Comparison of Positron Emission Tomography/Computed Tomography Imaging and Ultrasound in Staging and Surveillance of Head and Neck and Thyroid Cancer

Objectives/Hypothesis: Positron emission tomography (PET) combined with cross-sectional computed tomography (CT) is increasingly used for staging and surveillance of cancers in the head and neck region. Ultrasonography (US) is an alternative imaging technique that provides diagnostic information while enabling simultaneous image-guided biopsies. A comparison of these diagnostic modalities in cancer detection is warranted. Methods: All patients with malignant neoplasms in the head and neck region who were evaluated by both PET/CT and US were reviewed. Diagnostic accuracy rates of PET/CT and US were determined according to whether cytologically or histologically confirmed cancer was present in US-guided fine-needle biopsy or surgical specimens. Results: From October 2004 to December 2007, 42 patients with an ultimately confirmed tissue diagnosis of a head and neck malignancy underwent both neck US and PET/CT. The sensitivity and specificity of US in predicting malignancy in the head and neck was 96.8% and 93.3%, respectively, in those 42 individuals. The positive predictive value (PPV) was 96% and the negative predictive value (NPV) was 93%. In comparison, PET/CT in this group demonstrated a sensitivity of 90.3%, specificity 20%, PPV 70%, and NPV 50%. Conclusions: PET/CT and US, especially when combined with US-guided fine-needle biopsy, are complementary tools in the detection of cancers of the head and neck. The highly sensitive and specific nature of US, combined with its low cost, low morbidity, availability as an in-office examination, and ability to guide biopsies, warrant consideration of its routine use in the management of head and neck and thyroid cancer patients.