Kooy H M, Dunbar S F, Tarbell N J, Mannarino E, Ferarro N, Shusterman S, Bellerive M, Finn L, McDonough C V, Loeffler J S
Joint Center for Radiation Therapy, Boston, MA 02115.
Int J Radiat Oncol Biol Phys. 1994 Oct 15;30(3):685-91. doi: 10.1016/0360-3016(92)90956-i.
Stereotactic radiotherapy (SRT) combines techniques of stereotactic radiosurgery (SRS) with radiation therapy fractionation schemes. Fractionation in SRT necessitates a relocatable immobilization system to precisely reproduce the patient's position at each treatment. The Gill-Thomas-Cosman (GTC) head frame is such an immobilization device compatible with the Brown-Roberts-Wells (BRW) stereotactic system. We describe this device, our modifications to the original design, the repeat position accuracy, and the daily verification procedure.
The original GTC frame was tested on volunteers. This testing led to an improved strapping system, the decision to construct the oral fixation appliance at our dental clinic, and the construction of a depth confirmation helmet to rapidly confirm the position of the frame on a daily basis. The GTC frame, at our institution, is not acceptable for children requiring anesthesia, and a new frame, the "Boston Childrens' Hospital" frame, was designed. This device uses the base ring of the GTC frame. Airway access is maintained through fixation on the nasal-glabellar region and the ear canal rather than the hard palate and upper gingiva.
The modifications of the GTC frame and the verification protocol result in repeat positioning of the frame with respect to the patient anatomy, with a standard deviation of 0.4 mm for both the modified GTC frame and the Boston Childrens' Hospital frame. The relocatibility of the frames has been established in over 2,000 patient setups in over 60 patients to date.
The GTC frame is a noninvasive and versatile fixation system that provides patient comfort, as well as accurate relocatibility for SRT. The frame is not appropriate for single fraction radiosurgery, as a large setup error (> 2 mm) for a single treatment cannot be excluded. The GTC frame is compatible with the BRW system, and treatment planning for SRT and SRS patients is identical. We currently treat 10-13 SRT patients per day with intracranial neoplasms on a dedicated stereotactic therapy unit. In addition, the Boston Childrens' Hospital frame allows the use of stereotactic therapy in the treatment of children under 6 years of age. This population will benefit especially from precise and highly focal cranial irradiation.
立体定向放射治疗（SRT）将立体定向放射外科手术（SRS）技术与放射治疗分次方案相结合。SRT中的分次治疗需要一个可重新定位的固定系统，以便在每次治疗时精确再现患者的位置。吉尔 - 托马斯 - 科斯曼（GTC）头架就是这样一种与布朗 - 罗伯茨 - 韦尔斯（BRW）立体定向系统兼容的固定装置。我们描述了该装置、对原始设计的改进、重复定位精度以及日常验证程序。
在志愿者身上测试了原始的GTC头架。这次测试促成了一种改进的捆绑系统、在我们牙科诊所制作口腔固定器具的决定以及制作一个深度确认头盔，以便每天快速确认头架的位置。在我们机构，对于需要麻醉的儿童，GTC头架是不可接受的，因此设计了一种新的头架，即“波士顿儿童医院”头架。该装置使用GTC头架的基环。通过固定在鼻根区域和耳道而非硬腭和上牙龈来保持气道通畅。
对GTC头架的改进和验证方案使得头架相对于患者解剖结构的重复定位得以实现，改进后的GTC头架和波士顿儿童医院头架的标准偏差均为0.4毫米。到目前为止，在60多名患者的2000多次患者设置中已经确立了头架的可重新定位性。
GTC头架是一种无创且通用的固定系统，为SRT提供了患者舒适度以及精确的可重新定位性。该头架不适用于单次分割放射外科手术，因为无法排除单次治疗时较大的设置误差（>2毫米）。GTC头架与BRW系统兼容，SRT和SRS患者的治疗计划是相同的。我们目前在一个专门的立体定向治疗单元上每天治疗10 - 13例患有颅内肿瘤的SRT患者。此外，波士顿儿童医院头架允许在6岁以下儿童的治疗中使用立体定向治疗。这一人群将特别受益于精确且高度聚焦的颅脑照射。
