CXCR4-Targeted PET Imaging of Central Nervous System B-Cell Lymphoma
Peter Herhaus, Jana Lipková, Felicitas Lammer, Igor Yakushev, Tibor Vág, Julia Slotta‐Huspenina, Stefan Habringer, Constantin Lapa, Tobias Pukrop, D. Hellwig, Benedikt Wiestler, Andreas K. Buck, Martina Deckert, Hans‐Jürgen Wester, Florian Bassermann, Markus Schwaiger, Wolfgang Weber, Bjoern Menze, Ulrich Keller
Abstract
C-X-C chemokine receptor 4 (CXCR4) is a transmembrane chemokine receptor involved in growth, survival, and dissemination of cancer, including aggressive B-cell lymphoma. MRI is the standard imaging technology for central nervous system (CNS) involvement of B-cell lymphoma and provides high sensitivity but moderate specificity. Therefore, novel molecular and functional imaging strategies are urgently required. <b>Methods:</b> In this proof-of-concept study, 11 patients with lymphoma of the CNS (8 primary and 3 secondary involvement) were imaged with the CXCR4-directed PET tracer <sup>68</sup>Ga-pentixafor. To evaluate the predictive value of this imaging modality, treatment response, as determined by MRI, was correlated with quantification of CXCR4 expression by <sup>68</sup>Ga-pentixafor PET in vivo before initiation of treatment in 7 of 11 patients. <b>Results:</b><sup>68</sup>Ga-pentixafor PET showed excellent contrast with the surrounding brain parenchyma in all patients with active disease. Furthermore, initial CXCR4 uptake determined by PET correlated with subsequent treatment response as assessed by MRI. <b>Conclusion:</b><sup>68</sup>Ga-pentixafor PET represents a novel diagnostic tool for CNS lymphoma with potential implications for theranostic approaches as well as response and risk assessment.