Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University, No. 241 West Huaihai Road, Xuhui District, Shanghai, 200030, China.
Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers University, New Brunswick, NJ, 08903, USA.
Radiat Oncol. 2021 Aug 19;16(1):158. doi: 10.1186/s13014-021-01882-7.
To evaluate the dosimetric and biological benefits of the fixed-jaw (FJ) intensity-modulated radiation therapy (IMRT) technique for patients with T-shaped esophageal cancer.
FJ IMRT plans were generated for thirty-five patients and compared with jaw tracking (JT) IMRT, static jaw (SJ) IMRT and JT volumetric modulated arc therapy (VMAT). Dosimetric parameters, tumor control probability (TCP) and normal tissue complication probability (NTCP), monitor units (MUs), delivery time and gamma passing rate, as a measure of dosimetric verification, were compared. The correlation between the length of PTV-C below the upper boundary of lung tissue (PTV-C) and dosimetric parameters and NTCP of the lung tissue were analyzed.
The homogeneity and conformity of the target in the four plans were basically equivalent. When compared to the JT IMRT and SJ IMRT plans, FJ IMRT plan led to a statistically significant improvement in the NTCP and low-middle dosimetric parameters of the lung, and the improvement had a moderately positive correlation with the length of PTV-C, with a correlation coefficient ranging from 0.523 to 0.797; the FJ IMRT plan exhibited better lung sparing in low-dose volumes than the JT VMAT plan. The FJ IMRT plan had similar MUs (888 ± 99) and delivery times (516.1 ± 54.7 s) as the JT IMRT plan (937 ± 194, 522 ± 5.6 s) but higher than SJ IMRT (713 ± 137, 488.8 ± 45.2 s) and JT VMAT plan (517 ± 59, 263.7 ± 43.3 s).
The FJ IMRT technique is superior in reducing the low-dose volumes of lung tissues for patients with T-shaped esophageal cancer.
评估 T 型食管癌患者固定架（FJ）强度调制放疗（IMRT）技术的剂量学和生物学效益。
为 35 名患者生成 FJ IMRT 计划，并与 jaw tracking（JT）IMRT、static jaw（SJ）IMRT 和 JT 容积旋转调强放疗（VMAT）进行比较。比较了剂量学参数、肿瘤控制概率（TCP）和正常组织并发症概率（NTCP）、监测器单位（MUs）、治疗时间和伽马通过率（剂量验证的一种测量方法）。分析了 PTV-C 低于肺组织上边界的长度（PTV-C）与剂量学参数和肺组织 NTCP 的相关性。
四个计划的靶区均匀性和适形性基本相当。与 JT IMRT 和 SJ IMRT 计划相比，FJ IMRT 计划显著改善了肺组织的 NTCP 和中低剂量参数，改善程度与 PTV-C 的长度呈中度正相关，相关系数范围为 0.523 至 0.797；FJ IMRT 计划在低剂量体积中对肺的保护效果优于 JT VMAT 计划。FJ IMRT 计划的 MU（888±99）和治疗时间（516.1±54.7 s）与 JT IMRT 计划（937±194，522±5.6 s）相似，但高于 SJ IMRT（713±137，488.8±45.2 s）和 JT VMAT 计划（517±59，263.7±43.3 s）。
FJ IMRT 技术可降低 T 型食管癌患者肺组织的低剂量体积。
