康普顿背散射过程与放射治疗。

The Compton backscattering process and radiotherapy.

作者信息

Weeks K J, Litvinenko V N, Madey J M

机构信息

Department of Radiation Oncology, Duke University, Durham, North Carolina 27710, USA.

出版信息

Med Phys. 1997 Mar;24(3):417-23. doi: 10.1118/1.597903.

DOI:10.1118/1.597903

PMID:9089593

Abstract

Radiotherapy utilizes photons for treating cancer. Historically these photons have been produced by the bremsstrahlung process. In this paper we introduce Compton backscattering as an alternate method of photon production for cancer treatment. Compton backscattering is a well-established method to produce high-energy photons (gamma rays) for nuclear physics experiments. Compton backscattering involves the collision of a low-energy (eV) photon with a high-energy (hundreds of MeV) electron. It is shown that the photons scattered in the direction opposite to the direction of the initial photon (backscattered) will have the energy desired for photon beam therapy. The output of Compton backscattering is a high-energy photon beam (gamma-ray beam), which is well collimated and has minimal low-energy components. Such gamma beams may be used for conventional high-energy photon treatments, production of radionuclides, and generation of positrons and neutrons. The theoretical basis for this process is reviewed and Monte Carlo calculations of dose profiles for peak energies of 7, 15, and 30 MeV are presented. The potential advantages of the Compton process and its future role in radiotherapy will be discussed.

摘要

放射治疗利用光子来治疗癌症。从历史上看，这些光子是通过轫致辐射过程产生的。在本文中，我们引入康普顿背散射作为一种用于癌症治疗的光子产生的替代方法。康普顿背散射是一种为核物理实验产生高能光子（伽马射线）的成熟方法。康普顿背散射涉及一个低能（电子伏特）光子与一个高能（数百兆电子伏特）电子的碰撞。结果表明，在与初始光子方向相反的方向上散射的光子（背散射光子）将具有光子束治疗所需的能量。康普顿背散射的输出是一束高能光子束（伽马射线束），它具有良好的准直性且低能成分极少。这种伽马束可用于传统的高能光子治疗、放射性核素的产生以及正电子和中子的产生。本文回顾了该过程的理论基础，并给出了峰值能量为7、15和30兆电子伏特时剂量分布的蒙特卡罗计算结果。将讨论康普顿过程的潜在优势及其在放射治疗中的未来作用。