The role of external beam radiotherapy in the treatment of papillary thyroid cancer.

The role of external beam radiotherapy (EBRT) in treating thyroid cancer has brought forth controversy. Due to various histologic presentations and different natural histories, there is no uniform approach/recommendation among centers and/or authorities regarding the role of EBRT for thyroid cancer. This is particularly true for papillary thyroid carcinoma (PTC) where the clinical course can range from a disease that is cured with simple surgery to an aggressive form of poorly differentiated thyroid cancer with high rates of recurrence/death from disease. In addition, because the majority of the patients with PTC undergo postoperative radioactive iodine (RAI) treatment, the question remains as to what is the exact role of EBRT for PTC in the setting of RAI treatment? In this issue of Endocrine-Related Cancer, Chow and colleagues identified indications for EBRT and RAI therapy for PTC based on a retrospective review of 1300 patients. The authors concluded that postoperative RAI treatment is indicated in patients with pT2-pT4, pN0-pN1b while postoperative EBRT is recommended for patients with gross residual, positive margin, pT4, pN1b, and lymph nodes>2 cm disease. Other centers have also published their experience on the value of EBRT for PTC but with different indications. The reasons for the variations from different centers are complex. However, when all published results are taken together, the findings confirm the added value of EBRT to the present management of PTC in a select group of patients, particularly those with high risk features. In this commentary, these issues will be discussed and recommendations regarding the role of EBRT will be given.