Associations between (18)F-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 (18)F-FDG-PET/MR was performed. DWI was obtained by using of an axial EPI sequence. Minimal ADC values (ADC(min)), mean ADC values (ADC(mean)), and maximal ADC values (ADC(max)) were estimated. DCE MRI was performed by using dynamic T1w DCE sequence. The following parameters were estimated: K(trans), V(e), and K(ep). Spearman's correlation coefficient was used to analyze associations between investigated parameters. In overall sample, ADC(mean) correlated significantly with V(e) and K(trans), ADC(min) correlated with V(e), and ADC(max) correlated with K(trans) and V(e). SUV(mean) tended to correlate slightly with K(trans). In G1/2 tumors, only K(trans) correlated well with ADC(max) and SUV(mean). In G3 tumors, K(trans) correlated well with K(ep) and V(e). V(e) showed significant correlations with ADC(mean) and ADC(max). K(trans) correlated with ADC(max). K(ep) 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. K(ep) may predict lymphonodal metastasizing.