Brain edema in neurooncology: radiological assessment and management.

Vasogenic brain edema is a common diagnostic and management problem in brain tumor patients. Molecular mechanisms play a role in the pathophysiology, including abnormalities of tumor endothelium, vascular endothelial growth factor and leukotriene synthase. Edema diagnosis is facilitated by the development of neuroradiological imaging techniques, with diffusion-weighted imaging (DW-MRI) differentiating tumor grades or abscesses and tumors, and diffusion tensor imaging representing an advanced technique to potentially differentiate malignant glioma from metastasis or facilitate preoperative planning. Edema is a prognostic factor for meningioma and metastases but not for glioma. Therapy includes, amongst others, tumor-directed measures such as debulking surgery, radio- and chemotherapy. However, local therapeutic approaches might also induce or exacerbate edema formation. Peritumoral edema can usually be managed with corticosteroids. However, patients on corticosteroids are at greater risk of metabolic changes, Pneumocystis carinii pneumonia, and thromboembolism. More recently, inhibitors of cyclooxygenase-2 as well as boswellic acids have been explored as antiedema agents in patients with brain tumors.