Abstract
Novel radiopharmaceuticals for PET are being evaluated for the diagnosis of biochemical recurrence (BCR) of prostate cancer (PC). We compared the gastrin-releasing peptide receptor-targeting (68)Ga-RM2 with the prostate-specific membrane antigen (PSMA)-targeting (68)Ga-PSMA11 and (18)F-DCFPyL. Methods: Fifty patients underwent both (68)Ga-RM2 PET/MRI and (68)Ga-PSMA11 (n = 23) or (18)F-DCFPyL (n = 27) PET/CT at an interval ranging from 1 to 60 d (mean ± SD, 15.8 ± 17.7 d). SUV(max) was collected for all lesions. Results:(68)Ga-RM2 PET was positive in 35 and negative in 15 of the 50 patients. (68)Ga-PSMA11/(18)F-DCFPyL PET was positive in 37 and negative in 13 of the 50 patients. Both scans detected 70 lesions in 32 patients. Forty-three lesions in 18 patients were identified on only 1 scan: (68)Ga-RM2 detected 7 more lesions in 4 patients, whereas (68)Ga-PSMA11/(18)F-DCFPyL detected 36 more lesions in 13 patients. Conclusion:(68)Ga-RM2 remains a valuable radiopharmaceutical even when compared with the more widely used (68)Ga-PSMA11/(18)F-DCFPyL in the evaluation of BCR of PC. Larger studies are needed to verify that identifying patients for whom these 2 classes of radiopharmaceuticals are complementary may ultimately allow for personalized medicine.