1. Department of Surgery, Regional Academic Cancer Center Utrecht, UMC Utrecht Cancer Center & St. Antonius Hospital Nieuwegein, Nieuwegein, The Netherlands
2. Department of Radiation Oncology, UMC Utrecht Cancer Center, Utrecht University, Utrecht, The Netherlands
3. Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, USA
4. Division of Imaging, UMC Utrecht Cancer Center, Utrecht University, Utrecht, The Netherlands