放疗中小野剂量测量技术进展浅析  

A brief analysis of the progress of small field dosimetry technologies in radiotherapy

作　　者：令狐仁静 张静[1,2] 梁润成 陈法国 赵日[1,2] 刘鑫 LINGHU Renjing;ZHANG Jing;LIANG Runcheng;CHEN Faguo;ZHAO Ri;LIU Xin(Chinese Institute for Radiation Protection,Taiyuan 030006 China;Shanxi Provincial Key Laboratory of Nuclear Drug R&D,Transformation and Precision Protection,Taiyuan 030006 China)

机构地区：[1]中国辐射防护研究院,山西太原030006 [2]核药研发转化与精准防护山西省重点实验室,山西太原030006

出　　处：《中国辐射卫生》2024年第4期483-490,共8页Chinese Journal of Radiological Health

基　　金：山西省基础研究计划(202203021222407)。

摘　　要：相比于常规放疗射野,小野存在的高剂量梯度、带电粒子不平衡和源遮挡引起剂量效应等独特剂量学特点加大了剂量测量难度,临床剂量测量不确定度也相应增加,远超ICRU 24号报告中测量误差<5%的要求。近年来,随着新型放疗技术的发展,放疗技术射野最小可达mm级,大分割放疗单次照射剂量可至6 Gy以上,射野边缘剂量梯度更大,对剂量测量的准确性提出了更高的要求,精确的小野剂量测量技术已逐渐成为精准放疗领域研究热点。为确保测量结果具有更高的准确性,通过回顾国内外学者关于小野剂量测量方面的研究,梳理并总结小野剂量测量要点。本文介绍了小野剂量学特点,概述现阶段小野剂量测量技术及优化手段,包括探测器选型及探测器灵敏体积2方面的优化,并进一步对射野输出修正因子技术进行分析。针对小野剂量测量难等现状,结合临床需求及医用直线加速器等特点提出剂量测量建议,力争为放疗机构临床实践中的小野剂量测量提供科学参考,为放疗剂量验证的发展增注力量。Compared with conventional radiotherapy fields,small field has unique dosimetry characteristics such as high dose gradient,charged particle imbalance,and dose effect caused by source occlusion.These characteristics increase the difficulty of dose measurement and thus the uncertainty of clinical dose measurement,far exceeding the requirement of<5%measurement error in ICRU 24 report.In recent years,with the development of new radiotherapy technologies,the minimum radiotherapy field can reach the millimeter level,and the single irradiation dose of hypofractionated radiotherapy can exceed 6 Gy.The larger dose gradient at the edge of radiotherapy field requires higher accuracy of dose measurement,and accurate small field dosimetry technologies have gradually become a research hotspot in the field of precision radiotherapy.In order to ensure the high accuracy of measurement,this paper reviews the research on small field dosimetry worldwide,and summarizes the key points of small field dosimetry.In this paper,the characteristics of small field dosimetry are introduced,and the current small field dosimetry technologies and optimization methods are summarized,including the optimization of detector selection and detector sensitive volume.The field output correction factor technologies are analyzed.In view of the difficulty in small field dosimetry,this paper provides suggestions on dosimetry based on clinical needs and the characteristics of medical linear accelerators.Our suggestions provide a scientific reference for small field dosimetry in clinical practice in radiotherapy institutions,and facilitate the development of radiotherapy dose verification.

关 键 词：放射治疗 小野剂量 探测器响应 灵敏体积 输出修正因子 

分 类 号：X591[环境科学与工程—环境工程]