Early Clinical Outcomes And Safety Of Simultaneous Modulated Accelerated Radiotherapy Combined With Intracavitary Brachytherapy For Cervical Cancer Radical Radiotherapy

Objecive:To evaluate the early clinical outcomes and safety of external beam radiotherapy simultaneous integrated boost to cervical primary tumor combined with intracavitary brachytherapy for cervical cancer radical radiotherapy.Methods:During 2016.9~2018.1,78 patients with cervical cancer who underwent radical radiotherapy in the department of oncology of the Affiliated Hospital of North Sichuan Medical College were selected as the research objects.According to the way of combination of external beam radiotherapy(EBRT)and intracavitary brachytherapy,they were divided into observation group(58 cases)and control group(20 cases).Both groups,external beam radiotherapy delivererd to PTV 45Gy/25 Fx,1.8Gy/Fx,involved lateral parametrium and involved lymph node were simultaneous integrated boost to 55Gy,2.2Gy/Fx.In the observation group,the primary tumor of the cervix were simultaneous integrated boost to 55Gy,2.2Gy/Fx.The intracavitary brachytherapy were perfomed after 20 fractions of EBRT.The observation group was given 6Gy/Fx x 4 Fx,the control group received 6Gy/Fx x 5 Fx.The bladder and rectal dose parameters from the external beam radiotherapy plan were compared in two groups.and the withdrawal of the primary tumor before brachytherapy was performed,as well as early clinical outcomes and acute toxicity were compared in two groups.The analysis of counting data was conducted by chi-square test,and two independent samples were compared with t test,and P<0.05 was considered as statistically significant difference.Result:1.The Dmean,V40 and V45 of the rectum and bladder in the observation group were significantly increased compared with the control group(P<0.05).2.Volume of GTV in the observation group was decreased from(98.02±28.35)cm~3 to(49.32±18.52)cm~3 after 20 fractions of EBRT with a withdrawal rate of 50.58±6.32%,the control group decreased from(82.03±21.42)cm~3 to(42.93±14.53)cm~3 with a withdrawal rate of48.53±4.81%.The GTV withdrawal rate between the two groups was not statistically significant.3.In the observation group,38(65.5%)patients were evaluated as CR,20(34.5%)patients were evaluated as PR,in the control group 14(70%)patients were evaluated as CR,and 6(30%)patients were evaluated as PR.The CR rate and the PR rate between the observation group and the control group were no statistical difference(P>0.05).4.In the observation group,there were 18(31%)patients with level I acute blood toxicity,12(20.7%)patients with level II acute blood toxicity,and 5(8.6%)with level III acute blood toxicity.In the control group,there were 3(15%)patients with level I acute blood toxicity,2(10%)patients with level II acute blood toxicity.The incidence of acute blood toxicity was higher in the observation group than the control group,and there was a statistically significant difference in the incidence of acute blood toxicity in the two groups(P<0.05).In the observation group,there were 17 patients(29.3%)appeared level I acute rectal toxicity,12(20.7%)patients with level II acute rectal toxicity,4 patients(6.9%)developed level III acute rectal toxicity.In the control group,there were 2(10%)patients with level I acute rectal toxicity,2(10%)patients with level II acute rectal toxicity.The incidence of acute rectal toxicity was higher in the observation group than in the control group,there was a statistically significant difference in the incidence of acute rectal toxicity between the two groups(P<0.05).In the observation group,there were 7 patients(12.1%)appeared level I acute bladder toxicity,1(1.7%)patient with level II acute bladder toxicity,In the control group,there were 1(5%)patient with level I acute bladder toxicity,1(5%)patient with level II bladder toxicity.There was no statistical difference in the incidence of acute bladder toxicity in the two groups.Conclusions:Simultaneous modulated accelerated radiotherapy was not able to improve the early clinical efficacy,but it increased the occurrence of the acute toxicity of radiotherapy,and its long-term efficacy and complications need to be further observed.