Correlation between [¹⁸F]FDG PET/CT and volume perfusion CT in primary tumours and mediastinal lymph nodes of non-small-cell lung cancer.

Abstract

The aim of this study was to investigate correlations between glucose metabolism as determined by [(18)F]FDG PET/CT and tumour perfusion as quantified by volume perfusion CT in primary tumours and mediastinal lymph nodes (MLN) of patients with non-small-cell lung cancer (NSCLC). Enrolled in the study were 17 patients with NSCLC. [(18)F]FDG uptake was quantified in terms of SUVmax and SUVavg. Blood flow (BF), blood volume (BV) and flow extraction product (K(trans)) were determined as perfusion parameters. The correlations between the perfusion parameters and [(18)F]FDG uptake values were subsequently evaluated. For the primary tumours, no correlations were found between perfusion parameters and [(18)F]FDG uptake. In MLN, there were negative correlations between BF and SUVavg (r = -0.383), BV and SUVavg (r = -0.406), and BV and SUVmax (r = -0.377), but not between BF and SUVmax, K(trans) and SUVavg, or K(trans) and SUVmax. Additionally, in MLN with SUVmax >2.5 there were negative correlations between BF and SUVavg (r = -0.510), BV and SUVavg (r = -0.390), BF and SUVmax (r = -0.536), as well as BV and SUVmax (r = -0.346). Perfusion and glucose metabolism seemed to be uncoupled in large primary tumours, but an inverse correlation was observed in MLN. This information may help improve therapy planning and response evaluation.