MRI enhancement and microvascular density in gliomas. Correlation with tumor cell proliferation.

ABSTRACT

RATIONALE AND OBJECTIVES: Angiogenesis and proliferation activity are important indicators of tumor behavior in human gliomas. The authors studied how tumor enhancement in MR imaging and intratumoral vascular density were correlated with cell proliferation in cerebral gliomas. METHODS: The authors studied retrospectively 62 cerebral gliomas. Patients were examined before surgery with contrast-enhanced MR imaging. Microvessel density and the cell proliferation rate of tumor specimens were measured immunohistochemically using factor VIII and MIB-1 antibodies. Contrast enhancement of the tumors was evaluated by two radiologists. RESULTS: Contrast enhancement was observed in 45 tumors and was correlated with histologic cell proliferation (P = 0.0007) and microvessel density (P = 0.01). There was also a correlation between tumor vascular density and the cell proliferation rate (r = 0.51, P < 0.0001). Histologic tumor grade was associated with vascular density (P = 0.001). CONCLUSIONS: Lesion enhancement on preoperative contrast-enhanced MR imaging correlates with vascularity and proliferation activity of gliomas. The additional correlation between tumor vascularity and proliferation suggests that intratumoral microvessel density could be useful in estimating tumor proliferation.