1. Department of Clinical Oncology
2. Department of Orthopaedic Surgery
3. Department of Radiology
4. Department of Medical Statistics, Leiden University Medical Centre, Albinusdreef 2, 2300 RC, Leiden, The Netherlands.
5. Department of Radiotherapy, St Radboud University Medical Center, PB 9101 6500 HB, Nijmegen, The Netherlands.