(68) Ga-PSMA has a high detection rate of prostate cancer recurrence outside the prostatic fossa in patients being considered for salvage radiation treatment.

Abstract

ObjectivesTo examine the detection rates of (68) Ga-PSMA-positron emission tomography (PET)/computed tomography (CT) in patients with biochemical recurrence (BCR) after radical prostatectomy (RP), and also the impact on their management.Materials and methodsA total of 300 consecutive patients with prostate cancer (PCa) who underwent (68) Ga-PSMA-PET/CT between February and July 2015 were prospectively included in the Prostate Cancer Imaging (ProCan-I) database. For the present analysis, we included patients with BCR (prostate-specific antigen [PSA] level ≥0.05 and ResultsA total of 70 patients were included, and 53 positive (68) Ga-PSMA lesions were detected in 38 (54%) patients. Among patients with PSA levels 0.05-0.09 ng/mL, 8% were definitely positive; the corresponding percentages for the other PSA ranges were as follows: PSA 0.1-0.19 ng/mL, 23%; PSA 0.2-0.29 ng/mL, 58%; PSA 0.3-0.49 ng/mL, 36%; and PSA 0.5-0.99 ng/mL, 57%. Eighteen of 70 patients (27%) had pathological (68) Ga-PSMA uptake in the prostatic fossa, 11 (14.3%) in the pelvic nodes, and five (4.3%) in both the fossa and pelvic lymph nodes. Finally, there was uptake outside the pelvis with or without a lesion in the fossa or pelvic lymph nodes in four cases (8.6%). As a result of the (68) Ga-PSMA findings there was a major management change in 20 (28.6%) patients.Conclusions(68) Ga-PSMA appears to be useful for re-staging of PCa in patients with rising PSA levels who are being considered for salvage RT even at PSA levels <0.5 ng/mL. These results underline the need for further prospective trials to evaluate the changes in RT volume or management attributable to (68) Ga-PSMA findings.