Yorke E D, Williams L E, Demidecki A J, Heidorn D B, Roberson P L, Wessels B W
George Washington University Medical Center, Washington, DC 20037.
Med Phys. 1993 Mar-Apr;20(2 Pt 2):543-50. doi: 10.1118/1.597050.
Inhomogeneities in activity distributions over distances from 10 to 10(4) microns are observed in many tumors treated with radiolabeled antibodies. Resulting nonuniformities in absorbed dose may have consequences for the efficacy of radioimmunotherapy. Activity variations may be directly studied with quantitative autoradiography (ARG). Converting these data to absorbed dose distributions requires additional information about pharmacokinetics, the use of a point source function and consideration of the complete three-dimensional activity distribution, as obtained from sequential autoradiographic slices. Thermoluminescent dosimetry with specially prepared CaSO4:Dy dosimeters implanted into tissue can directly measure absorbed dose in selected regions. The conditions under which thermoluminescent dosimeters (TLD) are used differ markedly from "normal" use conditions in external beam radiotherapy. Therefore special calibration and quality assurance precautions are needed to assure the precision of this technique. Procedures and pitfalls in the use of both techniques in radioimmunotherapy are described.
在用放射性标记抗体治疗的许多肿瘤中，观察到在10至10⁴微米距离内活性分布的不均匀性。由此产生的吸收剂量不均匀性可能会对放射免疫治疗的疗效产生影响。活性变化可以通过定量放射自显影（ARG）直接研究。将这些数据转换为吸收剂量分布需要有关药代动力学的额外信息、点源函数的使用以及对从连续放射自显影片获得的完整三维活性分布的考虑。将特制的CaSO₄:Dy剂量计植入组织进行热释光剂量测定，可以直接测量选定区域的吸收剂量。热释光剂量计（TLD）的使用条件与外照射放疗中的“正常”使用条件明显不同。因此，需要采取特殊的校准和质量保证措施，以确保该技术的精度。本文描述了在放射免疫治疗中使用这两种技术的程序和陷阱。
