Abstract
1258
Introduction: Recurrences are common for head and neck cancers necessitating regular clincal follow up. Our objective was to evaluate the performance of FDG PET scan as a surveillance tool in detecting subclinical recurrence in patients with head and neck cancers.
Methods: Retrospective analysis of F18-FDG PET/CT scans between June 2007 and February 2017 showed a total of 600 patients with head and neck cancers. Cancers such as melanoma, lymphoma, or unknown primaries metastasizing to the head and neck were excluded. 160 patients with squamous cell carcinomas received “surveillance” scans. A PETCT scan on asymptomatic patients was considered surveillance, if there was no clinical evidence of disease before the scan or if there was a prior restaging scan with no evidence of residual disease. Disease recurrence was confirmed histologically or clinically following suspicious PET evaluation.
Results: Of the 160 patients, surveillance PETCT scans showed suspected recurrent malignancy in 14 patients. Of the 14 patients with positive PETCT scans, the primary site for the squamous cell carcinomas was in the tongue for 5 patients, tonsils for 4, glottic and supraglottic 2, pyriform sinus 2, and one floor of mouth and one in retromolar trigone. One patient refused invasive workup but was determined positive on clinical follow up. Suspected PET activity was confirmed histologically in 12 patients. Of the 14 positive PET scans, only one patient had a false positive, ie inflammation on biopsy. Of the true disease recurrences: 5 were at the primary site, 4 had regional nodal metastases, 1 had mediastinal nodal metastases, 1 had lung metastases, and 2 had osseous metastases. All recurrences were detected on surveillance PETCT scans between 8 and 36 months.
Conclusions: FDG PETCT scans accurately detected subclinical recurrence in 8% of patients surveyed. The systematic use of FDG PETCT as a surveillance tool for detection of recurrence in asymptomatic patients with treated head and neck cancers should be further evaluated in larger trials.
