Multiparametric functional MRI and18F-FDG-PET for survival prediction in patients with head and neck squamous cell carcinoma treated with (chemo)radiation

Objectives To assess (I) correlations between diffusion-weighted (DWI), intravoxel incoherent motion (IVIM), dynamic contrast-enhanced (DCE) MRI, and(18)F-FDG-PET/CT imaging parameters capturing tumor characteristics and (II) their predictive value of locoregional recurrence-free survival (LRFS) and overall survival (OS) in patients with head and neck squamous cell carcinoma (HNSCC) treated with (chemo)radiotherapy. Methods Between 2014 and 2018, patients with histopathologically proven HNSCC, planned for curative (chemo) radiotherapy, were prospectively included. Pretreatment clinical, anatomical, and functional imaging parameters (obtained by DWI/IVIM, DCE-MRI, and(18)F-FDG-PET/CT) were extracted for primary tumors (PT) and lymph node metastases. Correlations and differences between parameters were assessed. The predictive value of LRFS and OS was assessed, performing univariable, multivariable Cox and CoxBoost regression analyses. Results In total, 70 patients were included. Significant correlations between(18)F-FDG-PET parameters and DWI-/DCE volume parameters were found (r > 0.442,p < 0.002). The combination of HPV (HR = 0.903), intoxications (HR = 1.065), PT ADC(GTV)(HR = 1.252), K-trans(HR = 1.223), and V-e(HR = 1.215) was predictive for LRFS (C-index = 0.546;p = 0.023). N-stage (HR = 1.058), HPV positivity (HR = 0.886), hypopharyngeal tumor location (HR = 1.111), ADC(GTV)(HR = 1.102), ADC(mean)(HR = 1.137), D* (HR = 0.862), K-trans(HR = 1.106), V-e(HR = 1.195), SUVmax(HR = 1.094), and TLG (HR = 1.433) were predictive for OS (C-index = 0.664;p = 0.046). Conclusions Functional imaging parameters, performing DWI/IVIM, DCE-MRI, and(18)F-FDG-PET/CT, yielded complementary value in capturing tumor characteristics. More specific, intoxications, HPV-negative status, large tumor volume-related parameters, high permeability (K-trans), and high extravascular extracellular space (V-e) parameters were predictive for adverse locoregional recurrence-free survival and adverse overall survival. Low cellularity (high ADC) and high metabolism (high SUV) were additionally predictive for decreased overall survival. These different predictive factors added to estimated locoregional and overall survival.