Conventional imaging rarely localizes the site(s) of prostate cancer recurrence in patients undergoing evaluation for salvage radiotherapy (sRT) after radical prostatectomy (RP). XXX (NCTXXX) was a prospective multicenter study investigating the impact of 18F-fluciclovine positron emission tomography/computed tomography (PET/CT) on the management of patients with biochemical recurrence of prostate cancer after curative-intent radiation or RP and negative or equivocal conventional imaging.
Our objective was to determine the impact of 18F-fluciclovine PET/CT on treatment decisions for men planning to undergo sRT for biochemical recurrence post-RP.
We conducted a subgroup analysis of post-RP patients enrolled in XXX who were planning to undergo sRT with or without hormonal therapy based on pre-scan documentation. 18F-Fluciclovine PET/CT was performed according to standardized procedures. The treatment plan post-scan was compared with the pre-scan plan and the Fisher Exact test used to determine the impact of pre-scan PSA and Gleason sum (GS) on positivity and anatomic patterns of uptake.
A total of 114 patients (median pre-scan PSA 0.42 [interquartile range: 0.3-1.1] ng/mL) met selection criteria (54% of patients in XXX). Forty-eight (42%) had 18F-fluciclovine-avid lesions. Twelve patients (11%) had positive findings only in the prostate bed, 24 (21%) had positivity only in the pelvis (prostate bed or pelvic nodes), and 24 (21%) had extrapelvic findings. PSA >0.5 ng/mL and GS ≥8 were associated with a higher risk of extrapelvic positivity (p<0.05). Post-scan, 55 (48%) patients had a management change; 37 (32%) had a change in overall treatment approach (i.e. omission of sRT) and 18 (16%) had sRT target modification.
18F-Fluciclovine PET/CT is positive in nearly half of patients planning to undergo post-RP sRT with negative/equivocal conventional imaging, with findings frequently leading to changes in management. PSA >0.5 ng/mL and GS ≥8 are associated with a higher risk of extrapelvic positive findings.
Practical radiation oncology. 2020 May 25 [Epub ahead of print]
Abhishek A Solanki, Bital Savir-Baruch, Stanley L Liauw, Jeff Michalski, Jonathan D Tward, Neha Vapiwala, Eugene J Teoh, LOCATE study group
Department of Radiation Oncology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA. Electronic address: ., Department of Radiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA., Radiation Oncology, The University of Chicago Medicine, Chicago, IL, USA., Washington University School of Medicine, St Louis, MO, USA., University of Utah, Huntsman Cancer Institute, Salt Lake City, UT, USA., Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA., Departments of Radiology and Nuclear Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
PubMed http://www.ncbi.nlm.nih.gov/pubmed/32464368