Cerebral arteriovenous malformations treated by radiosurgery: a series of 705 cases

Background and purpose. After. a review of the main radiosurgical published series, to evaluate our own series of 705 patients with cerebral arteriove nous malformations treated by radiosurgery alone or in combination with emb olization or surgery. Patients and method From January 1984 to December 1998 705 patients were tr eated by a multidisciplinary ream including neurosurgeons, neuroradiologist s, radio-physicians and radiotherapists Age of revelation of the cerebral a rteriovenous malformations ranged between birth to 73 years (mean 27, media n 25). Age at time of radiosurgery ranged between 7 and 75 years (mean 33, median 31). There were 410 males for 295 females (sex- ratio 1.4). Symptoms of revelation were hen ton huge for 59 %, seizures for 23 %. headaches for 14 % and progressive deficits for 4 %. Discovery of cerebral arteriovenous malformation was fortuitous in 4 % of cases. Repartition following Spetzle r's grading was 12 % in grade I, 36 % in grade II, 40 % in grade III, 12 % in grade IV and 0 % in grade V Maximal size ranged between 4 and 60 mm (mea n 23, median 20). Volume ranged between 0.2 and 24.3 cc (mean 3.8, median 2 .8). Majority of cerebral arteriovenous malformations were large size (42 % with size higher than 25 mm) and large volume 54 % higher than 10 cc. 54 % of patients had treatment prior radiosurgery 38 % had embolization. 10 % w ere operated 4 % were treated by radiosurgery (reirradiation) and 3 % were operated and embolized. Results. Overall complete obliteration rate was 55 %. The obliteration rare was correlated with size (77 % for cAVMs lower than 15 mm, 62 % for cerebr al arteriovenous malformations between 15 and 25 mm, and 44 % for cerebral arteriovenous malformations higher than 25 mm), with volume (94 % for cereb ral arteriovenous malformations lower than 1 cc, 64 % between 1 and 4 cc, 4 8 % between 4 and 10 cc, and 62 % for cerebral arteriovenous malformations higher than 10 cc), dose at reference isodose, minimal dose, morphological parameters (presence of dural components, arteriovenous fistula, plexiform angioarchitecture, arterial steal, arterial recruitment, deep exclusive dra inage, venous plicature, venous confluence, venous ectasia, venous reflux), sectional topography and good recovery of the target. Embolization was a c onfusion factor not associated with obliteration rate. After multivariate a nalysis, only Dmin and complete coverage of the cerebral arteriovenous malf ormations were con elated with obliteration rate. Delay of obliteration was significantly correlated after multivariate analy sis with Dmin, complete coverage, arteriolovenulary angioarchitecture (posi tive correlation) and venous ectasia (negative correlation). Conclusion. Overall complete obliteration rare is unreliable data to assess efficacy of radiosurgical method in the treatment of cerebral arteriovenou s malformations. The obliteration rate must be interpretated after stratifi cation on several morphological and dosimetric parameters.