Patients who are undergoing radiation therapy on their head and/or neck, are highly likely to experience oral mucositis, which is inflammation and irritation of the mucus membranes in your mouth. This inflammation leads to difficulty eating and drinking normally as it becomes painful to do so. Currently, the Juravinski Cancer Centre (JCC) uses a standard mouth rinse to try and help prevent inflammation/soothe the pain of inflammation caused by radiation treatments, however, better options may exist. Biosyent's Gelclair is a widely available, safe-to-use mouth rinse that aims to create a protective coating on your mucus membranes to help reduce inflammation and discomfort during your radiation treatment. We aim to see if this product provides a more positive experience for patients then the current mouth rinse utilized by the JCC.

The current magic mouthwash being utilized at the JCC for standard of care for Heck and Neck Radiation patients has been shown to not be anymore effective than other standard sulcate-tantum mouthwashes in preventing discomfort or reducing the requirement of needing a feeding tube for sustenance during radiation treatments. More recently two mucoadhesive topical coating agents have been approved in Canada for this population of patients, Gengigel and Gelclair. These agents adhere to the mucosa and potentially improve efficacy of the therapeutic agent due to rapid absorption and easy application. A recent systematic review of bioadhesives for the treatment of RIOM found statistically significant decrease in severe oral mucositis. We aim to determine if patients tolerate gelclair use, and to determine their use of and satisfaction with gelclair. This will inform the need for a large national RCT on Gelclair use.

Inclusion Criteria:

• 18 years of age or older.
• Histologically proven (from either the primary lesion or regional lymph nodes) squamous cell carcinoma of the oropharynx or oral cavity.
• Plan to receive at least 60 Gy dose of radiotherapy to be delivered daily Monday to Friday for 6 to 7 weeks.

Exclusion Criteria:

• Patient is unable (i.e. insufficiently fluent) or unwilling to complete the weekly questionnaires which are written in English.
• Inability to provide informed consent.
• ECOG performance score 2 or better.
• Plan to receive a concurrent chemotherapy agent other than cisplatin.
• Investigational agent of any kind within 30 days prior to enrollment.
• Concurrent administration of any other experimental intervention given for the purpose of preventing RIOM (see section 7.5).
• History of allergies or hypersensitivity reactions to any of the components in Gelclair.

This is a small scale feasibility trial that will inform if a larger, more impact trial is warranted. To protect patient privacy and confidentiality, IDE will not be shared outside of the study team.