Clinical Value Of Selective High Dose In The Target Area In Radiotherapy For Large Tumor

Objective:1.To analyze the clinical effect of selective high-dose radiotherapy in radiotherapy for large tumor,providing clinical reference for the radiotherapy of large tumor;2.To analyze the survival and local control rate of selective high-dose radiotherapy in the treatment of large tumor,and to explore the factors of survival;3.To evaluate the short-term efficacy of target area selective high-dose radiotherapy in the treatment of large tumor,and to analyze the factors of efficacy.Methods:Select 50 patients with malignant tumors who were performed high dose radiotherapy in target area in×××hospital from September 2018 to October 2020.The maximum diameter of the tumor was from 50 mm to 206 mm.The KPS score was from70 to 90,and the expected survival time was more than 3 months.In order to evaluate efficacy,the patients were able to accept imaging and related examinations.The patients were treated with high-dose(from 50Gy-75Gy)radiation in the target area,which was named target in target radiotherapy by using the IMRT radiotherapy technology and the Varian Medical electron linear accelerator Clinac IX/-23EX.All patients were followed,so that the paper can collect survival datas of patients after radiotherapy.The paper analyses the overall survival time,median survival time,half year survival rate,one year survival rate,two years survival rate by Kaplan Meier method,and calculates the half year and one-year local control rate.The paper compares the mean and median survival time and rates of different clinical characteristics,including gender,age,KPS score,radiation dose,maximum tumor diameter,distant and combination therapy.The short-term curative effect of patients was analyzed by the evaluation standard of solid tumor curative effect.Univariate analysis was performed by long-rank method,andX~2test was used for comparison between groups.The factors influencing the short-term curative effect of patients were screened out and then multivariate analysis was performed by Cox regression model.Results:All patients were followed up until January 2021,and the follow-up time was 3-27months.The median follow-up time was 10 months,and the follow-up rate was 100%..Short term efficacy:Complete remission is 5 cases(10%),partial remission is 21cases(42%),stable disease is 23 cases(46%),progressive disease is 1 case(2%),the total effective rate was 52%,and the total control rate was 98%.Survival and local control:By the end of follow-up,14 patients died,including 5patients died of tumor recurrence,7 patients died of distant metastasis,and 2 patients died of other reasons.The half year survival rate was 74%,the one-year survival rate was 40%,and the two-year survival rate was 12%.The sufferers’survial time were between three and twenty seven months,and the median was ten months.The local control rate was 85.3%in half a year and 83.3%in one year,and the recurrence rate was16%.The survival time of group which the maximum diameter of the tumor was less than or equal to 70 mm,Irradiation dose more than 60Gy,no distant metastasis,and combined treatment was longer than that of the other group(P<0.05),but there was no significant difference in gender,age,KPS score and radiation dose(P>0.05).Analysis of curative effect factors:Radiation dose,maximum diameter of tumor,distant metastasis and combined treatment had statistical significance on curative effect(P<0.05),and the short-term curative effect of tumor was better when the radiation dose was larger(>60Gy);the smaller the maximum diameter of tumor(≤70mm),no distant metastasis,and combined therapy.Conclusions:1.In the radiotherapy of large tumor,the radiotherapy of selective local high-dose in the target area is based on the original GTV in the target area,and GTVn is sketched according to the tumor size and dosimetry requirements.The target dose was increased from PTV layer to GTVn layer,so that the dose in the target area increases layer by layer,to endure highest dose of GTVn,forming a new radiotherapy mode,and then enhancing the radiotherapy efficiency,increasing local control of carcinoma,decreasing the recurrence rate,with better short-term curative effect.It is an effective treatment for patients with large tumor.2.The survival time of patients with the maximum diameter of tumor less than or equal to70mm before radiotherapy,radiation dose more than 60Gy,without distant metastasis and combined therapy were longer than that of the other group.3.The patients with large tumor treated by target to target radiotherapy,the group of no distant metastasis,tumor maximum diameter less than or equal to 70mm,combined therapy and radiation dose more than 60Gy may have better curative effect.