RT Journal Article SR Electronic T1 [18F]-fluciclovine positivity rate is not affected by androgen deprivation therapy (ADT) in recurrent prostate cancer post-prostatectomy. JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1576 OP 1576 VO 60 IS supplement 1 A1 Olayinka Abiodun-Ojo A1 Ashesh Jani A1 Akinyemi Akintayo A1 Mehrdad Alemozaffar A1 Oladunni Akin-Akintayo A1 Oluwaseun Odewole A1 Funmialyo Tade A1 Peter Nieh A1 Viraj Master A1 Pretesh Patel A1 Joseph Shelton A1 Omer Kucuk A1 Zhengjia Chen A1 Bruce Hershatter A1 Bridget Fielder A1 Raghuveer Halkar A1 David Schuster YR 2019 UL http://jnm.snmjournals.org/content/60/supplement_1/1576.abstract AB 1576Objectives: [18F]-fluciclovine is a synthetic amino acid PET radiotracer with utility in recurrent prostate cancer detection. We examined the effect of ADT on recurrent prostate cancer detection in post-prostatectomy patients with detectable serum prostate-specific antigen (PSA). Methods: One hundred and sixty-two patients were enrolled in a randomized, prospective intention-to-treat clinical trial for potential salvage radiotherapy for recurrent prostate cancer post-prostatectomy. Seventy-seven of these patients underwent fluciclovine PET-CT prior to radiotherapy. Prostate bed, pelvis and extrapelvic uptake of fluciclovine were noted. Patients “on ADT” had either luteinizing hormone-releasing hormone (LHRH) agonist or testosterone receptor antagonist initiated any time before the fluciclovine scan was performed. ADT-naïve patients had no ADT prior to the fluciclovine scan. Fluciclovine positivity rates were compared between patients on ADT and ADT-naïve patients. Descriptive statistics were reported and statistical significance of difference was determined using two-sample t-test and Fisher’s exact test. Results: 12/77 (15.6%) patients were on ADT at the time of the scan. Average (±SD) time interval between start of ADT and PET-CT scan was 43.7 (±29.6) days. PSA values were not significantly different between patients on ADT and ADT-naïve patients (2.39 (±2.59) ng/ml vs. 1.65 (±4.38) ng/ml; p=0.57). Median (range) Gleason score was 8 (7-9) in the ADT group and 7 (6-9) in the non-ADT group. Overall, fluciclovine positivity rates were similar in the ADT group 10/12 (83.3%) compared to the non-ADT group 51/65 (78.5%) (p=1.00). Positivity rates increased with PSA in both the ADT group (71.4% at PSA <2 ng/ml and 100% at PSA ≥2ng/ml) and the ADT-naïve group (75% at PSA <2 ng/ml and 100% at PSA levels ≥2 ng/ml). Differences in positivity across PSA levels were not statistically significant (p=1.00). There was no difference in fluciclovine distribution of activity (prostate bed, pelvic and extrapelvic uptake) between ADT and ADT naive groups (p=1.00) (see table). Conclusions: Fluciclovine PET-CT can detect prostate cancer recurrence in patients on ADT, with similar positivity rates to ADT-naive patients. A potential reason for this finding is that fluciclovine uptake is mediated by amino acid transporters and is not directly related to testosterone receptor status.