Department of Health Sciences, Division of Medical Quantum Radiation Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Department of Radiology, Hospital of University of Occupational and Environmental Health, Fukuoka, Japan.
J Cancer Res Ther. 2023 Jul-Sep;19(5):1261-1266. doi: 10.4103/jcrt.jcrt_1740_21.
The objective of the study is to analyze the difference in target dose distributions between Acuros XB (AXB) and collapsed cone convolution (CCC)/superposition and the impact of the tumor locations in clinical cases of stereotactic ablative body radiotherapy (SABR) for lung cancer.
Ninety-six patients underwent SABR for lung cancers Kyushu University Hospital from 2014 to 2017. We recalculated clinical plans originally calculated by AXB using CCC with the identical monitor units (MUs) and beam arrangements. We calculated the following dosimetric parameters: maximum dose (Dmax), minimum dose (Dmin), homogeneity index (HI), conformity index (CI), and D95 of the planning target volume (PTV). We investigated the difference between the results of two calculations and examined the impact of tumor location. Moreover, we determined the target central dose using a thorax phantom and assessed the calculation accuracy of the two algorithms for each fraction.
CCC significantly overestimated the dose to PTV, compared to AXB (P < 0.05). The mean differences of Dmax, Dmin, and D95 were 1.17, 1.95, and 1.85 Gy, respectively. The mean differences of HI and CI were 0.02 and - 0.06. Dmin, HI, and D95 had significant correlations with the tumor location, and the difference was greater when the PTV was included the chest wall (P < 0.05). The discrepancy between the calculated and irradiated dose was 2.48% for CCC, whereas it was 0.14% for AXB.
We demonstrated that CCC significantly overestimated the dose to PTV relative to AXB in clinical cases of lung SABR.
本研究旨在分析 Acuros XB（AXB）与 collapsed cone convolution（CCC）/superposition 之间靶区剂量分布的差异，以及肿瘤位置对肺癌立体定向消融体放射治疗（SABR）临床病例的影响。
2014 年至 2017 年，我们在九州大学医院对 96 例肺癌患者进行了 SABR。我们使用与原始 AXB 相同的 MU 和射束排列重新计算了 CCC 临床计划。我们计算了以下剂量学参数：最大剂量（Dmax）、最小剂量（Dmin）、均匀性指数（HI）、适形性指数（CI）和计划靶区（PTV）的 D95。我们研究了两种计算结果的差异，并检查了肿瘤位置的影响。此外，我们使用胸部体模确定了靶区中心剂量，并评估了两种算法对每个部分的计算准确性。
与 AXB 相比，CCC 显著高估了 PTV 的剂量（P<0.05）。Dmax、Dmin 和 D95 的平均差异分别为 1.17、1.95 和 1.85 Gy。HI 和 CI 的平均差异分别为 0.02 和-0.06。Dmin、HI 和 D95 与肿瘤位置显著相关，当 PTV 包含胸壁时，差异更大（P<0.05）。CCC 的计算剂量与照射剂量之间的差异为 2.48%，而 AXB 为 0.14%。
我们证明了在肺癌 SABR 的临床病例中，CCC 相对于 AXB 显著高估了 PTV 的剂量。
