FOLH1 and prostate cancer: A number of imaging methods, such as C-11/F-18-choline, F-18-FACBC, and Ga-68-PSMA for positron emission tomography (PET) combined with CT (PET/CT) or magnetic resonance imaging (MRI), are currently under investigation to determine their utility for response assessment in prostate cancer and cannot yet be recommended for use in routine clinical practice.