The potential of FDG-PET in the detection of occult lymph node metastasis: importance of patient selection and reference standard

Excerpt

In patients with head and neck squamous cell carcinoma the presence of lymph node metastases is one of the most important prognostic factors. It is obvious that the patients with clinically manifest lymph node metastases require treatment of the neck. Therefore, the detection of lymph node metastases is of utmost importance. A meta-analysis showed that conventional imaging techniques, such as computed tomography (CT), magnetic resonance imaging (MRI), ultrasound (US) and especially US-guided fine needle aspiration cytology (USgFNAC), are more reliable than palpation [1]. Positron emission tomography (PET) imaging with F-18-fluorodeoxyglucose (18F-FDG) is a functional modality that has been used increasingly for staging head and neck cancer. Modern PET–CT imaging equipment combines both anatomic and functional imaging, potentially providing more accurate diagnosis and improved patient management. Here, the CT scan is used for attenuation correction of the PET images as well as for anatomic localisation; most scanners can provide state-of-the-art contrast-enhanced CT (CECT) (and not just the low-dose CT [ld-CT] required for attenuation correction) together with PET in a single scan session. …