Relationship between magnetic resonance imaging signs and immunohistochemistry of glioblastoma

Objective To study the relationship between magnetic resonance imaging (MRI) signs of glioblastoma (GBM) and the immunohistochemistry of isocitrate dehydrogenase 1 (IDH1), O6-methylguanine-DNA methyltransferase (MGMT). Methods The patients pathologically diagnosed as GBM were collected from January 2008 to December 2013. The relationship between MRI and immunohistochemistry of IDH1 and MGMT before procedure was analyzed. Results A total of 111 patients performed IDH1 and MGMT immunohistochemical examinations for postoperative pathology, 29 patients (26.1%) were IDH1 positive and 60 (54.1%) were MGMT positive. Univariate analysis showed that the maximum diameter of the tumors (χ2=9.400, P=0.009), MRI enhancement (t=2.204, P=0.030), peritumoral edema (PTE) indexed (χ2=6.411, P=0.041), and main invasive sites (t=2.788, P=0.006) were associated with the positive expression of IDH1. Multivariate logistic regression analysis showed that the maximum diameter of the tumors (P=0.015), MRI enhancement (P=0.037), and main invasive sites (P=0.024) were the main factors for predicting IDH1 positive expression, and the maximum diameter of the tumors was the most important predictor (P<0.05). The positive expression of MGMT was associated with the number of lesions (χ2=6.678, P=0.010), magnetic resonance diffusion weighted imaging (DWI) (t= -4.320, P=0.000), cystic change (χ2=16.185, P=0.000), necrosis (χ2=8.325, P=0.004), and main invasion sites (t=2.612, P=0.010). Multivariate logistic regression analysis showed that the number of lesions (P=0.008), cystic change (P=0.000), and DWI (P=0.000) were the major factors for predicting MGMT positive expression, and DWI hyperintensity was the most important predictor (P<0.05). Conclusions The results of IDH1and MGMT immunohistochemistry have some correlations with the performance of tumors on conventional MRI. It is conducive to screening and preliminary determination of the biological behavior of tumors and identifying its prognosis by analyzing the correlation between imaging and pathology. Key words: Glioblastoma; Isocitrate dehydrogenase; O (6)-methylguanine-DNA methyltransferase; Magnetic resonance imaging