The analysis of exposure dose for bladder, rectum and small intestine with brachytherapy for cervical cancer / 中华放射医学与防护杂志

ABSTRACT

Objective To analyze the relationship between different rectal volume,bladder volume and dose of organs at risk (OARs) in intracavitary brachytherapy for cervical cancer.Methods A total of 47 patients with cervical cancer were selected.All of them were treated with high dose rate (HDR) intracavitary brachytherapy with a 600 cGy dose for the dosage point.The effects of different volume of rectum bladder and small intestine for corresponding exposure dose under the standard planning were evaluated using a dose-volume histogram (DVH).According to bladder volume,patients were divided into three groups,＜ 80 cm3 group,80-120 cm3 group and ＞ 120 cm3 group.And according to rectum volume,patients were divided into ＞ 60 cm3 group and ≤ 60 cm3 group.The relationship between the volume and dosage were analyzed.The ANOVA test and t test were used for analyzing D1 cm3,D2 cm3,D30％ and D50％.Results Compared with the group with ＜ 80 cm3 bladder volume,D30％,D50％ value of bladder in groups with 80-120 cm3 and ＞ 120 cm3 of bladder volume increased (F =5.074,5.088,P ＜ 0.05).The difference of D1 cm3 and D2 cm3 value of the small intestine between 80-120 cm3 and ＞ 120 cm3 bladder volume groups were not statistically significant (P ＞ 0.05).D1 cm3 of rectum in groups with ≤ 60 cm3 rectum volume was decreased than that of ＞ 60 cm3 group (t =-2.045,P ＜ 0.05).Conclusions Keeping an appropriatly full bladder and reducing rectal volume in cervical cancers treated with intracavitary brachytherapy can make the exposure dose of bladder,rectum and small intestine relatively small,and reduce the adverse reactions of radiotherapy.