Application of dynamic jaw technique in helical tomotherapy for postoperative cervical cancer(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2020年第11期
- Page:
- 1356-1359
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Application of dynamic jaw technique in helical tomotherapy for postoperative cervical cancer
- Author(s):
- WU Junxiang; LIU Min; KANG Shengwei; WANG Pei; LI Jie; TANG Bin; WU Fan
- Sichuan Cancer Hospital & Research Institute/Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China/Sichuan Provincial Key Laboratory of Radiation Oncology, Chengdu 610041, China
- Keywords:
- Keywords: helical tomotherapy postoperative cervical cancer dynamic jaw dosimetry
- PACS:
- R815
- DOI:
- DOI:10.3969/j.issn.1005-202X.2020.11.003
- Abstract:
- Abstract: Objective To evaluate the plan quality and execution efficiency of dynamic jaw techniques and investigate the feasibility of replacing the fixed jaw 2.5 cm with dynamic jaw 5.0 cm in helical tomotherapy for postoperative cervical cancer. Methods A total of 25 cases of postoperative cervical cancer were sampled and divided into three groups and were applied fixed jaw 2.5 cm (2.5F), dynamic jaw 2.5 cm (2.5D) and dynamic jaw 5.0 cm (5.0D) separately in helical tomotherapy.The differences of D95, Dmean, Homogeneity Index (HI), Conformity Index (CI), dose to organs at risk (OARs), monitor unit and beam-on time were compared among these 3 groups. Results 2.5D plan was better in the aspects of the CI and HIin target area (P<0.05), but there were no statistically significant differences in other parameters (P>0.05). 2.5F plan was higher than 2.5D and 5.0D plans in the aspects of the V20, V40 and Dmean in the rectum and bladder and V20 in the intestine (P<0.05). As for the Dmean in the bone, femoral head and intestine, 2.5F plan was lower (P<0.05) than 5.0 D plan When it comes to the V20 in rectum, bladder and intestine and Dmean inintestine, 5.0D plan was higher (P<0.05) than 2.5D plan. The monitor unit and beam-on time in 5.0D plan was significantly reduced by 46.1%, 45.1%, 45.0%, 44.1% respectively,compared with those in 2.5D and 2.5F plans respectively (t=17.703, -40.698, 17.654, -40.414, P<0.05). Conclusion 5.0D plan could meet clinical requirements and its beam-on time was significantly reduced. 5.0D plan is recommended for treatment of postoperative cervical cancer when both plan quality and radiation efficiency are considered, but the 2.5D plan is recommended, if only plan quality is concerned.
Last Update: 2020-12-02