Managing recurrent prostate cancer after first-line treatment, such as prostatectomy or radiation therapy, remains a clinical challenge. Although PSMA PET imaging has improved disease detection, 30% of patients still have no detectable disease on initial imaging, even as rising prostate-specific antigen (PSA) levels suggest recurrence. Few studies have examined whether repeating PSMA PET in this situation is worthwhile.

“There is little information on the utility of repeating a PSMA PET after an initial negative scan,” said Ur Metser, BSc, MD, FRCPC, professor of radiology at the University of Toronto and head of the Division of Molecular Imaging at the Joint Department of Medical Imaging at Princess Margaret Cancer Centre in Toronto. “In our study, my colleagues and I sought to determine the benefit of a second PSMA PET scan, as well as to assess predictors for positive PSMA PET scans.”