Detection of Brain Metastasis in Occult Medullary Thyroid Carcinoma Using 68Ga-DOTATATE PET/CT: A Case Report

Abstract

Medullary thyroid carcinoma (MTC) is a neuroendocrine tumor that may express somatostatin receptors, enabling imaging with Ga-6(8)-DOTATATE PET/CT. Brain metastases from MTC are extremely rare, particularly in the absence of an identifiable primary tumor. We present a 63-year-old male with occult MTC and elevated serum calcitonin levels (27 pg/mL). Ga-6(8)-DOTATATE PET/CT demonstrated focal tracer uptake in the right parietal lobe (SUVmax: 9.1), which was confirmed by brain MRI as a 7-mm enhancing lesion consistent with metastasis. This case highlights the value of Ga-6(8)-DOTATATE PET/CT in detecting unusual metastatic presentations in occult MTC.