The use of SPECT-CT improves accuracy of post-radioiodine therapy imaging and changes the management strategy in a case of advanced follicular thyroid carcinoma

This is a case of follicular thyroid carcinoma with extensive lung, bone and brain metastases. Multi-modality treatments including total thyroidectomy, modified radical neck dissection, cranial radiotherapy and Iodine-131 (RAI) therapy were instituted. Post RAI therapy planar whole body scan showed RAI avid metastases in the skull, cervical spine, bilateral lungs and abdomen. With the use of SPECTCT imaging, rare adrenal metastasis and additional rib metastasis were identified. Besides, management strategy was altered due to detection of non-RAI avid brain and lung metastatic lesions.