RT Journal Article SR Electronic T1 3-Year Freedom from Progression After 68Ga-PSMA PET/CT–Triaged Management in Men with Biochemical Recurrence After Radical Prostatectomy: Results of a Prospective Multicenter Trial JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 866 OP 872 DO 10.2967/jnumed.119.235028 VO 61 IS 6 A1 Emmett, Louise A1 Tang, Reuben A1 Nandurkar, Rohan A1 Hruby, George A1 Roach, Paul A1 Watts, Jo Anne A1 Cusick, Thomas A1 Kneebone, Andrew A1 Ho, Bao A1 Chan, Lyn A1 van Leeuwen, Pim J. A1 Scheltema, Matthijs J. A1 Nguyen, Andrew A1 Yin, Charlotte A1 Scott, Andrew A1 Tang, Colin A1 McCarthy, Michael A1 Fullard, Karen A1 Roberts, Matthew A1 Francis, Roslyn A1 Stricker, Phillip YR 2020 UL http://jnm.snmjournals.org/content/61/6/866.abstract AB 68Ga-labeled prostate-specific membrane antigen (PSMA) PET/CT is increasingly used in men with biochemical recurrence (BCR) after radical prostatectomy (RP), but its longer-term prognostic or predictive potential in these men is unknown. The aim of this study was to evaluate the predictive value of PSMA PET for a 3-y freedom from progression (FFP) in men with BCR after RP undergoing salvage radiotherapy (sRT). Methods: This prospective multicenter study enrolled 260 men between 2015 and 2017. Eligible patients were referred for PSMA PET with a rising level of prostate-specific antigen (PSA) after RP. Management after PSMA PET was recorded but not mandated. PSMA PET protocols were standardized across sites and reported prospectively. Clinical, pathologic, and surgical information; sRT; timing and duration of androgen deprivation; 3-y PSA results; and clinical events were documented. FFP was defined as a PSA rise of no more than 0.2 ng/mL above nadir after sRT, with no additional treatment. Results: The median PSA was 0.26 ng/mL (interquartile range, 0.15–0.59 ng/mL), and follow-up was 38 mo (interquartile range, 31–43 mo). PSMA PET had negative results in 34.6% (90/260), showed disease confined to the prostatic fossa in 21.5% (56/260), showed disease in the pelvic nodes in 26.2% (68/260), and showed distant disease in 17.7% (46/260). Of the patients, 71.5% (186/260) received sRT: 38.2% (71/186) to the fossa only, 49.4% (92/186) to the fossa plus the pelvic nodes, and 12.4% (23/186) to the nodes alone or stereotactic body radiation therapy. PSMA PET was highly predictive of FFP at 3 y after sRT. Overall, FFP was achieved in 64.5% (120/186) of those who received sRT, 81% (81/100) with negative results or fossa-confined findings versus 45% (39/86) with extrafossa disease (P < 0.0001). On logistic regression, PSMA PET was more independently predictive of FFP than established clinical predictors, including PSA, T stage, surgical margin status, or Gleason score (P < 0.002). Thirty-two percent of men with a negative PSMA PET result did not receive treatment. Of these, 66% (19/29) progressed, with a mean rise in PSA of 1.59 ng/mL over the 3 y. Conclusion: PSMA PET results are highly predictive of FFP at 3 y in men undergoing sRT for BCR after RP. In particular, men with negative PSMA PET results or disease identified as still confined to the prostatic fossa demonstrate high FFP, despite receiving less extensive radiotherapy and lower rates of additional androgen deprivation therapy than those with extrafossa disease.