RESUMO
The role of intravascular embolization prior to radiosurgery of cerebral arteriovenous malformations was evaluated based on the basis of the results of gamma knife radiosurgery in relation to hemorrhage and early obliteration after treatment. Nine of 213 patients experienced hemorrhage 4 to 42 months after radiosurgery. All AVMs in these patients had dilated feeding arteries, and the flow of the AVM was rapid and/or high. An intranidal aneurysm was seen in one patient. Drainage of all AVMs consisted of a single and/or deep draining veins, and venous obstruction was found in six. Sixty-three of 87 patients followed for more than four years after radiosurgery were examined angiographically, and total obliteration of AVM was observed in 52 of them (82.5%). Early obliteration was found in 19 of the 34 patients examined within 12 months. The obliteration rate was significantly higher in slow- and low-flow AVMs (73.9%) than in rapid- and/or high-flow AVMs (18.2%). It is concluded that the role of intravascular embolization prior to radiosurgery is not only decreasing the size of the AVM but decreasing the risk of hemorrhage and shortening the latency period by decreasing their flow rate and flow volume.
RESUMO
Five patients with the squamous cell type of craniopharyngioma were examined clinically and pathologically, and comparisons were made with the adamantinomatous type of craniopharyngioma. In three patients, the tumor remaining after partial or subtotal resection was treated with conventional radiation therapy, and all three lesions disappeared completely. The squamous cell tumors consisted of basal cubodial cells and polygonal superficial cells with areas of cellular detachment and degeneration. Our findings suggest that these tumors are more radiosensitive than adamantinomatous craniopharyngiomas and represent a distinct clinical entity.
