Clinical values for abnormal ¹⁸F-FDG uptake in the head and neck region of patients with head and neck squamous cell carcinoma.

PURPOSE

Fluorine 18-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)/computed tomography (CT) is used to identify index or second primary cancer (SP) of the head and neck (HN) through changes in (18)F-FDG uptake. However, both physiologic and abnormal lesions increase (18)F-FDG uptake. Therefore, we evaluated (18)F-FDG uptake in the HN region to determine clinical values of abnormal tracer uptake.

METHODS

A prospective study approved by the institutional review board was conducted in 314 patients with newly diagnosed HN squamous cell carcinoma (HNSCC) and informed consent was obtained from all enrolled patients. The patients received initial staging workups including (18)F-FDG PET/CT and biopsies. All lesions with abnormal HN (18)F-FDG uptake were recorded and most of those were confirmed by biopsies. Diagnostic values for abnormal (18)F-FDG uptake were calculated.

RESULTS

Abnormal (18)F-FDG uptake was identified in primary tumors from 285 (91.9%) patients. False-negative results were obtained for 22.3% (23/103) T1 tumors and 2.2% (2/93) T2 tumors (P<0.001). Thirty-eight regions of abnormal (18)F-FDG uptake were identified in 36 (11.5%) patients: the thyroid (n=13), maxillary sinus (n=7), palatine tonsil (n=6), nasopharynx (n=5), parotid gland (n=2) and others (n=5). Synchronous SP of the HN was identified in eight (2.5%) patients: the thyroid (n=5), palatine tonsil (n=2), and epiglottis (n=1). The sensitivity and specificity of (18)F-FDG PET/CT for identification of SPs were 75.0% and 98.7%, respectively.

CONCLUSIONS

(18)F-FDG PET/CT is a reliable method for tumor staging and identify SP in HN region, promoting appropriate therapeutic planning. Additional examinations may be required to identify superficial or small-volume tumors.