Indications for the use of external beam radiation in thyroid cancer

The role of external beam radiation therapy (EBRT) in the management of thyroid cancer is not clearly defined. In the absence of randomized studies, the review aims to identify any recent literature that helps define the role.

In differentiated thyroid cancer, single institutional studies report durable locoregional disease control in patients considered to be at high risk of local relapse after EBRT and recent guidelines are consistent in their recommendations. In medullary thyroid cancer, the evidence is more limited but again there is benefit in selected cases. In anaplastic thyroid cancer, multimodality therapy is superior to surgery alone in achieving local control and possibly survival but the benefit must be weighed against the toxicity. Newer radiation techniques may help reduce toxicity.

Although surgery is the main treatment for thyroid carcinoma, EBRT has a role in the adjuvant setting following surgery in high-risk patients and in unresectable cancer. Advances in the delivery of external beam radiotherapy, including intensity-modulated radiotherapy reduces toxicity.