Dosimetric comparison and clinical application of RapidArc and intensity-modulated radiotherapy for postoperative radiotherapy of cervical cancer / 中华放射医学与防护杂志

ABSTRACT

Objective To compare the planning quality and acute toxicity between RapidArc and fixed gantry angle dynamic intensity modulated radiotherapy (IMRT) in the postoperative radiotherapy for cervical cancer patients.Methods All 35 patients with cervical cancer who had received postoperative radiotherapy were studied,including 17 patients with RapidArc and 18 patients with IMRT.All plans were prescribed 50 Gy in 25 fractions.The dose-volume histogram data,the conformity index and homogeneity index of the targets,the monitor units (MUs) and delivery time were compared.During the treatment,the incidence of acute intestinal and bladder side effects were also compared.Results Compared to IMRT,the conformity index of RapidArc was better(t =3.13,P ＜ 0.05),but the homogeneity index was slightly worse (t =-4.25,P ＜ 0.05).The V20 and V30 of femoral head planned by RapidArc was significantly lower than that by IMRT (t =2.56,2.34,P ＜ 0.05).The mean MU for RapidArc was reduced by 52.1％ compared with IMRT.The mean treatment time for RapidArc was decreased by 46.8％ compared with IMRT.There was no difference in the incidence of acute intestinal and bladder toxicity between the two groups.Conclusion For patients with cervical cancer who need prophylactic postoperative radiotherapy,both RapidArc and IMRT plan can achieve equal target coverage and organs at risk(OAR) sparing.There is no significant difference in dosimetric parameters and acute toxicity between the two groups.Compared with IMRT,RapidArc plan has fewer MUs and less treatment time and significantly improves the treatment efficiency.