Outcome on Mesenteric Mass Response of Small-Intestinal Neuroendocrine Tumors Treated by177Lu-DOTATATE Peptide Receptor Radionuclide Therapy: The MesenLuth Study, a National Study from the French Group of Endocrine Tumors and Endocan-RENATEN Network

• DOI: 10.2967/jnumed.123.266063
• Publication Date: 2024-01-11T16:10:26Z
• Authors: Laure Al Mansour; Louis De Mestier; Magalie Haissaguerre; Pauline Afchain; Julien Hadoux; Thierry Lecomte; David Morland; Anne Segolene Cot...; Ophelie De Rycke; Ghoufrane Tlili; Jérémie Tordo; Marc Janier; Agathe Deville; Thomas Walter
• Keywords: Radionuclide therapy; Peptide receptor; Clinical endpoint; Progression-free survival; Refractory (planetary science)

A mesenteric mass (MM), characterized by fibrotic reaction, is present in most small-intestinal neuroendocrine tumors (SI-NETs). ¹⁷⁷Lu-DOTATATE peptide receptor radionuclide therapy (PRRT) has shown its efficacy patients with progressive SI-NETs. However, because of specific tissue characteristics desmoplastic MMs, we hypothesize that these lesions may be refractory to PRRT. <b>Methods:</b> From the national French Groupe d'étude des Tumeurs Endocrines database, identified an advanced SI-NET and a MM (≥2 cm retractile aspect) treated at least 1 course The primary endpoint was objective response rate (ORR) less than 5%. Secondary endpoints were metabolic response, MM-related safety, clinical as well progression-free survival (PFS) non-MM PFS. <b>Results:</b> In total, 52 included. ORR 4% (<i>n</i> = 2), 8% 4). No patient had 12% 6). Among 26 baseline symptoms, 46% response. Four presented gastrointestinal complications during median PFS not reached, 50.3 mo (95% CI, 38.2–61.7 mo). <b>Conclusion:</b> This study confirms PRRT does lead morphologic on MMs (ORR &lt; 5%). it allows stability, few side effects, relevant impact symptoms.