Detection of recurrent head and neck squamous cell carcinomas after radiation therapy with 2-F-18-fluoro-2-deoxy-D-glucose positron emission tomography

Objectives/Hypothesis: Fluorodeoxyglucose positron emission tomography (FDG -PET) has been proposed as a sensitive method to diagnose and stage various malignancies. We assessed the efficacy of FDG-PET imaging in distinguishin g tumor persistence/recurrence from posttreatment changes following radiati on therapy for squamous carcinomas of the head and neck. Study Design: Retr ospective analysis of FDG-PET results compared with biopsy results or outco me, or both. Methods: Twenty-eight patients who had undergone radiation the rapy with or without surgery for treatment of squamous cell carcinoma were studied with FDG-PET imaging. There was clinical suspicion for recurrence i n each patient, but no obvious mass or lesion to biopsy was found on physic al examination or anatomic imaging. The results of FDG-PET imaging were com pared with those of biopsy or clinical follow-up of at least 6 months, or b oth. Results: FDG-PET imaging was positive in 13 patients, and the presence of active disease was confirmed in 12, Two thirds of the 12 received furth er cancer treatment. There were 15 negative FDG-PET images. Thirteen of the se were confirmed true-negative images, but two studies were false-negative images. The sensitivity and specificity of FDG-PET were 86% and 93%, respe ctively, with positive and negative predictive values of 92% and 87%, respe ctively. The overall accuracy was 89%. Conclusion: FDG-PET imaging is a use ful modality to distinguish tumor persistence/recurrence from radiation-ind uced tissue changes in the neck following treatment for head and neck cance r. FDG-PET can identify patients who may benefit from further treatment, an d may lead to improved out come for individual patients.