Fahey Frederic H, Goodkind Alison B, Plyku Donika, Khamwan Kitiwat, O'Reilly Shannon E, Cao Xinhua, Frey Eric C, Li Ye, Bolch Wesley E, Sgouros George, Treves S Ted
Department of Radiology, Boston Children's Hospital, Boston, MA; Department of Radiology, Harvard Medical School, Boston, MA.
Department of Radiology, Boston Children's Hospital, Boston, MA.
Semin Nucl Med. 2017 Mar;47(2):118-125. doi: 10.1053/j.semnuclmed.2016.10.006. Epub 2016 Nov 9.
The practice of nuclear medicine in children is well established for imaging practically all physiologic systems but particularly in the fields of oncology, neurology, urology, and orthopedics. Pediatric nuclear medicine yields images of physiologic and molecular processes that can provide essential diagnostic information to the clinician. However, nuclear medicine involves the administration of radiopharmaceuticals that expose the patient to ionizing radiation and children are thought to be at a higher risk for adverse effects from radiation exposure than adults. Therefore it may be considered prudent to take extra care to optimize the radiation dose associated with pediatric nuclear medicine. This requires a solid understanding of the dosimetry associated with the administration of radiopharmaceuticals in children. Models for estimating the internal radiation dose from radiopharmaceuticals have been developed by the Medical Internal Radiation Dosimetry Committee of the Society of Nuclear Medicine and Molecular Imaging and other groups. But to use these models accurately in children, better pharmacokinetic data for the radiopharmaceuticals and anatomical models specifically for children need to be developed. The use of CT in the context of hybrid imaging has also increased significantly in the past 15 years, and thus CT dosimetry as it applies to children needs to be better understood. The concept of effective dose has been used to compare different practices involving radiation on a dosimetric level, but this approach may not be appropriate when applied to a population of children of different ages as the radiosensitivity weights utilized in the calculation of effective dose are not specific to children and may vary as a function of age on an organ-by-organ bias. As these gaps in knowledge of dosimetry and radiation risk as they apply to children are filled, more accurate models can be developed that allow for better approaches to dose optimization. In turn, this will lead to an overall improvement in the practice of pediatric nuclear medicine by providing excellent diagnostic image quality at the lowest radiation dose possible.
核医学在儿童中的应用已得到充分确立，可对几乎所有生理系统进行成像，尤其是在肿瘤学、神经病学、泌尿学和矫形外科学领域。儿科核医学可生成生理和分子过程的图像，为临床医生提供重要的诊断信息。然而，核医学涉及放射性药物的施用，这会使患者暴露于电离辐射之下，而且人们认为儿童比成人更容易受到辐射暴露的不良影响。因此，谨慎考虑采取额外措施来优化与儿科核医学相关的辐射剂量可能是明智的。这需要对与儿童放射性药物施用相关的剂量学有扎实的了解。核医学与分子影像学会的医学内部辐射剂量学委员会及其他团体已开发出估算放射性药物内部辐射剂量的模型。但要在儿童中准确使用这些模型，需要开发出放射性药物更好的药代动力学数据以及专门针对儿童的解剖模型。在过去15年中，混合成像中CT的使用也显著增加，因此需要更好地了解适用于儿童的CT剂量学。有效剂量的概念已被用于在剂量学层面比较不同的辐射相关操作，但当应用于不同年龄的儿童群体时，这种方法可能并不合适，因为有效剂量计算中使用的辐射敏感性权重并非针对儿童，且可能因器官不同而随年龄变化存在偏差。随着适用于儿童的剂量学和辐射风险知识方面的这些空白得到填补，可开发出更准确的模型，从而实现更好的剂量优化方法。相应地，这将通过以尽可能低的辐射剂量提供出色的诊断图像质量，全面改善儿科核医学的实践。
