PSMA-PET is a novel imaging modality for the staging of prostate cancer (PCa). While there are several PSMA ligands available, F-18-PSMA-1007 is particularly of interest as it is not renally excreted and therefore does not impair the imaging of the pelvic area. Hence, this study aimed to investigate the F-18-PSMA-1007-PET for the primary staging of PCa and compared it to multi-parametric (mp) MRI and histopathology.
A retrospective study was performed of men with intermediate and high-risk PCa patients that underwent a F-18-PSMA-1007-PET after mpMRI with subsequent MR-guided target biopsy (MRGB). Suspicious mpMRI lesions and F-18-PSMA-1007-PET were simultaneously reviewed on both a per patient and per-lesion basis. Results were subsequently evaluated with histopathological outcome of MRGB, and if performed, the radical prostatectomy specimen.
A total of 66 suspicious mpMRI lesions were identified in 53 patients and underwent MRGB. Two lesions had a maximum standardized uptake value (SUVmax) less than the mean SUVmax of healthy prostate tissue and were considered as non-PSMA-expressing. All PSMA avid tumors had higher SUVmax than the mean SUVmean of the bladder/urine, therefore all lesions were clearly distinguishable in the pelvic area. Twenty-three patients received a radical prostatectomy of which the histopathology specimens were evaluated. F-18-PSMA-1007-PET/CT correctly staged seminal vesicle invasion (i.e. pT3b) more often than mpMRI (90 vs. 76%), whereas mpMRI more accurately detected extracapsular extension (i.e. pT3a) compared to F-18-PSMA-1007-PET (90% vs 57%).
The present study of a selected cohort suggest that dual imaging with mpMRI and F-18-PSMA-1007-PET may improve staging of primary PCa. F-18-PSMA-1007-PET/CT had low renal clearance, which could assist the evaluation of tumors in proximity of the bladder.
Prostate cancer and prostatic diseases. 2020 Sep 30 [Epub ahead of print]
Bastiaan M Privé, Bas Israël, Melline G M Schilham, Constantijn H J Muselaers, Patrik Zámecnik, Peter F A Mulders, J Alfred Witjes, Michiel Sedelaar, Niven Mehra, Fred Verzijlbergen, Marcel J R Janssen, Martin Gotthardt, Jelle O Barentsz, Inge M van Oort, James Nagarajah
Department of Radiology & Nuclear Medicine, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands. ., Department of Radiology & Nuclear Medicine, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands., Department of Urology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands., Department of Medical Oncology, Radboud University Medical Center, Nijmegen, The Netherlands.