Abstract
INTRODUCTION: There is limited evidence on the role of adjuvant external beam radiotherapy in differentiated thyroid cancer (DTC). METHODS: We conducted a retrospective study of patients with DTC treated with adjuvant Intensity Modulated radiotherapy (IMRT) from 2011 to 2024. RESULTS: Fifty-nine patients were analyzed with median follow-up of 53 months. All the patients had undergone total thyroidectomy. Gross extrathyroidal extension was seen in 76% of patients, while 54% had R1/R2 resection. High-risk histological types were seen in 51% of patients, while 34% had recurrent disease. The 5-year locoregional control (LRC) was 89.3% while 5-year overall survival (OS) was 84.6%. Acute Grade 3 dermatitis and dysphagia were seen in 12% and 10%, respectively. Late toxicity, including tracheostomy placement and feeding tube dependence, was seen in three and one patient, respectively. CONCLUSION: Adjuvant IMRT in patients with DTC with high risk of locoregional recurrence resulted in good LRC with acceptable toxicities.