Medical Physics Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
Phys Med Biol. 2010 Nov 21;55(22):6721-37. doi: 10.1088/0031-9155/55/22/008. Epub 2010 Oct 28.
We describe a method to calculate the relative biological effectiveness in mixed radiation fields of therapeutic ion beams based on the modified microdosimetric kinetic model (modified MKM). In addition, we show the procedure for integrating the modified MKM into a treatment planning system for a scanned carbon beam. With this procedure, the model is fully integrated into our research version of the treatment planning system. To account for the change in radiosensitivity of a cell line, we measured one of the three MKM parameters from a single survival curve of the current cells and used the parameter in biological optimization. Irradiation of human salivary gland tumor cells was performed with a scanned carbon beam in the Heavy Ion Medical Accelerator in Chiba (HIMAC), and we then compared the measured depth-survival curve with the modified MKM predicted survival curve. Good agreement between the two curves proves that the proposed method is a candidate for calculating the biological effects in treatment planning for ion irradiation.
我们描述了一种基于修正的微剂量动力学模型（修正的 MKM）来计算治疗性离子束混合辐射场中的相对生物效应的方法。此外，我们还展示了将修正的 MKM 整合到扫描碳束治疗计划系统中的步骤。通过该步骤，该模型完全集成到我们的研究版治疗计划系统中。为了考虑细胞系放射敏感性的变化，我们从当前细胞的单个存活曲线中测量了 MKM 三个参数中的一个，并在生物优化中使用了该参数。用人唾液腺肿瘤细胞在千叶重离子医用加速器（HIMAC）中用扫描碳束进行了照射，然后将测量的深度存活曲线与修正的 MKM 预测的存活曲线进行了比较。两条曲线之间的良好一致性证明了所提出的方法是计算离子照射治疗计划中生物效应的候选方法。
