Use of PSMA-PET/CT in Detecting Prostate Cancer

This study looked at how well a newer type of imaging called PSMA-PET/CT works in detecting cancer in patients with high-risk,

hormone-sensitive prostate cancer. These patients were similar to those included in the large EMBARK trial, which tested the drug enzalutamide, with or without another drug called leuprolide. However, the EMBARK trial used older imaging methods like CT and bone scans, which often miss small or hidden signs of cancer spread.

The researchers reviewed data from 182 patients across four previous studies conducted between 2016 and 2021. All of these patients had prostate cancer that had come back after treatments like surgery or radiation and had rising PSA levels—a sign the cancer might be returning or spreading. These patients were considered to have no distant metastasis based on traditional imaging, and they had not received hormone or systemic therapy.

When these same patients were scanned using PSMA-PET/CT, the results showed that conventional imaging had missed cancer in many of them. Overall, PSMA-PET was positive in 84% of patients, indicating the presence of cancer activity. Even more notably, PSMA-PET discovered that 46% of these patients actually had metastatic cancer (stage M1), and 24% had polymetastatic disease, which means cancer was found in five or more places.

These results suggest that many patients labeled as “nonmetastatic” using older scans may, in fact, have metastatic disease. This is important because having a more accurate picture of how far cancer has spread helps doctors choose the best treatment. The findings also raise questions about the design and results of earlier prostate cancer trials like EMBARK, which may have included patients with more advanced disease than originally thought.

In conclusion, PSMA-PET/CT appears to be more effective than traditional scans in detecting cancer spread. This could change how doctors stage prostate cancer, how they pick patients for certain treatments or trials, and how they predict patient outcomes. Further research is needed to confirm these benefits and determine the optimal use of PSMA-PET in clinical care.

JAMA Network Open. PMID:e2452971