Abstract
Around 20% of men with prostate cancer develop metastatic disease during the course of their disease. Accordingly, discovering and developing new potent treatment strategies for metastatic prostate cancer patients has been a major research focus of the last decades. Identifying disease progression, especially within clinical trials, is essential in determining drug effectiveness. One major remaining question is how to best define disease progression. The Prostate Cancer Clinical Trials Working Group (PCWG) Criteria include clinical and laboratory parameters, as well as conventional imaging modalities such as MRI, CT and bone scan findings but advanced molecular imaging techniques, especially PSMA PET findings are not considered. This is a problem as PSMA PET is not only used for detecting biochemical recurrence but also for restaging at various disease stages and as intermediate endpoint biomarker in ongoing clinical trials. Therefore, response criteria and PSMA PET progression criteria need to be established with some urgency. The intent of this manuscript is therefore to define prostate cancer progression by PSMA PET criteria. Our PPP (PSMA PET progression) proposal is based on the same principles that were applied for the PCGW2 criteria but adds value by including PSMA PET criteria. PPP defines PSMA treatment response in 3 different criteria: 1) Appearance of 2 or more new PSMA positive distant lesions, 2) Appearance of 1 new PSMA positive lesion plus consistent clinical and/or laboratory data and recommended confirmation by biopsy or correlative imaging within 3 months of PSMA PET, and 3) Increase in size or PSMA uptake of 1 or more existing lesions by 30% plus consistent clinical and/or laboratory data and/or confirmation by biopsy or correlative imaging within 3 months of PSMA PET.
- Copyright © 2019 by the Society of Nuclear Medicine and Molecular Imaging, Inc.