Morphological and biochemical heterogeneity in the tissue of pancreatic ductal adenocarcinoma (PDAC) according to structural and spectrometric MRI data

Autor: Nikolay S. Demchenko, Dmitry Ya. Iozefi, Dmitry S. Petrov, Oleg I. Kit, Yuriy A. Fomenko, Mikhail A. Vinidchenko
Rok vydání: 2020
Předmět:
Zdroj: Journal of Clinical Oncology. 38:e16727-e16727
ISSN: 1527-7755
0732-183X
Popis: e16727 Background: Comparing the MRI characteristics of pancreatic tissue in normal, solid adenocarcinomas and chronic pancreatitis in a multiparametric study, the radiologist needs tools that reduce the subjective component in making a diagnostic decision. The study is devoted to the assessment of structural heterogeneity, diffusion coefficient, lipid and lactate concentration according to MR spectroscopy in vivo. PDAС cells are proliferating and surviving within a particularly severe microenvironment characterized by relative hypovascularity, hypoxia, and nutrient deprivation. In this case cells have to show biochemical flexibility (survival phenotype) in order to adapt to unusual conditions. Methods: 20 patients with pancreatic adenocarcinomas (PDAC), 10 patients with chronic pancreatitis and 10 patients with unchanged pancreas were examined MRI using Signa HD 1.5 t General Electric. The results of their multiparametric imaging and NMR spectroscopy were investigated and compared.The heterogeneity coefficients (HC) were measured as ratio standard deviation in small region of interest to signal intensity in T1FS and T2. Lipid concentration was measured by Dixon method as the pancreatic -to-splenic attenuation ratio. Results: In a small sample, we observed a significant increase in HC in chronic pancreatitis, and in solid tissue in adenocarcinomas in comparison with normal tissue, depending on the main source of the MR signal (hydrogen in the macromolecules or hydrogen of water and fat). In adenocarcinomas, an increase in the signal from lipids (lip13a) peak was revealed, with a decrease in the total lipid concentration. A decrease in lipid concentration in the tumor in the presence of diffusion restriction (ADC 0,001-0,0016 мм2/s) and the appearance of a peak of lactate may be a biochemical marker of adenocarcinoma. In chronic pancreatitis, an increase in the mass fraction of lipids was revealed. Conclusions: The results obtained in current and future in-depth studies are promising for creation of a metabolically oriented diagnostic model of pancreatic cancer.
Databáze: OpenAIRE