Secondary neutron dose measurement for proton eye treatment using an eye snout with a borated neutron absorber

Radiation Oncology

Jung Keun Cho³  Dong Oh Shin⁴  Sung-Yong Park⁶  Myongguen Yoon²  Se Byeong Lee⁵  Dongho Shin⁵  Young Kyung Lim⁵  Jungwook Shin⁷  Weon Kuu Chung¹  Dong Wook Kim¹ 

[1] Department of Radiation Oncology, Kyung Hee University Hospital at Gandong, Seoul, Korea;Department of Radiological Science, Korea University, Seoul, Korea;Department of Radiological Science, Jeonju University, Jeonju, Korea;Department of Radiation Oncology, Kyung Hee University Medical Center, Seoul, Korea;Proton Therapy Center, National Cancer Center, Ilsan, Korea;Proton Therapy Center, McLaren Cancer Institute, Flint, MI, USA;Radiation Oncology, University of California, San Francisco, USA

关键词: Eye;    Boron;    CR-39;    Neutron;    Secondary;    Proton;   

Others  :  1153332
DOI  :  10.1186/1748-717X-8-182

 received in 2013-01-10, accepted in 2013-07-15,  发布年份 2013

【 摘 要 】

Background

We measured and assessed ways to reduce the secondary neutron dose from a system for proton eye treatment.

Methods

Proton beams of 60.30 MeV were delivered through an eye-treatment snout in passive scattering mode. Allyl diglycol carbonate (CR-39) etch detectors were used to measure the neutron dose in the external field at 0.00, 1.64, and 6.00 cm depths in a water phantom. Secondary neutron doses were measured and compared between those with and without a high-hydrogen–boron-containing block. In addition, the neutron energy and vertices distribution were obtained by using a Geant4 Monte Carlo simulation.

Results

The ratio of the maximum neutron dose equivalent to the proton absorbed dose (H(10)/D) at 2.00 cm from the beam field edge was 8.79 ± 1.28 mSv/Gy. The ratio of the neutron dose equivalent to the proton absorbed dose with and without a high hydrogen-boron containing block was 0.63 ± 0.06 to 1.15 ± 0.13 mSv/Gy at 2.00 cm from the edge of the field at depths of 0.00, 1.64, and 6.00 cm.

Conclusions

We found that the out-of-field secondary neutron dose in proton eye treatment with an eye snout is relatively small, and it can be further reduced by installing a borated neutron absorbing material.

【 授权许可】

   
2013 Kim et al.; licensee BioMed Central Ltd.

【 图 表 】

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