Effects of treatment paths on target dosimetric distribution in CyberKnife radiotherapy plan(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2018年第12期
- Page:
- 1408-1412
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Effects of treatment paths on target dosimetric distribution in CyberKnife radiotherapy plan
- Author(s):
- ZHOU Han; LI Aomei; JING Shenghua; ZHU Xixu; SHEN Zetian; LI Bing
- Department of Oncology, Nanjing General Hospital of Nanjing Military Region of PLA, Nanjing 210002, China
- Keywords:
- ; Keywords: brain tumor; CyberKnife; isocenter; conformity index; dose distribution
- PACS:
- R811.1
- DOI:
- DOI:10.3969/j.issn.1005-202X.2018.12.008
- Abstract:
- Abstract: Objective To analyze the effects of different treatment paths on the dosimetric distribution in CyberKinfe radiotherapy plan. Methods The clinical data of 10 patients receiving CyberKinfe treatment for brain tumors were retrospectively analyzed in this study. A total of 18 tumors were found in 10 patients, with a mean volume of (9.7±10.4) cc. Two dose-limit rings were created at the distance of 5 and 15 mm to target areas. Isocenter treatment model was adopted for 6 regular tumors, and non-isocenter treatment model was adopted for the rest. The target dosimetric distributions were analyzed. Results For 6 regular tumors, the conformity index, the new conformity index, coverage, and number of nodes of the first treatment path (P1) were significant different from those of the other two treatment paths. P value was 0.019, 0.076, 0.819 for conformity index, 0.031, 0.733, 0.014 for the new conformity index, 0.009, 0.960, 0.032 for coverage, and 0.000, 0.584, 0.000 for the number of nodes. Among the 12 tumors treated by non-isocenter treatment, only the tumor with a diameter of 4 cm were analyzed and the result showed that using 20 mm collimator achieved the best conformity index and acceptable treatment time. Conclusion Isocenter treatment for regular tumors achieves better conformity index. The 3 treatment paths on CyberKinfe treatment planning system have obvious differences in treatment planning. The first treatment path should be the first choice during the treatment planning, and the treatment paths on the side of organs-at-risk should be avoided. Non-isocenter treatment is adopted for irregular tumors, and selecting collimator which is 70% of the short diameter of the tumor will achieve an optimal treatment time and the best conformity index.
Last Update: 2018-12-26