Herman Tania De La Fuente, Hibbitts Kerry, Herman Terence, Ahmad Salahuddin
Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
J Med Phys. 2011 Oct;36(4):234-8. doi: 10.4103/0971-6203.89974.
The aim of this study was to evaluate differences in dose distributions in stereotactic body radiation therapy treatment plans for lung tumors calculated with pencil beam convolution (PBC) algorithm with modified Batho power law (MBPL) versus heterogeneity corrected anisotropic analytical algorithm (AAA) of the Varian Eclipse treatment planning system. The four-dimensional computed tomography images from 20 patients with lung cancer were used to create treatment plans. Plans used five to seven nonopposing coplanar 6 MV beams. Plans generated with the PBC algorithm and MBPL for tissue heterogeneity corrections were optimized to deliver 60 Gy in three fractions to at least 95% of the planned target volume, and the normal tissue doses for spinal cord, esophagus, heart, and ipsilateral bronchus were restricted to less than 18, 27, 30, and 30 Gy, respectively. Plans were recalculated with AAA, retaining identical beam arrangements, photon beam fluences, and monitor units. The pencil beam plans, designed to deliver 60 Gy, delivered on average 51.6 Gy when re-calculated with the AAA, suggesting a reduction of at least 10% to prescription dose is appropriate when calculating with the AAA.
本研究的目的是评估在瓦里安速锋刀治疗计划系统中，使用带有修正巴索幂律（MBPL）的笔形束卷积（PBC）算法与异质性校正各向异性分析算法（AAA）计算的肺癌立体定向体部放射治疗计划中剂量分布的差异。使用20例肺癌患者的四维计算机断层扫描图像来创建治疗计划。计划使用五到七个非对置共面6兆伏（MV）射束。使用PBC算法和MBPL进行组织异质性校正生成的计划经过优化，以分三次给予至少95%的计划靶体积60戈瑞（Gy），脊髓、食管、心脏和同侧支气管的正常组织剂量分别限制在18、27、30和30戈瑞以下。使用AAA重新计算计划，保持相同的射束排列、光子束注量和监测单位。设计给予60 Gy的笔形束计划，在用AAA重新计算时平均给予51.6 Gy，这表明在用AAA计算时将处方剂量降低至少10%是合适的。
