Results of Stereotactic Radiosurgery with Linear Accelerator for Intracranial Arteriovenous Malformation

Lee, Kang Kyoo; Park, Kyung Ran; Lee, Jong Young; Lee, Yong Ha

Abstract

PURPOSE
Stereotactic radiosurgery with external beam irradiation successfully obliterates carefully selected intracranial arteriovenous malformation (AVM). We present clinical and radiological long term results after treatment with a single high dose irradiation using a linear accelerator.
MATERIALS AND METHODS
From January 1991 to June 1994, fifteen patients with intracranial AVM were treated in our hospital with the stereotactic radiosurgery using a linear accelerator. The radiation was delivered using a 6 MV linear accelerator. The prescribed doses at the isocenter varied from 1800 to 2500cGy (median : 2000cGy) and were given as a single fraction. The radiation doses at the periphery of the lesion typically corresponded to the 80-90% isodose line. In 14 patients, complete clinical and/or radiological follow-up examination were available.
RESULTS
Angiography was available in 13 patients with a follow-up period from 18 months to 27 months. Of 13 patients, the overall complete obliteration rate was 92.3% (12 patients). This incidence did not correlate with lesion size. Seizure, headache and progressive neurologic deficit were complete recovered. One patient experienced hemorrhage at 2 months after treatment. One patient developed radiation induced brain edema in the white matter surrounding nidus at 16 months after treatment and showed complete resolution of the edema in MR image obtained at 27 months after treatment. After a follow-up period of up to 6 years, no radiation induced severe late complications occurred.
CONCLUSION
We conclude that stereotactic radiosurgery using a linear accelerator is an effective and safe therapy for symptomatic and surgically inaccessible intracranial AVMs and the results compare favorably to the more expensive and elaborate systems that are currently available for stereotactic radiosurgery.