Analysis of the statistical significance of the difference in patient setup error caused by the current staff and new staff in the radiotherapy

Abstract We verified the setup error (SE) in two persons' radiation therapist's team, which consist of staff and new face. We performed the significance test for SE by the staff group and the new face group. One group consists of four staff therapists with at least 5 to 30 years of experience. The other group consists of new face radiation therapists that have 1 to 1.5 years of experience. Analyzed were 53 patients diagnosed with pelvic cancer (seven patients who underwent 3 dimensional conformal radiation therapy (3DCRT) and 46 patients who underwent intensity modulated radiation therapy (IMRT). Image verification was 1460 times. It was performed through setup verification by cone beam computed tomography (CBCT), and we measured SE of four directions (lateral, long, vertical, 3D). We performed the student's t-test to get the difference of the average error between the staff group and the new face group. The results of significance tests show that there is no difference between SE in the staff group and the new face group in radiotherapy.