Ranking of stereotactic radiosurgery in the multimodal treatment of cerebral arteriovenous malformations - Own experiences and review of literature

Cerebral arteriovenous malformations are relatively rare. Early treatment i s important to avoid the risk of hemorrhage. Each hemorrhagic episode carri es a risk of death and the risk of long-term morbidity. As far as the treat ment of AVMs is concerned, no definitive conclusion has been reached. In es sence, three therapeutic options (microsurgery, radiosurgery, embolisation) are available all of which are performed with curative intention. This pap er describes the technique, indication and results of stereotactic radiosur gery in our own patient cohort. Three therapeutic modalities are also descr ibed with regard to their validity; a therapeutic algorithm is derived on t he basis of the literature. 16 patients underwent stereotactic radiosurgery of arteriovenous malformati ons (AVM) between November 1993 and February 1998 with a linear accelerator (LINAC). in 5 of 16 patients stereotactic radiosurgery took place after em bolisation and in four patients after incomplete resection. One patient wit h a newly developed dural arteriovenous fistula was treated with embolisati on one year after stereotactic radiosurgery. According to the Spetzler and Martin scale, four AVM were grade I, three grade II and ten grade Ill (one patient with two angiomas grade III). The 80% marginal nidus median dose wa s 20 Cy. For the treatment of 15 AVM we used one isocenter and two or three isocenters for the remaining two angiomas. The nidi were small in 15 AVM ( < 20 mm). In follow-up angiographies, after one year complete obliteration was detected in 5 of 11 patients, after two years in two of three patients, and after three years in one patient. Four patients were not followed up b y angiography after one year. Rebleeding from the nidus occurred in two cas es with a fatal outcome in one patient 5 months after treatment, and in ano ther patient with a seizure and no neurological deficit 9 months after trea tment. One patient with AVM of the thalamus and complete obliteration one y ear after treatment, developed a slight hemiparesis with hemihypaesthesia a nd disturbance of proprioception 15 months after treatment.