Dosimetric impact of optimization resolutions of the new photon optimizer in Eclipse treatment planning system(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2017年第11期
- Page:
- 1081-1085
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Dosimetric impact of optimization resolutions of the new photon optimizer in Eclipse treatment planning system
- Author(s):
- LI Sha1; 3; WANG Meijiao2; 3; YUE Haizhen3; HUANG Yuliang3; LIU Zhuolun3; ZHANG Jian3; GAO Song1; ZHANG Yibao3
- 1. Department of Medical Physics, Peking University Health Science Center, Beijing 100191, China; 2. National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing 100088, China; 3. Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China
- Keywords:
- ; new photon optimizer; optimization resolution; RapidPlan; radiotherapy
- PACS:
- R312
- DOI:
- DOI:10.3969/j.issn.1005-202X.2017.11.001
- Abstract:
- Abstract: Objective To investigate the effect of optimization resolutions of new photon optimizer in Eclipse treatment planning system on the dose to planning target volume (PTV) and organs-at-risk (OAR) of preoperational simultaneous-integrated-boosting volumetric modulated arc therapy plans for patients with rectal cancer, and provide clinical guidelines of resolution selection to strike a balance between plan quality and efficiency. Methods After the RapidPlan model applied in the research was set with a resolution of 1.25, 2.50 and 5.00 mm, respectively, the dose-volume histogram (DVH) were estimated, respectively, and Application Programming Interface (API) script was used to export these data for comparison. Herein, 3 plans using different resolutions were generated for 20 patients, and their DVH was exported. We applied the in-house MATLAB code to calculate the mean DVH, and SigmaPlot and SPSS software for plotting and statistical analysis. Time for DVH estimation and optimization were also recorded and analyzed. Results According to the API exportation, the DVH estimation and optimized parameters acquired by various resolutions were exactly the same. However, the optimization time using a resolution of 1.25 mm was about 3-4 times of that using the resolution of 2.50 and 5.00 mm. All the resolutions satisfied clinical requirements for target dose coverage. The differences in the conformity index of PTV and planning gross tumor volume, and the homogeneity index of PTV were not statistically significant (P>0.05). Though the homogeneity index of planning gross tumor volume was significantly different among 3 plans, the magnitude of deviations was within 0.01, which was considered clinically negligible. Relative to the resolutions of 2.50 and 5.00 mm, 1.25 mm did not always guarantee the best OAR sparing. The differences in mean DVH were marginal. Conclusion The impacts of optimization resolutions on the dose to target areas and OAR are trivial, but the differences in optimization time are dramatic. The plan with a resolution of 2.50 mm was most cost-effective.
Last Update: 2017-11-23