1. Department of Radiation Oncology-Research Unit, Las Palmas, Canary Islands, Spain
2. Canary Islands Institute for Cancer Research (ICIC), Las Palmas, Canary Islands, Spain
3. Department of Medical Physics, Las Palmas, Canary Islands, Spain
4. La Paterna Medical Center Las Palmas, Canary Islands, Spain
5. Department of Oral and Maxillofacial Surgery, Las Palmas, Canary Islands, Spain
6. Department of Otolaryngology, Las Palmas, Canary Islands, Spain
7. Department of Neurosurgery and Chronic Pain Unit of the Dr Negrín Hospital, Las Palmas, Canary Islands, Spain