Systematic review: Accuracy of imaging tests in the diagnosis of recurrent laryngeal carcinoma after radiotherapy

BACKGROUND: Diagnosing recurrent laryngeal tumor after radiotherapy is challenging. The most reliable method is direct laryngoscopy under general anesthesia. However, many futile laryngoscopies are performed in disease-free patients. Imaging tests selecting patients for this invasive procedure would be useful. The aim of this systematic review was summarizing the available evidence and determining the diagnostic accuracy of CT, MRI, thallium-201 (201Tl) scintigraphy, and F-18-fluorodeoxyglucose positron emission tomography (18FDG-PET). METHODS: A systematic review was performed according to the guidelines of the Cochrane Collaboration. Two reviewers scored the articles according to A-, B-, and C-items. Statistical meta-analysis was performed producing summary pooled estimates of sensitivity and specificity. RESULTS: There were 8 eligible studies on 18FDG-PET. The validity of the 18FDG-PET studies was reasonable; the pooled estimates (95% CI) for sensitivity and specificity were 89% and 74%. CONCLUSION: The diagnostic accuracy of 18FDG-PET is promising and warrants a randomized trial comparing a strategy based on conventional diagnostic work-up to one based on 18FDG-PET