Dosimetric comparison of volumetric modulated arc therapy for pancreatic cancer of the body and tail using flattening filter-free and flattening filter modes
10.3969/j.issn.1005-202X.2025.05.002
- VernacularTitle:均整与非均整模式下胰体尾癌容积旋转调强放疗的剂量学比较
- Author:
Jie DUAN
1
;
Li'na ZHAO
1
Author Information
1. 空军军医大学第一附属医院放射治疗科,陕西 西安 710032
- Publication Type:Journal Article
- Keywords:
pancreatic cancer;
flattening filter mode;
flattening filter-free mode;
dosimetric characteristics;
monitor unit
- From:
Chinese Journal of Medical Physics
2025;42(5):566-570
- CountryChina
- Language:Chinese
-
Abstract:
Objective To conduct a dosimetric comparison of volumetric modulated arc therapy(VMAT)plans with flattening filter(FF)and flattening filter-free(FFF)for pancreatic cancer of the body and tail,and to explore the clinical feasibility of FFF mode.Methods Fifteen patients with pancreatic cancer of the body and tail who received radiotherapy were selected.VMAT plans were designed using the Monaco 5.11.03 system for both 6 MV FF X-ray and 6 MV FFF X-ray.The dosimetric characteristics,machine unit and treatment time of the two plans were compared,with the prescription dose covering 95%of the target volume as the optimization goal.The prescription dose for planning target area was 60 Gy/20 F.Results Both 6FF and 6FFF plans met clinical requirements.The differences in the D2%,D98%,Dmean of planning target area,conformity index(CI),and homogeneity index(HI)between the two modes were trivial(P>0.05).For organs-at-risk,6FFF mode significantly reduced the dose to the duodenum,kidneys,liver,and spinal cord,showing statistical significance(P<0.05).The average monitor unit in FFF mode was higher than in FF mode,but treatment time was obviously reduced in FFF mode(P<0.05).Conclusion VMAT plan with either FF or FFF mode meet clinical treatment requirements.Notably,FFF mode offers significant advantages in protecting organs-at-risk,reducing treatment time,and improving treatment efficiency.
