Research On Different Registrations Of KV-CBCT Images Guide Radiotherapy Technology For The Setup Error Of Thoracic Cancer

To investigate and analyze the effect of setup errors on the radiotherapy of thoracic cancer,three groups of 38 patients,38 cases of lung cancer,38 cases of breast cancer,and 38 cases of esophagus cancer,were used in this study with three different registration regions of interesting(ROIs)and two registration algorithms based on kilo-voltage Cone Beam CT(kV-CBCT)images.Cases were selected from September2017 to July 2020 in Yichun People’s Hospital for this study and were treated by the intensity modulation technique combined with grayscale image kV-CBCT guided radiaotherapy.With the kV-CBCT image registration software,three different and asymptotical registration areas,ROIa,ROIb and ROIc,were used to get and analyze the group A,B and C setup errors for the Lat,Lng and Vert directions.There is no significant difference between each two groups of data(P>0.05);If the standard of≥2 mm was used as the setup error happened,the rate of setup error of B group is lower than A and C groups,and significant differences were found at Lat,Lng and Vert directions(P < 0.05).With the same registration ROI,two kinds of algorithms were used for the thoracic cancer patients: group auto grayscale registration and group auto bone registration.There is no significant difference between the two groups(P>0.05);If the standard of ≥2 mm was used as the setup error happened,the rate of setup error of group auto grayscale is lower than group auto bone,and significant differences were found in Lat,Lng and Vert directions(P< 0.05).The results of our study show that the right registration is instructive and useful for the setup work in kV-CBCT guided thoracic cancer radiotherapy,and it’s necessary to adjust the registration ROI and algorithm for the radiotherapy on different kinds of cancers.