68Ga-Prostate-Specific Membrane Antigen PET/CT in Cholangiocarcinoma: A Potential Biomarker for Targeted Radioligand Therapy?

Ga-PSMA is a promising tracer for both staging and detection of biochemical recurrence in prostate cancer. Prostate-specific membrane antigen is also expressed in the endothelium of neovasculature of various solid malignancies possibly due to tumor-associated angiogenic factors and endothelial cell sprouting. We report a case of 75-year-old man with metastatic cholangiocarcinoma to liver and lymph nodes progressing on chemotherapy. Ga-PSMA PET/CT was performed to assess PSMA expression and showed additional bone and hepatic lesions compared with F-FDG PET/CT. Ga-PSMA expression in the metastatic cholangiocarcinoma potentially guides radionuclide legend therapy with α/β-emitters especially after enervation of all approved therapeutic options.