Keall P J, Siebers J V, Arnfield M, Kim J O, Mohan R
Department of Radiation Oncology, Medical College of Virginia Hospitals at Virginia Commonwealth University, Richmond, USA.
Phys Med Biol. 2001 Apr;46(4):929-41. doi: 10.1088/0031-9155/46/4/302.
Dose calculations for intensity modulated radiation therapy (IMRT) face new challenges due to the complex leaf geometry and time dependent nature of the delivery. A fast method of particle transport through a dynamic multileaf collimator (MLC) geometry that accounts for photon attenuation and first-scattered Compton photon production has been incorporated into an existing Monte Carlo code used for patient dose calculations. Dosimetric agreement between calculation and measurement for two photon energies and MLC types is within experimental error for the sliding window tests. For a patient IMRT field, the Monte Carlo calculations are closer to measured dose than similar superposition or pencil beam calculations.
由于复杂的叶片几何形状和放疗过程的时间依赖性，调强放射治疗（IMRT）的剂量计算面临新的挑战。一种快速的粒子传输方法已被纳入现有的用于患者剂量计算的蒙特卡罗代码中，该方法可处理动态多叶准直器（MLC）几何形状，同时考虑光子衰减和首次散射康普顿光子的产生。对于两种光子能量和MLC类型，计算结果与测量结果之间的剂量学一致性在滑动窗口测试的实验误差范围内。对于患者的IMRT射野，蒙特卡罗计算结果比类似的叠加或笔形束计算结果更接近测量剂量。
