Radiomics signature based on FDG-PET predicts proliferative activity in primary glioma

AIM To investigate a radiomics method based on 2-[18F]-fluoro-2-deoxy- d- glucose (FDG) positron-emission tomography (PET) to non-invasively evaluate proliferative activity in gliomas. MATERIALS AND METHODS A total of 123 patients with histopathologically confirmed primary glioma were reviewed retrospectively and assigned randomly into the primary cohort (n=82) and validation cohort (n=41). Tumour proliferative activity was defined by the Ki-67 index based on immunohistochemistry. Standard uptake value (SUV) maps were generated, and 1,561 radiomics features were extracted. Radiomics features were selected through the sequential application of three algorithms. Three predictive signatures were generated: a radiomics signature, a clinical signature, and a fusion signature. The predictive performances were evaluated by receiver operating characteristic (ROC) curve analysis, and patient prognoses were stratified based on the Ki-67 index and the signature with the most reliable performance. RESULTS Nine radiomics features were selected to construct the radiomics signature that achieved an accuracy of 81.7% and 73.2% and an area under the curve (AUC) of 0.88 and 0.76 in the primary cohort and the validation cohort, respectively. The clinical signature and fusion signature demonstrated comparable performance in the primary cohort but were over-fitted judging from the result in the validation cohort. Both the Ki-67 index and the radiomics signature could stratify patients into two distinctive prognostic groups, and the difference within each prognostic group was not statistically significant. CONCLUSION Radiomics signature based on 18F-FDG-PET is a promising method for the non-invasive measurement of glioma proliferative activity and facilitates the prediction of patient prognoses.