Correlation between tumor glucose metabolism and multiparametric functional MRI (IVIM and R2*) metrics in cervical carcinoma: Evidence from integrated ¹⁸F‐FDG PET/MR

Abstract

Background Multiparameter, multimodality 18F‐FDG PET/MRI holds great potential for the diagnosis of cervical cancer based on the correlation between tumor glucose metabolism and imaging parameters. Purpose To characterize the heterogeneity of tumor glucose metabolism by evaluating the correlation between 18F‐FDG uptake parameters and multiparametric functional MRI metrics in cervical carcinoma. Study Type Retrospective. Population Fifty‐four patients with cervical carcinoma. Field Strength/Sequence Hybrid PET/MR (3T), multi‐b DWI, and R2* mapping. Assessment The maximum and mean standardized uptake values (SUVmax and SUVmean, respectively) from PET and functional MRI metrics (D, D*, f, and R2*) were obtained. Cervical carcinoma tissues also underwent HIF‐1α, VEGF, and GLUT‐1 immunohistochemical staining. Statistical Tests Single‐factor Spearman rank and Pearson correlation analysis and multiple linear regression (MLR) analysis were applied. Results R2*, D, and f have different degrees of correlation (moderate, weak, moderately strong correlation, respectively) with SUVmax and SUVmean (r = 0.530 and 0.527, and P < 0.001 for R2*; r = –0.292 and –0.291, and P < 0.05 for D; r = 0.539 and 0.520, and P < 0.001 for f, respectively). Immunohistochemical staining showed that HIF‐1α expression has a moderate degree of correlation with R2* (r = 0.491; P < 0.001); GLUT‐1 expression was significantly correlated with SUVmax and SUVmean (r = 0.633 and 0.622; P < 0.001), and VEGF expression had a moderately strong correlation with f (r = 0.457; P = 0.001). If SUVmax is the dependent variable, MLR yields an R‐squared value after adjustment (adjusted R‐squared) = 0.358, and F = 10.833 (P < 0.001), and the fitting linear equation is Y (SUVmax) = 9.184 + 0.161X1 (R2*)+50.343X2 (f)‐4.780 (D). Otherwise, MLR yields the adjusted R‐squared = 0.342, and F = 10.187 (P < 0.001), and the linear regression equation is Y (SUVmean) = 5.925 + 0.102X1 (R2*)+28.029X2 (f)‐2.907X3 (D). Data Conclusion The functional MRI sequence parameters R2*, f, and D can provide information on the hypoxic condition, blood perfusion, and molecular diffusion of the tumor. 18F‐FDG PET/MR multi‐imaging technique can be adopted to evaluate the heterogeneity of glucose metabolism in cervical carcinoma. Level of Evidence: 3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;49:1704–1712.

A correlative study between IVIM-DWI parameters and VEGF and MMPs expression in hepatocellular carcinoma

“…Perfusion-related IVIM-DWI parameters, such as D* and f, and the expression of angiogenic factors, such as VEGF, MMP-2, and MMP-9, in tumor tissue are significantly positively correlated with MVD (31,32,(37)(38)(39)(40)(41). IVIM-DWI parameters can be used to evaluate tumor angiogenesis (40,42,43). An IVIM-DWI study of a mouse lung cancer model showed that D* and f were positively correlated with VEGF expression (43).…”

“…Significant differences in the f values of colorectal cancer patients with different expression levels of mismatch repair proteins may be related to the differential expression of VEGF and its receptor, VEGFR2 (40). However, D* is reported to have no correlation with VEGF (42). The possible causes of these controversial findings may be that the structure and density of some capillaries cannot reflect the information from macroscopic tumors and blood vessels (42); other physiological processes, such as glandular secretion and fluid flows inside the glandular ducts and other ducts, may affect the measured D* values (45), and D* is associated with a low signal-to-noise ratio (46) and poor (C) MMP-9 (×200).…”

“…However, D* is reported to have no correlation with VEGF (42). The possible causes of these controversial findings may be that the structure and density of some capillaries cannot reflect the information from macroscopic tumors and blood vessels (42); other physiological processes, such as glandular secretion and fluid flows inside the glandular ducts and other ducts, may affect the measured D* values (45), and D* is associated with a low signal-to-noise ratio (46) and poor (C) MMP-9 (×200). VEGF, vascular endothelial growth factor; MMP, matrix metalloproteinase.…”