Journal of International Oncology

Journal of International Oncology››2021,Vol. 48››Issue (9): 532-536.doi:10.3760/cma.j.cn371439-20210520-00103

• Original Articles •Previous ArticlesNext Articles

Dosimetric study of helical tomotherapy and volumetric modulated arc therapy simultaneous integrated boost for patients receiving breast-conserving surgery of left breast

Ji Wei, Liu Menglan, Wen Xiaobo, Yuan Meifang, Zhao Biao, Yang Yi()

  1. Department of Radiation Oncology, Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan Province, Kunming 650118, China
  • Received:2021-05-20Revised:2021-06-17Online:2021-09-08Published:2021-09-22
  • Contact:Yang Yi E-mail:yiyangrt@126.com
  • Supported by:
    National Natural Science Foundation of China(81760423);Science and Technology Department of Yunnan Province of China(2017FE468(-212));Health Science and Technology Project of Yunnan Province of China(2017NS192)

RichHTML

30

PDF

161

Abstract:

ObjectiveTo compare the dosimetric characteristics of helical tomotherapy (HT) and volumetric modulated arc therapy (VMAT) after left breast conserving surgery.MethodsTwenty-four patients with left breast cancer after breast-conserving surgery who were admitted to the Department of Radiation Oncology of Tumor Hospital of Yunnan Province from May 2016 to May 2019 were selected. The HT plan and the VMAT plan were designed for the same patient. The target dose and the dose volume parameters of organs at risk were compared and analyzed in the two radiotherapy plans.ResultsThere were significant differences in the D2%[(59.68±0.46) Gyvs.(60.06±0.20) Gy,t=-4.229,P<0.001], D98%[(57.46±0.44) Gyvs.(57.20±0.07) Gy,t=2.912,P<0.001], conformity index (CI) (0.80±0.05vs.0.76±0.04,t=4.079,P<0.001) and homogeneity index (HI) (0.04±0.01vs.0.05±0.00,t=-5.505,P<0.001) of the planning gross tumor volume (PGTV) between the HT and VMAT plans. However, there was no significant difference in the D50%[(58.77±0.46) Gyvs.(58.75±0.11) Gy,t=0.179,P=0.859]. There were significant differences in the D50%[(51.99±0.39) Gyvs.(52.39±0.36) Gy,t=-5.278,P<0.001], D98%[(49.46±0.29) Gyvs.(48.35±0.46) Gy,t=9.538,P<0.001] and HI (0.19±0.01vs.0.21±0.01,t=-7.538,P<0.001) of the planned target volume (PTV) between the two plans. However, there were no significant differences in the D2%[(59.13±0.64) Gyvs.(59.09±0.46) Gy,t=0.511,P=0.614] and CI (0.83±0.04vs.0.82±0.04,t=1.637,P=0.115). In terms of organs at risk, there were significant differences in the V5[(57.90±1.42)%vs.(52.40±5.74)%,t=4.812,P<0.001], V20[(22.40±2.17)%vs.(18.40±3.16)%,t=5.573,P<0.001] and Dmean[(12.71±0.55) Gyvs.(11.46±1.26) Gy,t=4.963,P<0.001] of left lung, Dmeanof right lung [(3.42±0.27) Gyvs.(2.49±0.24) Gy,t=13.310,P<0.001], Dmeanof right breast [(4.41±0.50) Gyvs.(3.12±0.65) Gy,t=10.326,P<0.001], V30[(0.55±0.37)%vs.(1.24±1.11)%,t=-4.020,P=0.001] and Dmeanof heart [(4.68±0.62) Gyvs.(3.83±0.88) Gy,t=7.335,P<0.001], Dmeanof left atrium [(2.53±0.31) Gyvs.(2.16±0.28) Gy,t=5.488,P<0.001], Dmeanof right atrium [(2.77±0.43) Gyvs.(2.20±0.30) Gy,t=7.103,P<0.001], Dmeanof right ventricle [(5.10±0.72) Gyvs.(3.72±0.94) Gy,t=9.802,P<0.001] and D2%of spinal cord [(14.79±2.73) Gyvs.(5.42±2.23) Gy,t=14.788,P<0.001] between HT and VMAT plans. There was no significant difference in the Dmeanof left ventricle [(5.10±1.19) Gyvs.(4.80±1.54) Gy,t=1.250,P=0.224].ConclusionBoth the HT plan and the VMAT plan can meet the treatment requirements. The HT plan can provide better target area conformity and dose uniformity. The VMAT plan has more advantages in terms of organs at risk. The HT plan shows an advantage only in exposure to high-dose area.

Key words:Unilateral breast neoplasms,Breast conserving surgery,Helical tomotherapy,Volumetric modulated arc therapy,Dosimetry