1. Christchurch Hospital; Canterbury Regional Cancer and Haematology Service; Private Bag 4710 Christchurch New Zealand 8140
2. Princess Alexandra Hospital; Radiation Oncology Mater Service; 31 Raymond Terrace Brisbane Queensland Australia 4101
3. The University of Queensland; School of Medicine; Brisbane Australia
4. University of Otago, Christchurch; Department of Population Health; PO Box 4345 Christchurch New Zealand 8140