Efficacy of N-acetylcysteine in Preventing Radiotherapy-Induced Oral Mucositis in Head and Neck Cancer Patients.

Time to develop oral mucositis with grade ≥ 2.

Difference between the two arms regarding time to develop oral mucositis with grade ≥ 2 according to WHO scale for oral mucositis. World Health Organization scale for oral mucositis * Grade 0: no oral mucositis * Grade 1: erythema and soreness * Grade 2: ulcers, able to eat solids * Grade 3: ulcers, requires liquid diet * Grade 4: ulcers, alimentation not possible (due to mucositis).

Time frame: 8 weeks

Duration of oral mucositis with grade ≥ 2.

Difference between the two arms regarding duration of oral mucositis with grade ≥ 2 according to WHO scale for oral mucositis.

Time frame: 8 weeks

Pain assessed by Visual Analog Scale (VAS).

The pain VAS is a unidimensional measure of pain intensity, used to record patients' pain progression. The most simple VAS is a straight horizontal line of fixed length usually 100 mm. The ends are defined as the extreme limits of the parameter to be measured (pain) orientated from the left (worst) to the right (best). we will allocate this scale in comparing pain severity between the two arms.

Time frame: 8 weeks

Functional oral intake scale

TUBE DEPENDENT (levels 1-3) 1. No oral intake 2. Tube dependent with minimal/inconsistent oral intake 3 Tube supplements with consistent oral intake TOTAL ORAL INTAKE (levels 4-7) 4. Total oral intake of a single consistency 5. Total oral intake of multiple consistencies requiring special preparation 6. Total oral intake with no special preparation, but must avoid specific foods or liquid items 7. Total oral intake with no restrictions