Use of PET to monitor the response of lung cancer to radiation treatment

Approximately 170,000 people are diagnosed with lung cancer in the United S tates each year. Many of these patients receive external beam radiation for treatment. Fluorine-18 2-fluoro-2-deoxy-D-glucose positron emission tomogr aphy (FDG PET) is increasingly being used in evaluating non-small cell lung cancer and may be of clinical utility in assessing response to treatment. In this report, we present FDG PET images and data from two patients who we re followed with a total of eight and seven serial FDG PET scans, respectiv ely, through the entire course of their radiation therapy. Changes in sever al potential response parameters are shown versus time, including lesion vo lume (V-FDG) by PET, SUVav, SUVmax, and total lesion glycolysis (TLG) durin g the course of radiotherapy. The response parameters for patient 1 demonst rated a progressive decrease; however, the response parameters for patient 2 showed an initial decrease followed by an increase. The data presented he re may suggest that the outcome of radiation therapy can be predicted by PE T imaging, but this observation requires a study of additional patients.