Résultats du traitement radiochirurgical Gamma Knife des malformations artérioveineuses cérébrales

Gamma Knife treatments of arteriovenous malformations (AVM) are performed for about 40 years. This article presents the results of 123 patients treated for a brain AVM at the Gamma Knife Center ULB-Hôpital Erasme. Radiosurgical treatment is proposed following multidisciplinary discussion of the best therapeutic strategy based on specific parameters of the AVM. Gamma Knife irradiation was achieved for an AVM residue after endovascular embolization for 84 % of patients, after microsurgery for 7 % of patients, or after previous radiosurgical irradiation for 6 % of patients. The whole volume of the nidus was irradiated in a single session for all patients. A mean margin dose of 22.3 Gy was delivered to the nidus, which had a mean volume of 3.3 cc. The maximum dose ranged from 30 Gy to 50 Gy (mean 44.1 Gy). All patients were prospectively followed after treatment with serial angio-MR and/or conventional angiography. A retrospective analysis shows complete obliteration of the AVM for 109 patients (89 %) after 6 to 52 months (mean 32 months). For 14 patients the nidus was only partially obliterated from the radiosurgical procedure; for 9 patients a second irradiation was performed with subsequent complete occlusion of the AVM in all cases. So, 118 of 123 patients (96 %) irradiated by Gamma Knife in 1 or 2 sessions were cured. Four patients bled after irradiation and before complete occlusion of the AVM, with neurological deficit for 2 patients. Transient neurological symptoms develop after treatment for 12 patients (10 %), associated with postradic edema treated with corticoids. Permanent neurological worsening occurred in5 patients (4 %). Gamma Knife treatment of cerebral arteriovenous malformations is a highly efficient and low-risk therapy when used by a multidisciplinary team.SCOPUS: ar.j