The application of different Auto-shells and optimization steps of CyberKnife treatment plans for pancreatic cancer
10.3760/cma.j.issn.1674-1935.2018.01.009
- VernacularTitle:胰腺癌射波刀治疗计划中不同Auto-Shells及优化步骤的应用
- Author:
Yangsen CAO
1
;
Jian LI
;
Chunshan YU
;
Yongjian SUN
;
Xiaoping JU
;
Xiaofei ZHU
;
Yangyang GENG
;
Yin TANG
;
Huojun ZHANG
Author Information
1. 第二军医大学长海医院放疗科
- Keywords:
Pancreatic neoplasms;
Radiotherapy;
Radiotherapy planning;
computer-assisted;
Cyber knife
- From:
Chinese Journal of Pancreatology
2018;18(1):35-38
- CountryChina
- Language:Chinese
-
Abstract:
Objective To propose the method of dose distribution calculated by one-step optimization with 7 shells (Cao method) and compare with that by three-step optimization with 4 shells (Blanck method) and CyberKnife treatment plans for pancreatic cancer. Methods 20 cases of pancreatic cancer who underwent CyberKnife treatment were retrospectively analyzed,and CT was performed to localize and delineate the target area and endangering organs. Dosage was optimized and evaluated with Blanck method and Cao method. The planning target volume (PTV) conformity index (CI), new conformity index (nCI), homogeneity index (HI),gradient index (GI), coverage, dose-volume and doses to organs at risk were compared. Results Compared with Blanck method, CI (1.11 ± 0.05 vs 1.15 ± 0.05), nCI (1.20 ± 0.06 vs 1.23 ± 0.06), coverage [(92.48 ± 1.85)% vs (93.53 ± 2.15)%], volumes encompassed by 100% and 30% prescription dose line (36.46 ± 16.64 vs 38.19 ± 17.68; 286.19 ± 126.52 vs 320.93 ± 154.82) and monitor unit (56 369 ± 20 019 vs 57 814 ± 20 531) were significantly decreased,while GI was increased (3.22 ± 0.19 vs 3.11 ± 0.19), and all the differences were statistically significant (P<0.05). Additionally, Dmax of the intestine (21.17 ± 2.90 vs 20.63 ± 3.13), D10cc of the stomach (12.78 ± 2.57 vs 13.11 ± 2.43), D5ccof the duodenum (11.01 ± 3.45 vs 11.50 ± 3.25), D10ccof the duodenum (9.30 ± 3.31 vs 9.78 ± 3.07) and D0.35ccof the spinal cord (6.09 ± 0.98 vs 6.59 ± 0.92) were all significantly decreased (P<0.05). No significant differences were found on other parameters. Conclusions Better dose distributions are accessible by one-step optimization with 7 shells in CyberKnife treatment plans for pancreatic cancer.
