1. Department of Otolaryngology, Head Neck Surgery, Section of Surgical Oncology, Reconstructive and Skull Base Surgery, University Hospital VU, De Boelelaan 1117, Postbus 7057, 1007 MB Amsterdam, The Netherlands
2. Department of Radiotherapy, University Hospital VU, Amsterdam, The Netherlands
3. Department of Epidemiology and Biostatistics, Faculty of Medicine, Vrije Universiteit, Amsterdam, The Netherlands
4. Department of Maxillo Facial Surgery, University Hospital VU, Amsterdam, The Netherlands