作者机构：
[邱小平] School of Nuclear Science and Technology, University of South China, Hengyang, 421001, China;[尹勇; 韩柱君; 巩贯忠; Qiu Q.] Department of Radiation Physics Technology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, 250117, China;[苏铭] Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, 250117, China
通讯机构：
[Gong, G.] D;Department of Radiation Physics Technology, China
关键词：
surgical mask;setup error;head and neck radiotherapy;COVID-19;radiation therapy
摘要：
<jats:sec><jats:title>Purpose:</jats:title><jats:p> With the widespread prevalence of Corona Virus Disease 2019 (COVID-19), cancer patients are suggested to wear a surgical mask during radiation treatment. In this study, cone beam CT (CBCT) was used to investigate the effect of surgical mask on setup errors in head and neck radiotherapy. </jats:p></jats:sec><jats:sec><jats:title>Methods:</jats:title><jats:p> A total of 91 patients with head and neck tumors were selected. CBCT was performed to localize target volume after patient set up. The images obtained by CBCT before treatment were automatically registered with CT images and manually fine-tuned. The setup errors of patients in 6 directions of Vrt, Lng, Lat, Pitch, Roll and Rotation were recorded. The patients were divided into groups according to whether they wore the surgical mask, the type of immobilization mask used and the location of the isocenter. The setup errors of patients were calculated. A t-test was performed to detect whether it was statistically significant. </jats:p></jats:sec><jats:sec><jats:title>Results:</jats:title><jats:p> In the 4 groups, the standard deviation in the directions of Lng and Pitch of the with surgical mask group were all higher than that in the without surgical mask group. In the head-neck-shoulder mask group, the mean in the Lng direction of the with surgical mask group was larger than that of the without surgical mask group. In the lateral isocenter group, the mean in the Lng and Pitch directions of the with surgical mask group were larger than that of the without surgical mask group. The t-test results showed that there was significant difference in the setup error between the 2 groups ( p = 0.043 and p = 0.013, respectively) only in the Lng and Pitch directions of the head-neck-shoulder mask group. In addition, the setup error of 6 patients with immobilization open masks exhibited no distinguished difference from that of the patients with regular immobilization masks. </jats:p></jats:sec><jats:sec><jats:title>Conclusion:</jats:title><jats:p> In the head and neck radiotherapy patients, the setup error was affected by wearing surgical mask. It is recommended that the immobilization open mask should be used when the patient cannot finish the whole treatment with a surgical mask. </jats:p></jats:sec>
作者：
Su, Ming;Gong, Guanzhong;Qiu, Xiaoping;Yin, Yong*
期刊：
TRANSLATIONAL CANCER RESEARCH,2020年9(2):458-465 ISSN：2218-676X
通讯作者：
Yin, Yong
作者机构：
[Qiu, Xiaoping; Su, Ming] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Yin, Yong; Su, Ming; Gong, Guanzhong] Shandong First Med Univ & Shandong Acad Med Sci, Shandong Canc Hosp & Inst, Jinan 250117, Peoples R China.;[Yin, Yong] Shandong First Med Univ & Shandong Acad Med Sci, Shandong Canc Hosp & Inst, Dept Radiat Oncol, Jinan 250117, Peoples R China.
通讯机构：
[Yin, Yong] S;Shandong First Med Univ & Shandong Acad Med Sci, Shandong Canc Hosp & Inst, Dept Radiat Oncol, Jinan 250117, Peoples R China.
关键词：
Breast cancer;dose addition;deformation registration (DF);dose assessment
摘要：
Background: To evaluate the dosimetric changes in the target volume and organs at risk (OARs) of patients with left breast cancer (LBC) who underwent intensity-modulated radiation therapy (IMRT) based on a deformation registration (DF) method. Methods: Sixteen patients with LBC treated with 6 MV X-ray IMRT were retrospectively analyzed. All targets included the lymph node drainage area and chest wall. All patients underwent CT for simulation of the primary positioning and repositioning. Primary and secondary treatment plans were developed using primary positioning CT (CT1) and repositioning CT (CT2) images to obtain plan(1) and plan(2), respectively. Rigid and DF of the dose distribution of plan(2) to CT1 were applied; the results were then added to the dose distribution of plan(1), yielding plan(rig) and plan(def), respectively. The dosimetric differences between the target and OAR volumes of the four plans were compared. Results: The clinical target volume of CT2 was 8.74% less than that of CT1. The planned target volume of CT2 was 11.20% less than that of CT1. The Dice similarity coefficients (DSCs) of the heart, left lung and right lung were significantly lower after than before DF (0.94 +/- 0.01 vs. 0.89 +/- 0.05, 0.96 +/- 0.01 vs. 0.91 +/- 0.03, and 0.96 +/- 0.01 vs. 0.92 +/- 0.03, respectively; t=3.83, 7.28, and 6.70, P<0.05, respectively). There were no significant differences in the dose-volume indices of the heart or left lung between plan(1) and the other plans, while the dose-volume indices were higher in plan(rig) than in plan(def). Conclusions: Because of small changes in the target and OAR volumes during radiotherapy, we suggest the first IMRT plan could be used to evaluate the dose-volume indices of the lungs and heart for these patients.
摘要：
目的通过形变配准及刚性配准进行左侧乳腺癌放疗中靶区及危及器官剂量累加的研究,探讨二者受量的变化规律。方法回顾分析16例女性左侧乳腺癌根治术后患者,靶区包括锁上淋巴结引流区加胸壁,均采用6 MV X射线调强放疗(IMRT)。所有患者均接受定位、二程CT扫描,在定位图像(CT1)上制定放疗计划为Planl,在二程定位图像(CT2)上制定放疗计划为Plan2。利用Velocity软件将Plan2的剂量进行刚性、形变配准到CT1剂量累加后获得Planrigid、Plan-deform。比较4个计划中靶区及危及器官的剂量学差异。结果CT2比CT1的CTV体积平均缩小6.64%;形变后靶区剂量均匀性指数(HI)提高23.05%,而形变后心脏、左、右肺戴斯相似系数(DSC)均低于形变前(0.94±0.01 vs. 0.89±0.05、0.96 ±0.01 vs. 0.91±0.03、0.96±0.01 vs. 0.92±0.03),且差异均有统计学意义(Z = -3.208、-3.533、-3.535,P<0.05);心脏及左肺各剂量-体积指标在Plan2、Plan-rigid 、 Plan-deform与Plan1的组间差异均无统计学意义(P>0.05);在Plan-rigid组各剂量-体积指标均高于Plan-deform组。结论靶区及危及器官体积、剂量-体积指标变化较小的左乳癌根治术后患者在进行放疗剂量累加时,推荐使用刚性配准,且初次调强计划的剂量-体积指标可基本反映双肺及心脏的受量情况。
