Head and neck cancer: effect of food ingestion on uptake of C-11 methionine.

Abstract

To determine the influence of a standardized meal on tumor uptake measured with positron emission tomography (PET) and L-(methyl-carbon-11) methionine. Five patients with untreated squamous cell cancer of the head and neck underwent PET, first in a fasting state and then 6-7 days later after ingesting a liquid meal. All tumors were seen on PET scans, and image quality remained good after food ingestion. The standardized uptake values of the tumors were 3.7-11.4 in the fasting state but decreased after the meal (range, 3.3-10.0; P < .04). No substantial change was measured in tumor C-11 methionine influx constants (Ki values). Although cancer imaging with PET and C-11 methionine can be performed even in the patient has not fasted, a standardized meal may decrease tumor C-11 methionine uptake.