Three-dimensional MR rendering of brain tumors

This paper investigates the use of three-dimensional (3D) MR rendering to assist in the management of brain tumor before radiosurgery. Eight patients with lesions were imaged on a 1.5-T imager; the lesions included four gliomas and four metastases. 3D MR volume rendering of the brain was generated from axial or coronal postgadolinium T1-weighted images on a computer workstation (ISG, Toronto, Canada). Volume and configuration of the lesion were studied for accurate placement of isocenters. The 3D-rendered images provided excellent visualization of the lesion in all patients in terms of location, volume, configuration, and relation to eloquent brain. This morphologic characterization was critical for placement of radiation isocenters so that disruption to normal brain could be minimized. The gliomas had irregular margins of enhancement, requiring more than one isocenter to fit the tumor borders. One glioma that crossed the corpus callosum required three isocenters. Metastases generally were well defined and rounded, facilitating placement of a single isocenter. One patient with multiple contiguous metastases required three isocenters to fully cover all lesions