Dosimetric impacts of multichannel applicator in three-dimensional brachytherapy for advanced cervical carcinoma / 中华放射肿瘤学杂志

ABSTRACT

Objective To investigate the relationship between the channel design of tandem-andovoid (T&O) applicator and the doses to organs at risk (OARs) and target volume in three-dimensional brachytherapy for advanced cervical carcinoma.Methods The data on 15 patients with advanced cervical carcinoma treated with three-dimensional brachytherapy in our hospital from 2015 to 2016 were collected,and 30 randomly selected high-dose-rate titanium T&O plans were retrospectively studied.CT-guided,conformal brachytherapy plans were generated.To simulate T&O applicator,the tandem applicator was virtually compared with the T&O plans with the target volume and OARs remaining unchanged.The DVH parameters of the rectum,bladder,and sigmoid were compared using the paired t test.Results For T&O plans and tandem applicator plans,the mean D2cc of the rectum was 387.8±96.8 cGy and 340.8±88.1 cGy,respectively;the mean D2cc of the bladder was 443.2± 87.5 cGy and 719.4± 243.0 cGy,respectively;the mean D2cc of the sigmoid was 330.3±88.8 cGy and 383.1±105.6 cGy,respectively.In the T&O plans,the doses to the rectum,bladder,and sigmoid were within the limits (rectumD2cc ≤ 500 cGy;bladderD2cc ≤ 550 cGy;sigmoidD2c ≤ 500 cGy),while D2cc of the bladder and sigmoid was higher or partially higher than the limits.T&O plans showed a significant reduction in bladder D2cc and sigmoid D2cc compared with the tandem applicator plans (all P＜0.05).Conclusions Compared with tandem applicator plans,plans using T&O applicator provide significant sparing of bladder and sigmoid tissues in three-dimensional brachytherapy for cervical carcinoma,but the toxicities require further investigation.