Analysis on scattering dose mode of border distance in the Cyberknife plan for metastatic spinal carcinoma
10.3969/j.issn.1672-8270.2025.09.006
- VernacularTitle:脊柱转移癌射波刀治疗计划中的边界距离散射剂量模式分析
- Author:
Zhenyue WANG
1
;
Zhongze TIAN
1
;
Min ZHOU
1
;
Xingxin GAO
1
Author Information
1. 中国人民解放军联勤保障部队第九四〇医院放射治疗科 兰州 730050
- Publication Type:Journal Article
- Keywords:
Metastatic spinal carcinoma;
CyberKnife(CK);
Scattering dose of border distance;
Target volume
- From:
China Medical Equipment
2025;22(9):27-31
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the dosimetric influence of scattering dose mode of border distance on treatment plan when designed CyberKnife(CK)treatment plan for patients with metastatic spinal carcinoma.Methods:The located imaging data of 20 patients with metastatic carcinoma of thoracic vertebrae from radiotherapy of the 940th Hospital of People's Liberation Army Joint Service Support Force between January 2022 and March 2024 were retrospective selected.Using the G4 CyberKnife(CK)treatment plan system MultiPlan 4.0.3 to design respectively CK treatment plans for planning target volume(PTV)and gross tumor volume(GTV).They were divided into PTV group[20 cases who adopted conventional plan method on spinal cord of organs at risk(OAR)in limited dose],and GTV group(20 cases who adopted scattering dose mode of border distance on OAR spinal cord in limited dose).Finally,the prescription dose line was normalized to the PTV.The dosimetric parameters of the target volumes and normal tissues,as well as the distribution of dose curves,were compared between the two groups.Results:The GTV group showed a significant advantage in coverage rate(91.57%±8.73%)of target volume,which was significantly higher than(83.23%±16.05%)of PTV group,with a statistically significant difference(t=3.44,P<0.05).The conformity index(CI)values of GTV group and PTV group were respectively(1.07±0.35)and(1.14±0.04),and there was statistically significant difference between two groups(t=14.69,P<0.05),which indicated better conformity in the GTV group.The distance dose gradient index(DDGI)values per unit distance of GTV group and PTV group were respectively(89.43±46.12)mm and(152.07±109.81)mm,and the difference of that was significant between two groups(t=4.89,P<0.05),the gradient of dropping dose in normal tissue of GTV group had more advantages.The homogeneity index(HI)values of the dose within target volume in GTV group and PTV group were respectively(1.55±0.84)and(1.42±0.20),which also showed a statistically significant difference(t=24.37,P<0.05),and the dose gradient within target volume of GTV group was higher.At the same time,the differences of the parameters of absorbed dose within GTV target volume included D2,Dmean and D95 between two groups were significant(t=14.96,4.71,3.03,P<0.05),and the absorbed dose within GTV target volume in GTV group was higher.Additionally,there were significant differences in the parameters of absorbed dose within PTV target volume included D2,Dmean,D95(cGy)between two groups(t=8.27,5.51,2.50,P<0.05).Within the PTV target volume,the absorbed doses of GTV group was higher than that of PTV group.There were not statistically significant differences between the two groups in terms of the exposure dose of spinal cord,monitor units(MU),total treatment time(times),and total number of beams(beams)(P>0.05).Conclusion:When designing CK treatment plans,the plan that uses GTV as target to utilize scattering dose mode of border distance to design plan in GTV group is better than the plan in PTV group that uses PTV as target in coverage rate of target volume,CI,DDGI,HI and absorbed dose of target volume,which is better design mode of CK plan.
