Analysis of dosimetric characteristics of proton radiotherapy in 4 cases of breast cancer
10.3760/cma.j.cn371439-20250217-00078
- VernacularTitle:乳腺癌4例质子放疗剂量学特点分析
- Author:
Chengqiang LI
1
;
Yungang WANG
;
Yishan YU
;
Shizhang WU
;
Cheng TAO
;
Xingmin MA
;
Tianyuan DAI
;
Jinghao DUAN
;
Jinhu CHEN
;
Tong BAI
;
Jian ZHU
Author Information
1. 山东省肿瘤防治研究院（山东省肿瘤医院）放射物理技术科，山东第一医科大学（山东省医学科学院），济南 250117
- Keywords:
Breast neoplasms;
Radiotherapy;
Proton therapy;
Radiotherapy dosage
- From:
Journal of International Oncology
2025;52(7):448-454
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore the dosimetric characteristics of proton and photon radiotherapy in the treatment of breast cancer.Methods:Four female breast cancer patients who needed radiotherapy at Shandong Cancer Hospital and Institute from January 2024 to May 2024 were selected as the research subjects. The target area ranges of 4 patients were left-sided breast cancer with lymph node involvement, left-sided breast cancer with lymph node involvement and internal mammary node, right-sided breast cancer with lymph node involvement and internal mammary node and synchronous bilateral breast cancer. Intensity modulated proton therapy (IMPT) and intensity modulated radiation therapy (IMRT) plans were designed respectively based on the prescribed dose in the target area and the limits of organs at risk (tomotherapy plan for bilateral breasts). The conformity index (CI), homogeneity index (HI), gradient index (GI) and organs at risk doses were evaluated. The dosimetric characteristics of IMPT and photon radiotherapy were compared.Results:Both IMPT and photon radiotherapy plans of the 4 breast cancer cases met the clinical dose requirements. The HI value of IMPT plans (0.10-0.14) was comparable to that of photon radiotherapy plans (0.10-0.12), and the average CI of the photon radiotherapy plans was 0.10 higher than that of the IMPT plans, and the average GI was 0.55 lower than that of the IMPT plans. The D mean of ipsilateral lung and heart of IMPT was lower, especially in the low-dose area (V 0-3), which was significantly lower than the photon radiotherapy plans, D mean of ipsilateral lung was reduced by 12.2%, 6.1%, 16.1% and 34.8%, respectively, D mean of heart was reduced by 47.2%, 57.0%, 72.4% and 83.0%, respectively. The ipsilateral lung V 20 of IMPT was not lower than photon radiotherapy plans (unilateral breast: IMPT was 30.0%-34.0%, IMRT was 29.0%-35.9%) . Conclusions:IMPT significantly reduces the D mean to the ipsilateral lung and heart while ensuring dose coverage of the target in breast cancer, preventing more volume of surrounding normal tissues from being irradiated. However, IMPT does not show much more advantage than photon radiotherapy plans in the ipsilateral lung V 20.
