A Comparative Dosimetric Study of Volumetric-Modulated Arc Therapy Versus Conventional Intensity-Modulated Radiotherapy in Postoperative Irradiation of Rectal Cancer
LIU Huan
ZHANG Hongyan
ZHU Baojie
HAO Yongxin
Abstract：Objective To assess the dosimetric characteristics of traditional intensity-modulated radiotherapy(IMRT)and volumetric-modulated arc therapy(VMAT)for rectal cancer postoperative irradiation.Methods Seventy-eight patients who underwent VMAT or IMRT after rectal cancer surgery in Hebei China petroleum central hospital from March 2022 to April 2023 were selected and divided into the VMAT and IMRT groups,with 38 cases each.The study compare the target dose,organ involvement dose,planned treatment time,machine hop count,and incidence of adverse reactions between two groups.Results The dose distribution in the planning target volume of both groups met clinic dosimetry requirements.The minimum dose(Dmin)of VMAT group was higher than that of IMRT group(P＜0.05),and conformity index(CI)of VMAT group was lower than that of IMRT group(P＜0.05),while no statistical difference was found in maximum dose(Dmax),mean dose(Dmean),volume of the target receiving 95％of the prescribed dose(V95％)and homogeneity index(HI)between two groups(all P＞0.05).The percent volume of bladder receiving 30 Gy(V30)and Dmean of VMAT group were lower than those of IMRT group,and the V30 and Dmean of right and left femur were higher than those of IMRT group(P＜0.05).The V50 of bladder and left and right femur yielded no statistical difference between two groups(all P＞0.05).VMAT group had more total machine hop count and total subfield number than IMRT group(P＜0.05),and the treatment time of VMAT group was shorter than that of IMRT group(P＜0.05).The incidence rate of grade 3 adverse reactions such as leukopenia,nausea and vomiting,diarrhea,abdominal pain,radiation cystitis and radiation dermatitis demonstrated no statistical difference between two groups(P＞0.05).Conclusion The dose distributions of postoperative radiotherapy for rectal cancer using both photon VMAT and IMRT plans can meet clinical requirements,in which the conformity index of VMAT are slightly lower than that of IMRT,but VMAT can improve the treatment efficiency and shorten the treatment time.Clinicians can choose the appropriate radiotherapy method based on the needs of different patients.
Keywords：Rectal cancerVolumetric-modulated arc therapyDosimetryComparative study
Publication Date：2024-11-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 1574-1578 )