Monday, December 2 | 8:30 a.m.-8:40 a.m. | M1-SSNMMI02-4 | Room S405
PET radiopharmaceuticals F-18 prostate specific membrane antigen (PSMA)-DCFPyL and a gallium-68 (Ga-68) PSMA-11 appear equivalent for determining patient eligibility for prostate cancer treatment with lutetium-177 (Lu-177) PSMA-617, say researchers in this session.
While numerous tracers are currently available, to date, there is a lack of consensus on the optimal radiotracer for PSMA PET/CT. Presenter Yalda Nikanpour, MD, and colleagues at the Mayo Clinic in Rochester analyzed whether molecular imaging PSMA expression (miPSMA) scores differed among Lu-177 PSMA-617 when each of the PET radiotracers was used. miPSMA scores are a visual rating system for disease severity, with scores of 0, 1, 2, or 3 for no, low, intermediate, or high PSMA expression.
In total, they included 68 patients in the analysis. On Ga-68 PSMA-11 PET, 56 scans showed miPSMA scores of 3, and 12 showed scores of 2. On F-18 PSMA-DCFPyL PET, 54 patients had scores of 3, and 14 scans had scores of 2. No patients had miPSMA scores of 0 to 1, according to the findings.
Moreover, discordant miPSMA scores between the two tracers were observed in six cases (8.82%). In 4 patients, the scores were higher on Ga-68 PSMA-11 and in two patients, scores were higher on F-18 PSMA-DCFPyL.
“Selection of radiotracer did not impact patient eligibility for Lu-177 PSMA-617,” the group noted.
Still, there’s more work to do. Further analysis, including in patients with miPSMA scores of 0 or 1, would be helpful, the group concluded. Check out this Monday morning session to learn the details.
