The role of Nuclear Medicine in the management of patients with anaplastic and poorly differentiated Thyroid Cancer.

2038 Objectives: 1. To highlight the importance of Nuclear Medicine imaging in the evaluation of radioactive iodine (RAI) refractory Thyroid Cancer. 2. To present the contribution of FDG PET/CT on poorly differentiated thyroid cancer (PDTC) or anaplastic thyroid cancer (ATC) patients’ management. 3. To discuss the future role of theranostics using PSMA ligands. Abstract Body: Thyroid cancer is the most common endocrine malignancy, with the vast majority of such patients respond favorably to surgery and risk-adapted postoperative treatment with TSH suppression and RAI. The best response is seen in well-differentiated thyroid cancers (WDTC), papillary thyroid cancer (PTC) and follicular thyroid cancer (FTC). However, a subset of patients presents with aggressive and less differentiated thyroid cancer refractory to RAI therapy. While DTC can become resistant to RAI therapy, resistance is most commonly seen in dedifferentiated subtypes, such as PDTC and ATC. Both PDTC and ATC may arise from WDTC. Surgery is often considered the only chance for survival, while the benefit of subsequent multimodal therapy is unclear. Among several clinical factors that predict RAI refractory at early evaluation, Nuclear Imaging plays a crucial role with F-18 FDG PET positivity - no Iodine uptake. Additionally, F-18 FDG PET scan is suggested having impact on PDTC or ATC patients’ management, indicating extended survival, if negative. The effect of targeted treatment protocols is also assessed in several studies by F-18 FDG PET scans. Furthermore, PSMA expression in aggressive forms of thyroid cancer gives opportunities for imaging and therapy. This educational exhibit aims to provide a brief but comprehensive review of recent developments to the clinical management of patients with anaplastic and poorly differentiated Thyroid Cancer.