Dual Time Point Positron Emission Tomography Imaging in the Head and Neck

Abstract

Objective: Dual time point 18F-fluorodeoxyglucose-positron emission tomography (DTP-PET) is a new modality which may detect malignancy more accurately than standard PET/CT. 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. Method: A total of 36 patients with previously untreated HNSCC underwent preoperative PET/CT at 2 time points (mean 41-minute time difference) from 2007 to 2010. Mean and maximum standardized uptake values (SUV) were measured for the primary lesion and cervical lymph node metastases at both time points, and change in SUV over time was calculated. Results: A total of 32 of 36 primary tumors (89%) had an increase in maximum SUV, between 13.93% and 264.65% (mean 43.7%) normalized to a 1-hour time difference. A total of 16 of 21 lymph node metastases (76%) had an increase in maximum SUV, between 13.49% and 284.15% (mean 57.1%). Change in mean SUV did not correlate as well with the presence of tumor. Conclusion: This is the first description of DTP-PET in HNSCC. A total of 89% of primary tumors 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 after treatment.