1. The Canberra Hospital, Department of Radiation Oncology, Garran, Australian Capital Territory, Australia
2. University of Notre Dame Australia, School of Medicine, Darlinghurst, New South Wales, Australia
3. University of Adelaide, School of Medical Sciences, Adelaide, South Australia, Australia
4. The Canberra Hospital, Department of Surgery, Garran, Australian Capital Territory, Australia
5. Australian National University, College of Medicine, Biology and Environment, Canberra, Australian Capital Territory, Australia
6. The Canberra Hospital, Department of Medical Oncology, Garran, Australian Capital Territory, Australia
7. Hampton University Proton Therapy Institute, Hampton, Virginia, USA
8. University of Virginia School of Medicine, Department of Radiation Oncology, Charlottesville, Virginia, USA