Cerebral arteriovenous malformations re-irradiations. Experience of the Sainte-Anne - Tenon Group

Background and purpose. Between 20 to 50 % of cerebral arteriovenous malfor mations treated with radiosurgery (RS) fail to obliterate 2 to 5 years afte r irradiation. Patients are not protected against the risks lending to trea tment. Two therapeutic options can be rued to eradicate the persisting nidu s: micro-surgery and a second irradiation. Our group has reirradiated 39 su ch patients. Material. Front 1989 to 2000, 39 patients have been reirradiated (14 female s and 25 males; median age 31 years). There were more:left lesions: 59 % th an right (35 %) and 5 % on midline. The most frequent locations were: tempo ral 12 cases; parietal 8 cases; frontal 7 cases; thalamus 7 cases. The pred ominant first symptoms were hemorrhage (68.5 %) and seizure (15.8 %) Prior RS, 21/39 patients had embolization (53.8 %) and 3 surgery. Method. Treatment has been performed with the same system for the first and the second radiosurgery for 37 patients. Plantification and dosimetry impr oved during that period. The level of dose was similar for the 2 RS. MRl ha s been used as a non invasive follow-up tool. Results. Only 28 patients were evaluable because 7/39 patients had the seco nd radiosurgery in 1999 or in 2000 and data were lacking at the time of wri ting for 4 patients. Obliteration rate was 17/28 (60.7%).Nine patients bled between the two radiosurgery procedures. Complications : 4 new regressive deficits occurred after the second radiosurgery. The rate of parenchymal ch anges were higher; after the second radiosurgery. Except one patient who di ed of a non-related affection 2 years after obliteration of his cerebral ar teriovenous malformation, thus 38/39 patients were alive. Conclusion. This series was small compared to the porential number of candi dates suffering front failure of the first radiosurgery, but the results ar e promising.