Dual Time Point PET Imaging in Head and Neck Squamous Cell Carcinoma

Abstract

Dual Time Point PET Imaging in Head and Neck Squamous Cell Carcinoma Objective: Dual time point 18F-fluorodeoxyglucose -positron emission tomography (DTP-PET) is a technique which may detect malignancy more accurately than standard PET/CT imaging. Our main objective was to perform a pilot study to evaluate the characteristics of DTP-PET in primary head and neck squamous cell carcinomas (HNSCC) and lymph node metastases. Study design: Case series Setting: University hospital tertiary care center Subjects and methods: 35 patients with previously untreated HNSCC underwent preoperative PET/CT at two time points (mean 41 minute time difference) from 2007-2010. Mean and maximum standardized uptake values (SUV) were measured for the primary lesion and cervical lymph node metastases at both times points and change in SUV over time was calculated. An SUV increase of 10% was used as the threshold for positivity. Results: 30 of 35 primary tumors (86%) were positive by DTPPET with an average increase in maximum SUV of 28%. 16 of 21 lymph node metastases (76%) were positive by DTP-PET with an average increase in maximum SUV of 35%. Change in mean SUV did not correlate as well with the presence of tumor. Conclusion: 86% of primary tumors and 76% of cervical lymph node metastases showed an increase in maximum SUV over time. These findings justify further study of DTP-PET as a method of detecting tumor in initial staging and restaging of HNSCC after treatment to improve the accuracy of standard PET/CT.