Multifunctional profiling of non-small cell lung cancer using 18F-FDG PET/CT and volume perfusion CT

Abstract

The aim of this study was to investigate correlations between glucose metabolism registered by 18F-FDG PET/CT and tumor perfusion quantified by volume perfusion CT and immunohistochemical markers Ki67 and microvessel density (MVD) in patients with non-small cell lung cancer (NSCLC). Methods: Between February 2010 and April 2011, 24 consecutive patients (21 women, 3 men; mean age ± SD, 67.6 ± 6.8 y; age range, 55.6-81.3 y) with histologically proven NSCLC (14 adenocarcinoma, 9 squamous cell lung carcinoma [SCC], and 1 mixed adenocarcinoma and SCC) underwent 18F-FDG PET/CT and additional volume perfusion CT. Maximum standardized uptake value (SUV max), mean SUV, and the metabolic tumor volume were used for 18F-FDG uptake quantification. Blood flow (BF), blood volume (BV), flow extraction product (K trans), and standardized perfusion value (SPV) were determined as CT perfusion parameters. Both perfusion parameters and 18F-FDG uptake values were subsequently related to the histologic subtypes, proliferation marker Ki67, MVD according to CD34 staining, and total tumor volume. Results: Mean SUV, SUV max, and the metabolic tumor volume (mL) were 5.8, 8.7, and 32.3, respectively, in adenocarcinoma and 8.5, 12.9, and 16.8, respectively, in SCC. Mean BF (mL/100 mL/min), mean BV (mL/100 mL), and K trans (mL/100 mL/min) were 35.4, 7.3, and 27.8, respectively, in adenocarcinoma and 35.5, 10.0, and 27.8, respectively, in SCC. Moderate correlations were found between the 18F-FDG PET/CT parameters and Ki67 as well as between CT perfusion parameters and MVD but not vice versa. For all tumors, the following correlations were found: between SUV max and Ki67, r = 0.762 (P = 0.017); between SUV max and MVD, r = 20.237 (P = 0.359); between mean BF and Ki67, r = 20.127 (P = 0.626); and between mean BF and MVD, r = 0.467 (P = 0.059). Interestingly, correlations between the BF-metabolic relationship and total tumor volume were higher in SCC (r = 0.762, P = 0.017) than in adenocarcinoma (r5 20.0791, P 5 0.788). Conclusion: 18F-FDG uptake correlates with Ki67, whereas BF, BV, and Ktrans correlate with MVD. Therefore, 18F-FDG uptake and perfusion parameters provide complementary functional information. An improved tumor profiling will be beneficial for both prognosis and therapy response evaluation in these tumors. Copyright © 2012 by the Society of Nuclear Medicine, Inc.