1. Musculoskeletal Tumour Center, Department of Orthopedics/Oncology, Haukeland University Hospital, 5021 Bergen, Norway
2. Department of Orthopedics, Oslo University Hospital, Radiumhospitalet, 0310 Oslo, Norway
3. Division of Orthopedics, Department of Molecular Medicine and Surgery, Karolinska Institute, Karolinska University Hospital, 17176 Stockholm, Sweden
4. Department of Orthopedics, Institute of Clinical Sciences, Skane University Hospital, Lund University, 22185 Lund, Sweden