Effect of 0.15% Benzydamine Hydrochloride (Difflam) Oral Spray on Established Radiation-Induced Oral Mucositis Progression During High-Dose Radiotherapy: An Open-Label Randomized Pilot Trial

Oral mucositis (OM) is a common and clinically important complication of radiotherapy, particularly in patients with head and neck cancer. It may lead to pain, dysphagia, impaired oral intake, weight loss, increased infection risk, treatment interruption, and reduced quality of life. Benzydamine is a topical non-steroidal anti-inflammatory agent with analgesic and anesthetic properties and has been recommended for the prevention of OM in selected patients receiving moderate-dose radiotherapy (up to 50 Gy) without concurrent chemotherapy. However, evidence regarding its effectiveness in patients receiving high-dose radiotherapy (>50 Gy) remains limited, and its role in managing established OM after clinical onset has not been adequately explored. This study was designed to evaluate whether 0.15% benzydamine hydrochloride oral spray reduces the progression and severity of radiation-induced oral mucositis after OM onset in patients receiving high-dose radiotherapy.