MR imaging correlates of survival in patients with high-grade gliomas

For patients with malignant gliomas, clinical data-including age, perioperative Karnofsky Performance Status (KPS), and tumor resection-and tumor imaging features-including necrosis and edema-have been found to correlate with survival. The purpose of this study was to assess the validity of these results and determine whether other imaging features are useful in predicting survival.

We analyzed the relationship between 15 imaging variables obtained from contrast-enhanced MR imaging scans and survival in patients with grade III (n = 43) and grade IV (n = 110) glioblastoma multiforme (GBM) gliomas. Image analysis was performed by 2 neuroradiologists who were blinded to clinical data. The Kaplan-Meier method was used to estimate survival probabilities. Univariable Cox models were used to assess the impact of imaging features on survival. A recursive partitioning analysis also was performed.

As expected, age and KPS scores had significant prognostic value for both tumor grades. The extent of resection was not a statistically meaningful predictor of survival. For GBM, univariable analysis revealed the following imaging features to be significant, (hazard ratios in parentheses): noncontrast-enhancing tumor (nCET, 0.55), edema (1.62), satellites (1.74), and multifocality (4.34). For grade III tumors, the Cox hazard ratio for necrosis was 4.43 (P = .014) and correlated with a poor outcome and survival rates comparable to GBM patients. Lack of nCET, multifocality, and satellite lesions also were correlated with shortened survival.

Of 15 tumor imaging features in GBM patients, only nCET, edema, and multifocality/satellites are statistically significant prognostic indicators. The survival advantage of nCET is a novel finding.