1 Department of Biostatistics and Translational Medicine, Medical University of Lodz, Poland.
2 Oncology Center of Radom, Department of Radiation Oncology, Radom, Poland.
3 Holycross Cancer Centre, Radiotherapy Department, Kielce, Poland.
4 Department of Biostatistics and Translational Medicine, Medical University of Lodz, Poland; Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, United States.
5 Department of Biostatistics and Translational Medicine, Medical University of Lodz, Poland; Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, United States. Electronic address: bartlomiej_tomasik@dfci.harvard.edu.