PSMA-targeted (18)F-DCFPyL PET/CT in the Preoperative Staging of Men with High-risk Prostate Cancer: Results of a Prospective Phase II Single-Center Study

To prospectively evaluate the diagnostic performance of PSMA-targeted (18)F-DCFPyL PET/CT in the preoperative staging of men at high risk of harboring metastatic prostate cancer despite a negative conventional staging evaluation.

Men with clinically localized high or very-high risk prostate cancer were imaged with (18)F-DCFPyL PET/CT prior to undergoing radical prostatectomy with a standardized pelvic lymph node dissection. PET/CT scans were interpreted by two blinded nuclear medicine readers and were assessed for inter-reader variability as well as diagnostic accuracy for pelvic lymph node staging. Surgical pathology served as the reference standard to which findings on (18)F-DCFPyL PET/CT were compared.

A total of 25 men contributed analyzable data to this study. Of these patients, 7 (28%) were found to have ≥1 positive lymph nodes on surgical pathology. (18)F-DCFPyL PET/CT identified sites of radiotracer uptake within the prostate glands of all imaged patients. The two readers identified the same number of prostatic lesions in 22 (88%) cases, with all patients having at least one intraprostatic lesion in common between the two reads. Additionally, the readers assigned the same N stage to 46 of 50 (92%) individual lymph node packets. Following reconciliation of the relatively few discordant imaging reads, 7 (28%) patients were found to have ≥1 site of focal radiotracer within the pelvis consistent with N1 disease, resulting in a sensitivity and specificity of 71.4% (95% CI 29.0-96.3) and 88.9% (95% CI 65.3-98.6), respectively. Analysis at the level of the individual nodal packets resulted in a sensitivity of 66.7% (95% CI 29.9-92.5) and specificity of 92.7% (95% CI 80.1-98.5). Three (12%) men were found to have evidence of M1a disease on PET/CT.

(18)F-DCFPyL PET/CT allowed for the accurate detection of sites of prostate cancer in men believed to have clinically localized disease on the basis of conventional imaging. Our results support the need for a larger study to more precisely define the diagnostic accuracy of this novel molecular imaging test.

The Journal of urology. 2017 Jul 20 [Epub ahead of print]

Michael A Gorin, Steven P Rowe, Hiten D Patel, Igor Vidal, Margarita Mana-Ay, Mehrbod S Javadi, Lilja B Solnes, Ashley E Ross, Edward M Schaeffer, Trinity J Bivalacqua, Alan W Partin, Kenneth J Pienta, Zsolt Szabo, Angelo M De Marzo, Martin G Pomper, Mohamad E Allaf

The James Buchanan Brady Urological Institute and Department of Urology, Johns Hopkins University School of Medicine, Baltimore, MD, USA. Electronic address: ., The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA., The James Buchanan Brady Urological Institute and Department of Urology, Johns Hopkins University School of Medicine, Baltimore, MD, USA., Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA., Department of Urology, Northwestern University Feinberg School of Medicine, Chicago IL USA.