Lamichhane Narottam, Patel Vivek N, Studenski Matthew T
University of Miami.
J Appl Clin Med Phys. 2016 Mar 8;17(2):63-73. doi: 10.1120/jacmp.v17i2.5913.
Accurate dose calculation and treatment delivery is essential for total body irradiation (TBI). In an effort to verify the accuracy of TBI dose calculation at our institution, we evaluated both the Varian Eclipse AAA and Acuros algorithms to predict dose distributions at an extended source-to-surface distance (SSD) of 400 cm. Measurements were compared to calculated values for a 6 MV beam in physical and virtual phantoms at 400 cm SSD using open beams for both 5 × 5 and 40 × 40cm2 field sizes. Inline and crossline profiles were acquired at equivalent depths of 5 cm, 10 cm, and 20 cm. Depth-dose curves were acquired using EBT2 film and an ion chamber for both field sizes. Finally, a RANDO phantom was used to simulate an actual TBI treatment. At this extended SSD, care must be taken using the planning system as there is good relative agreement between measured and calculated profiles for both algorithms, but there are deviations in terms of the absolute dose. Acuros has better agreement than AAA in the penumbra region.
准确的剂量计算和治疗投送对于全身照射（TBI）至关重要。为了验证我们机构TBI剂量计算的准确性，我们评估了Varian Eclipse AAA和Acuros算法，以预测在400 cm的扩展源皮距（SSD）下的剂量分布。在400 cm SSD下，使用5×5和40×40 cm²射野大小的开放射束，将物理和虚拟体模中6 MV射束的测量值与计算值进行比较。在5 cm、10 cm和20 cm的等效深度处采集了轴向和横向剖面。使用EBT2胶片和电离室获取了两种射野大小的深度剂量曲线。最后，使用RANDO体模模拟实际的TBI治疗。在这种扩展的SSD下，使用计划系统时必须小心，因为两种算法的测量和计算剖面之间有良好的相对一致性，但在绝对剂量方面存在偏差。在半影区，Acuros比AAA具有更好的一致性。
