Effects of three-dimensional respiratory motions simulated by HexaMotion system on superficial dose distribution of chest wall in patients receiving radical mastectomy for breast cancer(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2018年第10期
- Page:
- 1134-1138
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Effects of three-dimensional respiratory motions simulated by HexaMotion system on superficial dose distribution of chest wall in patients receiving radical mastectomy for breast cancer
- Author(s):
- DING Xiaoge1; QIU Xiaoping1; YANG Zhen2; CAO Ying2
- 1. School of Nuclear Science and Technology, University of South China, Hengyang 421001, China; 2. Radiotherapy Centre, Xiangya Hospital, Central South University, Changsha 421000, China
- Keywords:
- ; Keywords: HexaMotion system; MOSFET detector; respiratory motion; breast cancer; superficial dose
- PACS:
- R811.1
- DOI:
- DOI:10.3969/j.issn.1005-202X.2018.10.004
- Abstract:
- Abstract： Objective To simulate the three-dimensional respiratory motions of patients receiving radical mastectomy by HexaMotion system, and to combine HexaMotion system with metal oxide semiconductor filed effect transistor for studying the effects of respiratory motions on the superficial dose distribution of the chest wall during the radiotherapy for breast cancer. Methods The average motion amplitude of the chest in 57 patients with breast cancer in X, Y and Z directions were investigated, and RPM system was used to measure the average respiratory amplitude of 9 patients with breast cancer. The respiratory motion generator was used to generate three-dimensional motion curves which were then input into ScandiDoseHexaMotion software to drive the Delta4 phantom to simulate the respiratory motions of patients. The MOSFET dosimeter was fixed at the surface of Delta4 which was at cross-hatch angles of 0°, 30° (330°), and 60° (300°) to measure the doses at the medial, middle and lateral side of chest wall in the patients with left (right) breast cancers. Then plans were implemented, and the doses of phantom at rest and in motion state were measured. The effects of respiratory motions on the superficial dose distribution of the chest wall were evaluated. Results The relative dose differences of phantom at rest and in motion state was basically about ±3%, and all of them were within ±5%. No significant differences were found in the measurements between rest state and motion state with Delta4 at cross-hatch angles of 0°, 30° (330°), and 60 ° (300°) (P=0.73, 0.28 and 0.52). When the respiratory amplitude was in a certain range, hybrid intensity-modulated radiotherapy had little effects on the superficial dose distribution of chest wall. However, when the respiratory amplitude was increased to cm magnitude, the superficial dose distribution of chest wall would be significantly increased with the increase of amplitude. Conclusion The slight changes of respiratory amplitude don’t cause obvious changes in chest wall superficial dose, but with the significant increase of respiratory amplitude, the superficial dose distribution of chest wall also increases.
Last Update: 2018-10-22