Open AccessDual-Tracer (68Ga-DOTATOC and 18F-FDG-)-PET/CT Scan and G1-G2 Nonfunctioning Pancreatic Neuroendocrine Tumors: A Single-Center Retrospective Evaluation of 124 Nonmetastatic Resected Cases
Author(s) -
Salvatore Paiella,
Luca Landoni,
Sarah Tebaldi,
Michele Zuffante,
Matteo Salgarello,
Sara Cingarlini,
Mirko D’Onofrio,
Alice Parisi,
Giacomo Deiro,
Erminia Manfrin,
Beatrice Bianchi,
Greta Montagnini,
Stefano Francesco Crinò,
Claudio Bassi,
Roberto Salvia
Publication year - 2021
Publication title -
neuroendocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.493
H-Index - 101
eISSN - 1423-0194
pISSN - 0028-3835
DOI - 10.1159/000514809
Subject(s) - medicine , neuroendocrine tumors , interquartile range , nuclear medicine , positron emission tomography , pathological , retrospective cohort study , radiology
The combined use of 68 gallium ( 68 Ga)-DOTA-peptides and 18 fluorine-fluoro-2-deoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) scans in the workup of pancreatic neuroendocrine tumors (PanNETs) is controversial. This study aimed at assessing both tracers’ capability to identify tumors and to assess its association with pathological predictors of recurrence. Methods: Prospectively collected, preoperative, dual-tracer PET/CT scan data of G1-G2, nonmetastatic, PanNETs that underwent surgery between January 2013 and October 2019 were retrospectively analyzed. Results: The final cohort consisted of 124 cases. There was an approximately equal distribution of males and females (50.8%/49.2%) and G1 and G2 tumors (49.2%/50.8%). The disease was detected in 122 (98.4%) and 64 (51.6%) cases by 68 Ga-DOTATOC and by 18 F-FDG PET/CT scans, respectively, with a combined sensitivity of 99.2%. 18 F-FDG-positive examinations found G2 tumors more often than G1 (59.4 vs. 40.6%; p = 0.036), and 18 F-FDG-positive PanNETs were larger than negative ones (median tumor size 32 mm, interquartile range [IQR] 21 vs. 26 mm, IQR 20; p = 0.019). The median Ki67 for 18 F-FDG-positive and -negative examinations was 3 (IQR 4) and 2 (IQR 4), respectively ( p = 0.029). At least 1 pathological predictor of recurrence was present in 74.6% of 18 F-FDG-positive cases (vs. 56.7%; p = 0.039), whereas this was not found when dichotomizing the PanNETs by their dimensions (≤/>20 mm). None of the 2 tracers predicted nodal metastasis. The receiver operating characteristic curve analysis showed that 18 F-FDG uptake higher than 4.2 had a sensitivity of 49.2% and specificity of 73.3% for differentiating G1 from G2 (AUC = 0.624, p = 0.009). Conclusion: The complementary adoption of 68 Ga-DOTATOC and 18 F-FDG tracers may be valuable in the diagnostic workup of PanNETs despite not being a game-changer for the management of PanNETs ≤20 mm.