RT Journal Article SR Electronic T1 Salvage Radiotherapy Management Decisions in Postprostatectomy 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 1089 OP 1096 DO 10.2967/jnumed.120.256784 VO 62 IS 8 A1 Olayinka A. Abiodun-Ojo A1 Ashesh B. Jani A1 Akinyemi A. Akintayo A1 Oladunni O. Akin-Akintayo A1 Oluwaseun A. Odewole A1 Funmilayo I. 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/62/8/1089.abstract AB Imaging with novel PET radiotracers has significantly influenced radiotherapy decision making and radiation planning in patients with recurrent prostate cancer (PCa). The purpose of this analysis was to report the final results for management decision changes based on 18F-fluciclovine PET/CT findings and determine whether the decision change trend remained after completion of accrual. Methods: Patients with detectable prostate-specific antigen (PSA) after prostatectomy were randomized to undergo either conventional imaging (CI) only (arm A) or CI plus 18F-fluciclovine PET/CT (arm B) before radiotherapy. In arm B, positivity rates on CI and 18F-fluciclovine PET/CT for detection of recurrent PCa were determined. Final decisions on whether to offer radiotherapy and whether to include only the prostate bed or also the pelvis in the radiotherapy field were based on 18F-fluciclovine PET/CT findings. Radiotherapy decisions before and after 18F-fluciclovine PET/CT were compared. The statistical significance of decision changes was determined using the 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 to receive 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 a significantly higher positivity rate than CI did for the 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 the overall radiotherapy decision changed after 18F-fluciclovine PET/CT; in 4 of 79 (5.1%), the decision to use radiotherapy was withdrawn because of extrapelvic disease detected on 18F-fluciclovine PET/CT. In 24 of 75 (32.0%) patients with a final decision to undergo radiotherapy, the radiotherapy field was changed. Changes in overall radiotherapy decisions and radiotherapy fields were statistically significant (P < 0.001). Overall, the 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 PCa after prostatectomy. Further analysis to determine the impact of 18F-fluciclovine PET/CT guidance on clinical outcomes after radiotherapy is in progress.