Both chemotherapy and PSMA-ligand therapy can lead to a loss of PSMA expression in metastases, giving the false impression of a response to therapy; this was shown in a therapy study, as well as in a single case report using a combination of PSMA PET/CT and an additional [18F]FDG PET/CT to detect dedifferentiated metastases of PCa [53,54]. This evidence concerns the gene FOLH1 and posterior cortical atrophy.