PD41-11: Update from the PEDAL trial: A prospective single arm paired comparison of ability to diagnose and locate prostate cancer between multiparametric MRI and 18F-PSMA-PET/CT

Vy Tran*, Thomas Sutherland, Kim Taubman, Su-Faye Lee, Daniel Lenaghan, Niall Corcoran, Nathan Lawrentschuk, Melbourne, Australia, Henry Woo, Lisa Tarlinton, Sydney, Australia, Tim Spelman, Lauren Thomas, Russell Booth, Melbourne, Australia, Elisa Perry, Justin Hegarty, Christchurch, New Zealand, Lih-Ming Wong, Melbourne, Australia

Introduction: To investigate the accuracy of 18F-DCFPyl prostate specific membrane antigen (PSMA)-PET/CT to detect and localize prostate lesions compared to multiparametric MRI (mpMRI) prostate in men with suspected prostate cancer.

Methods: This is a prospective single arm paired comparison of ability to diagnose and locate prostate cancer between mpMRI and 18F-DCFPyL-PSMA PET/CT. Detection and localisation of suspicious prostate lesions were compared between mpMRI, PET/CT and fused PET/MR images. Radiological findings were correlated with histological findings following a targeted prostate biopsy.

Results: One hundred and thirty-nine men who completed both imaging arms were analysed. The median age was 58 years and median prostate specific antigen (PSA) level 6.3ng/ml. Prostate mpMRI detected 70 index lesions (PIRADS=3), compared to 72 index lesions on PET/CT (SUVmax =7.0). Fifty four index lesions were detected on both mpMRI and PET/CT, with 16 lesions identified by PET/CT alone. Prostate cancer was detected in 59 of 92 men (64.1%) who underwent prostate biopsy. In 43 men with clinically significant prostate cancer (Grade group =2), 35 lesions (81.4%) were visualized on both imaging arms. PET/CT visualized 4 (9.3%) clinically significant lesions that were undetected by mpMRI, and identified 21 patients with metastatic disease. One clinically significant lesion was detected by mpMRI alone.

Conclusions: 18F-DCFPyl PSMA-PET/CT appears to detect lesions seen on mpMRI prostate, as well as identify additional clinically significant prostate lesions. The ability of PSMA-PET/CT to diagnose metastatic disease also saves the need for further staging following diagnosis. These early results provide promising evidence for a fully-powered trial to follow.

Source of Funding: Cyclotek Aust Pty Ltd, General Electrical Healthcare and philanthropic grants