Prognostic significance of CT contrast enhancement within histological subgroups of intracranial glioma

We report the prognostic significance of tumor CT contrast enhancement with in histological subgroups in 831 consecutive adult glioma patients of high- grade (n = 516) and low-grade (n = 315) histology. In the present report, a negative prognostic factor is associated with shortened survival. Methods: Survival analysis including Kaplan-Meier plots, log-rank tests, Cox analys is, and Aalen's linear model as implemented in SPSS and S-PLUS. Results: Se nsitivity and specificity of contrast enhancement as a test for high-grade glioma was 0.87 and 0.79, respectively. Enhancement was a strong negative p rognostic factor comparable to high-grade histology in the total patient po pulation. Enhancement was also a negative prognostic factor within the subg roups adult high-grade (Grade 3-4), anaplastic (Grade 3), and low-grade (Gr ade 1-2) gliomas (p < 0.001). The prognostic implications of initial enhanc ement declined in high-grade patients surviving beyond 36 months. Tumor con trast enhancement or calcifications (in parentheses) were present in 96% (3 .6%) of glioblastomas, in 87% (7.4%) of high-grade gliomas, in 56.5% of ana plastic gliomas, and in 21% (16.2%) of low-grade gliomas. Calcification was a positive prognostic factor within the high-grade group of patients (p < 0.0001). Conclusion: Enhancement was a major prognostic factor comparable t o high-grade: histology in this glioma patient population. Enhancement was a negative prognostic factor within each of the adult subgroups high-grade, anaplastic (grade 3), and low-grade gliomas. Enhancement was strongly asso ciated with but not pathognomonic for high-grade histology.