Early prediction of response in patients with NSCLC during platin based chemotherapy by FDG-PET

The aim of this study was to evaluate whether FDG-PET allows to detect tumour response early during the course of chemotherapy (CTX) of NSCLC. This study included 41 patients with advanced inoperable NSCLC, who underwent platin based combination CTX. A FDG-PET of the primary tumour was performed prior to and after one cycle of CTX. Changes of tumour FDG-uptake measured by standardized uptake values (SUV) were correlated with best response to therapy as assessed by CT according to RECIST criteria. Best response measured by CT were 16/40 partial responses, 14/40 stable diseases and 10/40 progressive diseases. I patient was not evaluable for response due to early death. There was a significant correlation between the decrease of SUV and subsequent response (p = 0.0002). Using a cut-off value of 20% reduction of FDG-uptake response was predicted with a sensitivity of 88% and a specificity of 72%.