An analysis of dose-volume-time relationship for acute radiation proctitis in cervical cancer patients / 中华放射医学与防护杂志

ABSTRACT

Objective To investigate the relationship between acute radiation proctitis and radiation dose,volume as well as radiation time,in the process of intensity-modulated radiation therapy (IMRT) for the cervical cancer patients.Methods A total of 51 patients with locally advanced cervical cancer were enrolled from January 2011 to December 2013.Those patients were then classified into grade 1 to 4 groups,according to the RTOG/EORTCtoxicity grading standard.The exposure dose volume and the average dose of rectum under the standard plan were evaluated with dose-volume histogram (DVH).The ANOVA test was used for analyzing Dmax,D mean,D1 cm3,D2cm3,D40 and V40 values of rectum and the average exposure dose of rectum.Results The average time of acute radiation proctitis with clinical symptoms was (23.06 ± 12.01) d after radiotherapy.Dmaxvalues of rectum in grade 2 group was lower than those in grade 3 and 4 groups (F =5.268,P ＜ 0.05).Moreover,D1 cm3 and D2 cm3 values of rectum in grade 1 and 2 groups were also lower than those in grade 3 and 4 groups (F =4.893,4.406,P ＜ 0.05).There was no statistically significant difference between D40 and V40 values.Conclusions The acute radiation proctitis could be frequently found around 20 days during the IMRT for cervical cancer patients.Mild and moderate acute radiation proctitis are more common,while severe acute radiation proctitis is rare.Minimizing Dmax,D1 cm3 and D2 cm3 values of rectum might reduce the incidence of severe acute radiation proctitis in cervical cancer patients receiving IMRT.