1. Maria Skłodowska-Curie Institute - Oncology Center, Gliwice Branch, 44-101, Gliwice, Poland
2. Silesian University of Technology, 44-100, Gliwice, Poland
3. Department of Histology and Cell Pathology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Katowice, Poland
4. University of Texas Southwestern Medical Center, Department of Radiation Oncology, Dallas, Texas 75390