Bibliografisk note

Funding Information:
This work was supported by a grant from the Danish Childhood Cancer Foundation (grant no 2015-9) and the Danish Cancer Society (grant no R248-A14714). This work was also supported by Kræftens Bekæmpelse. We would like acknowledge colleagues Thomas Carlslund, Bob Smulders, Nora Forbes, and Deborah Anne Schut at the Department of Clinical Oncology, Section of Radiotherapy, Copenhagen University Hospital, for their help to extract the data. Also, an acknowledgement to Heidi Rønde and Camilla Kronborg from the Danish Centre for Particle therapy, for helping with dose summation.