1. Rigshospitalet; Copenhagen; Denmark
2. The Norwegian Radium Hospital; Oslo; Norway
3. Uppsala University Hospital; Uppsala; Sweden
4. Skane University Hospital; Lund; Sweden
5. Helsinki University Central Hospital; Helsinki; Finland
6. Karolinska Institute; Stockholm; Sweden
7. Aarhus University Hospital; Aarhus; Denmark
8. Oulu University Hospital; Oulu; Finland
9. Sahlgrenska Hospital; Gothenburg; Sweden