Factors influencing the severity of radiation skin and oral mucosal reactions: development of a conceptual framework

Radiation skin and oral mucosa reactions are common side-effects of head and neck radiation therapy caused by damage to normal tissue. This damage can be dose-limiting, meaning that the severity of acute reactions particularly in the oral mucosa may require time off treatment, potentially interfering with the effectiveness of radiation therapy in terms of tumour eradication. The purpose of this paper was to identify potential individual patient factors that may contribute to increasing severity of radiation skin and mucosal reactions. Sufficient literature and clinical observation is available to suggest that the variability in the degree of radiation reaction experienced by the patient is not due solely to the radiation received but that particular individual characteristics contribute to the expression of radiation damage in normal tissue. The identified factors fall into three broad categories: radiation therapy, genetic and personal factors. The research conducted on the predictive value of these factors is discussed. The inclusion of influencing factors in the assessment of people at risk for radiation skin and oral mucosa reactions has particular relevance for individualizing the prevention and management of radiation reactions.