Accuracy of gallium-68 PSMA-11 PET in localising recurrent prostate cancer: a prospective single-arm clinical trial

In a single-arm prospective trial at two universities, 635 men with biochemically recurrent prostate cancer after prostatectomy (262, 41%), radiation therapy (169, 27%) or both (204, 32%) underwent gallium-68 PSMA-11 PET, with the presence of prostate cancer recorded by three blinded readers on a per-patient and per-region basis and lesions validated by histopathology and by a composite reference standard. Median age was 69 years. Positive predictive value was 0.84 by histopathological validation in 87 men and 0.92 by the composite reference standard in 217 men. The scan localised recurrent prostate cancer in 475 of 635 men, 75%, and detection rates rose significantly with PSA: 38% below 0.5 ng/mL in 136 men, 57% at 0.5 to under 1.0 in 79, 84% at 1.0 to under 2.0 in 89, 86% at 2.0 to under 5.0 in 158 and 97% at 5.0 or above in 173. Interreader reproducibility was substantial, Fleiss kappa 0.65 to 0.78, and there were no serious adverse events. PET-directed focal therapy alone led to a PSA drop of 50% or more in 31 of 39 men, 80%.