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

The aim of this study was to investigate correlations between glucose metabolism registered by (18)F-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).

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 (18)F-FDG PET/CT and additional volume perfusion CT. Maximum standardized uptake value (SUV(max)), mean SUV, and the metabolic tumor volume were used for (18)F-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 (18)F-FDG uptake values were subsequently related to the histologic subtypes, proliferation marker Ki67, MVD according to CD34 staining, and total tumor volume.

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 (18)F-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 = -0.237 (P = 0.359); between mean BF and Ki67, r = -0.127 (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 (r = -0.0791, P = 0.788).

(18)F-FDG uptake correlates with Ki67, whereas BF, BV, and K(trans) correlate with MVD. Therefore, (18)F-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.