A 10-year experience of radiosurgical treatment for cerebral arteriovenous malformations: a perspective from a series with large malformations Clinical article

Object. The purpose of this study was to describe a 10-year experience in the use of radiosurgery (RS) for patients with arteriovenous malformations (AVMs) in Puerto Rico. Methods. This retrospective analysis was performed for all patients with AVMs treated with RS by the senior author (R.H.B.) in Puerto Rico. Between February 1999 and December 2009, a total of 83 patients underwent the procedure. All charts were reviewed for recollection of demographic data, and AVM and treatment characteristics. Clinical and radiographic follow-up information was collected retrospectively. Results. Eighty-three patients were treated and 86 RS procedures for AVMs were performed during a 10-year period. Eight patients were lost to follow-up. The remaining 75 patients included 36 males and 39 females, whose median age was 34.5 years. Hemorrhage was the initial presentation in 40% of patients. Fifty-seven AVMs (73%) were treated previously with endovascular neurosurgery, without success. The median volume of the malformation was 17.7 ml. Nearly 65% of the malformations were considered large (>= 10 ml) in volume. Forty patients had AVMs with largest diameter >= 3.5 cm. The overall obliteration rate was 56.4%, and the median time for obliteration was 29 months. The AVMs >= 3.5 cm in diameter had a greater latency period than those < 3.5 cm (31 months vs 46 months, respectively; p = 0.01). In addition, AVM obliteration was inversely associated with its volume, especially in large lesions (p = 0.037). In bivariate analysis, patients achieving obliteration had lower Spetzler-Martin scores compared with patients in whom obliteration was not achieved (p = 0.009). Postradiosurgery hemorrhages were seen in 9 cases. Eleven patients underwent surgery after RS. Major neurological deficits developed in 9 patients, whereas 17 had only minor deficits. The occurrence of neurological deficits was significantly associated with lesions with volume >= 10 ml. Conclusions. Radiosurgery is a reasonable treatment option for AVMs in the majority of cases, in spite of the large, difficult-to-treat malformations. (DOI: 10.3171/2011.3.JNS10814)