Diagnostic value of only 18F-fluorodeocyglucose positron emission tomography/computed tomography-positive lymph nodes in head and neck squamous cell carcinoma.

OBJECTIVE: The role of (18)F-fluorodeocyglucose positron emission tomography (PET)/computed tomography (CT) in only PET/CT-positive lymph nodes (LNs) is not well elucidated yet. This study was conducted to evaluate the diagnostic value of only PET/CT-positive LNs without correlating positive findings on conventional imaging modalities (CT, magnetic resonance imaging [MRI], and ultrasound [US]) in patients with head and neck squamous cell carcinoma (HNSCC).

STUDY DESIGN: Case series with chart review.

SETTING: Hallym University School of Medicine.

SUBJECTS AND METHODS: From January 2006 to September 2009, 114 patients with HNSCC who underwent CT, MRI, US, and PET/CT before definitive surgery with neck dissection were reviewed. All imaging tests were interpreted on imaging-based nodal classification and were compared with histopathological findings.

RESULTS: Only PET/CT-positive LNs were found at 48 nodal levels in 33 patients. Thirteen of 48 (27%) nodal levels were true-positive (TP), and 35 of 48 (73%) were false-positive (FP). Fourteen nodal levels were included on N+ necks, and 34 were included on N0 necks. In N0 necks, the FP rate was significantly higher than the TP rate (28 vs 6, P = .034). Eleven only PET/CT-positive nodal levels in 10 patients were found on the contralateral neck side, and FP was significantly more prevalent than TP (8 vs 3, P = .041). No significant difference was observed for mean standardized uptake value and LN sizes between TP and FP.

CONCLUSION: Only PET/CT-positive LNs can frequently be found and do not predict LN metastasis, because a high percentage of results were FP. Our results suggest that only PET/CT-positive LNs should be considered negative, especially in N0 and contralateral necks.