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

Purpose: Because the tumor stage is the most significant prognostic factor for non-small cell lung cancer (NSCLC) and given that NSCLC [ ¹⁸F]fluorodeoxyglucose (¹⁸F-FDG) uptake appears to have prognostic significance, we examined the relationship between NSCLC ¹⁸F-FDG uptake and surgical stage. Experimental Design: One hundred seventy-eight patients with a proven diagnosis of NSCLC were enrolled, then imaged with ¹⁸F-FDG positron emission tomography and their disease thoroughly staged. Primary tumor size at computed tomography and ¹⁸F-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. Results: 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 (N₀M₀) versus tumors with nodal spread (N_1,2,3M₀); or tumors without spread (N₀M₀) versus all others. Conclusions: We found an association between tumor stage and ¹⁸F-FDG maxSUV, but this relationship disappeared after correction of tumor uptake for lesion size. Therefore, if partial-volume-corrected ¹⁸F-FDG uptake is prognostic of NSCLC outcome, it is not on the basis of a relationship with tumor stage but through a different mechanism.