1. Department of Surgery, Radboud University Medical Centre, Nijmegen, the Netherlands
2. Department of Research, Netherlands Comprehensive Cancer Organisation, Utrecht, the Netherlands
3. Department of Health Technology and Services Research, Technical Medical Centre, University of Twente, Enschede, the Netherlands
4. Department of Radiation Oncology, Radboud University Medical Centre, Nijmegen, the Netherlands
5. Department of Radiation Oncology, Institut Curie, Paris, France
6. Department of Pathology, Radboud University Medical Centre, Nijmegen, the Netherlands