DOSE COMPARISON OF STEREOTACTIC RADIOSURGICAL MODALITIES

小野立体定向外照射不同技术， 也被称为立体定向放射外科手术，或颅内病变， 通过使用基于CT的3- 三维治疗计划计算机程序。 放射外科治疗 颅内肿瘤和血管畸形已经被证明是一个非常 治疗危及生命和使人衰弱的病变的成功方法， 成千上万的病人。 这些成果是少数人取得的 放射外科模式与特定的治疗方案。 近日一 已经实施或提出了许多新的放射外科模式， 这些技术的使用正在迅速普及。 为了评价 不同的放射外科模式，剂量的系统比较 将进行分配，并通过以下方式评价结果： 剂量-体积直方图。 将被研究的辐射类型是带电的 粒子（质子、氦离子、碳离子和氖离子）和光子 (Co来自线性加速器的60伽马射线和兆伏光子）。 辐照几何形状（辐照的数量、方向和权重） beamports），将被研究的是目前使用的带电粒子 劳伦斯伯克利实验室（LBL）和哈佛回旋加速器的方法， 钴60伽玛刀，和一些基于直线加速器的旋转弧方法， 包括海德堡、波士顿和蒙特利尔使用的方法。 剂量 与目标体积和正常组织区域的关系将被比较。 的 靶大小、形状和位置对剂量模式的影响 将对分布进行研究，以确定最佳病变类别 用特殊的放射外科方法治疗。 将使用临床 数据，以帮助确定剂量-体积关系 临床效果

Different techniques of small field stereotaxic external beam radiotherapy, also known as stereotactic radiosurgery, or intracranial lesions will be compared by means of dose distributions calculated using a CT-based, 3- dimensional treatment planning computer program. Radiosurgical treatment of intracranial tumors and vascular malformations has proven to be a very successful means of curing life-threatening and debilitating lesions in thousands of patients. These results have been achieved by a small number of radiosurgical modalities with specific treatment protocols. Recently, a number of new radiosurgical modalities have been implemented or proposed, and the use of these techniques is spreading rapidly. In order to evaluate different radiosurgical modalities, a systematic comparison of dose distributions will be performed, and the results evaluated by means of dose-volume histograms. Radiation types that will be studied are charged particles (protons, helium ions, carbon ions, and neon ions) and photons (Co 60 gamma-rays and megavoltage photons from linear accelerators). Irradiation geometries (the number, orientation, and weighting of beamports) that will be studied are the currently-used charged particle methods at Lawrence Berkeley Laboratory (LBL) and the Harvard Cyclotron, the Co 60 Gamma Knife, and a number of Linac-based rotational arc methods, including the methods used in Heidelberg, Boston, and Montreal. The dose to the target volume and to regions of normal tissue will be compared. The effects of the target size, shape, and location on the patterns of dose distribution will be studied in order to determine classes of lesions best treated by particular radiosurgical methods. Use will be made of clinical data at LBL in order to help determine dose-volume relationships of clinical effects.