Sequential Use of (90)Y Microspheres Radioembolization and (177)Lu-Dotatate in Pluri-Metastatic Neuroendocrine Tumors: A Case Report.

Abstract 90Y radioembolization and peptide-receptor radionuclide therapy (PRRT) with177Lu-DOTATATE are both effective treatments for patients with inoperable neuroendocrine metastatic tumors (NET). We report the case of a 72-year-old man with severe functional syndrome due to a metastatic NET. 68Ga-DOTATOC positron-emission tomography (PET) revealed high somatostatin receptor expression in a gross liver metastasis, in one abdominal lymph node and in several skeletal lesions. The patient underwent liver radioembolization with 90Y-resin microspheres followed by four cycles of PRRT with177Lu-DOTATATE. After 3 months, a complete remission of the functional syndrome was observed. 68Ga-DOTATOC PET demonstrated a complete response for skeletal and lymph nodal lesions with a residual bulky mass in the liver. Therefore a further 90Y radioembolization was performed as consolidation treatment for the hepatic lesion. Six months after these combined treatments, 68Ga-DOTATOC PET demonstrated complete metabolic response in liver and stable extrahepatic lesions. No significant long-term adverse reactions were registered. To our knowledge, the sequential use of 90Y radiembolization before and after PRRT in a liver-dominant advanced NET has not been reported in the literature and this case suggests that these combined treatments can be safe and effective.