ABSTARACTConclusion. Grade≧3 mucositis/stomatitis and inability to feed orally were problematic for patients undergoing cetuximab-based bioradiotherapy (BRT) as well as platinum-based chemoradiotherapy (CRT). Severe mucositis/stomatitis and radiation dermatitis should be addressed carefully in patients undergoing cetuximab-based BRT as well.Objectives. The efficacy of cetuximab-based BRT in locally advanced head and neck squamous cell carcinomas has been established. However, the safety of cetuximab-based BRT in comparison with platinum-based CRT is currently under investigation.Method. We retrospectively analyzed 14 patients undergoing cetuximab-based BRT and 29 patients undergoing platinum-based CRT to compare the incidence of acute toxicities.In BRT group, an initial cetuximab loading dose of 400 mg/m 2 was delivered one week before the start of radiotherapy. Seven weekly infusions of 250 mg/m 2 of cetuximab followed during the definitive radiotherapy. In CRT group, cisplatin was administered at a dose of 40mg/m 2 weekly during the definitive radiotherapy.Results. The BRT group had a higher incidence of Grade≧3 radiation dermatitis than did the CRT group (36% vs 3%, respectively, p<0.01). The incidence rate of Grade≧3 mucositis/stomatitis was 64.3 % and 41.4% in the BRT and CRT group, respectively (p=0.1484), while the incidence rate of the inability to feed orally was 38.5% and 55.2%, respectively (p=0.2053).