1. Department of Haematology; University Medical Centre Groningen; Groningen The Netherlands
2. Department of Epidemiology; Medical Centre Leeuwarden; Leeuwarden The Netherlands
3. Department of Radiotherapy; Isala Clinics; Zwolle The Netherlands
4. Department of Radiotherapy; Medical Spectrum Twente; Enschede The Netherlands
5. Department of Radiotherapy; Radiotherapeutisch instituut Friesland; Leeuwarden The Netherlands
6. Department of Haematology; Nij Smellinghe Hospital; Drachten The Netherlands
7. Department of Haematology; Medical Centre Leeuwarden; Leeuwarden The Netherlands
8. Laboratory for Pathology East Netherlands Hengelo; Hengelo The Netherlands
9. Department of Radiotherapy; University Medical Centre Groningen; Groningen The Netherlands
10. Department of Pathology; University Medical Centre Groningen; Groningen The Netherlands