FIRST-LINE USE OF DOTATATE-177LUTETIUM THERAPY IN THE TREATMENT OF NEUROENDOCRINE TUMOR OF THE PANCREAS: CASE SERIES (Atena Editora)

Abstract

Neuroendocrine tumors (NET) of the pancreas are a heterogeneous and rare group of neoplasms, corresponding to 1% to 2% of primary pancreatic tumors. Although most present indolent behavior, metastases are not infrequent and reduce overall survival. Complete surgical resection is the treatment of choice, although not all patients are eligible. In this scenario, there are other therapeutic options, such as radionuclide therapy, whose effectiveness in neoadjuvance has been demonstrated in the literature. We report a series of 3 cases of patients with pancreatic NET treated with somatostatin analogue labeled with Lutetium-177 (DOTA-177Lu) or peptide radionuclide receptor therapy (PRRT) as first line. Reports: Female, 33 years old, with a large tumor involving the head of the pancreas and the proximal portion of the duodenum; Biopsy revealed adenocarcinoid tumor of the pancreas. Abdominal CT showed inoperability, in addition to liver implants. Scintigraphy with somatostatin analogue showed the presence of marked expression of receptors in the primary tumor and secondary lesions. Male, 37 years old, diagnosed with NET of inoperable pancreas. After multidisciplinary discussion and review of the literature, we opted for PRRT (according to the Rotterdam protocol) in the first line with neoadjuvant intention in both cases, with good initial response, tumor reduction and the possibility of a surgical approach. In the first case, the liver implants were no longer identified. The patients underwent pathologically confirmed complete tumor resection and currently have no evidence of disease. Female, 67 years old, with radiological suspicion of NET of the body of the pancreas. PET-DOTA showed a single lesion with high expression of somatostatin receptors. Upon refusal of biopsy and surgery and negative PET-FDG, it was suggested that PRRT be performed in the first line. MRI after 4 doses of 150 mCi of DOTA-177Lu no longer showed the primary lesion. He has been disease-free for 2 years. Discussion: PRRT is known to be effective in NET with high expression of somatostatin receptors, and the use of DOTA-177Lu as a second or third line of treatment in these cases is well established. As a first-line therapy for pancreatic tumors, its use has been demonstrated in the literature with high efficacy in tumor reduction, making surgical and curative approaches possible, as well as controlling symptoms, making it an interesting neoadjuvant therapeutic strategy, especially in locally advanced and inoperable. Final comments: In the first two cases, in which neoadjuvant PRRT was used, there was a good clinical response and tumor reduction, allowing surgery. In the third case, there was a complete radiological response to date. Patients showed good tolerance to the treatment, with no evidence of renal or hematological toxicity, suggesting that the therapy can be used upfront in occasional cases of resectable and unresectable localized disease.