Outcome on Mesenteric Mass Response of Small-Intestinal Neuroendocrine Tumors Treated by 177Lu-DOTATATE Peptide Receptor Radionuclide Therapy: The MesenLuth Study, a National Study from the French Group of Endocrine Tumors and Endocan-RENATEN Network

J Nucl Med. 2024 Feb 1;65(2):258-263. doi: 10.2967/jnumed.123.266063.

Abstract

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

Keywords: 177Lu-DOTATATE; PRRT; mesenteric mass; neuroendocrine tumor; objective response.

MeSH terms

  • Endocrine Gland Neoplasms*
  • Humans
  • Intestinal Neoplasms* / drug therapy
  • Intestinal Neoplasms* / radiotherapy
  • Neuroendocrine Tumors* / metabolism
  • Octreotide / adverse effects
  • Organometallic Compounds* / adverse effects
  • Positron-Emission Tomography*
  • Radioisotopes / therapeutic use
  • Radionuclide Imaging*
  • Receptors, Peptide / metabolism
  • Treatment Outcome

Substances

  • copper dotatate CU-64
  • Octreotide
  • Radioisotopes
  • Receptors, Peptide
  • Organometallic Compounds