Purpose: This study aimed to determine whether intravenous contrast-enhanced dual-phase fluorine-18--fluorodeoxyglucose (F-FDG) PET/CT scans provide additional diagnostic information compared with the MRI/CT in patients with laryngeal carcinoma during the initial staging.
Patients and methods: Forty-five consecutive patients (44 men, one woman; mean age±SD, 67.0±9.0 years, range: 45-80 years) with carcinoma of the larynx who had MRI/CT and intravenous contrast-enhanced PET/CT were enrolled. Each patient was scanned on the PET/CT system 1 h (early) and 2 h (delayed) after injection. The maximum standardized uptake values of the primary tumor, nodal, and distant metastatic lesions were measured using the dual-time-point method. Double-blinded F-FDG PET/CT and MRI/CT staging data were compared. The diagnostic accuracy of each modality was compared for primary tumors, nodal metastasis, and the tumor staging.
Results: For primary tumor detection, the sensitivity of PET/CT was higher (100%) than MRI/CT (93.3%). The accuracy for N status was 88.8% for PET/CT, being superior to MRI, which had an accuracy of 66.6%. The sensitivity and specificity for the detection of nodal metastasis were 100 and 84.6% for PET/CT compared with 100 and 50% for MRI/CT, respectively. As an initial TNM-staging method, the PET/CT had a diagnostic accuracy of 86.6% compared with 44.4% for MRI/CT.
Conclusion: The results suggest that contrast-enhanced dual-phase PET/CT imaging contributes additional diagnostic information compared with the conventional methods for the initial evaluation of primary laryngeal tumors. F-FDG PET/CT has a good diagnostic performance for the detection of regional nodal and distant metastasis, and also synchronous tumors in patients with laryngeal carcinoma.