FDG PET evaluation of head and neck cancer: value of imaging the thorax

Patients with primary tumors of the head and neck have been reported to have a high rate of synchronous primary tumors of the upper aerodigestive tract. This study was performed to determine whether inclusion of the thorax in the scan volume would be diagnostically useful for positron emission tomography (PET) with [F-18] fluorodeoxy-D-glucose (FDG) in patients with primary tumors of the head and neck.

FDG PET scans from the midcranium to the diaphragm were obtained on 56 patients with a variety of head and neck tumors on initial examination before definitive therapy. PET findings in the chest were correlated with results of all other imaging studies, biopsy results, and clinical follow-up.

In nine studies (16%), areas of increased FDG uptake in the chest were seen and were judged to be tumors. Six of these probably were false-positive results, although one of these six may have been unconfirmed true positives. Of the three confirmed true-positive studies, two were obvious from other routine studies. In only one case did the PET study reveal a significant lesion not found by means of routine evaluation, resulting in a case-finding yield of 2%. If the unconfirmed possible true-positive results are included, the case-finding yield increases to 4%.

No compelling indication was seen for including the chest in PET studies of patients with head and neck cancer.