Grading of pancreatic neuroendocrine neoplasms using pharmacokinetic parameters derived from dynamic contrast‑enhanced MRI

Abstract

The present study aimed to evaluate the diagnostic efficacy of pharmacokinetic parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in prospective evaluation of pancreatic neuroendocrine neoplasms (pNENs) grading. A total of 25 histologically proven patients with pNENs (30 lesions in total) who underwent DCE-MRI were enrolled. Lesions were divided into G1, G2 neuroendocrine tumor (NET) and G3 NET/neuroendocrine carcinoma (NEC) groups based on their histological findings according to 2017 World Health Organization Neuroendocrine Tumor Classification Guideline. In addition, the same numbers of tumor-free regions were selected using as normal control group. For each group, pharmacokinetic DCE parameters: volume transfer constant (Ktrans); contrast transfer rate constant (kep); extravascular extracellular space volume fraction (ve); and plasma volume fraction (vp) were calculated with Extended Tofts Linear model. Receiver operator characteristics analysis was conducted to assess the diagnostic efficacy of these parameters in pNENs grading. There were significant differences of Ktrans, kep, ve and vp between tumor-free areas and G1, G2 NET (P<0.001). The Ktrans and kep of G1 NET were significantly lower compared with those of G2 ones (P<0.005). The area under the curve of Ktrans and kep in differentiating G2 from G1 NET were 0.767 and 0.846, respectively. When Ktrans was >0.667 and kep >1.644, the sensitivity of diagnosing G2 NET was the lowest (53.85%), but the specificity was the highest (93.75%). When Ktrans was >0.667 or kep >1.644, the sensitivity of diagnosing G2 NET was 92.31%, but the specificity was 75.00%. Pharmacokinetic parameters of DCE-MRI, particularly the quantitative values of Ktrans and kep, are helpful for differentiating G2 NET from G1 ones.

Grading of Neuroendocrine Carcinomas: Correlation of 68Ga-PET/CT Scan with Tissue Biomarkers

“…The use of imaging analysis for the grading and prognosis assessment of NEN patients has been investigated by other groups. In a recent study by Zhao et al, pharmacokinetic parameters of dynamic contrast-enhanced magnetic resonance imaging were found to be predictive of NET grading, helping to distinguish between G1 and G2 tumors [33]. Another study reported that CT texture analysis and CT features were predictive of pancreatic NET aggressiveness and could be used to identify patients at risk of early disease progression after surgical resection [34].…”

The multidisciplinary team for gastroenteropancreatic neuroendocrine tumours: the radiologist’s challenge

“…3.378 ± 0.378, respectively; p = 0.045) 64. Furthermore, the quantitative values of Ktrans and the contrast rate between the extracellular extravascular space and the vascular space (kep), are helpful for differentiating G2 NET from G1 ones 65…”

Pancreatic grade 3 neuroendocrine tumors behave similarly to neuroendocrine carcinomas following resection: a multi-center, international appraisal of the WHO 2010 and WHO 2017 staging schema for pancreatic neuroendocrine lesions

“…Reports from multiple centers worldwide began to challenge the notion that these lesions were biologically indistinct from their poorly-differentiated counterparts, especially with respect to responsiveness to chemotherapies. [3][4][5][6] In 2017, the classification for PNETs was updated to acknowledge that highly-proliferative PNETs should be treated differently if they are well-differentiated tumors (NETG3) compared to carcinomas (NECs).…”