Avoiding a Collision in Gamma Knife Radiosurgery : A Modified Mask Fixation Method
- Author:
Hyeong Cheol MOON
1
;
Doheui LEE
;
Byung Jun MIN
;
Young Gyu KIM
;
Yun-Sik DHO
Author Information
- Publication Type:Technical Note
- From:Journal of Korean Neurosurgical Society 2023;66(4):476-481
- CountryRepublic of Korea
- Language:English
-
Abstract:
Objective:: The latest version of the Leksell Gamma Knife IconTM allows for mask- and frame-based fixation. Although mask fixation provides fractionated treatment and immobilization using a noninvasive method, it is not free from collision. The authors investigated the collision problem with a modified mask fixation method.
Methods:: This study presents a case of two meningiomas in the frontal area, where a collision occurs in the occipital area. A modified mask fixation method was introduced to avoid the collision : first, the edges of the head cushion were cut off and polystyrene beads with a diameter of approximately 5 cm were removed. Next, the head cushion was sealed using a stapler. Finally, the head cushion was flattened in the adapter. We compared the shot coordinates, 3-dimensional (3D) error, clearance distance, and vertical depth of the head cushion between the initial and modified mask fixations.
Results:: When comparing the initial and modified mask fixations, the difference in the shot coordinates was +10.5 mm along the y-axis, the difference in the 3D error was approximately 18 mm, and the difference in clearance was -10.2 mm. The head cushion was approximately 8 mm deeper in the modified mask fixation.
Conclusion:: Based on these findings, we recommend a modified mask fixation method for gamma knife radiosurgery using ICON with a collision.
