Clarke Michelle J, Foy Andrew B, Garces Yoldana I, Link Michael J
Department of Neurosurgery, Mayo Clinic, Rochester, Minnesota 55906, United States.
J Neurol Surg A Cent Eur Neurosurg. 2012 Aug;73(4):243-8. doi: 10.1055/s-0032-1304214. Epub 2012 May 10.
Gamma Knife targeting is geometrically limited by the physical dimensions of the head, helmet, headframe, and the radiation target position. All four aspects need to be considered for accurate treatment planning. Within the available space, delivery of the treatment isodose is based on the target position, which must be brought into the center of the collimator. In cases of anatomically challenging target positions in far eccentric locations of the head, careful treatment planning needs to be performed that does not exceed the limits of the system.
We describe a case of a challenging far anterior ethmoid sinus hemangiopericytoma in an 80-year-old woman.
The tumor was treated successfully by positioning the patient prone on a Model C Gamma unit. The physical restrictions of the Gamma Knife surgical system and the rationale for improved anterior targeting using the prone position are discussed.
A thoughtful approach to positioning in challenging anterior lesions extends the targeting capabilities of certain Gamma units.
伽玛刀靶点定位在几何上受到头部、头盔、头架的物理尺寸以及辐射靶点位置的限制。为了进行精确的治疗计划，所有这四个方面都需要考虑。在可用空间内，治疗等剂量线的传递基于靶点位置，该靶点必须置于准直器的中心。对于位于头部远偏心位置且解剖结构具有挑战性的靶点位置，需要进行仔细的治疗计划，且不能超出系统的限制。
我们描述了一名80岁女性患有具有挑战性的远侧筛窦血管外皮细胞瘤的病例。
通过将患者俯卧在C型伽玛刀设备上，成功治疗了该肿瘤。讨论了伽玛刀手术系统的物理限制以及使用俯卧位改善前侧靶点定位的原理。
对于具有挑战性的前部病变，采用深思熟虑的定位方法可扩展某些伽玛刀设备的靶点定位能力。
