Intraindividual comparison of 18 F-FDOPA and 68 Ga-DOTATOC PET/CT detection rate for metastatic assessment in patients with ileal neuroendocrine tumours.

Abstract

INTRODUCTION:

In patients with ileal neuroendocrine tumours (ileal NETs), head-to-head evaluation of diagnostic performances of 68 Ga-DOTA-peptides and 18 F-fluorodihydroxyphenylalanine (18 F-FDOPA) positron emission tomography/computed tomography (PET/CT) has been performed in only few small patients' cohorts. The aim of this retrospective study was to compare 68 Ga-DOTATOC and 18 F-FDOPA PET/CT for metastatic disease assessment in a homogeneous large series of patients with well-differentiated ileal NETs.

METHODS:

All patients with ileal NETs who underwent both 18 F-FDOPA and 68 Ga-DOTATOC PET/CT within a 3-month period and no therapeutic change between the two studies were retrospectively included. The detection rates of both modalities were calculated using per-patient, per-region and per-lesion analyses.

RESULTS:

Forty one patients with ileal NETs were evaluated. 18 F-FDOPA and 68 Ga-DOTATOC showed similar detection rates according to per-patient (97% for both) and per-region analyses (94% for 18 F-FDOPA vs 88% for 68 Ga-DOTATOC, P = .35). For a total of 605 positive lesions, 458 (76%) were detected by both modalities, 122 (20%) exclusively by 18 F-FDOPA PET/CT, and 25 (4%) by 68 Ga-DOTATOC PET/CT only. In a per-lesion analysis, 18 F-FDOPA PET/CT performed better than 68 Ga-DOTATOC PET/CT (overall detection rates of 96% vs 80%; P < .001). 18 F-FDOPA PET/CT detected significantly more metastases than 68 Ga-DOTATOC PET/CT in the liver, peritoneum, abdominal and supra-diaphragmatic lymph nodes.

CONCLUSION:

18 F-FDOPA PET/CT seems not inferior than 68 Ga-DOTATOC PET/CT for the delineation of metastatic spread of ileal NETs. Therefore, according to local expertise and technical availability, 18 F-FDOPA should be considered as a valid clinical diagnostic option for exhaustive metastatic assessment in patients with ileal NETs. Obviously, 68 Ga-DOTATOC PET/CT remains mandatory for PRRT assessment. Further comparative studies are needed to determine the optimal approach in various clinical scenarios such as preoperative staging and primary tumour detection.

• Authors: Eric Ouvrard, Elodie Chevalier, Pietro Addeo, Nicolas Sahakian, Julien Detour, Bernard Goichot, Philippe Bachellier, Gilles Karcher, David Taïeb, Alessio Imperiale
• Journal: Clinical endocrinology (Clin Endocrinol (Oxf)) Vol. 94 Issue 1 Pg. 66-73 (01 2021) ISSN: 1365-2265 [Electronic] England
• PMID: 32790887 (Publication Type: Journal Article)
• Copyright: © 2020 John Wiley & Sons Ltd.

Chemical References

• Organometallic Compounds
• Radiopharmaceuticals
• Octreotide
• Edotreotide

Topics

• Humans
• Neuroendocrine Tumors (diagnostic imaging)
• Octreotide (analogs & derivatives)
• Organometallic Compounds
• Positron Emission Tomography Computed Tomography
• Positron-Emission Tomography
• Radiopharmaceuticals
• Retrospective Studies