Concordance of the WHO, RTOG, and CTCAE v4.0 grading scales for the evaluation of oral mucositis associated with chemoradiation therapy for the treatment of oral and oropharyngeal cancers.

Discordance was seen with patients who exhibited mild to moderate OM or most severe OM (grade 4) as described by WHO criteria. Whereas scale selection seems less critical in studies in which general "severe mucositis" is the primary outcome, it is particularly important in accurately describing OM's clinical trajectory and the frequency and impact in its most severe forms.