PSMA and FDG PET/CT Findings for Differential Diagnosis of Bone Metastasis in a Patient With Synchronous Small-cell Lung Cancer and Prostate Cancer

A 66-year-old man presented with both small-cell lung cancer and prostate adenocarcinoma. Staging PET with 18 F-FDG PET/CT revealed increased uptake in the right pulmonary hilum, mediastinum, fifth cervical vertebra, and fifth lumbar vertebra. In contrast, subsequent 68 Ga-PSMA PET/CT revealed intense uptake only in the prostate and vertebrae, which demonstrated that the bone lesions had metastasized from prostate cancer.