Digital PET and detection of recurrent prostate cancer: what have we gained, and what is still missing?

Abstract

Defined by the TIME magazine medical invention of the year 2000 , positron emission computed tomography (PET/CT) has experienced impressive improvements in technology and clinical applications over time. In recent years, silicon photomultipliers (SiPMs) detectors, characterized by excellent intrinsic time resolution and high photon-detection efficiency, have been introduced as an alternative to the classic photomultiplier tubes (PMTs), thus moving the field of PET technology forward and leading to the so-called digital PET/CT (dPET/CT). On the other side, the radiopharmaceutical 68Ga-PSMA-11, approved by Food And Drug Administration in December 2020, proved to strongly impact on prostate cancer (PCa) diagnosis and management. In the study under evaluation, Alberts et al. retrospectively compared the performance of dPET/CT and PMTs-based PET/CT, namely analogue PET/CT (aPET/CT), in 2 cohorts, each one including 65 patients undergoing PET/CT with 68Ga-PSMA-11 for suspected recurrent PCa. The authors found that dPET/CT presented higher detection rate of pathological lesions respect to aPET/CT. Of note, dPET/CT s higher sensitivity resulted associated with an increased true-positive rate and high inter-reader agreement. This report underscores how the innovative PET/CT instrumentation, by utilizing novel radiopharmaceuticals targeting specific metabolic/molecular signatures expressed by PCa, may represent a successful weapon in uro-oncology.