Abstract：
Internal dosimetry evaluates the amount and spatial and temporal distributions of radiation energy deposited in tissue from radionuclides within the body. Historically, nuclear medicine had been largely a diagnostic specialty, and the implicitly performed risk-benefit analyses have been straightforward, with relatively low administered activities yielding important diagnostic information whose benefit far outweighs any potential risk associated with the attendant normal-tissue radiation doses. Although dose estimates based on anatomic models and population-average kinetics in this setting may deviate rather significantly from the actual normal-organ doses for individual patients, the large benefit-to-risk ratios are very forgiving of any such inaccuracies. It is in this context that the MIRD schema was originally developed and has been largely applied. The MIRD schema, created and maintained by the MIRD committee of the Society of Nuclear Medicine and Molecular Imaging, comprises the notation, terminology, mathematic formulas, and reference data for calculating tissue radiation doses from radiopharmaceuticals administered to patients. However, with the ongoing development of new radiopharmaceuticals and the increasing therapeutic application of such agents, internal dosimetry in nuclear medicine and the MIRD schema continue to evolve-from population-average and organ-level to patient-specific and suborgan to voxel-level to cell-level dose estimation. This article will review the basic MIRD schema, relevant quantities and units, reference anatomic models, and its adaptation to small-scale and patient-specific dosimetry.
摘要：
内部剂量测定评估从体内放射性核素沉积在组织中的辐射能量的量以及时空分布。历史上,核医学主要是诊断专业，隐含地执行的风险收益分析很简单，相对较低的给药活动可产生重要的诊断信息，其益处远远超过与随之而来的正常组织辐射剂量相关的任何潜在风险。尽管在这种情况下基于解剖模型和人口平均动力学的剂量估计可能与个体患者的实际正常器官剂量有很大偏差，巨大的收益-风险比对于任何这样的不准确都是非常宽容的。正是在这种情况下，MIRD模式最初是在这种情况下开发的，并得到了广泛的应用。MIRD模式，由核医学和分子影像学会MIRD委员会创建和维护，包括符号，术语,数学公式，和用于计算来自给予患者的放射性药物的组织辐射剂量的参考数据。然而,随着新放射性药物的不断发展和此类药物的治疗应用日益增多，核医学中的内部剂量学和MIRD模式继续发展-从人口平均和器官水平到患者特异性和下器官水平，再到体素水平到细胞水平的剂量估计。本文将回顾基本的MIRD模式，相关数量和单位，参考解剖模型，以及它对小规模和患者特异性剂量学的适应性。
