Figure 3.

Radioiodine-refractory metastatic differentiated thyroid cancer with positive lesions on [¹⁸F]FDG PET and [⁶⁸Ga]Ga-DOTANOC PET. Legend: Eighty-four-year-old patient with advanced follicular thyroid cancer and (new) pulmonary and lymph node metastases, after 17 GBq ¹³¹I, Tg: 8660 ng/mL. (Left): diagnostic ¹³¹I imaging showing radioiodine-avid lymph node metastases (yellow arrows) in the chest. (Middle): [¹⁸F]FDG PET depicts discordance with RAI-imaging lymph node metastases in the upper mediastinum and lung metastases (blue arrows). (Right): [⁶⁸Ga]Ga-DOTANOC PET shows SSTR-expression in some but not all lymph node metastases in the upper mediastinum; additionally, visualization of a lesion in the left neck not seen with [¹⁸F]FDG and ¹³¹I (red arrow). However, no SSTR expression in the lung metastases was observed.