@article {Meijerjnumed.120.252528, author = {Dennie Meijer and Maarten L. Donswijk and Yves J. L. Bodar and Pim J. van Leeuwen and Henk G. van der Poel and Wouter V. Vogel and Jakko A. Nieuwenhuijzen and N. Harry Hendrikse and Daniela E. Oprea-Lager and Andr{\'e} N. Vis}, title = {Biochemical Persistence of Prostate-specific Antigen after Robot-assisted Laparoscopic Radical Prostatectomy: Tumor localizations using PSMA PET/CT imaging}, elocation-id = {jnumed.120.252528}, year = {2020}, doi = {10.2967/jnumed.120.252528}, publisher = {Society of Nuclear Medicine}, abstract = {Since the introduction of radiolabeled prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT), the ability to visualize recurrent prostate cancer has improved substantially. However, the diagnostic accuracy of radiolabeled PSMA PET/CT in patients with biochemical persistence (BCP; i.e., persistently measurable prostate-specific antigen (PSA)-values after robot-assisted laparoscopic radical prostatectomy (RARP)) is largely lacking. Therefore, the aim of this study was to determine the role of PSMA (i.e.,18F-DCFPyL or 68Ga-PSMA-11) PET/CT imaging in patients who experience BCP after RARP and to evaluate the sites of persistent disease on PSMA PET/CT. Methods: A total of 150 consecutive patients with BCP after RARP who underwent radiolabeled PSMA PET/CT imaging were retrospectively evaluated. BCP was defined as any detectable first serum PSA-value after RARP (>=0.1 ng/mL) at least 6 weeks after surgery, in the absence of an undetectable PSA-value after RARP. A multivariable logistic regression analysis was performed to identify predictors for the detection of metastases outside the prostatic fossa (>=miN1) on PSMA PET/CT. Results: A PSMA PET/CT was performed at a median PSA-value of 0.60 ng/mL (interquartile range (IQR) 0.3-2.4) after a median period of 6 months (IQR 4-10) following RARP. In total, 101/150 patients (67\%) had lesions with PSMA-expression on PET/CT, of which 89/150 patients (59\%) had lesions with increased PSMA-expression sites outside the prostatic fossa. Moreover, 39/150 patients (26\%) had PSMA-positive lesions outside the pelvis. On multivariable analysis, higher PSA-values after RARP (P = 0.004) and positive pathological lymph node status (P = 0.006) were independent predictors for >=miN1. Conclusion: In presence of BCP, a high proportion of patients already had metastatic disease to pelvic lymph nodes or showed evidence of distant metastases, as indicated by PSMA PET/CT. Higher PSA-levels after RARP and positive pathological lymph node status were significantly associated with metastases outside the prostatic fossa. In conclusion, in patients with BCP, PSMA PET/CT imaging is warranted to guide (salvage) treatment strategies.}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/early/2020/11/06/jnumed.120.252528}, eprint = {https://jnm.snmjournals.org/content/early/2020/11/06/jnumed.120.252528.full.pdf}, journal = {Journal of Nuclear Medicine} }