Introduction: It has been shown that co-deletion of chromosome 1p and 19q (-1p/19q) is a genetic marker associated with oligodendroglial tumors, and gain of chromosome 7 (+7) is frequently seen in astrocytic tumors. Many studies have been published to genetically characterize gliomas. Meanwhile, previous radiological studies suggest that some features, such as calcifications, appeared to be related to clinical nature of glioma patients, although their relation to the tumor biology persists unclear, and genetic information provides more prognostic value than radiologic information. We hypothesized that some radiological features could be correlated to specific genetic aberrations, and tried to identify important factors for pre-surgical diagnosis of the tumor type that is validated by genetics at present.
Methods: We analyzed WHO grade II and III tumor diagnosed as astrocytic, oligodendroglial or oligoastrocytic tumors. Pre-surgical Radiological features were retrospectively investigated with computed tomography (CT) and magnetic resonance imaging (MRI) included calcification, location of tumor (gray matter or white matter, and gray matter involvement), and contrast enhancement. MIB-1/Ki-67 proliferation index was calculated using immunohistochemistry. -1p/19q and +7 were analyzed by comparative genomic hybridization.
Results: Calcification and surface localization (multivariable logistic regression analysis: P=0.006 and P= 0.049, respectively) were more common in tumors with -1p/19q. There was no relation between +7 and radiological features. On the contrary, gadolinium (Gd) enhancement and MIB-1 index were not associated with genotype but with WHO grades.
Conclusions: We suggest that our pilot study provides information related to pre-surgical evaluation for the tumor genotype.
Patient Care: To predict genetic characters by pre-surgical radiological features, patients would receive adjuvant therapy correctly and quickly.
Learning Objectives: By the conclusion of this session, participants should be able to predict an effective treatment by pre-surgical MRI and CT .