Dosimetric Study of Helical Tomotherapy in Breast Cancer After
Modified Radical Mastectomy
ZHANG Yanqiu1, XIAO Zhiqing2, ZHANG Qinghuai1, HAN Ameng3, LI Xiumei1
1. Department of Radiotherapy, The First Hospital of Qinhuangdao, Qinhuangdao Hebei 066000, China;
2. Department of Radiotherapy, The Second Hospital of Hebei Medical University, Shijiazhuang Hebei 050000, China;
3. Information Technology Center, Yanshan University, Qinhuangdao Hebei 066000, China
Abstract：Objective To explore the dosimetric characteristics of helical tomographic radiotherapy after modified radical mastectomy
for breast cancer, and to provide evidences for the selection of clinical plan. Methods A total of 30 patients with modified radical
mastectomy who received treatment in the Department of Radiotherapy, Qinhuangdao First Hospital from January 2020 to October
2021 were randomly selected, and two plans were designed for each patient. In the first scheme, helical tomotherapy (HT) plan was
designed on Accuray Hi-Art system (V5.1.6); in the second scheme, 7 fields intensity modulated radiation therapy (7F-IMRT) plan
was designed on Varian Eclipse planning system (V15.6). Results The conformal index of planned target volume (PTV) of HT plan
was significantly higher than that of 7F-IMRT plan (P<0.05), and the maximum dose of PTV in the HT plan was significantly than
that of 7F-IMRT plan (P<0.05). The D5 of contra-lateral lung, V10 of heart, Dmax of spinal cord, and Dmean of contra-lateral mammary
gland in the HT plan were all higher than those of 7F-IMRT plan (P<0.05). The V30, V20, V10, V5 of double lungs, V30, V20, V10, V5
of ipsilateral lung, and V30, V20 of heart in the HT plan were significantly lower than those in 7F-IMRT plan (P<0.05). The V20, V25,
V30, V35, V40, V45, V50 of B-P in the HT plan were significantly lower than those of 7F-IMRT plan (P<0.05). There were statistically
significant differences in cumulative sum of monitor unit of each field in the single plan and single treatment time between HT plan
and 7F-IMRT plan (P<0.05). Conclusion For breast cancer after modified radical mastectomy, the HT plan is superior to 7F-IMRT
plan in terms of target dose distribution and dose-receiving of organs at risk, but the treatment efficiency is lower than 7F-IMRT plan.
The appropriate plan can be selected according to the actual situation and requirements in clinical application.
张彦秋1，肖志清2，张庆怀1，韩阿蒙3，李秀梅1. 螺旋断层调强放疗在乳腺癌改良根治术后的剂量学研究[J]. 中国医疗设备, 2023, 38(2): 25-29.
ZHANG Yanqiu1, XIAO Zhiqing2, ZHANG Qinghuai1, HAN Ameng3, LI Xiumei1. Dosimetric Study of Helical Tomotherapy in Breast Cancer After
Modified Radical Mastectomy. China Medical Devices, 2023, 38(2): 25-29.
