PSMA Expression Assessed by PET Imaging Is a Required Biomarker for Selecting Patients for Any PSMA-Targeted Therapy

PSMA PET/CT of patient with metastatic castration-resistant prostate cancer before treatment with ¹⁷⁷Lu-PSMA therapy. (A) Maximum-intensity-projection image shows extensive metastatic disease (lymph nodes, bone, liver) with low or no PSMA expression (below, equal to, or just above liver background uptake). (B) Patient received 1 cycle of ¹⁷⁷Lu-PSMA therapy, with no response and rapid PSA progression. (C) Presence of multiple liver metastases on CT (left panel) without visible PSMA uptake on corresponding fused PET/CT (middle panel) and PET images (right panel).