Gallbladder Neuroendocrine Tumor and 177 Lu DOTATATE: High Somatostatin Receptor Expression Without Clinical Response.

Gallbladder neuroendocrine tumors (GB-NETs) are rare, accounting for <0.5% of all NETs, and little is known about somatostatin receptor expression (SSTR) and its response to SSTR-targeted treatment such as Lutetium-177 ( 177 Lu) DOTATATE. 68 Ga DOTATATE PET/CT is a valuable imaging modality for SSTR expression and 177 Lu DOTATATE treatment planning. We present a case of a 74-year-old man with recurrent WHO grade 3 GB-NET. 177 Lu DOTATATE failed to control hepatic metastases despite high DOTATATE uptake, which led to treatment discontinuation. This case highlights the fact that positive SSTR imaging in GB-NETs does not always lead to a favorable response to 177 Lu DOTATATE.