FIG. 3.

Illustration of similarity between histology and MRI in untreated controls and animals that survived to 200 days. Upper left panels: Untreated 9L (panel UL.a) hematoxylin and eosin (H&E)-stained slides and (panel UL.b) corresponding T1-weighed image estimated volume of 264 mm³. Upper right panels: Example of a 9L tumor (panel UR.a) pre-irradiation, post-contrast T1, (panel UR.b) pre-sacrifice, post-contrast T1 and (UR.c) post-sacrifice H&E-stained section from an animal that survived to 200 days. Note the florid enhancing tumor in panel UR.a that is absent in panel UR.b. The enhancement medial to the tumor location seen in panel UR.b is partly from the enlarged 3rd ventricle below and partly due to possible radiation necrosis or pseudo progression-like development. Lower left panels: Untreated U-251N (panel LL.a) hematoxylin and eosin (H&E)-stained slides and (panel LL.b) corresponding T1-weighed image estimated volume of 2054 mm³. H&E staining demonstrates that tumors in both tumors had well-defined boundaries. Lower right panels. Example of a U251 tumor (panel LR.a) pre-irradiation, post-contrast T1, (panel LR.b) pre-sacrifice, post-contrast T1, and (panel LR.c) post-sacrifice H&E-stained section from an animal that survived to 200 days. Note the florid enhancing tumor in panel LR.a that is absent in panel LR.b. Ventricular enlargement seen in panels LR.b and LR.c is the result of tissue loss.