FOLH1 and neoplasm: Therefore, due to significant interpatient and intrapatient heterogeneity of PSMA expression as described above (Laidler et al., 2005; Mannweiler et al., 2009; Damjanovic et al., 2019), pretreatment PSMA-PET/CT imaging is necessary prior to PSMA-RLT to verify the tumor PSMA expression.