Simultaneously acquired rSUV and rCBF of 18F-FDG/MRI in peritumoral brain zone can help to differentiate the grade of gliomas

Abstract

ObjectivesThe purpose of this study is to investigate the diagnostic performance of the peritumoral brain zone (PBZ) in differentiating glioma grades. This is accomplished by comparing the relative standardized uptake values (rSUV) and relative cerebral blood flow (rCBF) obtained from hybrid 18F-fluoro-2-deoxy-d-glucose positron emission tomography/magnetic resonance imaging (18F-FDG PET/MRI) within different regions of interest, including the solid portion (SP) and the PBZ. MethodsTwenty-four patients with gliomas who underwent preoperative 18F-PET/MRI were enrolled in this study. The maximum standardized uptake values (SUVmax) and relative maximum cerebral blood flow (rCBFmax) were obtained from the FDG-PET and ASL data, respectively. The relative SUVmax (rSUVmax) was calculated by standardizing against the contralateral normal-appearing brain cortex. Data from the solid portion (SP) of tumor and the peritumoral brain zone (PBZ) at distance of 5 ​mm, 10 ​mm, 15 ​mm, and 20 ​mm from the SP margin were recorded. Logistic regression was used to generate receiver-operating characteristic (ROC) curves. The areas under the ROC curves (AUCs) were calculated and compared to analyze the diagnostic utility of each parameter. ResultsIn comparison to low-grade glioma (LGG), high-grade glioma (HGG) exhibited significantly higher rSUVmax and rCBFmax values in both the SP and the proximal PBZ (P ​< ​0.05). Among the various distance parameters and their combinations, the single parameter rSUVmax-SP demonstrated the highest diagnostic efficacy with an AUC of 0.788 (P ​< ​0.05). However, the AUC of rSUVmax-SP did not show a significantly improvement when combined with PBZs (P ​> ​0.05). When combining PBZs and SP with rSUVmax and rCBFmax, the rSUVmax and rCBFmax values of SP to PBZ 20 ​mm exhibited superior performance compared to single parameters and smaller regions of interest, with an AUC of 0.848. The sensitivity and specificity were determined as 73.8% and 83.6%, respectively. ConclusionThe combination of rSUVmax and rCBFmax in the SP and PBZ, based on hybrid PET/MRI, proves to be superior to using parameters solely in the SP when it comes to differentiating between HGG and LGG. Expanding the study appropriately and incorporating the use of multiple parameters can offer more valuable diagnostic information, which holds potential for clinical applications.