Defining clinical workflow and PSMA PET/MR protocol for prostate cancer evaluation: Initial experience and results

Purpose.-To evaluate the clinical workflow and the PET/MR protocol of prostate cancer (PCa) evaluation according to the indication. Methods.-Eleven patients underwent to PSMA PET/MR both for primary staging (PS) and assessment of biochemical recurrence (BCR) of PCa. The clinical workflow was evaluated regarding patient preparation, total uptake time and total acquisition time. The PET/MR protocol was defined according to indication, using a biparametric MRI for PS and a multiparametric MRI for BCR. One reader analyzed the PET/MR for TNM lesion in the PS setting and for locoregional and distant metastasis in the BCR patients. Results.-Four patients (36%) were included for PS and 7 (64%) for assessing BCR of prostate cancer. PSA levels ranged from 0.26 to 33.94 ng/mL and the most prevalent ISUP grade score was 3 (4/11 patients). The average total scan time when including DCE-MR was 73 minutes versus 64 minutes when performing biparametric MR. Nine out of the eleven (82%) patients presented positive findings on PSMA PET/MR. The most prevalent site of disease was local (primary or recurrent tumor) in 6/11 patients (55%) followed by regional lymph nodes in 4/11 (36%). In primary staging patients, the PCa index lesion was depicted in all four patients. In BCR patients, five out of seven patients had positive PET/MR scans. Conclusion.-PET/MRI for prostate cancer evaluation is feasible with a tolerable scan time and, although very preliminary, it reinforces the high detection rate of PSMA PET imaging both for PS and for assessment of BCR. (C) 2019 l'Academie nationale de medecine. Published by Elsevier Masson SAS. All rights reserved.