Prognostic Value of ⁶⁸Ga-DOTANOC PET/CT SUV_max in Patients with Neuroendocrine Tumors of the Pancreas

Abstract

This study was performed to investigate the role of 68 Ga-DOTANOC SUV max as a potential prognostic factor in patients with pancreatic neuroendocrine tumor (pNET). Methods: Among the patients who underwent 68 Ga-DOTANOC PET/CT, we retrospectively collected the data of those who had G1 or G2 pNET (2010 World Health Organization classification), presented with disease on PET/CT and CT, and had at least 6 mo of follow-up. Patients with multiple endocrine neoplasia were excluded. Results: Overall, 43 patients were included. No significant differences in SUV max were observed with respect to sex, tumor syndrome, stage, World Health Organization classification, or Ki-67. During follow-up (median, 20 mo), 11 patients (35.6%; median, 33 mo; interquartile range, 20-48 mo) had stable disease and 32 (74.4%; median, 19 mo; interquartile range, 14-26 mo) had progressive disease. SUV max at 24 mo of follow-up was significantly higher (P 5 0.022) in patients with stable disease than in patients with progressive disease. The best SUV max cutoff ranged from 37.8 to 38.0. The major risk factors for progression included an SUV max of no more than 37.8 (hazard ratio, 3.09; P 5 0.003), a Ki-67 of more than 5% (hazard ratio, 2.89; P 5 0.009), and medical therapy alone (hazard ratio, 2.36; P 5 0.018). Advanced stage (IV) (P 5 0.026), an SUV max of less than 37.8 (P 5 0.043), and medical therapy alone (P 5 0.015) were also confirmed at multivariate analysis. Median progression-free survival was 23 mo. Significant differences in progression-free survival were observed in relationship to Ki-67 (median, 45 mo for Ki-67 # 5% and 20 mo for Ki-67 . 5%; P 5 0.005), SUV max (,37.8 vs. .38.0: 16.0 vs. 27.0 mo; P 5 0.002), and type of therapy (medical vs. peptide receptor radionuclide therapy: 16.0 vs. 26.0 mo; P 5 0.014). Conclusion: 68 Ga-DOTANOC SUV max is a relevant prognostic factor in patients with G1 and G2 pNET, and its routine use will improve disease characterization and management in these patients, who may present with atypical cases showing heterogeneous clinical behavior.

Current knowledge on the sensitivity of the 68Ga-somatostatin receptor positron emission tomography and the SUVmax reference range for management of pancreatic neuroendocrine tumours

“…2) typically contains multiple small NET-microadenomas [56]. It is supposed that the allelic loss of 11q13 in an islet cell sets the stage of NET development [57]. …”

Association between pathologic grade and multiphase computed tomography enhancement in pancreatic neuroendocrine neoplasm

“…Several studies have evaluated the role of DOTA‐PET/CT as a prognostic factor . There was relationship between low SUV max and poor prognosis, but no association between SUV max and grade has been found . Recently, dual‐tracer PET/CT using both DOTA peptide and FDG has been studied, but further researches should be warranted.…”

Molecular imaging in neuroendocrine tumors: recent advances, controversies, unresolved issues, and roles in management

“…SUV/max on 68 Ga-DOTA-peptide-PET/CT has also been reported to be predictive in patients with advanced NETs regarding their response to octreotide therapy with a SUV/MAX>29.4 associated with a longer PFS[72]. In patients with well-differentiated G1/G2 pNETs[73], a SUV/Max >37.8 on 68 Ga-DOTA-peptide-PET/CT was an independent predictor of PFS.…”