Possible diagnostic pitfalls in 68Ga-PSMA PET/CT interpretation

Introduction/Aim 68 Ga-PSMA PET/CT is increasingly used in the evaluation of prostate cancer (PC), particularly in the detection and localization of disease recurrence. The main aim of the current study is to present physiological variation in distribution of PSMA activity and avidity in various benign and neoplastic conditions, as well as false-negative findings that may be misinterpreted. Materials and Methods PSMA represents an excellent biological target for high quality PET imaging of PC. However, PSMA uptake is not prostate-specific and is also expressed in other pathologic conditions. The causes of false-positive and false-negative 68 Ga-PSMA PET/CT findings are described. It is important for reporting physicians to recognize these findings. Results and Discussion PSMA is expressed in various benign and pathologic conditions. A wide range of malignancies other than PC have been reported to express PSMA as part of tumor neovasculature. Conclusion The nonexclusivity of PSMA avidity can potentially pave the way to expand the PSMA theranostic concept outside of PC.