RT Journal Article SR Electronic T1 3-year freedom from progression following 68GaPSMA PET CT triaged management in men with biochemical recurrence post radical prostatectomy. Results of a prospective multi-center trial. JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP jnumed.119.235028 DO 10.2967/jnumed.119.235028 A1 Emmett, Louise A1 Tang, Reuben A1 Nandurkar, Rohan H A1 Hruby, George A1 Roach, Paul J A1 Watts, Jo Anne A1 Cusick, Thomas A1 Kneebone, Andrew A1 Ho, Bao A1 Chan, Lyn A1 van Leeuwen, Pim A1 Scheltema, Matthijs 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 2019 UL http://jnm.snmjournals.org/content/early/2019/11/01/jnumed.119.235028.abstract AB Background: 68Ga PSMA PET CT (PSMA) is increasingly used in men with biochemical recurrence (BCR) post radical prostatectomy (RP), but its longer term prognostic / predictive potential in these men is unknown. The aim of this study was to evaluate the predictive value of PSMA PET for 3 year freedom from progression (FFP) in men with BCR post RP undergoing salvage radiotherapy (sRT). Methods: This prospective multi-center study enrolled 260 men between 2015 and 2017. Eligible patients were referred for PSMA with rising PSA following RP. Management following PSMA was recorded but not mandated. PSMA protocols were standardised across sites and reported prospectively. Clinical, pathological and surgical information, sRT, timing and duration of androgen deprivation (ADT), 3 year PSA results and clinical events were documented. FFP was defined as a PSA rise ≤ 0.2ng/mL above nadir post sRT, with no additional treatment. Results: The median PSA was 0.26ng/mL (IQR 0.15 - 0.59) and follow-up 38 months (IQR 31-43). PSMA was negative in 34.6% (90/260), confined to prostate fossa 21.5% (56/260), pelvic nodes 26.2% (68/260), and distant disease 17.7% (46/260). 71.5% (186/260) received sRT, 38.2% (71/186) to the fossa only, 49.4% (92/186) fossa + pelvic nodes and 12.4% (23/186) nodes alone/SBRT. PSMA was highly predictive of FFP at 3 years following sRT. Overall, FFP was achieved in 64.5% (120/186) of those who received sRT, 81% (81/100) with negative/fossa confined vs. 45% (39/86) for extra fossa disease (p<0.0001). On logistic regression PSMA was more independently predictive of FFP than established clinical predictors, including PSA, T-stage, surgical margin status or Gleason score (P < 0.002). 32% of men with a negative PSMA PET did not receive treatment. Of these, 66% (19/29) progressed, with a mean rise in PSA of 1.59ng/mL over the 3 years. Conclusion: PSMA PET result is highly predictive of FFP at 3 years in men undergoing sRT for BCR following RP. In particular, men with negative PSMA PET or disease identified as still confined to the prostate fossa demonstrate high FFP, despite receiving less extensive radiotherapy and lower rates of additional ADT than those with extra fossa disease.