Comparison of Dosimetric Parameters between Three-dimensional Conformal and Intensity modulated Radiotherapy for Cervicothoracic Spine Metastases
10.3969/j.issn.1005-202X.2010.01.005
- VernacularTitle:颈胸段脊椎骨转移癌三维适形与调强放疗剂量学比较的研究
- Author:
Jian HU
;
Liming XU
;
Weiguo HU
;
Changhu LI
;
Chengjun LI
;
Aihua ZHANG
- Publication Type:Journal Article
- Keywords:
vertebral;
bone metastases;
3 dimensional conformal radiothrapy;
intensity-modulated radiotherapy;
dosimetry
- From:
Chinese Journal of Medical Physics
2010;27(1):1588-1591,1602
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To compare the dosimetric parameters between three-dimensional conformal and intensity-modulated radiotherapy for cervicothoracic spine metastases.Methods:Totally 10 cases of patients with cervicothoracic spine metastases were devided into 2 groups:3 patients with vertebral metastases;the other 7 patients with vertebral+annex metastases.The prescription dose for gross target was 60 Gy,D_(max) of spinal cord≤50 Gy,D_1≤45 Gy.Each patient was designed.One set of 3DCRT plan and three sets of IMRT plan were designed for each patient.We used 6 beams for 3DCRT plan,including 2 beams for the upper neck.3 sets of Step and shoot IMRT plans were consisted of 5-fields,7-fields and 9-fields,respectively,with equal angle and coplanar.DVH.CI and HI dose distributions of PTV and OARs were compared between 3DCRT and different set of IMRT plans.Results:(1)When the gross target included only vertebral,the CI of 3DCRT plan was lower than that of IMRT plan,but the HI of3DCRT plan was higher than that of IMRT plan.Moreover,5-fields IMRT plan was better than other plans.(2)When the gross target included vertebral and annex,the D_(80)、D_(mean) of IMRT PTV were higher than that of 3DCRT.As for spinal cord,5-fields D_(max)＜50Gy,7-fields D_(max)=49 Gy-51 Gy,9-fields D_(max)＞50 Cry.The CI of 3 sets of IMRT plans were 0.69,0.66,0.69,respectively.The CI of 3DCRT PTV was 0.53,worse than that of IMRT(P＜0.05).The average segments of 3 sets of IMRT plans were 83,104,160,and the average Mu of IMRT plans were 727,755,953,respectively.Conclusion:Compared with 3DCRT plan,the dose distribution,OAR and CI Of MRT plans were better.5-fields IMRT plan is recommended strongly.
