Radiation therapy (RT) is used in at least 50% of cancer patients and is critical in treating and palliating tumor-related symptoms. Normal tissue radiation toxicity remains an overwhelming obstacle in treating cancer patients with localized tumors.

Mucositis is the inflammation and ulceration of the oral and gastrointestinal mucosa observed with different cancer therapies. Oral mucositis is a common, severe, and debilitating complication of RT occurring several days to weeks after RT initiation.

This study is a single blind randomized controlled clinical trial with a parallel-group design conducted in the clinical oncology department of Beni-Suef University Hospital.

A total of 50 patients with head and neck cancer receiving RT were randomly assigned into either study group:

Group 1 (Intervention group):

This group included twenty-five patients given Mebo ointment in combination with the symptomatic therapy 3 times daily for 7 weeks

Group 2 (Control group):

This group included twenty-five patients given symptomatic therapy 3 times daily for 7 weeks.

These therapies included anti-fungal agents (Miconaz oral gel), topical anesthetics and anti-inflammatory drugs (BBC oral spray), topical analgesic gel (Oracure gel), sodium bicarbonate mouthwash (Alkamisr sachets)

1. Oral mucositis severity was measured by the World Health Organization Toxicity Scale (WHO grading system). Based on the symptomatic (oral pain), and functional clinical features of every patient (ability to drink and eat) as well as the presence of lesions (ulcers, erythema), the measurements were categorized to Grade I: presence of soreness and erythema, Grade II: presence of painful erythema and ulcerations that do not affect the patient solid food intake, Grade Ш: confluent ulceration that affect the solid food intake and require liquid diet, and Grade ΙV: the patient requires parenteral nutrition.
2. Discomfort and pain severity were recorded using the Numeric Rating Scale (NRS), which is categorized to no pain (NRS 0), mild pain (NRS 1-3), moderate pain (NRS 4-7), and unbearable pain (NRS 8-10). Patients were asked to assign a numerical score on the scale verbally to rate their pain intensity, and the number was recorded
3. Dry mouth, Dysphagia was measured by Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0 Grade 1 Mild; asymptomatic or mild symptoms; clinical or diagnostic observations only; intervention not indicated.

Grade 2 Moderate; minimal, local or noninvasive intervention indicated. Grade 3 Severe or medically significant but not immediately life-threatening; hospitalization or prolongation of hospitalization indicated; disabling; limiting self care.

Grade 4 Life-threatening consequences; urgent intervention indicated. Grade 5 Death related to AE.

Inclusion Criteria:

1. Adults (>18 years) with histopathologically confirmed Head and Neck Cancer (HNC), primary tumor in the stages T1, T2, T3, or T4, a regional node of any N status, and distant metastases absent.
2. All patients who were going to receive RT (dose between 60-70 Gy) on the head and neck region as postoperative (adjuvant) or definitive therapy. Either these patients had received chemotherapy prior or in concomitant to radiotherapy.
3. Eastern Cooperative Oncology Group (ECOG) performance score (PS) of 0 to 2 and normal hematologic and biochemical parameters.

Exclusion Criteria:

1. patients undergoing previous radiotherapy
2. uncontrolled systemic or widely disseminated disease
3. having any physical or mental abnormality,
4. pregnant and lactating women
5. presence of a synchronous double primary malignancy or simultaneous participation in another clinical trial