18F-Fluciclovine Positron Emission Tomography in Men With Biochemical Recurrence of Prostate Cancer After Radical Prostatectomy and Planning to Undergo Salvage Radiation Therapy: Results from LOCATE
Published on Sep 1, 2020in Practical radiation oncology2.948
· DOI :10.1016/J.PRRO.2020.05.007
Purpose 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. Methods 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. Results 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 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. Conclusions 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.