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

BACKGROUND

Multiparameter, multimodality F-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 F-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 (SUV and SUV , 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 SUV and SUV (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 SUV and SUV (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 SUV 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 (SUV ) = 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 (SUV ) = 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. F-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.