Microdosimetric measurements for neutron-absorbed dose determination during proton therapy.
Microdosimetric measurements for neutron-absorbed dose determination during proton therapy.
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质子治疗期间用于确定中子吸收剂量的微剂量测量。
DOI：
10.1093/rpd/ncs002
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发表时间：
2012
影响因子：
1
通讯作者：
Farr,Jonathan
中科院分区：
文献类型：
--
作者：
Pérez-Andújar,Angélica;DelucaJr,PaulM;Thornton,AllanF;Fitzek,Markus;Hecksel,Draik;Farr,Jonathan
这项工作提出了在印第安纳州布卢明顿的中西部质子放射治疗研究所进行的微剂量测量。使用水模体模拟临床设置并针对各种停止目标进行测量。水模体被质子扩散布拉格峰（SOBP）和质子笔形束辐照。停止目标的测量只进行笔形波束。使用的目标是由聚乙烯，黄铜和铅。这项工作的目的是确定被动和主动质子治疗输送的中子吸收剂量，以及质子束与质子治疗喷嘴束线中典型材料的相互作用。与笔形射束相比，SOBP配置在与射束方向成45°和90°处的中子剂量分别高出1.1和1.3倍。同时，笔形束配置产生的中子吸收剂量在0°比SOBP高2.2倍。对于停止目标，铅被发现占主导地位的中子吸收剂量的大部分角度，由于大量生产的低能中子发射各向同性。
This work presents microdosimetric measurements performed at the Midwest Proton Radiotherapy Institute in Bloomington, Indiana, USA. The measurements were done simulating clinical setups with a water phantom and for a variety of stopping targets. The water phantom was irradiated by a proton spread out Bragg peak (SOBP) and by a proton pencil beam. Stopping target measurements were performed only for the pencil beam. The targets used were made of polyethylene, brass and lead. The objective of this work was to determine the neutron-absorbed dose for a passive and active proton therapy delivery, and for the interactions of the proton beam with materials typically in the beam line of a proton therapy treatment nozzle. Neutron doses were found to be higher at 45° and 90° from the beam direction for the SOBP configuration by a factor of 1.1 and 1.3, respectively, compared with the pencil beam. Meanwhile, the pencil beam configuration produced neutron-absorbed doses 2.2 times higher at 0° than the SOBP. For stopping targets, lead was found to dominate the neutron-absorbed dose for most angles due to a large production of low-energy neutrons emitted isotropically.