Kolacio Manda Švabić, Rajlić David, Radojčić Milan, Radojčić Đeni Smilović, Obajdin Nevena, Debeljuh Dea Dundara, Jurković Slaven
Medical Physics Department, Clinical Hospital Center Rijeka, Rijeka, Croatia.
Clinic for Radiotherapy and Oncology, Clinical Hospital Center Rijeka, Rijeka, Croatia.
Rep Pract Oncol Radiother. 2022 Mar 22;27(1):86-96. doi: 10.5603/RPOR.a2022.0013. eCollection 2022.
Study determines differences in calculated dose distributions for non-small cell lung carcinoma (NSC LC) patients. NSC LC cases were investigated, being the most common lung cancer treated by radiotherapy in our clinical practice.
A retrospective study of 15 NSCLC patient dose distributions originally calculated using standard superposition (SS) and recalculated using collapsed cone (CC ) and Monte Carlo (MC) based algorithm expressed as dose to medium in medium (MCD) and dose to water in medium (MCD) was performed so that prescribed dose covers at least 99% of the gross target volume (GTV). Statistical analysis was performed for differences of conformity index (CI), heterogeneity index (HI), gradient index (GI), dose delivered to 2% of the volume (D), mean dose (D) and percentage of volumes covered by prescribed dose (V). For organs at risk (OARs), D and percentage of volume receiving 20 Gy and 5Gy (V, V) were analysed.
Statistically significant difference for GTVs was observed between MCD and SS algorithm in mean dose only. For planning target volumes (PTVs), statistically significant differences were observed in prescribed dose coverage for CC, MCD and MCD. The differences in mean CI value for the CC algorithm and mean HI value for MCD and MCD were statistically significant. There is a statistically significant difference in the number of MUs for MCD and MCD compared to SS.
All investigated algorithms succeed in managing the restrictive conditions of the clinical goals. This study shows the drawbacks of the CC algorithm compared to other algorithms used.
本研究旨在确定非小细胞肺癌（NSCLC）患者计算剂量分布的差异。NSCLC病例是我们临床实践中接受放疗的最常见肺癌类型，对其进行了调查。
对15例NSCLC患者的剂量分布进行回顾性研究，最初使用标准叠加（SS）算法进行计算，然后使用基于坍缩圆锥（CC）和蒙特卡罗（MC）的算法重新计算，结果以介质中剂量（MCD）和介质中水剂量（MCD）表示，以使处方剂量覆盖至少99%的大体靶体积（GTV）。对适形指数（CI）、异质性指数（HI）、梯度指数（GI）、2%体积所接受的剂量（D）、平均剂量（D）以及处方剂量覆盖的体积百分比（V）的差异进行统计分析。对于危及器官（OARs），分析了D以及接受20 Gy和五Gy的体积百分比（V、V）。
仅在平均剂量方面，观察到MCD与SS算法在GTVs之间存在统计学显著差异。对于计划靶体积（PTV），在CC、MCD和MCD的处方剂量覆盖方面观察到统计学显著差异。CC算法的平均CI值以及MCD和MCD的平均HI值的差异具有统计学显著性。与SS相比，MCD和MCD的监测单元数量存在统计学显著差异。
所有研究算法均成功实现了临床目标的限制性条件。本研究显示了CC算法与其他所用算法相比的缺点。
