Positron emission tomography with fluorodeoxyglucose for suspected head and neck tumor recurrence in the symptomatic patient

Objective: To analyze the impact of positron emission tomography with fluorodeoxyglucose (FDG-PET) in the treatment of patients suspected of having head and neck cancer recurrence. Study Design: Prospective and consecutive inclusion of 44 patients presenting with clinical symptoms suggestive of head and neck tumor recurrence. Methods: FDG-PET was compared with combined computed tomography (CT) plus magnetic resonance imaging (MRI) procedures for the differential diagnosis between tumor recurrence and benign post-therapeutic changes. For FDG-PET, the potential additional value of semiquantitative indexes was studied. The impact on patient treatment (i.e., their ability to accurately select patients for panendoscopic exploration) was analyzed retrospectively for both CT+MRI and PET workups. Results: The diagnostic accuracy was found higher for PET than for combined CT-MRI: sensitivity ranged from 96% to 73%, specificity from 61% to 50%, and accuracy from 81% to 64% for PET and CT+MRI, respectively. The accuracy of FDG-PET was the highest (94%) in patients included more than 12 weeks after the end of therapy. In 15 discordant cases, PET was correct in 11 and CT+MRI in 4. Patient selection for panendoscopic exploration and biopsy was correct in 79% and 50% of patients with FDG-PET and CT+MRI, respectively, Quantification of FDG uptake had no additional value over visual analysis alone, although we found that a SWlbm (standardized uptake value corrected for lean body mass) threshold of 3 could be helpful in patients scanned less than 12 weeks after the end of therapy. Conclusion: FDG-PET has a major additional diagnostic value to CT+MRI for the evaluation of the symptomatic patient suspected of having head and neck cancer recurrence. PET could have a direct impact on management by correctly selecting patients in whom a panendoscopic exploration with biopsy is indicated.