A Comparison of PSMA PET/CT Scan and MRI in Men with Intermediate- or High-Risk Prostate Cancer

This study focused on comparing two imaging methods—18F-PSMA-1007 PET/CT and multiparametric MRI—to see which one is more accurate at detecting the extent of prostate cancer before surgery in men with intermediate- or high-risk disease. Prostate-specific membrane antigen (PSMA) is a protein that is found in higher levels in aggressive prostate cancers, and imaging that targets PSMA has been shown to be better than traditional scans for spotting cancer that has spread to other parts of the body. However, there has been limited research on how effective these newer PSMA-based scans are for detecting cancer that is still near the prostate, which is known as locoregional staging.

In this phase 2 study, researchers followed 134 men who had both types of scans—PET/CT and MRI—before undergoing prostate removal surgery. The study took place in two hospitals in Alberta, Canada. All the patients had to be candidates for surgery and had either intermediate- or high-risk prostate cancer. The scans were done within two weeks of each other, and then the researchers compared the imaging results with what was found during surgery.

The main goal was to see which scan could most accurately identify the tumor stage. The study found that the PSMA PET/CT scan was more accurate than MRI in determining the correct tumor stage (45% vs. 28%). It also did a better job in locating the dominant tumor, determining which side of the prostate the tumor was on, and identifying whether the cancer had spread beyond the prostate capsule. However, to detect whether the cancer had reached the seminal vesicles, both imaging types performed similarly.

In conclusion, this study demonstrates that 18F-PSMA-1007 PET/CT is more effective than MRI for detailed pre-surgical imaging of prostate cancer in men with more advanced forms of the disease.

JAMA Onc. PMID: 38949926