177 Lu-DOTATATE PRRT for Multiple Unusual Metastatic Sites in Neuroendocrine Tumor

Area of Science:

• Oncology
• Nuclear Medicine
• Endocrinology

Background:

• Neuroendocrine tumors (NETs) are rare neoplasms.
• Metastases to the thyroid gland and orbit are exceptionally uncommon sites for NETs.
• Somatostatin receptor (SSTR) expression is a hallmark of many NETs, making them targets for diagnostic and therapeutic radiopharmaceuticals.

Observation:

• A patient with rectal neuroendocrine tumor presented with metastases to the thyroid gland and intra-orbital regions.
• The metastatic lesions exhibited high avidity on somatostatin receptor-based 68 Ga-DOTATATE Positron Emission Tomography/Computed Tomography (PET/CT).

Findings:

• Following peptide receptor radionuclide therapy (PRRT) using 177 Lu-DOTATATE, significant reduction in the size and radiotracer uptake of the metastatic lesions was observed.
• The 68 Ga-DOTATATE PET/CT demonstrated a marked decrease in metabolic activity and tumor burden post-therapy.

Implications:

• This case highlights the therapeutic efficacy of 177 Lu-DOTATATE PRRT in managing metastatic neuroendocrine tumors, even in rare extranodal sites.
• PRRT represents a promising treatment option for SSTR-expressing, tracer-avid metastatic lesions in challenging locations.
• The successful cytoreduction underscores the potential of targeted radionuclide therapy for improving outcomes in advanced neuroendocrine neoplasms.