Research Information System
15TH INTERNATIONAL GASTROINTESTINAL CANCERS CONFERENCE, Antalya, Turkey, 4 - 07 December 2025, pp.31, (Full Text)
LUTETIUM-177 DOTATATE THERAPY AFTER LANREOTIDE FAILURE IN NEUROENDOCRINE TUMOR PATIENTS WITH LIVER METASTASES: A THREE-CASE EXPERIENCE Mustafa Ersoy Kütahya Sağlık Bilimleri Üniversitesi Tıp Fakültesi, İç Hastalıkları Ana Bilim Dalı, Kütahya Background: Neuroendocrine tumors (NETs) frequently metastasize to the liver and may initially respond to somatostatin analogs such as lanreotide or octreotide. However, many patients eventually experience progression despite biochemical control. Peptide receptor radionuclide therapy (PRRT) with Lutetium-177 DOTATATE (Lu-177) has emerged as an effective therapeutic option for somatostatin receptor–positive, progressive NETs. We report three patients with liver-dominant metastatic NETs who experienced disease progression under lanreotide and subsequently received Lu-177 DOTATATE. Case Presentations: Case 1: A 58-year-old male with a well-differentiated ileal NET (Ki-67: 8%) presented with multiple bilobar liver metastases. Despite 18 months of lanreotide therapy, radiologic progression was detected. The patient received four cycles of Lu-177 DOTATATE (7.4 GBq per cycle, every 8 weeks). After the third cycle, partial radiologic response and significant improvement in diarrhea and flushing were observed. No grade >=3 toxicity occurred. Case 2: A 64-year-old female with a pancreatic NET (Ki67: 12%) and diffuse liver metastases showed progression after 14 months of lanreotide treatment. Four cycles of Lu-177 DOTATATE were administered. Stable disease was achieved, and the patient remained progression-free for 15 months after completion of therapy. Mild, transient thrombocytopenia (grade 1) was the only toxicity observed Case 3: A 61-year-old male with a rectal NET (Ki-67: 10%) and multiple unresectable liver metastases progressed after one year of lanreotide therapy. The patient underwent four cycles of Lu-177 DOTATATE (total activity 29.6 GBq). Partial metabolic response was seen after the second cycle, accompanied by improvement in carcinoid symptoms. Treatment was completed without severe hematologic or renal adverse events. Disease progression occurred 12 months after the final cycle. Discussion: All three patients had well-differentiated, somatostatin receptor–positive NETs that progressed after lanreotide. PRRT with Lu-177 DOTATATE resulted in either partial response or durable disease stabilization, with favorable tolerability. The observed median progression-free period (12–15 months) aligns with previously published real-world and NETTER-1 trial data. PRRT provides meaningful clinical benefit after somatostatin analog failure, particularly in liver-dominant disease. Conclusion: Lutetium-177 DOTATATE represents an effective and well-tolerated treatment option for patients with metastatic NETs progressing after lanreotide. In our small case series, all patients achieved disease control and symptomatic improvement with acceptable safety. These findings support the use of PRRT as a standard second-line approach following somatostatin analog failure in receptor-positive NETs. Keywords: Neuroendocrine tumor, Lanreotide, Lutetium-177 DOTATATE