Quantification of oral mucositis due to radiotherapy by determining viability and maturation of epithelial cells

Background: An in-vitro assay has been developed for quantitative assessment of chemotherapy induced oral mucositis. In the present study this method was evaluated for assessment of irradiation mucositis at a cellular level.Methods: Ten patients participated in this consecutive study. All patients were treated with conventional fractionated curative postoperative radiotherapy. Prior to, and weekly during, the irradiation course, oral washings were obtained to determine viability of epithelial cells by trypan blue dye exclusion. Maturation of epithelial cells was assessed from smears (Papanicolaou staining). The viability data were compared with the WHO-score for mucositis.Results: Epithelial cell viability increased during the first three weeks of radiation (P = 0.04), and was seen earlier than the subjective mucosal changes with the WHO-score. Cell maturity shifted from immature and intermediate to mature (P = 0.03).Conclusions: The cell viability assay can be considered an objective method for following the development of irradiation mucositis, and seems to be more sensitive during the first three weeks of irradiation than the WHO-scoring method.