PURPOSE: To evaluate the precision of hypofractionated radiosurgery using the Gamma Knife Extend relocatable system in @entity1 with @entity5 located close to the optic pathways. METHODS AND MATERIALS: A series of 59 irradiation procedures with the Extend system were performed on 12 @entity1 . We treated 11 @entity1653 and 1 @entity976 . All @entity1 except 1 were treated with 5 daily fractions of a 5-Gy margin dose; 1 @entity1 was treated with 4 fractions of 6 Gy. The deviations on the X, Y, and Z axes were calculated as the mean value of all measures performed on each plate of the reposition check tool. An estimation of the @entity1 's head motion during treatment was calculated as the difference between the radial deviations measured before and after each irradiation procedure. RESULTS: The maximum deviation of all measures was 0.9 mm for the 59 procedures. The mean deviations in the X, Y, and Z axes were 0.23 mm (standard deviation [SD], 0.17; maximum, 0.85), 0.31 mm (SD, 0.21; maximum, 0.90), and 0.27 mm (SD, 0.20; maximum, 0.80), respectively. The mean radial intrafraction difference was 0.16 mm (SD 0.14) and the maximum intrafraction deviation was of 0.7 mm. The mean follow-up duration was 19.3 months (range, 6-32 months). The visual status remained stable for 11 @entity1 and improved in 1 @entity1 ; the @entity5 volume remained stable for 4 @entity1 and decreased for 8 @entity1 . From a clinical point of view, no new symptoms were recorded and no vision deterioration occurred. CONCLUSIONS: The Extend system provides good repositioning accuracy and adequate immobilization of the @entity1 's head for multisession treatment. The clinical and radiological outcomes of a series of 12 @entity1 who underwent 59 irradiation fractions were excellent.

Five-fraction Gamma Knife radiosurgery using the Extend relocatable system for XXXX close to optic pathways.

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity1653 :: ('MESH:D008579', 'Disease') :: ['meningiomas'] @entity976 :: ('MESH:D003397', 'Disease') :: ['craniopharyngioma'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'benign neoplasms']
@entity5 :: (MESH:D009369,Disease) :: ['benign neoplasms']
