Initial Results and Clinical Application of Non Dedicated 18-FDG/PET in Head and Neck Oncology

ABSTRACT

Imaging procedures are important methods for properstage and treatment planning. Especially in previouslytreated patients, although not perfectly accurate. PETscan is a functional and imaging technique that has beenused to diagnose and stage recurrent cancer fromdifferent sites. The combination of computedtomography coupled with FDG-PET (18-FDG-PET/CT)reaches high quality anatomical and functional images.OBJECTIVE: To describe the initial results of FDG-PET/CT performed at a single institution. MATERIAL ANDMETHODS: This technique was used in 63 patients withhead and neck tumors. The purpose of the exam was a)to rule out recurrent disease - 55 patients; b) to search forhidden primary tumor - 2 patients; and c) postoperativefollow-up of residual disease - 6 patients. Computedtomography (CT) was performed in 56 cases (88.9%).Pathological confirmation was obtained in 24 cases(38.1%), all the remaining cases were considered negativebased on clinical follow-up information with no evidenceof recurrent disease 12 months after the PET/CT exam.RESULTS: Overall results for the accuracy of FDG-PETwere 93.9% of sensitivity, 64.2% of specificity, 75.6% ofpositive predictive value and 90.0% of negativepredictive value. FDG-PET was able to find 1 out of 2undetected primary tumors (base of the tongue). Thebest results were obtained regarding the detection oflocal and distant recurrences of larynx, thyroid and oralcavity cancers. CONCLUSION: The FDG-PET/CT fusionimage makes anatomical localization easier and theaccuracy for detection of recurrent disease was found tobe higher than CT alone.