Endocrine Abstracts

Background: To evaluate outcomes and toxicities in patients with non-anaplastic thyroid cancer treated with intensity modulated radiation therapy (IMRT).

Materials and methods: This was a single institution retrospective review of 18 patients with non-anaplastic thyroid cancer treated with IMRT at King Fahad Medical City between April 2005 and December 2010. The median age was 69 years. Among the 18 patients, fifteen had papillary carcinoma, two had T3 and 12 had T4 disease, twelve had N1 disease, and one had distant metastases. Radioactive iodine was given to all patients, while the median radiotherapy (RT) dose was 60 Gy (range; 60–66Gy).

Results: Median follow-up was 30 months (range: 6-to-64 months). The Kaplan-Meier estimates of 3-year local control, locoregional control, and overall survival rates 90, 90, and 80% respectively. Nine patients (50%) had grade 2 skin toxicity, nine had grade two mucositis (pharyngitis, esophagitis), 1(11.1%) had grade G4 mucositis, 2 (22.2%) had grade 2 laryngitis, and 1(11.1%) had grade 3 laryngitis. Few grade 1 late toxicities were observed. Multivariate analysis showed poor prognostic factors for local and overall survival were; age above 45, postoperative gross residual disease, distant metastasis (DM) and no radioactive iodine (RAI) treatment. In patients with no DM and no postoperative LR disease, adjuvant RAI ablation reduced both LR failure (relative risk (RR) 0.29) and DM (RR 0.2).

Conclusion: IMRT is effective in the postoperative setting for high risk patients of thyroid cancer to reduce locoregional recurrences with acceptable morbidity. Long-term follow-up is still needed to assess the incidence of late toxicities.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.