Relationship between non-small cell lung cancer fluorodeoxyglucose uptake at positron emission tomography and surgical stage with relevance to patient prognosis.

Abstract

Because the tumor stage is the most significant prognostic factor for non-small cell lung cancer (NSCLC) and given that NSCLC [(18)F]fluorodeoxyglucose ((18)F-FDG) uptake appears to have prognostic significance, we examined the relationship between NSCLC (18)F-FDG uptake and surgical stage. One hundred seventy-eight patients with a proven diagnosis of NSCLC were enrolled, then imaged with (18)F-FDG positron emission tomography and their disease thoroughly staged. Primary tumor size at computed tomography and (18)F-FDG uptake were compared to overall tumor stage and to T, N, and M stage descriptors. Tumor uptake was quantitated by maximum pixel-standardized uptake value (maxSUV) and then partial volume corrected for lesion size using recovery coefficients. A significant difference in tumor size was associated with tumors of different TNM stage, T status, N status, or M status. Similarly, the primary tumor maxSUV was significantly associated with TNM stage, T status, and M status. However, we observed no significant difference in the partial-volume-corrected tumor maxSUV for different stages; different T, N, or M descriptors; tumors without evidence of spread (N(0)M(0)) versus tumors with nodal spread (N(1,2,3)M(0)); or tumors without spread (N(0)M(0)) versus all others. We found an association between tumor stage and (18)F-FDG maxSUV, but this relationship disappeared after correction of tumor uptake for lesion size. Therefore, if partial-volume-corrected (18)F-FDG uptake is prognostic of NSCLC outcome, it is not on the basis of a relationship with tumor stage but through a different mechanism.