Investigation of the neutron contamination in IMRT deliveries with a paired magnesium and boron coated magnesium ionization chamber system

被引：12

作者：

Becker, Julian ^{[1
]}

Brunckhorst, Elin ^{[1
]}

Schmidt, Rainer ^{[1
]}

机构：

[1] Univ Hamburg, Univ Med Ctr Hamburg, Dept Radiotherapy & Radiooncol, D-20246 Hamburg, Germany

来源：

RADIOTHERAPY AND ONCOLOGY | 2008年 / 86卷 / 02期

关键词：

neutrons; neutron contamination in high energy photon fields; IMRT; paired chamber system;

D O I：

10.1016/j.radonc.2007.10.033

中图分类号：

R73 [肿瘤学];

学科分类号：

100214 ;

摘要：

Background and Purpose: Photon beams used in IMRT treatments with high energies (> 10 MV) are contaminated with neutrons. Measurement of this neutron dose is of significance to the overall risk estimate of high energy radiotherapy. Materials and methods: For measuring neutron doses a paired magnesium and boron coated magnesium chamber system was used. All measurements were performed inside the solid water phantom EasyCube using abdominal extensions. 4 different clinical treatment plans were studied. Results: The measured neutron dose showed to be homogeneous inside the phantom and increased with increased number of applied monitor units. The sum over all fractions showed neutron doses of 1 - 2 mGy, depending on the kind of treatment. Conclusions: Using large conversion factors of 25 Sv/Gy, none of the studied treatment plans exceeded dose equivalents of 50 mSv for the whole treatment. This dose equivalent has to be considered whole body dose due to the homogeneous distribution of neutrons. (c) 2007 Elsevier Ireland Ltd. All rights reserved.

引用

页码：182 / 186

页数：5

共 8 条

[1] Photoneutron production of a Siemens Primus linear accelerator studied by Monte Carlo methods and a paired magnesium and boron coated magnesium ionization chamber system [J].