Assessment of tissue perfusion of pancreatic cancer as potential imaging biomarker by means of Intravoxel incoherent motion MRI and CT perfusion: correlation with histological microvessel density as ground truth
Philipp Mayer, Franziska Fritz, Marco Koell, Stephan Skornitzke, Frank Bergmann, Matthias M. Gaida, Thilo Hackert, Klaus Maier‐Hein, Frederik B. Laun, Hans‐Ulrich Kauczor, Lars Grenacher, Miriam Klauß, Wolfram Stiller
Abstract
Abstract Background/objectives The aim of this study was to compare intravoxel incoherent motion (IVIM) diffusion weighted (DW) MRI and CT perfusion to assess tumor perfusion of pancreatic ductal adenocarcinoma (PDAC). Methods In this prospective study, DW-MRI and CT perfusion were conducted in nineteen patients with PDAC on the day before surgery. IVIM analysis of DW-MRI was performed and the parameters perfusion fraction f , pseudodiffusion coefficient D*, and diffusion coefficient D were extracted for tumors, upstream, and downstream parenchyma. With a deconvolution-based analysis, the CT perfusion parameters blood flow (BF) and blood volume (BV) were estimated for tumors, upstream, and downstream parenchyma. In ten patients, intratumoral microvessel density (MVD tumor ) and microvessel area (MVA tumor ) were analyzed microscopically in resection specimens. Correlation coefficients between IVIM parameters, CT perfusion parameters, and histological microvessel parameters in tumors were calculated. Receiver operating characteristic (ROC) analysis was performed for differentiation of tumors and upstream parenchyma. Results f tumor significantly positively correlated with BF tumor (r = 0.668, p = 0.002) and BV tumor (r = 0.672, p = 0.002). There were significant positive correlations between f tumor and MVD tumor / MVA tumor (r ≥ 0.770, p ≤ 0.009) as well as between BF tumor and MVD tumor / MVA tumor (r ≥ 0.697, p ≤ 0.025). Correlation coefficients between f tumor and MVD tumor / MVA tumor were not significantly different from correlation coefficients between BF tumor and MVD tumor / MVA tumor ( p ≥ 0.400). Moreover, f , BF, BV, and permeability values (PEM) showed excellent performance in distinguishing tumors from upstream parenchyma (area under the ROC curve ≥0.874). Conclusions The study shows that IVIM derived f tumor and CT perfusion derived BF tumor similarly reflect vascularity of PDAC and seem to be comparably applicable for the evaluation of tumor perfusion for tumor characterization and as potential quantitative imaging biomarker. Trial registration DRKS, DRKS00022227, Registered 26 June 2020, retrospectively registered. https://www.drks.de/drks_web/navigate.do?navigationId=trial . HTML&TRIAL_ID=DRKS00022227.