Tyagi K, Jain S C, Jain P C
Centre for Environment and Explosive Safety, Metcalfe House, Delhi 110054, India.
Radiat Prot Dosimetry. 2001;95(1):37-42. doi: 10.1093/oxfordjournals.rpd.a006520.
ICRP Publications 53, 62 and 80 give organ dose coefficients and effective doses to ICRP Reference Man and Child from established nuclear medicine procedures. However, an average Indian adult differs significantly from the ICRP Reference Man as regards anatomical, physiological and metabolic characteristics, and is also considered to have different tissue weighting factors (called here risk factors). The masses of total body and most organs are significantly lower for the Indian adult than for his ICRP counterpart (e.g. body mass 52 and 70 kg respectively). Similarly, the risk factors are lower by 20-30% for 8 out of the 13 organs and 30-60% higher for 3 organs. In the present study, available anatomical data of Indians and their risk factors have been utilised to estimate the radiation doses from administration of commonly used 99Tcm-labelled radiopharmaceuticals under normal and certain pathological conditions. The following pathological conditions have been considered for phosphates/phosphonates--high bone uptake and severely impaired kidney function; IDA--parenchymal liver disease, occlusion of cystic duct, and occlusion of bile duct; DTPA--abnormal renal function; large colloids--early to intermediate diffuse parenchymal liver disease, intermediate to advanced parenchymal liver disease; small colloids--early to intermediate parenchymal liver disease, intermediate to advanced parenchymal liver disease; and MAG3--abnormal renal function, acute unilateral renal blockage. The estimated 'effective doses' to Indian adults are 14-21% greater than the ICRP value from administration of the same activity of radiopharmaceutical under normal physiological conditions based on anatomical considerations alone, because of the smaller organ masses for the Indian; for some pathological conditions the effective doses are 11-22% more. When tissue risk factors are considered in addition to anatomical considerations, the estimated effective doses are still found to be generally somewhat higher for the Indian, for both normal and pathological states (but lower than the values based on anatomical considerations alone). However, when the radiopharmaceutical is administered in quantities proportional to the body mass, the effective doses are 11-28% lower for the Indian under both normal and pathological conditions. It may be concluded that Indians are at a lower risk of radiation health detriment in comparison with the ICRP adult on administration of the various 99Tcm-labelled radiopharmaceuticals considered in this study.
国际放射防护委员会第53号、62号和80号出版物给出了既定核医学程序对国际放射防护委员会参考成人和儿童的器官剂量系数及有效剂量。然而，印度成年男性在解剖学、生理学和代谢特征方面与国际放射防护委员会参考成人有显著差异，并且也被认为具有不同的组织权重因子（这里称为风险因子）。印度成年男性的全身及大多数器官的质量明显低于国际放射防护委员会参考成人（例如，体重分别为52千克和70千克）。同样，13个器官中有8个器官的风险因子低20% - 30%，3个器官的风险因子高30% - 60%。在本研究中，利用印度人的现有解剖学数据及其风险因子，估算了在正常和某些病理条件下常用的99锝标记放射性药物给药后的辐射剂量。对于磷酸盐/膦酸盐考虑了以下病理状况——高骨摄取和严重肾功能损害；缺铁性贫血——实质性肝病、胆囊管阻塞和胆管阻塞；二乙三胺五乙酸——肾功能异常；大颗粒胶体——早期至中期弥漫性实质性肝病、中期至晚期实质性肝病；小颗粒胶体——早期至中期实质性肝病、中期至晚期实质性肝病；以及巯基乙酰三甘氨酸——肾功能异常、急性单侧肾梗阻。基于解剖学考虑，在正常生理条件下给予相同活度的放射性药物时，印度成年男性估算的“有效剂量”比国际放射防护委员会的值高14% - 21%，这是因为印度人的器官质量较小；对于某些病理状况，有效剂量要高11% - 22%。除了解剖学考虑因素外，再考虑组织风险因子时，无论是正常状态还是病理状态，印度人估算的有效剂量通常仍然略高一些（但低于仅基于解剖学考虑得出的值）。然而，当按体重比例给予放射性药物时，无论是正常还是病理条件下，印度人的有效剂量都低11% - 28%。可以得出结论，与国际放射防护委员会的成年人相比，在给予本研究中考虑的各种99锝标记放射性药物时，印度人辐射健康损害的风险较低。
