CT in the Differentiation of Gliomas from Brain Metastases: The Radiomics Analysis of the Peritumoral Zone

Abstract

Due to their similar imaging features, high-grade gliomas (HGGs) and solitary brain metastases (BMs) can be easily misclassified. The peritumoral zone (PZ) of HGGs develops neoplastic cell infiltration, while in BMs the PZ contains pure vasogenic edema. As the two PZs cannot be differentiated macroscopically, this study investigated whether computed tomography (CT)-based texture analysis (TA) of the PZ can reflect the histological difference between the two entities. Thirty-six patients with solitary brain tumors (HGGs, n = 17; BMs, n = 19) that underwent CT examinations were retrospectively included in this pilot study. TA of the PZ was analyzed using dedicated software (MaZda version 5). Univariate, multivariate, and receiver operating characteristics analyses were used to identify the best-suited parameters for distinguishing between the two groups. Seven texture parameters were able to differentiate between HGGs and BMs with variable sensitivity (56.67–96.67%) and specificity (69.23–100%) rates. Their combined ability successfully identified HGGs with 77.9–99.2% sensitivity and 75.3–100% specificity. In conclusion, the CT-based TA can be a useful tool for differentiating between primary and secondary malignancies. The TA features indicate a more heterogenous content of the HGGs’ PZ, possibly due to the local infiltration of neoplastic cells.

A Systematic Review of the Current Status and Quality of Radiomics for Glioma Differential Diagnosis

“…All studies except one investigated the power of radiomic features arising from MRI for DDx. Only two investigated radiomic features from 18FDG-PET [ 23 , 24 ] and only one investigated the power of CT radiomics for glioma DDx [ 25 ]. A total of 20 studies focused on radiomics for DDx of primary nervous system lymphoma (PCNSL) and glioma (47.6%), with all but one involving IV glioma grade (GBM) patients.…”

“…A total of 16 studies explored the diagnostic feasibility of radiomic features for DDx of glioma and metastases. All but two of them extracted radiomic features from MRI sequences, while one evaluated features from CT [ 25 ] and one extracted features from PET [ 24 ]. In all but three studies [ 25 , 46 , 58 ], the glioma group consisted of patients with grade IV glioma (GBM).…”

“…All but two of them extracted radiomic features from MRI sequences, while one evaluated features from CT [ 25 ] and one extracted features from PET [ 24 ]. In all but three studies [ 25 , 46 , 58 ], the glioma group consisted of patients with grade IV glioma (GBM). Six studies extracted radiomic features from contrast-enhanced T1-weighted MRI scans [ 20 , 31 , 38 , 54 , 55 , 59 ].…”

“…In particular, CE-T1WI sequence was the most investigated since it is the first-line MRI sequence for glioma assessment. Only two studies investigated the ability of PET radiomic features to differentiate gliomas from metastases [ 24 ] and glioma from PCNSL [ 23 ], and only one study was on CT [ 25 ].…”

“…It should also be considered that the area considered for feature extraction was extremely variable across studies. It is worth noting that some studies targeted the enhancing tumor (with or without the inclusion of necrosis and intratumoral cysts) [ 27 , 36 , 54 ], while others targeted the peritumoral zone [ 25 , 51 , 60 ].…”