The role of CT and 18F-FDG PET in managing the neck in node-positive head and neck cancer after chemoradiotherapy

Conclusion. Patients showing a complete response on computed tomography (CT) can be spared from neck dissection. Objective. To determine whether CT or fluorine-18-fluorodeoxyglucose positron emission tomography (F-18-FDG PET) is superior in the evaluation of persistent nodal disease after chemoradiotherapy in patients with node-positive head and neck squamous cell carcinoma (HNSCC). Patients and methods. Study entry criteria included node-positive HNSCC treated with definitive chemoradiotherapy, a local complete response, and post-treatment CT and F-18-FDG PET studies 7 weeks after chemoradiotherapy. Forty-eight patients with 60 node-positive necks were eligible. Nodes larger than 1 cm, or with central necrosis on CT, or any visually hypermetabolic nodes on F-18-FDG PET were considered positive. Regardless of PET findings, necks with positive CT were subjected to neck dissection, whereas those with negative CT were observed without neck dissection. Results. Twenty-two necks showed positive CT, 20 and 2 of which underwent neck dissection and fine needle aspiration cytology, respectively, resulting in pathologic evidence of persistent nodal disease in 13 necks. Five of 38 necks with negative CT developed regional recurrence. Diagnostic accuracy was equivalent between CT and F-18-FDG PET. There was no difference in 3-year cause-specific survival between patients with positive and negative CT (79% and 81%, respectively).