Figure 2

Neuropathologic correlates. (A) Brain of an untreated F98 glioma bearing rat that died on d. 26 following tumor implantation. The tumor measured 4 mm in diameter, had a central zone of necrosis, and was highly infiltrative of normal brain. (B) Brain of an F98 glioma bearing rat that received 20 μg of carboplatin by CED, followed 24 hrs later by the first of four 5 Gy fractions of 6 MV photons, and was euthanized one week later (25 d after tumor implantation). No tumor cells were identified in this and two additional sections. There is a focal area of gliosis. The superficial white matter shows debris, which possibly could have represented tumor cells that had been killed as a result of treatment, scattered lymphocytes and macrophages, and prominent white matter vacuolation. Otherwise, the remainder of the brain was histologically unremarkable. (C) Brain of an F98 glioma bearing rat that received four 5 Gy fractions, administered on days 14, 15, 16 and 17 following tumor implantation and died on d 34. The tumor measured 5 mm with a prominent, necrotic central core and was infiltrative of surrounding white matter. There are scattered dilated (ectatic) vessels and prominent areas of hemorrhage, both of which may be radiation related. (D) Brain of an F98 glioma bearing rat that received 20 μg of carboplatin on d 7 after implantation followed by four 5 Gy fractions of 6 MV photons and died on d. 44. The tumor measured 3 mm with a central necrotic core. There are focal collagen deposits with hyalinization and multiple microscopic foci of hemorrhage, which most likely are radiation related changes. All sections were stained with H & E and photographed at a magnification of 200x.