Evaluating the setup uncertainties by different registration method in 3DCRT ca breast patients using onboard cone beam ct

Aim: The aim of this study is to find out the difference in setup errors when registering cone beam conventional tomography on couch with planning CT simulator images with 2 different registration method in ca breast patient treating with 3DCRT technique Objective: following study is to compare the patient setup uncertainties using two different registration method, one with standard clip box registration method and other with mask registration method. Methodology: Ten patient with ca breast are taken for the study. All patients are undergone standard 3dcrt planning and pushed to xvi for further analysis. CBCT scans were taken and two types of registration were done each under by mask based and clip box based method. Shifts on all 3 axes such x,y,z is noted with rotational shift. Comparison were done on systematic error (Σ), random error (σ), mean displacement vector (R), mean setup error (M). Result: Out of all this registration method mask based grey registration (T+R) shows some superior quality for soft tissue verification. But again One can use any of the registration method for patient setup verification depending on their institution protocol and site to be treated.