1. Radiation Physics Department, Oncology and Hematology Hospital, Maadi Armed Forces Medical Compound, Cairo, Egypt
2. Radiotherapy Physics Department, Oncology Centre, International Medical Centre, 42 Km Cairo, Ismailia Road, Cairo, Egypt
3. Radiotherapy Physics Department, The Beatson West of Scotland Cancer Centre, Scotland, UK
4. Physics Department, Faculty of Science, Ain Shams University, Cairo, Egypt