Thomas S J
Medical Physics Department, Addenbrooke's Hospital, Cambridge, United Kingdom.
Med Phys. 1991 Jul-Aug;18(4):719-23. doi: 10.1118/1.596665.
The Batho power-law formula is in common use in many treatment planning systems to correct for the presence of lungs and other inhomogeneities. While giving excellent agreement with measurement for Cobalt-60 radiation, it tends to underestimate the lung correction required for higher energy x rays and is undefined for distances beyond an interface less than the buildup distance. This paper suggests a simple modification that greatly improves the agreement with measured data and gives a continuously defined function at all depths. Measurements have been made in a polystyrene and cork phantom to simulate the effects of lung; data are presented for beams of 8-MV x rays, 16-MV x rays, and Cobalt-60 gamma rays.
巴索幂律公式在许多治疗计划系统中被普遍用于校正肺部和其他不均匀性的影响。虽然它与钴 - 60 辐射的测量结果吻合度很高，但对于更高能量的 x 射线，它往往会低估所需的肺部校正值，并且对于超出界面小于积累距离的距离是未定义的。本文提出了一种简单的修正方法，该方法极大地提高了与测量数据的吻合度，并在所有深度给出了连续定义的函数。已在聚苯乙烯和软木模型中进行测量以模拟肺部的影响；给出了 8 兆伏 x 射线、16 兆伏 x 射线和钴 - 60 伽马射线束的数据。
