OBJECTIVE : Early and accurate localisation of lesions in patients with biochemical recurrence (BCR) of prostate cancer may guide salvage therapy decisions. The present study, XXX, aimed to evaluate the impact of 18F-fluciclovine on management of men with BCR of prostate cancer. METHODS : Men with a first episode of BCR following curative-intent primary therapy were enrolled at 6 UK sites. Patients underwent 18F-fluciclovine PET/CT according to standardised procedures. Clinicians documented management plans before and after scanning, recording changes to treatment modality as 'major' and changes within a modality as 'other'. The primary outcome measure was record of a revised management plan post-scan. Secondary endpoints were evaluation of optimal PSA threshold for detection, salvage treatment outcome assessment based on 18F-fluciclovine-involvement, and safety. RESULTS : 18F-Fluciclovine was well tolerated in the 104 scanned patients (median PSA=0.79 ng/mL). Lesions were detected in 58/104 (56%) patients. Detection was broadly proportional to PSA level; ≤1 ng/mL, 1/3 of scans were positive, while 93% scans were positive at PSA >2.0 ng/mL. Sixty-six (64%) patients had a post-scan management change (80% following a positive result). Major changes (43/66; 65%) were: salvage or systemic therapy to watchful waiting (16/66; 24%); salvage therapy to systemic therapy (16/66; 24%); alternative changes to treatment modality (11/66, 17%). The remaining 23/66 (35%) management changes were modifications of the pre-scan plan: most (22/66; 33%) were adjustments to planned brachytherapy/radiotherapy to include a 18F-fluciclovine-guided boost. Where 18F-fluciclovine guided salvage therapy, the PSA response rate was higher than when 18F-fluciclovine was not involved (15/17 [88%] vs 28/39 [72%]). CONCLUSIONS : 18F-Fluciclovine PET/CT located recurrence in the majority of men with BCR, frequently resulting in major management plan changes. Incorporating 18F-fluciclovine PET/CT into treatment planning may optimise targeting of recurrence sites and avoid futile salvage therapy.