SU-E-T-519：使用放射物理中心的肺部体模对用于异质性剂量计算的确定性Acuros XB辐射传输算法进行实验评估。

SU-E-T-519: Experimental Evaluation of Deterministic Acuros XB Radiation Transport Algorithm for Heterogeneity Dose Calculation Using the Radiological Physics Center's Lung Phantom.

作者信息

Han T, Mourtada F, Repchak R, Tonigan J, Mikell J, Howell R, Salehpour M, Molineu A, Followill D

机构信息

MD Anderson Cancer Center, Houston, TX.

Christiana Care Hospital, Newark, DE.

出版信息

Med Phys. 2012 Jun;39(6Part18):3825. doi: 10.1118/1.4735608.

DOI:10.1118/1.4735608

PMID:28518535

Abstract

PURPOSE

To evaluate the heterogeneity corrected dose calculations from the Acuros XB (AXB), a novel deterministic dose calculation algorithm based on grid-based Boltzmann transport equation solver (GBBS), for IMRT and VMAT plans.

METHODS

The Radiological Physics Center's lung phantom was used to create clinically equivalent IMRT and VMAT plans (RapidArc) with the Eclipse planning system 10.0 that were delivered using a Varian 23 iX. Absolute doses and relative dose distributions were measured with thermoluminescent dosimeters (TLDs) and radiochromic film. The measured dose distributions were compared with calculated doses from both AXB (11.0.3) and AAA (10.0.24) dose calculation algorithms. The AXB calculated dose-to-water and dose-to-medium were both compared to measurements. Gamma analysis (±7%/4mm, ±5%/3mm, and ±3%/3mm) was used to quantify correspondence between AXB dose distributions and the film measurements. The computation time between AAA and AXB were also evaluated.

RESULTS

For TLD point doses, both AAA and AXB heterogeneity corrected dose calculations are within 5% inside the PTV for both IMRT and VMAT plans. The agreements observed between the measured and calculated doses for both AXB dose reporting methods are better than those observed with the AAA algorithm. The gamma analysis showed that the differences between AAA, AXB and film measurement met the RPC ±7%/4 mm criteria. The percent of pixels passing rate for both the AXB dose to medium and AXB dose to water are higher than AAA. The computation time between AAA and AXB are comparable for IMRT plans but AXB is significantly faster (4 times) than AAA for VMAT plans.

CONCLUSIONS

The AXB implemented in the Eclipse planning system calculates a more accurate heterogeneity corrected dose than the AAA algorithm as compared to measurement in lung and improve the calculation speed for VMAT radiotherapy. Work supported by grants CA10953, CA81647, 2R44CA105806-02, CA016672 (NCI, DHHS).

摘要

目的

评估基于网格玻尔兹曼输运方程求解器（GBBS）的新型确定性剂量计算算法Acuros XB（AXB）对调强放疗（IMRT）和容积调强弧形放疗（VMAT）计划进行的异质性校正剂量计算。

方法

使用放射物理中心的肺部体模，通过Eclipse计划系统10.0创建临床等效的IMRT和VMAT计划（快速弧形放疗），并使用Varian 23 iX进行照射。使用热释光剂量计（TLD）和放射变色胶片测量绝对剂量和相对剂量分布。将测量的剂量分布与AXB（11.0.3）和AAA（10.0.24）剂量计算算法计算的剂量进行比较。将AXB计算的水剂量和介质剂量与测量值进行比较。使用伽马分析（±7%/4mm、±5%/3mm和±3%/3mm）来量化AXB剂量分布与胶片测量值之间的对应关系。还评估了AAA和AXB之间的计算时间。

结果

对于TLD点剂量，AAA和AXB的异质性校正剂量计算在IMRT和VMAT计划的计划靶体积（PTV）内均在5%以内。两种AXB剂量报告方法的测量剂量与计算剂量之间的一致性均优于AAA算法。伽马分析表明，AAA、AXB与胶片测量值之间的差异符合放射物理中心±7%/4mm标准。AXB介质剂量和AXB水剂量的像素通过率百分比均高于AAA。IMRT计划中AAA和AXB之间的计算时间相当，但VMAT计划中AXB比AAA快得多（4倍）。