Imply on diagnosis and early prognosis of preoperative [ ⁶⁸Ga]Ga-PSMA-11 PET/CT in patients with suspected brain tumours of glial origin

Abstract

PET/CT targeting prostate-specific membrane antigen (PSMA) is commonly used in patients with prostate cancer. PSMA has been found in other solid tumours, including primary brain tumours. The aim of this study was to evaluate the usefulness of [ ⁶⁸Ga]Ga-PSMA-11 PET/CT for preoperative diagnosis and 2-year prognosis. We prospectively screened patients with suspected glioma tumour. The PET/CT qualitative and quantitative results were compared to the histopathological examination. We compared glioblastoma (GBM) diagnostic data or between high-grade (HGG) and low-grade (LGG) gliomas. Overall (OS) and progression free survival (PFS) were analysed. Forty-four patients met the inclusion criteria. Twenty of them had positive and twenty-four negative scans. The sensitivity, specificity, positive predictive value, and negative predictive value for HGG diagnosis were 71.4 (95% confidence interval – 51.3–86.8), 100.0 (79.4–100.0), 100.0 (83.1–100.0), and 66.7 (44.7–84.4), respectively. For differentiation between GBM vs non-GBM tumours, the best parameter was the tumour-to-background ratio, with the area under the receiver operating characteristic curve 0.81 (0.66–0.96; 42.2) (95% CI; cut-off). Patients with positive PET/CT scans had similar PFS and OS to patients with HGG. PSMA accumulation negatively affected the PFS and OS of patients with diagnosed GBM. [ ⁶⁸Ga]Ga-PSMA-11 PET/CT showed optimistic diagnostic results and may be prognostic a factor.

Registration at www.clinicaltrials.gov 09/06/2023 with number NCT05896449.