Ozturk K, et al. - In this investigation, researchers identified the prognostic value of ¹⁸F-fluoro-deoxy-glucose positron emission/CT (¹⁸F-FDG PET/CT) and diffusion-weighted (DW) MRI for the determination of overall survival (OS), progression-free survival (PFS), and distant metastasis-free survival (DMFS) of sinonasal malignancies. From January 2009 through August 2017, 68 patients with sinonasal cancer who had both pretreatment ¹⁸F-FDG PET/CT scan and head-neck MRI were retrospectively reviewed. Cox regression analysis found that all ¹⁸F-FDG PET/CT and DW-MRI quantitative parameters were independently associated with PFS, DMFS, and OS. Perineural invasion and undefined margin were found to be significantly correlated with shorter OS after controlling for imaging variables while the perineural invasion was significantly correlated with shorter PFS. Findings suggested that DW-MRI and ¹⁸F-FDG PET/CT parameters for pretreatment could be significant surrogate markers for sinonasal malignancies.