Dosimetric prerequisites for routine clinical use of new low energy photon interstitial brachytherapy sources. Recommendations of the American Association of Physicists in Medicine Radiation Therapy Committee. Ad Hoc Subcommittee of the Radiation Therapy Committee.
Dosimetric prerequisites for routine clinical use of new low energy photon interstitial brachytherapy sources. Recommendations of the American Association of Physicists in Medicine Radiation Therapy Committee. Ad Hoc Subcommittee of the Radiation Therapy Committee.
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新型低能光子间质近距离放射治疗源常规临床使用的剂量测定先决条件。
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
R. Nath
中科院分区：
文献类型：
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作者：
J. Williamson;B. Coursey;L. Dewerd;W. Hanson;R. Nath
更高能量光子发射近距离放射治疗源周围的剂量分布-例如，Ir和Cs！，对内部结构的微小差异相对不敏感。相比之下，低能量源，如I和Pd，由于自吸收和过滤效应，剂量测定特性对封装几何形状和源内部结构的细节更加敏感。含有相同放射性核素的不同种子模型之间的剂量学显著差异可能由设计规范或制造过程中的相对较小差异引起。因此，必须单独评估每个新的低能量（小于50 keV）的剂量测定特性，光子发射近距离放射治疗源产品。对于当前可用的I ~阿默舍姆型号6711和6702，不适合应用Task Group 43报告中公布的剂量率常数、径向剂量函数、各向异性函数、各向异性因子和几何函数！和Pd ~Theragenics型号200！其他低能量种子产品的间隙源。以下建议旨在为参与开发和批准新密封近距离放射治疗源的制造商和监管机构提供指导。它们反映了AAPM关于应进行何种剂量测定测量以及在释放放射源用于常规患者治疗之前应向用户提供何种剂量测定测量的共识。这些建议不适用于FDA和/或机构IRB批准的人体临床研究中使用的研究性近距离放射治疗源。
The dose distributions around higher energy photon-emitting brachytherapy sources ~e.g., Ir and Cs!, are relatively insensitive to small differences in internal structure. In contrast, the dosimetric characteristics of low energy sources, such as I and Pd, are much more sensitive to the details of encapsulation geometry and source internal structure due to self-absorption and filtration effects. Dosimetrically significant differences between different seed models containing the same radionuclide may result from relatively minor differences in design specifications or in manufacturing processes. It is therefore important to individually evaluate the dosimetric characteristics of each new low energy ~less than 50 keV!, photon-emitting brachytherapy source product. It is inappropriate to apply the dose-rate constants, radial dose functions, anisotropy functions, anisotropy factors, and geometry functions published in the Task Group 43 report for currently-available I ~Amersham models 6711 and 6702! and Pd ~Theragenics model 200! interstitial sources to other low-energy seed products. The recommendations below are intended as guidance to manufacturers and regulatory agencies involved in development and approval of new sealed brachytherapy sources. They reflect the consensus views of the AAPM as to what dosimetric measurements should be made and should be available to users before releasing the sources for routine patient treatments. These recommendations do not apply to investigational brachytherapy sources used in human clinical studies approved by FDA and/or the institution’s IRB.