TY - JOUR T1 - A Phase 3 study of <sup>18</sup>F-DCFPyL-PET/CT in Patients with Biochemically Recurrent Prostate Cancer (CONDOR): An Analysis of Disease Detection Rate and Positive Predictive Value (PPV) by Anatomic Region JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 123 LP - 123 VL - 62 IS - supplement 1 AU - Steven Rowe AU - Michael Gorin AU - Lawrence Saperstein AU - Frederic Pouliot AU - David Josephson AU - Peter Carroll AU - Jeffrey Wong AU - Austin Pantel AU - Morand Piert AU - Kenneth Gage AU - Steve Cho AU - Andrei Iagaru AU - Janet Pollard AU - Vivien Wong AU - Jessica Jensen AU - Nancy Stambler AU - Michael Morris AU - Barry Siegel Y1 - 2021/05/01 UR - http://jnm.snmjournals.org/content/62/supplement_1/123.abstract N2 - 123Background: PSMA-targeted PET/CT is an effective imaging modality for localizing and determining the extent of biochemically recurrent prostate cancer (PCa) after local therapy, particularly in patients (pts) with low PSA (&lt;2 ng/mL). 18F-DCFPyL is a novel PET agent for imaging PCa that binds selectively with high affinity to PSMA. CONDOR was a prospective, multicenter study designed to demonstrate the diagnostic performance of 18F-DCFPyL-PET/CT for regulatory approval. Here, we report the positive predictive value (PPV) and detection rate (DR) of 18F-DCFPyL-PET/CT by anatomic region: prostate/prostate bed, pelvic lymph nodes and extra-pelvic regions (including lymph nodes, bone, and viscera/soft tissue). Methods: Men with rising PSA after definitive therapy and negative or equivocal conventional imaging were eligible. 18F-DCFPyL (9 mCi ± 20%) was injected, followed by PET/CT 1-2 hours later. Patients with positive 18F-DCFPyL-PET/CT based on local interpretation were scheduled for follow up within 60 days to verify suspected lesion(s) using a composite standard of truth (SOT) consisting of histopathology, subsequent correlative imaging findings, or post-radiation PSA response. The primary endpoint was correct localization rate (CLR) defined as PPV with the requirement of anatomic lesion co-localization between 18F-DCFPyL-PET/CT and the SOT. The trial was successful if the lower bound of the 95% confidence interval for CLR exceeded 20% for at least two of three independent, blinded central PET/CT reviewers. PPV within anatomic regions without lesion-level matching was calculated for patients with positive 18F-DCFPyL-PET/CT as TP/(TP+FP) × 100%. The disease DR was defined as the percent of positive 18F-DCFPyL-PET/CT scans identified by each central imaging reader and was calculated as the number of patients with positive scans divided by the number of patients scanned × 100%. Results: 208 men (median: PSA 0.8 ng/mL; range: 0.17, 98.45) underwent 18F-DCFPyL-PET/CT and the primary endpoint was met. The median PPV (≥1 lesion confirmed) of three independent readers for 18F-DCFPyL-PET/CT by anatomic region was: 31/39 (79.5%, CI: 66.8-92.2%) for prostate/prostate bed, 39/55 (70.9%, CI: 58.9-82.9) for pelvic lymph nodes, and 31/46 (67.4%, CI: 53.8-80.9) for extra-pelvic region. Median DRs (N=208) for prostate/prostate bed, lymph nodes and extra-pelvic region were: 20.2% (CI: 14.7-25.6), 35.1% (CI: 28.6-41.6%), and 26.4% (CI: 20.4-32.4%), respectively. Further analyses of the extra-pelvic region results showed median PPVs of 16/26 (61.5%, CI: 42.8-80.2) for lymph nodes, 15/24 (62.5%, CI: 43.1-81.9) for bone, and 2/7 (28.6%, CI: 7.6-64.8%) for visceral/soft tissue. Conclusions: 18F-DCFPyL-PET/CT detected and localized metastatic lesions with high PPV regardless of anatomic region in men with biochemically recurrent prostate cancer who had negative or equivocal baseline imaging. Higher PPVs were observed in extra-pelvic lymph nodes and bone compared to viscera/soft tissue. Clinicaltrials.gov: NCT03739684 ER -