RT Journal Article SR Electronic T1 Salvage Radiotherapy Management Decision in Post-prostatectomy Patients with Recurrent Prostate Cancer Based on 18F-Fluciclovine PET/CT Guidance JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP jnumed.120.256784 DO 10.2967/jnumed.120.256784 A1 Olayinka A. Abiodun-Ojo A1 Ashesh B. Jani A1 Akinyemi A. Akintayo A1 Oladunni O. Akin-Akintayo A1 Oluwaseun A. Odewole A1 Funmilayo Tade A1 Shreyas S. Joshi A1 Viraj A. Master A1 Bridget Fielder A1 Raghuveer K. Halkar A1 Chao Zhang A1 Subir Goyal A1 Mark M. Goodman A1 David M. Schuster YR 2021 UL http://jnm.snmjournals.org/content/early/2021/01/29/jnumed.120.256784.abstract AB This study evaluated the impact of 18F-fluciclovine positron emission tomography/computed tomography (PET/CT) on salvage radiotherapy management decisions in patients with recurrent prostate cancer (PCa) post-prostatectomy. Methods: Patients with detectable prostate-specific antigen (PSA) post-prostatectomy were randomized to undergo either conventional imaging (CI) only (Arm A) or CI plus 18F-fluciclovine PET/CT (Arm B) prior to radiotherapy. In Arm B, positivity rates on CI and 18F-fluciclovine PET/CT for detection of recurrent PCa were determined. Final radiotherapy decisions, a) to offer radiotherapy or not and b) extent of radiotherapy field - prostate bed only or to include pelvis, were based on 18F-fluciclovine PET/CT findings. Radiotherapy decisions before and after 18F-fluciclovine PET/CT were compared. Statistical significance of decision changes was determined using Clopper-Pearson (exact) binomial method. Prognostic factors were compared between patients with and without decision changes. Results: All 165 patients enrolled in the study had standard-of-care CI and were initially planned for radiotherapy. Sixty-three of 79 (79.7%) patients (median PSA 0.33 ng/mL) who underwent 18F-fluciclovine PET/CT (Arm B) had positive findings. 18F-Fluciclovine PET/CT had significantly higher positivity rate than CI for whole body (79.7% vs 13.9%; P <0.001), prostate bed (69.6% vs 5.1%; P <0.001), and pelvic lymph nodes (38.0% vs 10.1%; P <0.001). Twenty-eight of 79 (35.4%) patients had overall radiotherapy decision changed following 18F-fluciclovine PET/CT; 4 of 79 (5.1%) had radiotherapy decisions withdrawn due to extrapelvic disease detected on 18F-fluciclovine PET/CT. Twenty-four of 75 (32.0%) patients with the final decision to undergo radiotherapy had radiotherapy fields changed. Changes in overall radiotherapy decision and radiotherapy fields were statistically significant (P <0.001). Overall mean PSA at PET was significantly different between patients with and without radiotherapy decision changes (P = 0.033). Conclusion: 18F-fluciclovine PET/CT significantly altered salvage radiotherapy decisions in patients with recurrent prostate cancer post-prostatectomy. Further analysis to determine the impact of 18F-fluciclovine PET/CT guidance on clinical outcomes post-radiotherapy is in progress.