Prognostic value of serial [18F]fluorodeoxyglucose PET-CT uptake in stage III patients with non-small cell lung cancer treated by concurrent chemoradiotherapy.

OBJECTIVE: To evaluate (18)FDG PET-CT for the assessment of therapy response and prediction of patient outcome after concurrent chemoradiotherapy (CCRT) for non-small cell lung cancer (NSCLC). METHODS: Forty-six patients with pathologically proven stage III NSCLC had 2 serial FDG PET-CT scans, before and during CCRT. The maximum standardized uptake value (SUV(max)) of the primary lung lesion was calculated. The value changes of SUV(max) before and during treatment were calculated according to the following equation: SUV=(SUV(before)-SUV(during))100%/SUV(before). The relationship between changes of the SUV(max) and the therapy response as well as long-term survival was studied in the responsive and non-responsive groups after CCRT. RESULTS: Of the 46 enrolled patients, after a medicine follow-up of 2 years, the initial SUV(max) in the responsive and non-responsive groups was 7.59±3.14 and 14.72±4.67, respectively. The SUV(max) during treatment in the two groups was 2.89±1.39 and 9.82±3.31, respectively. Significant difference (P=0.001; P=0.001) in SUV(max) was observed either before or during treatment. Furthermore, the percent change of SUV(max) before and during treatment was 61.91±86.69 and 33.56±90.37, respectively. There was significant difference between these two groups (P=0.007). In addition, the 1-year survival rate in the responsive and non-responsive group was 73% and 69%, respectively. The 2-year survival rate in the two groups was 40% and 37%, respectively. There was significant difference between these two groups (P=0.001). CONCLUSIONS: (18)FDG PET-CT is an effective method in the prediction of therapy response in patients with stage III NSCLC. The analysis of percent change of SUV(max) provides additional value in early prediction of therapy response and patient outcome.