Dosimetry study and measured dose comparison of Tomotherapy and intensity-modulated radiotherapy for breast cancer(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2018年第3期
- Page:
- 269-274
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Dosimetry study and measured dose comparison of Tomotherapy and intensity-modulated radiotherapy for breast cancer
- Author(s):
- SHEN Yichen; WANG Wei; ZHANG Songfang; TU Yongqing; ZHA Yuanzi; JIANG Mawei
- Department of Oncology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
- Keywords:
- ; breast cancer; Tomotherapy; intensity-modulated radiotherapy; TomoDirect intensity-modulated radiotherapy; thermoluminescent dosimeter
- PACS:
- R737.9；R811.1
- DOI:
- DOI:10.3969/j.issn.1005-202X.2018.03.005
- Abstract:
- Objective To evaluate the dosimetry differences in dose-volume parameters of the breast and normal tissues in Tomotherapy and conventional Linac for breast cancer, and verify the advantages and disadvantages of various technologies by performing absorbed dose measurement based on dosimetry study. Methods Three radiotherapy treatment plans, namely TomoDirect intensity-modulated radiotherapy (IMRT), TomoHelical and IMRT, were designed for 10 patients receiving breast-conserving surgery for breast cancer (T1N0M0), with a prescribed dose of 50 Gy/25 F and without supraclavicular irradiation area. The dose of target areas and normal tissues, conformity index, homogeneity index, and dose-volume parameters of normal tissues were compared to evaluate the advantages and disadvantages of different technologies. Meanwhile, the dose of surface target was measured with thermoluminescent dosimeter for comparing the effects of respiratory motion on surface dose and assessing the effects of time factor on treatment efficiency. Results In TomoDirect IMRT, TomoHelical, IMRT plans for breast cancer in 10 patients, the homogeneity index of planning target volume was 0.15±0.01, 0.06±0.01 and 0.20±0.15, respectively (P<0.001); conformity index was 0.76±0.00, 0.81±0.03 and 0.74±0.04, respectively (P>0.05). For the organs-at-risk, the mean dose of the heart was (4.12±0.87), (3.82±0.53) and (6.33±2.49) Gy, respectively (P<0.001); the maximum dose of left anterior descending artery was (20.38±5.66), (13.34±3.78) and (34.56±4.12) Gy, respectively (P<0.001); and the mean dose of the ipsilateral lung was (6.78±1.33), (7.22±2.34) and (12.76±2.10) Gy, respectively (P<0.001). The absorbed dose at 6 measurement points also showed statistical significances (P<0.001). Conclusion Compared with the other two technologies, TomoDirect IMRT had the advantages of small low-dose region, better dose coverage and reducing the effects of respiration motion. TomoDirect IMRT is recommended for patients with breast cancer.
Last Update: 2018-03-21