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The aim of this work is to identify MRI texture features able to predict the response to radio-chemotherapy (RT-CHT) in patients with naso-oropharyngeal carcinoma (NPC-OPC) before treatment in order to help clinical decision making. Textural features were derived from ADC maps and post-gadolinium T1-images on a single MRI machine for 37 patients with NPC-OPC. Patients were divided into two groups (responders/non-responders) according to results from MRI scans and 18F-FDG-PET/CT performed at follow-up 3–4 and 12 months after therapy and biopsy. Pre-RT-CHT lesions were segmented, and radiomic features were extracted. A non-parametric Mann–Whitney test was performed. A p-value < 0.05 was considered significant. Receiver operating characteristic curves and area-under-the-curve values were generated; a 95% confidence interval (CI) was reported. A radiomic model was constructed using the LASSO algorithm. After feature selection on MRI T1 post-contrast sequences, six features were statistically significant: gldm_DependenceEntropy and DependenceNonUniformity, glrlm_RunEntropy and RunLengthNonUniformity, and glszm_SizeZoneNonUniformity and ZoneEntropy, with significant cut-off values between responder and non-responder group. With the LASSO algorithm, the radiomic model showed an AUC of 0.89 and 95% CI: 0.78–0.99. In ADC, five features were selected with an AUC of 0.84 and 95% CI: 0.68–1. Texture analysis on post-gadolinium T1-images and ADC maps could potentially predict response to therapy in patients with NPC-OPC who will undergo exclusive treatment with RT-CHT, being, therefore, a useful tool in therapeutical–clinical decision making. Full article

The purpose of this study was to differentiate post-chemoradiotherapy (CRT) changes from tumor persistence/recurrence in early follow-up of naso-oropharyngeal carcinoma on magnetic resonance (MRI) with diffusion (DWI) and dynamic contrast-enhanced perfusion-weighted imaging (DCE-PWI). A total of 37 patients were assessed with MRI both for tumor staging and 4-month follow-up from ending CRT. Mean apparent diffusion coefficient (ADC) values, area under the curve (AUC), and K(trans) values were calculated from DWI and DCE-PWI images, respectively. DWI and DCE-PWI values of primary tumor (ADC, AUC, K(trans)_pre), post-CRT changes (ADC, AUC, K(trans)_post), and trapezius muscle as a normative reference before and after CRT (ADC, AUC, K(trans)_muscle pre and _muscle post; AUC_{post/muscle post}:AUC_{pre/muscle pre} (AUC_{post/pre/muscle}); K(trans)_{post/muscle post}:K(trans)_{pre/muscle pre} (K(trans)_{post/pre/muscle}) were assessed. In detecting post-CRT changes, ADC_post > 1.33 × 10⁻³ mm²/s and an increase >0.72 × 10⁻³ mm²/s and/or >65.5% between ADC_post and ADC_pre values (ADC_post-pre; ADC_post-pre%) had 100% specificity, whereas hypointense signal intensity on DWIb800 images showed specificity 80%. Although mean AUC_{post/pre/muscle} and K(trans)_{post/pre/muscle} were similar both in post-CRT changes (1.10 ± 0.58; 1.08 ± 0.91) and tumor persistence/recurrence (1.09 ± 0.11; 1.03 ± 0.12), K(trans)_{post/pre/muscle} values < 0.85 and >1.20 suggested post-CRT fibrosis and inflammatory edema, respectively. In early follow-up of naso-oropharyngeal carcinoma, our sample showed that ADC_post > 1.33 × 10⁻³ mm²/s, ADC_post-pre% > 65.5%, and ADC_post-pre > 0.72 × 10⁻³ mm²/s identified post-CRT changes with 100% specificity. K(trans)_{post/pre/muscle} values less than 0.85 suggested post-CRT fibrosis, whereas K(trans)_{post/pre/muscle} values more than 1.20 indicated inflammatory edema. Full article