Additional diagnostic value of 18F-FDG PET-CT in detecting retropharyngeal nodal metastases

OBJECTIVE: This study investigated whether preoperative (18)fluorine-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) scanning improve the diagnosis of retropharyngeal lymph node (RPLN) metastasis in patients with head and neck squamous Cell carcinoma (HNSCC) relative to conventional Imaging alone STUDY DESIGN: Case series with chart review SETTING: University hospital cancer center SUBJECTS AND METHODS: Sixty-three patients with HNSCC underwent RPLN dissection in accordance with our indications and were subsequently divided into two groups. CT/magnetic resonance Imaging (MRI) only (group A, n = 33) and CT/MRI with PET-CT (group B. n = 30) The preoperative radiological findings of each group were compared with the RPLN histopathologic findings. which served as die standard of reference. RESULTS: RPLN metastasis was confirmed histopathologically in 17 of 63 patients (270%) eight front group A and nine front group B With the additional use of PET-CT in group B. the sensitivity (88 9%), specificity (85 7%). and accuracy (86 7%) were higher than the respective Values III group A (62 5%, 60 0%. and 60.6%) The positive and negative predictive Values for group B (72.7% and 94 7%. respectively) were also higher than those for group A (33 3% and 83 3%, respectively). False-positive results were obtained in 10 patients from group A and three patients from B. false-negative findings occurred in three patients front group A and one patient from group B The predictive power of the radiological findings was statistically significant in group B (P = 0.0017). with an odds ratio of 47.987 (95% confidence interval. 4 3-535.0). CONCLUSION: F-18-FDG PET-CT, when used in combination with CT/MRI increases diagnostic efficacy in the detection of RPLN metastases and may therefore be useful in screening high-fisk patients 0 2009 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved.