Open Access
CC BY 4.0 · World J Nucl Med 2023; 22(02): 152-170
DOI: 10.1055/s-0043-1769945
Presentation Abstracts

Efficacy of Second 177Lu-DOTATATE PRRT Course in Patients with Progressive GEP-NET Using Dual-Tracer Imaging with 18FDG and 68Ga-DOTA-TOC/TATE PET/CT: Results of a WARMTH Multicenter Study

Margarida Rodrigues
1   Department of Nuclear Medicine, Innsbruck Medical University, Innsbruck, Austria
,
Diana Paez
2   Nuclear Medicine and Diagnostic Imaging Section, Division of Human Health, International Atomic Energy Agency, Vienna, Austria
,
Levent Kabasakal
3   Department of Nuclear Medicine, Faculty of Medicine, Yeditepe University School of Medicine, Istanbul, Turkey
,
Kalevi Kairemo
4   Nuclear Medicine & Theragnostics, Docrates Cancer Center, Helsinki, Finland
,
Chiara Maria Grana
5   Radiometabolic Therapy Unit, IRCCS IEO European Institute of Oncology, Milan, Italy
,
Richard Baum
6   Theranostics Centre for Molecular Radiotherapy and Precision Oncology, Zentralklinik, Bad Berka, Germany
,
Irene Virgolini
1   Department of Nuclear Medicine, Innsbruck Medical University, Innsbruck, Austria
› Author Affiliations
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    rodriguesradischat@hotmail.com

    Introduction: Peptide receptor radionuclide therapy (PRRT) appears to be the most effective therapeutic option in the management of inoperable or metastasized neuroendocrine tumors (NET) patients. 18FDG PET/CT has been used increasingly for evaluation of NET.

    The purpose of this multicenter retrospective study was to evaluate the efficacy of 177Lu-DOTATATE PRRT retreatment in patients with advanced gastroenteropancreatic (GEP) NET with disease progression during follow-up after first PRRT course.

    Methods: A total of 100 patients (64 male, 36 female; age: 29–83, mean 57.24 years) with progressive GEP-NET (pancreas 42, other GEP-NET 58; G1 16, G2 66, G3 18) who underwent two 177Lu-DOTATATE PRRT courses and combined 68Ga-DOTA-TOC/TATE PET/CT and 18FDG PET/CT investigations (before PRRT, 3 months after completion of first PRRT course, and every 6–9 months thereafter) were evaluated. 68Ga-DOTA-TOC/TATE and 18FDG PET/CT were performed within 2 days-6 weeks of each other. Between these scans, no therapy including PRRT was given.

    Results: After second PRRT course, 59 patients were 18FDG-negative and 41 patients 18FDG-positive. A total of 27 patients were in partial remission, 34 patients in stable disease, and 39 patients in progressive disease. Median time to progression was 43.52 months. Median overall survival was 134.61 months. Overall survival was significantly higher (p < 0.05) in 18FDG-negative than in 18FDG-positive patients. 18FDG-negative patients after second PRRT course were still alive at end of observation time and had partial remission to stable disease while 18FDG-positive patients deceased under stable or progressive disease.

    Conclusion: PRRT retreatment with 177Lu-DOTATATE was effective for the majority of GEP-NET patients with progression after the first PRRT course. Patients with 18FDG-negative after two PRRT courses had significantly longer overall survival and progression-free survival than those with 18FDG-positive. 18FDG PET/CT may contribute to management and prognosis evaluation of GEP-NET patients. The dual-tracer approach with 68Ga-TOC/TATE and 18FDG-PET/CT imaging can help the decision-making process for therapy selection in GEP-NET patients.


     

    No conflict of interest has been declared by the author(s).

    Publication History

    Article published online:
    25 May 2023

    © 2023. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

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