Dose-response analysis of acute oral mucositis and pharyngeal dysphagia in patients receiving induction chemotherapy followed by concomitant chemo-IMRT for head and neck cancer

Dose-response curves (DRCs) and the quantitative parameters describing these curves were generated for grade 3 oral mucositis and dysphagia in 144 patients using individual patient DVHs. Curve fits to the oral mucositis clinical data yielded parameter values of mean dose in 2 Gy equivalent, MD50 = 51 Gy (95% CI 40-61), slope of the curve, k = 1(95% CI 0.6-1.5). R2 value for the goodness of fit was 0.80. Fits to the grade 3 dysphagia clinical data yielded parameter values of MD50 = 44.5 Gy (95% CI 36-53), k = 2.6 (95% CI 0.8-4.5). R2 value for the goodness of fit was 0.65. This is the first study to derive DRCs in patients receiving induction chemotherapy followed by chemo-radiation (IC-C-IMRT) for head and neck cancer. The dose-response model described in this study could be useful for comparing acute mucositis rates for different dose-fractionation schedules when using IMRT for head and neck cancer.