APPLICATION OF AN IMAGE-ANALYSIS SYSTEM TO THE QUANTITATION OF TUMOR PERFUSION AND VASCULARITY IN HUMAN GLIOMA XENOGRAFTS

A semiautomatic method based on a computerized digital image analysis system was developed to quantitate the perfused fraction of blood vess els and the relative vascular area in cross-sections of human glioma x enografts, implanted subcutaneously in athymic mice or intracerebrally in nude rats. The fluorescent dye Hoechst 33342 was injected intraven ously to detect perfused tumor vessels. An immunofluorescent staining of Collagen type TV visualized the vascular structures in the same tum or section. Whole tumor sections were automatically scanned twice on a computer-controlled motorized stage of a fluorescence microscope unde r two different settings of the image analysis system. At the beginnin g of a scanning session an interactive routine was used to determine t he threshold value for segmentation of vascular structures from the da rker background. After the first scan a composite image was created, f rom the individually processed microscopic images, containing the dete cted vascular structures. The second scan yielded another composite im age with objects representing the perfused areas. When both composite images were combined the overlapping structures showed the perfused ve ssels. Differences in perfused fractions and relative vascular areas w ere found between different tumors. The reproducibility of this analys is system was tested and evaluated. The method developed here provides a fast and accurate technique for simultaneous quantitative analysis of tumor perfusion and vasculature. (C) 1995 Academic Press, Inc.