RT Journal Article SR Electronic T1 18F-DCFPyL PET/CT Imaging in Patients with Biochemically Recurrent Prostate Cancer After Primary Local Therapy JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 881 OP 889 DO 10.2967/jnumed.119.234799 VO 61 IS 6 A1 Esther Mena A1 Maria Liza Lindenberg A1 Ismail Baris Turkbey A1 Joanna H. Shih A1 Stephanie A. Harmon A1 Ilhan Lim A1 Frank Lin A1 Stephen Adler A1 Philip Eclarinal A1 Yolanda L. McKinney A1 Deborah Citrin A1 William Dahut A1 Bradford J. Wood A1 Venkatesh Krishnasamy A1 Richard Chang A1 Elliot Levy A1 Maria Merino A1 Peter Pinto A1 Janet F. Eary A1 Peter L. Choyke YR 2020 UL http://jnm.snmjournals.org/content/61/6/881.abstract AB Our objective was to investigate the lesion detection rate of 18F-DCFPyL PET/CT, a prostate-specific membrane antigen (PSMA)–targeted PET agent, in patients with biochemically relapsed prostate cancer after primary local therapy. Methods: This was a prospective institutional review board–approved study of 90 patients with documented biochemical recurrence (median prostate-specific antigen [PSA], 2.5 ng/mL; range, 0.21–35.5 ng/mL) and negative results on conventional imaging after primary local therapies, including radical prostatectomy (n = 38), radiation (n = 27), or a combination of the two (n = 25). Patients on androgen deprivation therapy were excluded. Patients underwent whole-body 18F-DCFPyL PET/CT (299.9 ± 15.5 MBq) at 2 h after injection. The PSMA PET lesion detection rate was correlated with PSA, PSA kinetics, and original primary tumor grade. Results: Seventy patients (77.8%) showed positive PSMA PET results, with a total of 287 lesions identified: 37 prostate bed foci, 208 lesions in lymph nodes, and 42 in distant sites in bones or organs, Eleven patients had negative results, and 9 patients showed indeterminate lesions, which were considered negative in this study. The detection rates were 47.6% (n = 10/21), 50% (n = 5/10), 88.9% (n = 8/9), and 94% (n = 47/50) for PSA levels of >0.2 to <0.5, 0.5 to <1.0, 1 to <2.0, and ≥2.0 ng/mL, respectively. In postsurgical patients, PSA, PSA doubling time, and PSA velocity correlated with PET results, but the same was not true for postradiation patients. These parameters also correlated with the extent of disease on PET (intrapelvic vs. extrapelvic). There was no significant difference in the rate of positive scans between patients with higher-grade and lower-grade primary tumors (Gleason score of ≥4 + 3 vs. <3 + 4). Tumor recurrence was histology-confirmed in 40% (28/70) of patients. On a per-patient basis, positive predictive value was 93.3% (95% confidence interval, 77.6%–99.2%) by histopathologic validation and 96.2% (95% confidence interval, 86.3%–99.7%) by the combination of histology and imaging/clinical follow-up. Conclusion: 18F-DCFPyL PET/CT imaging offers high detection rates in biochemically recurrent prostate cancer patients and is positive in about 50% of patients with a PSA level of less than 0.5 ng/mL, which could substantially impact clinical management. In postsurgical patients, 18F-DCFPyL PET/CT correlates with PSA, PSA doubling time, and PSA velocity, suggesting it may have prognostic value. 18F-DCFPyL PET/CT is highly promising for localizing sites of recurrent prostate cancer.