Associations between 18F-FDG-PET, DWI, and DCE Parameters in Patients with Head and Neck Squamous Cell Carcinoma Depend on Tumor Grading

Our purpose was to analyze associations between positron emission tomography (PET), diffusion weighted imaging (DWI), and dynamic contrast-enhanced (DCE) imaging in patients with head and neck squamous cell carcinoma (HNSCC).The study involved 34 patients (9 women, 25 men, mean age: 56.7 ± 10.2 years). In all patients a simultaneous 18F-FDG-PET/MR was performed. DWI was obtained by using of an axial EPI sequence. Minimal ADC values (ADCmin), mean ADC values (ADCmean), and maximal ADC values (ADCmax) were estimated. DCE MRI was performed by using dynamic T1w DCE sequence. The following parameters were estimated: 𝐾trans, 𝑉𝑒, and 𝐾ep. Spearman’s correlation coefficient was used to analyze associations between investigated parameters. In overall sample, ADCmean correlated significantly with 𝑉𝑒 and 𝐾trans, ADCmin correlated with 𝑉𝑒, and ADCmax correlated with 𝐾trans and 𝑉𝑒. SUVmean tended to correlate slightly with 𝐾trans. In G1/2 tumors, only 𝐾trans correlated well with ADCmax and SUVmean. In G3 tumors, 𝐾trans correlated well with 𝐾ep and 𝑉𝑒. 𝑉𝑒 showed significant correlations with ADCmean and ADCmax. 𝐾trans correlated with ADCmax. 𝐾ep was higher in cancers with N2/3 stages. Tumor metabolism, water diffusion, and tumor perfusion have complex relationships in HNSCC. Furthermore, these associations depend on tumor grading. 𝐾ep may predict lymphonodal metastasizing.