Relationship between 18F-FDG PET metabolic parameters and MRI intravoxel incoherent motion (IVIM) histogram parameters and their correlations with clinicopathological features of cervical cancer: evidence from integrated PET/MRI.

ABSTRACT

AIM: To explore the relationship between positron-emission tomography (PET) and intravoxel incoherent motion (IVIM) histogram parameters and their correlations with the clinicopathological features of cervical squamous cell cancer (CSCC). MATERIALS AND METHODS: Forty-four patients with CSCC underwent pelvic combined PET/magnetic resonance imaging (MRI) including IVIM sequences. The maximum/mean standardized uptake value (SUVmax/SUVmean), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) of PET, histogram parameters of apparent diffusion coefficient (ADC), IVIM biomarkers of tissue diffusivity (D), and perfusion fraction (F) were calculated. Correlations between SUV and IVIM (including ADC) histogram parameters, imaging parameters and clinicopathological features were evaluated. RESULTS: SUV showed weak or no correlations with most histogram parameters of ADC, D, and F, except for a moderate correlation between SUVmax or SUVmean and ADCmin (r=-0.69, p<0.001; r=-0.66, p=0.005). MTV, TLG were significantly higher (p<0.05) in tumours with larger diameters, advanced stages, and higher squamous cell carcinoma antigen (SCC-ag). SkewnessADC, kurtosisADC, entropyADC, and kurtosisD for tumour diameters, skewnessF and kurtosisF for tumour stages, kurtosisADC and entropyADC for SCC-ag were statistically significant (p<0.05). MTV (p=0.003), TLG (p=0.004), P10ADC (p=0.001), P25ADC (p=0.021), P10D (p<0.001) and P75F (p=0.014) were significantly different between G1/2 and G3 tumours. The receiver operating characteristic (ROC) curve indicated that P10D had the largest area under curve (AUC=0.868). CONCLUSION: No universal correlations between SUV and IVIM parameters were found in this study, and further investigation of PET and IVIM parameters as independent potential biomarkers should be investigated for evaluating the clinicopathological characteristics of cervical cancer.