Direct dose confirmation of quantitative autoradiography with micro-TLD measurements for radioimmunotherapy.
Direct dose confirmation of quantitative autoradiography with micro-TLD measurements for radioimmunotherapy.
复制标题
使用放射免疫治疗的微 TLD 测量进行定量放射自显影的直接剂量确认。
作者：
Max H. Griffith;E. Yorke;B. Wessels;G. Denardo;W. Neacy
放射自显影显示我们实验室对小鼠放射免疫治疗 (RIT) 进行评估的所有十种放射性标记单克隆抗体/肿瘤组合中的放射性分布明显不均匀。对其中两种组合（131I-B72.3/结直肠癌和 131I-LYM-1/Raji B 细胞淋巴瘤）进行定量放射自显影，以获得胶片密度与放射性标记抗体分布的相关性。通过使用分段式微型热释光剂量计 (TLD) 或微型 TLD，从薄膜梯度密度线生成等剂量曲线。编写了一个计算机程序来将理论吸收剂量计算值与测量的微 TLD 值进行比较。抗体/肿瘤系统均达到一级一致性：(a) B72.3/结直肠系统——每注射 200 microCi 测量 810 cGy/计算 824 cGy，(b) LYM-1/淋巴瘤系统——每注射 656 microCi 测量 1,740 cGy/计算 1,580 cGy（1 cGy = 1 rad）。此外，在 500 微米长度范围内测得的吸收剂量异质性高达 400%，这表明有必要使用定量放射自显影术来正确确定 RIT 的潜在放射生物学效应。基于类似放射自显影活性分布的理论计算机模型也提供了一种评估其他放射性标记（例如 90Y）的吸收剂量变化模式的便捷方法。
Autoradiography has shown marked heterogeneous distribution of radioactivity in all ten radiolabeled monoclonal antibody/tumor combinations evaluated by our laboratories for radioimmunotherapy (RIT) in mice. Quantitative autoradiography was performed on two of these combinations (131I-B72.3/colorectal carcinoma and 131I-LYM-1/Raji B-cell lymphoma) to obtain a correlation of film density with radiolabeled antibody distribution. Through the use of sectioned mini-thermoluminescent dosimeter(s) (TLD) or micro-TLD, isodose curves were generated from the film gradient density lines. A computer program was written to compare theoretical absorbed dose calculations to measured micro-TLD values. First-order agreement was reached for both antibody/tumor systems: (a) B72.3/colorectal system--810 cGy measured/824 cGy calculated per 200 microCi injected and (b) LYM-1/lymphoma system--1,740 cGy measured/1,580 cGy calculated per 656 microCi injected (1 cGy = 1 rad). Additionally, the measured absorbed dose heterogeneity over a 500-micron length of up to 400% which suggests that the use of quantitative autoradiography is necessary in order to correctly determine the underlying radiobiological effects of RIT. Theoretical computer modeling based on similar autoradiographic activity distributions has also provided a convenient means of assessing absorbed dose variation patterns from other radiolabels such as 90Y.