Abstract
Seventy-three patients with arteriovenous malformation (AVM) were treated with gamma knife. The patient's mean age was 29.9 presenting symptoms included prior hemorrhage in 60 (82%) and seizure in 6 (8%). Neurological dificits were present in 33 patients (45%). Eighty-one percent of AVMs were located in eloquent areas and the mean size was 19.6×19.8×20.2mm. AVM volume of less than 10cm3 was found in 60 patients (82%). The lesions were classified according to the Spetzler grading system: 42 (58%) wer Grade III, 10 (14%) were Grade II, and 11 (15%) were Grade VI. Prior surgery had been performed in 30 patients. Embolization procedures were performed in 7 patients. Conventional external irradiation was done in 4 patients. All patients were irradiated to the entire volume of the AVM nidus. The mean dose delivered to the AVM margin was 19.2 Gy and that delivered to the center was 36.9 Gy. Embolization was very useful in reducing some lesions larger than 3 cm in diameter.
