1 Breast Cancer Center, Maria Sklodowska-Curie National Research Institute of Oncology Gliwice Branch, Poland. Electronic address: marcin.kubeczko@gliwice.nio.gov.pl.
2 Breast Cancer Center, Maria Sklodowska-Curie National Research Institute of Oncology Gliwice Branch, Poland.
3 Department of Radiotherapy, Maria Sklodowska-Curie National Research Institute of Oncology Gliwice Branch, Poland.
4 Department of Biostatistics and Bioinformatics, Maria Sklodowska-Curie National Research Institute of Oncology Gliwice Branch, Poland.
5 Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York City, United States.