Exploration of 68Ga-labelled prostate-specific membrane antigen-11 PET/CT parameters for identifying PBRM1 status in primary clear cell renal cell carcinoma

Abstract

To investigate the predictive value of 68Ga-labelled prostate-specific membrane antigen-11 (68Ga-PSMA-11) integrated positron-emission tomography (PET)/computed tomography (CT) in PBRM1-deficient clear cell renal cell carcinoma (ccRCC). A total of 41 patients with ccRCC, were enrolled retrospectively and underwent 68Ga-PSMA-11 PET/CT preoperatively. Radiological parameters, including CT attenuation value and maximum standard uptake value (SUVmax), were derived. Immunohistochemical and multiple immunofluorescences staining were performed to evaluate the PBRM1 status and immune response. The predictive value of imaging factors was analysed using a receiver operator characteristic curve analysis. Univariate and multivariate logistic regression analyses were used to investigate the relationship between clinical and radiological variables and PBRM1 status. A total of 41 patients were included in this study, with 14 patients having PBRM1-deficient status. The tumour diameter on imaging and SUVmax differed significantly in patients with different PBRM1 expression statuses and no difference in CT attenuation was identified. Univariate and multivariate logistic regression analyses showed SUVmax was an obvious predictor for identification of PBRM1-deficient tumours. In addition, PBRM1-deficient tumours tended to be accompanied by greater cytotoxic T-cell infiltration, although most of them were in an exhausted state. 68Ga-PSMA-11 PET/CT could be used to discriminate invasive PBRM1-deficient ccRCC.