Improving quality of radiotherapy requires constant evaluation of key elements of care. In order to foster the quality and efficacy of radiotherapy, we decided to establish a joint project aimed at interinstitutional comparison of chosen quality indicators in radiotherapy procedures. This project is a continuation of the previous project which was accomplished in 2014 – A two institution study on rectal cancer radiotherapy indicators (Fundowicz et al. Radiology and Oncology 2014; 25;48(2):210-8).