 to 20 percent of cases where low PSMA expression might cause the PET scan to miss certain features, the PSMA PET is vital for selecting appropriate candidates for treatment. While FDG PET is not always accessible within the US healthcare system to fill these diagnostic gaps, the current framework for PSMA PET is firmly established for these three uses.

Looking toward the future, the focus is shifting to using PSMA PET for assessing treatment response. Dr. Tagawa notes that the Prostate Cancer Working Group 4 has provided a standardized framework to move beyond inconsistent SUV measurements. By focusing on a specific threshold, such as the number five to define disease progression, researchers hope to validate PSMA PET as an earlier endpoint for drug development. This evolution aims to move beyond traditional radiographic progression free survival, potentially speeding up the delivery of new therapies to patients.