Efficacy and morbidity of arc-therapy radiosurgery for cerebral arteriovenous malformations: a comparison with the natural history
Résumé
Purpose: To report the results of arc-therapy radiosurgery for cerebral arteriovenous malformation (AVM) and to compare the adverse event rate with the rate expected from the natural history.
Methods and materials: We performed a retrospective study of our 118 first patients with a mean follow-up of 46 months (range, 5–105 months). The AVMs had features indicating a poor prognosis at initial presentation and had already been treated by previous embolizations in 88% of patients. The mean volume of the targets was 7.4 cm3 (range, 0.3–28.3 cm3). The mean minimal and maximal dose was 17.7 Gy (range, 10–25 Gy) and 24.5 Gy (range, 17–36 Gy), respectively.
Results: The crude and 5-year actuarial rate of cure (total obstruction of the AVM shunt at angiography) was 54% (60 of 112) and 77%, respectively. The only independent prognostic factor of cure was the AVM volume (crude cure rate 67% for <7 cm3 vs. 35% for ≥7 cm3; p = 0.001). No patient died. Transient and permanent complications and hemorrhage occurred in 5%, 1.7%, and 6% of patients, respectively. The annual risk of an adverse event (hemorrhage or complication) was 3.9%.
Conclusion: The results of our series showed that radiosurgery, performed alone or after prior shrinkage of the AVM by embolization, is both effective and well tolerated, with a rate of adverse events comparable to that expected from the natural history.