PSMA PET/CT detected more lesions in patients with prostate cancer and resulted in more changes in management than CT alone when utilized prior to radiotherapy, reported authors of a Dec. 14 study in the Journal of Nuclear Medicine.
As part of the study, Nina-Sophie Schmidt-Hegemann, of University Hospital at LMU Munich, Germany, and colleagues included 172 patients who received 68Ga-PSMA PET/CT prior to radiotherapy. Of that, 22 were referred for primary definitive radiotherapy, 88 patients for prostate-specific antigen (PSA) persistence and 62 for PSA recurrence following radical prostatectomy. A radiation oncologist blinded to PET/CT and CT results decided the treatment pathways based on clinical and pathological findings.
Overall, 70 percent of patients had at least one suspicious lesion detected by PSMA PET/CT which identified 171 total lesions. In comparison, PET alone found 156 and CT identified 85.
Additionally, several participants showed the “superiority” of PSMA PET/CT in lymph node and bone metastases staging. PET/CT found an overall increase in pelvic lymph node metastases of 44 percent compared to 21 percent using CT. And in distant metastases, those percentages were 7 and 19 percent for CT and PET/CT, respectively.
Finally, Schmidt-Hegemann et al. found PET/CT information led to a change of treatment in 62 percent of patients. That broke down to a change in 36 percent of patients who had not yet received any treatment, alterations in half of those with PSA recurrence and 77 percent of people with PSA persistence. However, the low number of patients directed for definitive radiotherapy warrants further validation, according to the authors.
“Compared to conventional CT, PSMA PET/CT had a remarkable impact on radiotherapeutic approach especially in postoperative patients,” the authors wrote.
And in light of their findings, and other research, PSMA PET/CT has been championed for use in patients with PSA persistence/recurrence in a handful of cancer guidelines, including the European Association of Urology guidelines.