1. Department of Otolaryngology, Head and Neck SurgeryOslo University Hospital, Rikshospitalet Oslo Norway
2. Institute of Clinical MedicineUniversity of Oslo Oslo Norway
3. Department of Health Science and BiostatisticsOslo Metropolitan University Norway
4. Department of OncologyAkershus University Hospital Norway
5. Norway National Resource Center for Late Effects after Cancer TreatmentOslo University Hospital, Radiumhospitalet Oslo Norway