RT Journal Article SR Electronic T1 18F-Fluciclovine Parameters on Targeted Prostate Biopsy Associated with True Positivity in Recurrent Prostate Cancer JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1531 OP 1536 DO 10.2967/jnumed.119.227033 VO 60 IS 11 A1 Olayinka A. Abiodun-Ojo A1 Akinyemi A. Akintayo A1 Oladunni O. Akin-Akintayo A1 Funmilayo I. Tade A1 Peter T. Nieh A1 Viraj A. Master A1 Mehrdad Alemozaffar A1 Adeboye O. Osunkoya A1 Mark M. Goodman A1 Baowei Fei A1 David M. Schuster YR 2019 UL http://jnm.snmjournals.org/content/60/11/1531.abstract AB We evaluated 18F-fluciclovine uptake parameters that correlate with true positivity for local recurrence in non–prostatectomy-treated patients. Methods: Twenty-one patients (prostate-specific antigen level, 7.4 ± 6.8 ng/mL) with biochemical recurrence after nonprostatectomy local therapy (radiotherapy and cryotherapy) underwent dual–time-point 18F-fluciclovine (364.1 ± 37.7 MBq) PET/CT from pelvis to diaphragm. Prostatic uptake over background was delineated and coregistered to a prostate-biopsy–planning ultrasound. Transrectal biopsies of 18F-fluciclovine–defined targets were completed using a 3-dimensional visualization and navigation platform. Histologic analyses of lesions were completed. Lesion characteristics including SUVmax, target-to-background ratio (TBR), uptake pattern, and subjective reader’s suspicion level were compared between true-positive (malignant) and false-positive (benign) lesions. Univariate analysis was used to determine the association between PET and histologic findings. Receiver-operating-characteristic curves were plotted to determine discriminatory cutoffs for TBR. Statistical significance was set at a P value of less than 0.05. Results: Fifty lesions were identified in 21 patients on PET. Seventeen of 50 (34.0%) targeted lesions in 10 of 21 patients were positive for malignancy. True-positive lesions had a significantly higher SUVmax (6.62 ± 1.70 vs. 4.92 ± 1.27), marrow TBR (2.57 ± 0.81 vs. 1.69 ± 0.51), and blood-pool TBR (4.10 ± 1.17 vs. 2.99 ± 1.01) than false-positive lesions at the early time point (P < 0.01) and remained significant at the delayed time point, except for blood-pool TBR. Focal uptake (odds ratio, 12.07; 95% confidence interval, 2.98–48.80; P < 0.01) and subjective highest suspicion level (odds ratio, 10.91; 95% confidence interval, 1.19–99.69; P = 0.03) correlated with true positivity. Using the receiver-operating-characteristic curve, optimal cutoffs for marrow TBR were 1.9 (area under the curve, 0.82) and 1.8 (area under the curve, 0.85) at early and delayed imaging, respectively. With these cutoffs, 15 of 17 malignant lesions were identified at both time points; however, fewer false-positive lesions were detected at the delayed time point (5/33) than at the early time point (11/33). Conclusion: True positivity of 18F-fluciclovine–targeted prostate biopsy in non–prostatectomy-treated patients correlates with focal uptake, TBR (blood pool and marrow), and subjective highest suspicion level. A marrow TBR of 1.9 at the early time point and 1.8 at the delayed time point had optimal discriminating capabilities. Despite the relatively low intraprostate positive predictive value (34.0%) with 18F-fluciclovine, application of these parameters to interpretative criteria may improve true positivity in the treated prostate.