Radiological Protection Research and Instrumentation, AECL Chalk River Laboratory, Chalk River, Ontario, Canada.
Int J Radiat Biol. 2010 Apr;86(4):300-20. doi: 10.3109/09553000903564075.
To determine the relative toxicity of alpha- and beta-radiations under conditions of controlled temporal and spatial dose distribution.
Fused aluminosilicate particles were radiolabelled with either (45)Ca (a beta-emitter) or (242)Cm (an alpha-emitter). These were injected into CBA/Ca mice to give lifespan, whole-body doses of approximately 0.5, 1.0 or 1.5 Gy. Most animals were entered into a lifespan toxicity study, but some were killed for radiochemical analysis and autoradiography.
Twenty-seven tumour types were identified. The most common malignant tumours were: Mammary carcinoma; liver carcinoma; malignant lymphoma; uterine histiocytic sarcoma. Excess relative risk (strictly hazard ratio) was higher for radiation-induced carcinomas than for sarcomas. The carcinomas, but not sarcomas showed a reduction in relative risk at the highest radiation dose employed. This reduction was most easily attributed to a systemic effect. The highest relative toxicity measured was for liver carcinoma (5.9, 95% confidence intervals [CI] 2.4, 14) and the lowest for uterine carcinoma (0.6, CI 0.03, 9.7). Overall, the excess relative risk ratio for SURVIVAL WAS 1.9 (CI 1.1, 3.2), FOR ALL CARCINOMA WAS 2.3 (CI 1.7, 3.0) AND FOR ALL SARCOMA WAS 2.7 (CI 0.72, 10).
The 10-fold variability in the observed toxicity ratio for different tumour endpoints shows that tissue sensitivity is a more important determinant of relative toxicity than radiation quality. The use of single radiation-weighting (w(R)) factors for radiation risk prediction and for radiological protection dosimetry is inconsistent with scientific observation.
在控制时空剂量分布的条件下，确定α和β辐射的相对毒性。
用（45）Ca（β发射体）或（242）Cm（α发射体）标记熔凝的铝硅酸盐颗粒。将这些颗粒注射到 CBA/Ca 小鼠体内，使其寿命期全身剂量约为 0.5、1.0 或 1.5Gy。大多数动物被纳入寿命毒性研究，但有些动物被处死用于放射化学分析和放射自显影。
共确定了 27 种肿瘤类型。最常见的恶性肿瘤是：乳腺癌；肝癌；恶性淋巴瘤；子宫组织细胞肉瘤。辐射诱导的癌的超额相对风险（严格的危害比）高于肉瘤。在使用的最高辐射剂量下，癌的相对风险降低，但肉瘤没有。这种降低最容易归因于全身效应。测量的最高相对毒性为肝癌（5.9，95%置信区间[CI]2.4，14），最低的为子宫癌（0.6，CI0.03，9.7）。总的来说，生存的超额相对风险比为 1.9（CI1.1，3.2），所有癌的超额相对风险比为 2.3（CI1.7，3.0），所有肉瘤的超额相对风险比为 2.7（CI0.72，10）。
不同肿瘤终点观察到的毒性比的 10 倍变化表明，组织敏感性是相对毒性的一个更重要决定因素，而不是辐射质量。使用单一辐射加权（w（R））因子进行辐射风险预测和放射防护剂量学与科学观察不一致。
