A random controlled trial was performed to compare long and short fractionation of radiotherapy in patients with head and neck cancer with a poor prognosis. Ninety-eight matched pairs were treated, one member of each pair received 10 fractions in 22 days, the other 30 fractions in 42 days. The same nominal standard dosages were used in each arm of the trial. Mucosal reactions were more severe with 10 fractions, skin reactions more severe with 30 fractions. No difference in survival, local tumour control rates or late normal tissue effects could be demonstrated. It is suggested that any possible therapeutic advantage of prolonged fractionation is minimal and that it is justified to use a small number of large fractions in clinical trials involving hyperbaric oxygen or electron-affinic sensitizers.

Henk, James, , , , , , , (1978). Comparative trial of large and small fractions in the radiotherapy of head and neck cancer. Clinical radiology, 1978 Nov;29(6):611-6. https://www.ncbi.nlm.nih.gov/pubmed/367679