A Prospective Study of 18F-DCFPyL PSMA PET/CT Restaging in Recurrent Prostate Cancer following Primary External Beam Radiotherapy or Brachytherapy

Authors

Wei Liu, London Health Sciences Centre
Katherine Zukotynski, Hamilton Health Sciences
Louise Emmett, UNSW Sydney
Hans T. Chung, Sunnybrook Health Sciences Centre
Peter Chung, University of Toronto
Robert Wolfson, Sunnybrook Health Sciences Centre
Irina Rachinsky, London Health Sciences Centre
Anil Kapoor, McMaster University
Ur Metser, Ontario Cancer Institute University of Toronto
Andrew Loblaw, Sunnybrook Health Sciences Centre
Gerard Morton, Sunnybrook Health Sciences Centre
Tracy Sexton, London Health Sciences Centre
Michael Lock, London Health Sciences Centre
Joelle Helou, University of Toronto
Alejandro Berlin, University of Toronto
Colm Boylan, St. Joseph's Healthcare Hamilton
Susan Archer, London Health Sciences Centre
Gregory R. Pond, McMaster University
Glenn Bauman, London Health Sciences Centre

Document Type

Article

Publication Date

3-1-2020

Journal

International Journal of Radiation Oncology Biology Physics

Volume

106

Issue

3

First Page

546

Last Page

555

URL with Digital Object Identifier

10.1016/j.ijrobp.2019.11.001

Abstract

Purpose: Radio-recurrent prostate cancer is typically detected by a rising prostate-specific antigen and may reflect local or distant disease. Positron emission tomography (PET) radiotracers targeting prostate-specific membrane antigen, such as 18F-DCFPyL have shown promise in restaging men with recurrent disease postprostatectomy but are less well characterized in the setting of radio-recurrent disease. Methods and Materials: A prospective, multi-institutional study was conducted to evaluate the effect of 18F-DCFPyL PET/computed tomography (CT) when added to diagnostic imaging (DI; CT abdomen and pelvis, bone scan, multiparametric magnetic resonance imaging pelvis) for men with radio-recurrent prostate cancer. All men were imaged with DI and subsequently underwent 18F-DCFPyL PET/CT with local and central reads. Tie break reads were performed as required. Management questionnaires were completed after DI and again after 18F-DCFPyL PET/CT. Discordance in patterns of disease detected with 18F-DCFPyL PET/CT versus DI and changes in management were characterized. Results: Seventy-nine men completed the study. Most men had T1 disease (62%) and Gleason score <7 (95%). Median prostate-specific antigen at diagnosis was 7.4 ng/mL and at relapse was 4.8 ng/mL. DI detected isolated intraprostatic recurrence in 38 out of 79 men (48%), regional nodal recurrence in 9 out of 79 (11%), distant disease in 12 out of 79 (15%), and no disease in 26 out of 79 (33%). 18F-DCFPyL PET/CT detected isolated intraprostatic recurrence in 38 out of 79 men (48%), regional nodal recurrence in 21 out of 79 (27%), distant disease in 24 out of 79 (30%), and no disease in 10 out of 79 (13%). DI identified 8 out of 79 (10%) patients to have oligometastatic disease, compared with 21 out of 79 (27%) with 18F-DCFPyL PET/CT. 18F-DCFPyL PET/CT changed proposed management in 34 out of 79 (43%) patients. Conclusions: 18F-DCFPyL PET/CT identified extraprostatic disease in twice as many men with radio-recurrent prostate cancer compared with DI and detected a site of recurrence in 87% of men compared with 67% with DI. Furthermore, 18F-DCFPyL PET/CT identified potentially actionable disease (prostate only recurrence or oligometastatic disease) in 75% of men and changed proposed management in 43% of men.