Adjuvant External Beam Radiotherapy in Differentiated Thyroid Cancers: An Audit of Clinical Practice, Adapting to New Evidence.

Abstract

There is limited evidence on the role of adjuvant external beam radiotherapy in differentiated thyroid cancer (DTC). We conducted a retrospective study of patients with DTC treated with adjuvant Intensity Modulated radiotherapy (IMRT) from 2011 to 2024. 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. Adjuvant IMRT in patients with DTC with high risk of locoregional recurrence resulted in good LRC with acceptable toxicities.