Effect Of Normal Tissue Dose Induced In Bladder Filling Condition By Brachytherapy Of Uterine Cervix Carcinoma

Objective:To analyze the bladder during filling and emptying state of cervical cancer brachytherapy treatment planning dose to normal tissue distribution and influence, in order to reduce cervical cancer brachytherapy after complications on.Method:Thoose25cases of complete pelvic external irradiation for stage FIGOⅡ a～Ⅲb stage cervical cancer patients, application of Holland nuclear Fletcher system gives three tube brachytherapy, the other selected25cases in stage FIGOⅡ a～Ⅱb stage cervical cancer patients after radical mastectomy, given two tube implantation brachytherapy. Using radiation simulation, image data into PLATO planning system by CT simulation, into the bladder are injected into the7·5%Meglucamine prolyl amine50ml and100ml, CT scan. In bladder emptying state and a two state filling CT image drawing target outline; normal tissue sketches including bladder, rectum, sigmoid colon, small intestine. In order to bladder emptying state CT image as the reference image, in order to bladder filling50ml and100ml state image make two treatment planning, plan prescription dose was500cGy/, according to DVH imaging in evaluation of tumor target volume and organ at risk levels. In order to evaluate the normal tissue dose distribution better cervical cancer brachytherapy treatment planning.Results:1.Three tube implantation brachytherapy bladder during filling condition:bladder dose was D2:365±40(cGy) was significantly greater than the filling302±24(cGy), the difference was statistically significant p<0.05); small dose was D2:291±16(cGy) is significantly less than the full top391±23(cGy), the difference was statistically significant (p<0.05); rectum in filling50ML D1:324±12(cGy) is significantly less than the full100ML341±66(cGy), the difference was statistically significant (p<0.05); sigmoid colon in filling50ML DO.1:307±10(cGy) is significantly less than the full100ML357±96(cGy), the difference was statistically significant (p<0.05).2.two tube implantation brachytherapy bladder during filling condition:bladder dose was D2:365±51(cGy) was significantly greater than the filling312±43(cGy), the difference was statistically significant (p<0.05); small dose was D2:306±63(cGy) is significantly less than391±43(cGy filling), the difference was statistically significant (p<0.05).conclusions:1.Patients with cervical cancer3D brachytherapy, bladder filling on the surrounding normal tissue dose effect exists, bladder filling volume50ML a100ML can better reduce the rectum and sigmoid colon by volume, bladder, intestine on the influence of dose not.2.Small intestine tumor near distance can be taken in patients with bladder filling method for reducing the amount of the small intestine by, increased bladder dose, small distance from the tumor distant patients take bladder emptying method for reducing bladder dose, as far as possible to reduce radiation complications.