Gamma knife radiosurgery for XXXX : long-term results in the first Swedish @entity1 .

@entity1 @entity4611 @entity976 @entity5
OBJECT: The purpose of this study was to assess the long-term treatment efficacy and morbidity of @entity1 who undergo gamma knife radiosurgery (GKS) for @entity976 . METHODS: Twenty-one consecutive Swedish @entity1 were evaluated retrospectively: 11 @entity1 (< or = 15 years) and 10 adults. The time from diagnosis to the most recent follow-up imaging study was 6.3 to 34.3 years (mean 18.2 years, median 16.8 years). @entity5 volumes and morbidity from GKS or other treatments were assessed at the time of the most recent imaging study or at the time of a subsequent new treatment. The observation period ranged from 0.5 to 29 years (mean 7.5 years, median 3.5 years). The prescription dose ranged from less than 3 Gy to 25 Gy. The mean @entity5 volume was 7.8 cm3 (range 0.4-33 cm3). There were 22 @entity5 in 21 @entity1 treated with GKS. Five of these @entity5 were reduced in size, three were unchanged, and 14 increased. @entity5 progression correlated with a low dose to the @entity5 margin. Eleven (85%) of 13 @entity5 that received a dose of less than 6 Gy to the margin increased in size, whereas only three (33%) of nine @entity5 that received 6 Gy increased. This difference was statistically significant (p = 0.01). In five of six @entity1 @entity5 that became smaller after GKS there were no recurrences within a mean follow-up period of 12 years. Nine (82%) of 11 @entity5 in @entity1 ultimately increased after GKS, compared with five (50%) of 10 in adults. In eight @entity1 there was a deterioration of visual function. In all except one this could be related to a volume increase but radiation-induced damage could not be excluded as a factor in any of them. Four @entity1 developed @entity4611 . CONCLUSIONS: Gamma knife radiosurgery is effective in controlling growth of @entity976 with a minimum dose of 6 Gy. The findings also suggest that other stereotactic techniques, such as cyst aspiration and intracystic treatment, are only of value in reducing @entity5 volume in preparation for safe GKS.
