Background:A major limitation of Radiotherapy (RT) in an adjuvant setting for oral tongue cancer is the development of acute oral mucositis. By employing intensity-modulated radiotherapy (IMRT), it is possible to minimize the RT dose to the mucosa and potentially reduce the incidence and severity of acute mucositis. Therefore, we conducted a randomized trial to evaluate the efficacy of oral mucosa-sparing radiotherapy (OMSRT) compared to oral mucosa-non-sparing radiotherapy (OMNSRT) in patients with oral tongue cancer.Methods:A prospective randomized study was conducted, including patients diagnosed with oral tongue squamous cell carcinoma (SCC), who underwent upfront surgery and were eligible for adjuvant radiotherapy. Patients were randomized into OMSRT and OMNSRT groups. IMRT was employed for the treatment of all the cases. In the OMSRT arm, the dose to the oral mucosa was restricted to a D mean of 32Gy. Patients were followed up regularly to assess treatment response, and toxicities. Statistical analysis was performed using appropriate tests.Results:The study included 32 patients, with 16 patients in each group. The dose to the oral mucosa was significantly lower in the OMSRT group compared to the OMNSRT group (Dmean: 29.16 Gy vs. 32.14 Gy, p = 0.00). The OMNSRT arm had a significantly higher number of patients suffering from higher-grade mucositis (grades 2 and 3) (p = 0.032). Additionally, these toxicities were delayed in the mucosa-sparing arm. Even though a higher percentage of patients had to use analgesics in the OMSRT arm, this difference was not statistically significant.Conclusion:OMSRT using IMRT effectively reduced the dose to the oral mucosa in patients with oral tongue SCC, thereby addressing one of the major limitations of RT in this setting - acute oral mucositis.