Dual Somatostatin Receptor/ 18 F-FDG PET/CT Imaging in Patients with Well-Differentiated, Grade 2 and 3 Gastroenteropancreatic Neuroendocrine Tumors
Our purpose was to prospectively assess the distribution of NETPET scores in well-differentiated (WD) grade 2 and 3 gastroenteropancreatic (GEP) neuroendocrine tumors (NETs) and to determine the impact of the NETPET score on clinical management. This single-arm, institutional ethics review board-app...
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Published in | Journal of Nuclear Medicine Vol. 65; no. 10; pp. 1591 - 1596 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
01.10.2024
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Subjects | |
Online Access | Get full text |
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Summary: | Our purpose was to prospectively assess the distribution of NETPET scores in well-differentiated (WD) grade 2 and 3 gastroenteropancreatic (GEP) neuroendocrine tumors (NETs) and to determine the impact of the NETPET score on clinical management.
This single-arm, institutional ethics review board-approved prospective study included 40 patients with histologically proven WD GEP NETs.
Ga-DOTATATE PET and
F-FDG PET were performed within 21 d of each other. NETPET scores were evaluated qualitatively by 2 reviewers, with up to 10 marker lesions selected for each patient. The quantitative parameters that were evaluated included marker lesion SUV
for each tracer;
F-FDG/
Ga-DOTATATE SUV
ratios; functional tumor volume (FTV) and metabolic tumor volume (MTV) on
Ga-DOTATATE and
F-FDG PET, respectively; and FTV/MTV ratios. The treatment plan before and after
F-FDG PET was recorded.
There were 22 men and 18 women (mean age, 60.8 y) with grade 2 (
= 24) or grade 3 (
= 16) tumors and a mean Ki-67 index of 16.1%. NETPET scores of P0, P1, P2A, P2B, P3B, P4B, and P5 were documented in 2 (5%), 5 (12.5%), 5 (12.5%) 20 (50%), 2 (5%), 4 (10%), and 2 (5%) patients, respectively. No association was found between the SUV
of target lesions on
Ga-DOTATATE and the SUV
of target lesions on
F-FDG PET (
= 0.505).
F-FDG/
Ga-DOTATATE SUV
ratios were significantly lower for patients with low (P1-P2) primary NETPET scores than for those with high (P3-P5) primary NETPET scores (mean ± SD, 0.20 ± 0.13 and 1.68 ± 1.44, respectively;
< 0.001). MTV on
F-FDG PET was significantly lower for low primary NETPET scores than for high ones (mean ± SD, 464 ± 601 cm
and 66 ± 114 cm
, respectively;
= 0.005). A change in the type of management was observed in 42.5% of patients after
F-FDG PET, with the most common being a change from systemic therapy to peptide receptor radionuclide therapy and from debulking surgery to systemic therapy.
There was a heterogeneous distribution of NETPET scores in patients with WD grade 2 and 3 GEP NETs, with more than 1 in 5 patients having a high NETPET score and a frequent change in management after
F-FDG PET. Quantitative parameters including
F-FDG/
Ga-DOTATATE SUV
ratios in target lesions and FTV/MTV ratios can discriminate between patients with high and low NETPET scores. |
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ISSN: | 0161-5505 1535-5667 2159-662X |
DOI: | 10.2967/jnumed.124.267982 |