PET Using Other Agents: There are many additional prostate-specific tracers that are not FDA approved, including 11C-acetate [70,71], 18F-choline [72-74], Bombesin, 18F-fluorodihydrotestosterone [78], and a family of related PSMA tracers [76,77,140], that are in various stages of investigation and have been reported to detect local and metastatic recurrent disease in patients with biochemical failure after local treatment. These agents remain investigational, but some have shown excellent results and hold great potential. FDG-PET/CT FDG is an inferior tracer to choline and other prostate-specific agents [79,80,147-149] and has limited use in standard practice. However, as advanced metastatic prostate cancer migrates to a high Gleason grade, dedifferentiates, or transforms to other aggressive variants, such as small cell type, the tumor cells are more likely to convert to a higher glucose metabolism, and FDG can become useful in the detection and monitoring of this subset of patients, although the literature data are limited [150-152]. PSMA PET/CT Skull Base To Mid-Thigh PSMA was FDA approved in December 2020 for imaging of prostate cancer patients with BCR, and its use in metastatic prostate cancer is not as commonly reported as in BCR, and it is mostly limited to research use. In 1 study that compared visual and semiautomatic bone scan evaluations with PSMA PET/CT in 30 patients, visual and semiautomatic bone scan evaluation showed similar results with an average of 19.4 and 17.8 detected bone lesion per patient, whereas PSMA PET/CT revealed 40 lesions per patient [153]. In a study with 51 patients who had inconclusive F-18-NaF PET/CT findings for bone metastases, additional PSMA PET/CT ultimately diagnosed bone metastases in 13 patients (25% of the entire cohort). Patient-based sensitivity, specificity, and accuracy of additional PSMA PET/CT were 100%, 95%, and 96%, respectively [154].
Post Treatment Follow up of Prostate Cancer. PET Using Other Agents: There are many additional prostate-specific tracers that are not FDA approved, including 11C-acetate [70,71], 18F-choline [72-74], Bombesin, 18F-fluorodihydrotestosterone [78], and a family of related PSMA tracers [76,77,140], that are in various stages of investigation and have been reported to detect local and metastatic recurrent disease in patients with biochemical failure after local treatment. These agents remain investigational, but some have shown excellent results and hold great potential. FDG-PET/CT FDG is an inferior tracer to choline and other prostate-specific agents [79,80,147-149] and has limited use in standard practice. However, as advanced metastatic prostate cancer migrates to a high Gleason grade, dedifferentiates, or transforms to other aggressive variants, such as small cell type, the tumor cells are more likely to convert to a higher glucose metabolism, and FDG can become useful in the detection and monitoring of this subset of patients, although the literature data are limited [150-152]. PSMA PET/CT Skull Base To Mid-Thigh PSMA was FDA approved in December 2020 for imaging of prostate cancer patients with BCR, and its use in metastatic prostate cancer is not as commonly reported as in BCR, and it is mostly limited to research use. In 1 study that compared visual and semiautomatic bone scan evaluations with PSMA PET/CT in 30 patients, visual and semiautomatic bone scan evaluation showed similar results with an average of 19.4 and 17.8 detected bone lesion per patient, whereas PSMA PET/CT revealed 40 lesions per patient [153]. In a study with 51 patients who had inconclusive F-18-NaF PET/CT findings for bone metastases, additional PSMA PET/CT ultimately diagnosed bone metastases in 13 patients (25% of the entire cohort). Patient-based sensitivity, specificity, and accuracy of additional PSMA PET/CT were 100%, 95%, and 96%, respectively [154].