Impact of reduced scan extent on tumor detection in 68Ga-PSMA PET/CT for biochemical recurrence of prostate cancer

Background

PSMA PET/CT plays an important role in biochemically recurrent prostate cancer (BCR-PCa). In general, PET/CT is performed as a limited or true whole-body examination. The majority of PET/CT scanners operate by measuring several bed positions or continuous motion with a limited axial field of view (FOV). Shortening the scan area thus results in a time saving, with unknown information loss regarding the detection of tumor manifestations. Methodology: This retrospective single-center study included 200 patients with BCR-PCa after initial curative therapy who underwent a 68Ga-PSMA-PET/CT scan from vertex to toe (true whole-body). Using retrospective subdivision into hypothetical partial body measurement protocols, the undetected tumor manifestations were examined. Classic PET/CT protocols were used: vertex to mid-thigh, skull base to mid-thigh, as well as CT-equivalent examination areas: chest/abdomen/pelvis (CAP), abdomen/pelvis (AP) and pelvis.