Clinical value of 18 FDG PET/CT in screening for distant metastases in head and neck squamous cell carcinoma

Objectives: The detection of distant metastases is of major importance in management of head and neck squamous cell carcinoma patients. Design: All patients underwent ¹⁸ FDG PET/CT for the detection of distant metastases. Setting: Retrospective single-centre study. Participants: Head and neck squamous cell carcinoma patients with high-risk factors for distant metastases. Main outcome measures: Accuracy of ¹⁸ FDG PET/CT for the detection of distant metastases using clinical development of distant metastases and a minimal follow-up of twelve months as reference standard. Comparison of overall survival between patients diagnosed with distant metastases during initial screening and patients diagnosed with distant metastases during follow-up. Results: In 23 (12%) of the 190 patients, ¹⁸ FDG PET/CT detected distant metastases at screening. Sensitivity and negative predictive value were 46.2% (95% CI 32.6-59.7) and 82.6% (95% CI 76.8-88.5). No difference in median overall survival from the time of distant metastases detection was found between patients diagnosed with DM during work-up or during follow-up. Conclusions: In head and neck squamous cell carcinoma patients with high-risk factors, ¹⁸ FDG PET/CT has a high negative predictive value for the detection of distant metastases and should be used in daily clinical practice, although the sensitivity is limited when long-term follow-up is used as reference standard.