MR‐guided simulation is superior than FDG/PET‐guided simulation for local control in nasopharyngeal cancer patients treated with intensity‐modulated radiotherapy

Background MRI and PET/CT scans are the main supportive methods for nasopharyngeal cancer (NPC) for staging and planning. The aim of this study is to compare MRI and PET/CT scanning in terms of survival in patients with NPC who had MRI or PET/CT-simulated radiotherapy planning. Methods Pathological diagnosed nonkeratinized undifferentiated type and stage II-IVA 91 NPC patients with treated intensity-modulated radiotherapy plus chemotherapy were scanned. The patients were immobilized by a customized thermoplastic mask for fusion images both MRI scans and PET/CT scans. CTVs were created via MR-guided simulation and PET/CT-guided simulation. Results PET/CT-guided simulation was performed with 44 patients (56.4%) and MR-guided simulation was performed with 34 patients (43.6%). Local recurrence-free survival (LRFS) of patients was 68.1 months. LRFS of patients with PET/CT-guided simulation was 59.9, while LRFS of patients with MR-guided was 66.9 months. There was a statistically significant difference between groups (P = .03). In the subgroup analyses, the patients were assessed by dividing into the three groups for the T1-T2 stage, T-3 stage, and T-4 stage. In the patients with T1-T2 stage, 5-year LRFS rates were found %74.4 for PET/CT-guided simulation and %83.3 for MR-guided simulation. There was no statistically significant difference between groups (P = .33). In the patients with T-3 stage, 5-year LRFS rates were found %55.6 for PET/CT-guided simulation and %83.3 for MR-guided simulation. There was not a statistically significant difference between groups (P = .59). In the patients with T-4 stage, 5-year LRFS rates were found %42.2 for PET/CT-guided simulation and %85.1 for MR-guided simulation. The difference between groups was found to be statistically significant (P = .04). Conclusion In this study, we founded that MR-guided simulation has better than PET/CT-guided simulation for LRFS

Comparison of dynamic contrast-enhanced MRI and PET/CT in the evaluation of laryngeal cancer after inadequate CT results

BACKGROUND: To investigate the diagnostic value of dynamic magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) for laryngeal cancers after inadequate CT results. MATERIAL AND METHODS: The study comprised 45 patients investigated for primary laryngeal cancer or recurrence-residue in which CT was considered inadequate. A mass was found in 20 patients. Dynamic MRI and PET/CT were compared for diagnosis of mass, lymph node involvement, recurrence and residue. The dynamic curves formed in dynamic MRI were investigated for diagnostic contributions. RESULTS: The sensitivity and specificity of the dynamic MRI, for supraglottic, glottic and subglottic location, was 100%, 80%, and 92%; 100%, 85%, and 100%, respectively. In PET/CT the sensitivity and specificity were 100% for all of those localizations. For lymph node involvement, the sensitivity of dynamic MRI and PET/CT was 100%, the specificity was 100% and 93%, respectively. For recurrence-residue, the sensitivity and specificity of dynamic MRI were 86% and 67%, respectively, with 100% sensitivity and specificity in PET/CT. The sensitivity of type A curve for detection of malignancy was 40%, and specificity was 100%. When type A and B curves were included, the sensitivity was 100%. CONCLUSIONS: For patients investigated for laryngeal cancer in which CT is considered inadequate, dynamic MRI or PET/CT is useful