Positron Emission Tomography in the Early Follow-up of Advanced Head and Neck Cancer

Abstract

Positron emission tomography (PET) with fludeoxyglucose F18 (FDG) has widely been used for follow-up examinations of patients with mucosal head and neck squamous cell carcinoma (HNSCC). In most studies, FDG-PET was performed when recurrent disease was clinically suspected.1-6 Only a few publications report the use of PET examinations at a fixed time interval after the end of treatment.7-12 Previous reports suggest that a follow-up FDG-PET examination performed soon after the end of treatment is less reliable for the identification of residual tissue than a scan acquired after several months because an inflammatory reaction after therapy may cause false-positive results.7,8 Additionally, a negative PET scan 1 month after the end of treatment cannot reliably rule out the presence of viable tumor cells.7 However, early identification of residual vital tumor tissue has the potential to improve local control by facilitating early salvage surgery. In the early posttreatment period after completion of radiation therapy, edema can complicate the clinical examination; during this early period, noninvasive imaging could help to assess treatment success.