Ishikawa Y, Humphreys J A, Wesch H, Priest N D
Department of Pathology, The Cancer Institute, Tokyo, Japan.
Radiat Res. 1998 Sep;150(3):369-72.
Risk estimates for alpha-particle-induced malignancies have been based mainly on studies of Thorotrast patients, but certain aspects of its deposition in the body have been at issue: the partition between the liver, spleen and red bone marrow, and the deposition at lower concentrations in other organs, such as muscle and fat, which may contribute to the risk. To supplement the existing data for humans, thorium concentrations were measured in the organs of two female monkeys 3-4 years after injection with Thorotrast. Relative deposits (liver:spleen:red bone marrow) were 54:6:41 and 75:4:21, in better agreement with the most recent observations in Thorotrast patients than with previous reports. Whereas the human testis had ranked among intermediate-level organs such as the adrenal glands and pancreas, the ovary of the monkey was among the organs with the lowest concentrations. The data suggest that risk factors for induction of malignancies by alpha-particle irradiation should be re-examined.
α粒子诱发恶性肿瘤的风险估计主要基于对注入钍胶体的患者的研究，但钍在体内沉积的某些方面一直存在争议：钍在肝脏、脾脏和红骨髓之间的分配，以及在肌肉和脂肪等其他器官中的低浓度沉积，这可能会增加风险。为了补充现有的人类数据，在两只雌性猴子注射钍胶体3-4年后，测量了它们器官中的钍浓度。相对沉积量（肝脏：脾脏：红骨髓）分别为54:6:41和75:4:21，与最近对钍胶体患者的观察结果比之前的报告更一致。人类睾丸曾被列为中等水平的器官，如肾上腺和胰腺，而猴子的卵巢是钍浓度最低的器官之一。数据表明，应重新审视α粒子辐射诱发恶性肿瘤的风险因素。
