Combined 18F-fluorodeoxyglucose-positron emission tomography and computed tomography as a primary screening method for detecting second primary cancers and distant metastases in patients with head and neck cancer

Background: The aim of this study was to evaluate the ability of F-18-fluorodeoxyglucose- positron emission tomography/computed tomography (FDG-PET/CT) to detect second primary cancers and distant metastases in patients with head and neck cancer (HNC). Patients and methods: Patients with previous untreated HNC, between 2004 and 2005, underwent head and neck CT and whole-body FDG-PET/CT, before and at fixed intervals after therapy, for staging and detection of second primary cancers and distant metastases. Patients with malignant or equivocal findings on FDG-PET/CT underwent further imaging, endoscopy and/or biopsy. Results: Of the 349 eligible patients (267 men and 82 women), 14 (4.0%) had second primary cancers and 26 (7.4%) had distant metastases at initial staging or during mean follow-up of 15 months after treatment. FDG-PET/CT correctly identified second cancers or distant metastases in 39 of these 40 patients; there was one false negative and 23 false positive FDG-PET/CT results. Therefore, FDG-PET/CT had a sensitivity of 97.5%, a specificity of 92.6%, a positive predictive value of 62.9% and a negative predictive value of 99.7% in detecting second primary cancers and distant metastases. Conclusion: Combined FDG-PET/CT is useful as a primary method for detecting second cancers and distant metastases in patients with HNC.