Diagnostic accuracy of 68Ga-PSMA-11 PET for pelvic nodal metastasis detection prior to radical prostatectomy and pelvic lymph node dissection: a multicenter prospective phase 3 imaging trial

Report of the investigator-initiated, prospective, multicentre, single-arm, open-label phase 3 imaging trial of 68Ga-PSMA-11 PET at UCSF and UCLA (NCT03368547, NCT02611882 and NCT02919111), which enrolled 764 men with intermediate- to high-risk prostate cancer considered for prostatectomy between December 2015 and December 2019. Each man had one PET scan with 3 to 7 mCi of 68Ga-PSMA-11, read by three blinded central readers with a majority rule. The primary endpoint was per-patient sensitivity and specificity for pelvic lymph node metastasis against histopathology, with nodal-region correlation.

Of the 764 men, 277 (36 percent) underwent prostatectomy with lymph node dissection and formed the efficacy cohort; 75 (27 percent) had pelvic nodal metastasis on pathology. PET was positive in 40 (14 percent), 2 (1 percent) and 7 (3 percent) of the 277 for pelvic nodal, extrapelvic nodal and bone disease. Sensitivity, specificity, positive predictive value and negative predictive value for pelvic nodal metastasis were 0.40 (95 percent CI 0.34 to 0.46), 0.95 (0.92 to 0.97), 0.75 (0.70 to 0.80) and 0.81 (0.76 to 0.85). Of the 487 men who did not have surgery, 108 were lost to follow-up; the rest mostly had radiotherapy (69 percent) or systemic therapy (22 percent). The authors describe the collaboration as the largest of its kind and the foundation of the New Drug Application for 68Ga-PSMA-11.