Impact Of Image-Guided High-Dose Rate Brachytherapy On Local Control In Locally Advanced Cervical Cancer

Objective:To investigate the impact of image-guided high-dose-rate brachytherapy on local control in LACCand the factors of radiosensitivity in cervical cancer patiengs treated with vivo and vitro radiotherapy.Methods:A restropective analysis of 132 patiengts treated with radical radiotheray by a combination of external beam radiotheray(IMRT) and image-guided high-dose-rate brachytherapy from March 2013 to March 2015 in Guangxi Medical Univesity Tumour Hospital.All cases were diagnosed by histophathology and stage Ⅱb to stage Ⅲb were included;all patients received concomitant chemotherapy.It started within 1 week after the start of EBRT, consisting of weekly injections of cisplatin 40mg/m2 or carboplatin 40mg/ m2.Dose of 45-50Gy was used in external irradiation and a total dose of 24-30Gy in brachytherapy. HDR-ICBT started after the initial 40Gy of EBRT or one week before EBRT would finish, two fractions per week.The primary endpoint of this study was the outcome and the prognostic factors.All the data was Proeessed through the software SPSS 17.Results:90% of stage II a patients received 87Gy to HR-CTV,79% of stage Ⅲa patients received 90Gy to HR-CTV,92.8% of stage Ⅲb patients received 92Gy to HR-CTV.The rate of complete regression is 83.3%.16.7% encoutered local failure.The prevalence of grade 1-3 rectal acute toxicity and late complication was 25.8%%、1.5%、0% and 6.8%、0% 、0%.The same to bladder acute toxicity and late complication was 24.2%、0%、0%、and 6.1%、1.5%、0% respectively.Among the selected parameters, the tumor size,the pathologic types,the overall treatment timet,the total A point dose,the average hemoglobin and the differation appeared significantly correlated with local control in univariate analysis.Conclusion:IMRT combined with brachytherapy have favorable outcomes for cervical cancer, which may escalate dose with cervical tumor and lymph nodes metastasis, not increasing normal-tissue dose. It can diminish irradiation damage of the rectum and bladder.The FIGO stage,tumor size, pathologic types, overall treatment time, radiotherapy dose(point A dose), average hemoglobin and differation are the factors associated with the prognosis of the patients with cervical cancer treated with only radiotherapy.