Objective: To evaluate the value of (18)F-FDG PET-CT for assessment of therapeutic response and prediction of patient outcome after concurrent chemoradiotherapy (CCRT) of non-small cell lung cancer (NSCLC).
Methods: Forty six patients with histologically proven stage III NSCLC had two repeated (18)F-FDG PET-CT scans either one week before therapy and at the dose of 40 ∼ 50 Gy. The SUV(max) and changes of the two groups were compared with (1) the therapeutic response and (2) treatment results and long-term survival.
Results: Of the 46 eligible cases, the pretreatment SUV(max) of the responding and non-responding groups was 7.59 ± 3.14 and 14.72 ± 4.67, respectively. The midtreatment SUV(max) of the two groups was 2.89 ± 1.39 and 9.82 ± 3.31, respectively. Significant difference(t = 4.74, P = 0.001;t = 7.23, P = 0.001) in SUV(max) was observed both before and during treatment. Furthermore, the percentage change of pretreatment and midtreatment SUV(max) was ΔSUV(max) = 61.9% ± 8.7% and ΔSUV(max) = 33.6% ± 9.0%, also with a significant difference between the two groups (t = 2.83, P = 0.007). In addition, the 1-year survival rate of the the responding and non-responding groups was 68.0% and 38.1%, respectively. The 2-year survival rate of the two groups was 64.0% and 33.3%, respectively, with a significant difference between the two groups (P = 0.043, P = 0.038).
Conclusion: (18)F-FDG PET-CT is highly effective in detecting therapeutic response in stage III NSCLC patients. The analysis of percentage change of SUV(max) provides incremental value in early prediction of therapeutic response and patient outcome.