Outcomes of volume-staged radiosurgery for cerebral XXXX larger than 20cm3 with more than 3years of follow-up.

@entity1 @entity7026 @entity2758 @entity548 @entity1939
OBJECTIVE: Treatment of extremely large @entity7026 ( @entity2758 ) remains challenging. Although volume-staged stereotactic radiosurgery (SRS) is a possible multimodal treatment option for such lesions, reports of these procedures are scarce. In this study, we evaluated the efficacy and safety of volume-staged SRS in @entity1 with @entity2758 >20 cm(3) with more than 3 years of follow-up. MEHODS: Between 2005 and 2012, 18 @entity1 with AVMs >20 cm(3) were treated by volume-staged SRS. The median target volume was 38 cm(3) (interquartile range, IQR, 31-53 cm(3)). Treatment was 2-3 staged with a median 6 months interval. RESULTS: The median follow up period from last SRS treatment was 53 months (IQR, 41-75 months). @entity1939 was achieved in 6 @entity1 (33%), and the obliteration rate at 5 years after initial SRS was 35% by the Kaplan-Meier method. The annual @entity548 rate after last SRS treatment was 3.9% (95% confidence interval, 0.8-11.5%). Two @entity1 experienced radiation-induced adverse effects. CONCLUSINOS: In our series, volume-staged SRS for @entity2758 > 20cm(3) achieved nidus obliteration at the rate of 35% at 5 years. There was still a high risk for @entity548 (approximately 4 % / year) after treatment, which seemed to be higher than the rate observed in common post-treatment course of single-session SRS for @entity2758 with average size. Further cases will help determine whether this challenging treatment method could be regularly considered, based on its efficacy and risks, including comparison with the natural history of large AVMs.
