The purpose of this study is to explore the protective effect and safety of soluble beta-1,3/1,6-glucan compared to placebo in oral mucositis in head and neck patients receiving radiotherapy or chemoradiotherapy. Hypothesis: Soluble beta-1,3/1,6-glucan will through its immunomodulating activities prevent oral mucositis

Oral mucositis is defined as inflammation and ulceration of the mucous membranes of the mouth. The condition is very painful and might put the patient at risk of serious systemic infections and is a common dose-limiting toxicity of chemotherapy and radiotherapy. The present treatment of mucositis is primarily supportive; strong analgesics in addition to oral hygiene. Prophylactic antibiotics have been used and many topical agents are available to palliate mucositis, but no standard therapy has been accepted. Comparison: Methyl cellulose has been chosen as placebo due to its close resemblance to soluble beta-1,3/1,6-glucan in terms of general appearance and viscosity. Methyl cellulose is a viscous solution which might form a mucosal barrier. Physical barriers are considered having a protective function in oral mucositis, and methyl cellulose might be considered as an active control.