Comparison of forward and inverse intensity modulation radiotherapy planning for breast cancer after breast-conservative surgery
10.3760/cma.j.issn.0254-5098.2009.04.015
- VernacularTitle:乳腺癌保乳术后正向与逆向调强放疗计划的比较
- Author:
Tao SUN
;
Jie LU
;
Yong YIN
;
Tonghai LIU
;
Jinhu CHEN
;
Xiutong LIN
;
Jian ZHU
;
Tong BAI
;
Bo LIU
- Publication Type:Journal Article
- Keywords:
Breast neoplasm;
Breast-conservative surgery;
Forward intensity-modulated radiotherapy;
Inverse intensity-modulated radiotherapy
- From:
Chinese Journal of Radiological Medicine and Protection
2009;29(4):401-404
- CountryChina
- Language:Chinese
-
Abstract:
Objective To compare the dosimetric difference in forward intensity modulation radiotherapy (fIMRT)and inverse IMRT(iIMRT)planning for breast cancer.Methods Six patients received radiotherapy alone after left breast-conserving surgery were selected.For each patient,two treatment phns(flMRT and iIMRT)were designed with Pinnacle3 7.4f.In each plan,the volume of PIT received prescription dose was not less than 95 %.The dosimetrie parameters were assessed with dose volume histograms in planning target volume (PIT)and organ of around risk(OAR).Results Of flMRT and ilMRT plans,the PTV average canformal indexwere(0.67±0.06)and(0.66±0.06)(t = 2.423,P ＞ 0.05),average homogeneity index were (28.2±6.0)% and(26.1±6.8)%(t = 2.164,P ＞ 0.05);the volume of left lung received 20 Gy(V20)were(18.7±3.3)% and(17.0±2.8)%(t =5.087,P<0.05),and V30 of left lung were(15.5±3.0)%and(14.0±2.6)%(t =7.272,P<0.05);V30 of heart were(4.1±3.1)% and(3.5±2.5)%(t=1.916,P ＞ 0.05);the total monitor units were(262±5)MU and(308±14)MU(t = 7.515,P < 0.05).Conclusions There were no significant differences of CI,HI,and V30 of heart between flMRT and iIMRT.Because of fewer MUs,fIMRT plan could reduce the machine abrasion and treatment time,but V30 and V30 of left lung are higher significantly than iIMRT plan.
