Evaluation of Two Methods of Administration of Photobiomodulation in the Context of the Prevention and Treatment of Mucositis Induced by Radiotherapy, During the Treatment of Head and Neck Cancers

Inclusion Criteria: * Adult patient (18 years old and older); * Patients with oral cavity or oropharynx cancer treated with radiotherapy or chemo-radiotherapy; * Karnofsky Performance Status \> 60%; * Able to understand French; * With signed informed consent; * Affiliated to French Health Security Insurance Exclusion Criteria: * Allergy to polyurethanes; * Head and Neck tumors that are localized to other sites than oral cavity or oropharynx * Previous irradiation of Head and Neck (whatever the time lapse between the two irradiations) * Pregnant and breastfeeding woman; * Patients with pacemaker device * Epileptic patients; * Concomitant treatment or treatment within the 7 days before inclusion with one of several drugs from the following list: fluoroquinolones, cycline, methotrexate, auranofin * Patients with ophthalmic diseases (such as maculopathy, retinopathy, glaucoma and cataract, retinal damage) * Patients under judicial protection