The Role of Postoperative External Beam Radiotherapy for Differentiated Thyroid Carcinoma

Objectives To synthesize current evidence defining the role of external beam radiotherapy (RT) in the postoperative management of differentiated thyroid carcinomas (DTC). Materials and Methods A systematic review and meta-analysis were done. Included studies compared oncologic outcomes and toxicity of RT versus no RT in patients with DTC after curative surgery and RAI. Results Nine studies were included in this review, two prospective and seven retrospective cohorts. RT was associated with an improved 5-year LRRFS but not OS and DMFFS. The locoregional control benefit was seen in patients at increased risk for recurrence, including those with advanced age, locoregionally advanced disease, positive resection margins with gross or microscopic residual tumor, and structural invasion. Serious RT-related acute and late toxicities were rare. Conclusion Available evidence suggests that postoperative RT can improve locoregional control in high-risk DTC with acceptable toxicity. Prospective studies are warranted to define the role of RT in DTC.