68Ga-Pentixafor-PET/CT imaging represents a novel approach to detect chemokine receptor CXCR4 expression in myeloproliferative neoplasms.

C-X-C motif chemokine receptor 4 (CXCR4) is an attractive target for cancer diagnosis and treatment, as it is overexpressed in many solid and hematological malignancies. This study investigated the feasibility of CXCR4-directed imaging with positron emission tomography/computed tomography (PET/CT) using 68Ga-Pentixafor to visualize and quantify disease involvement in myeloproliferative neoplasms (MPNs). Methods: 12 patients with MPNs (n = 4 primary myelofibrosis, n = 6 essential thrombocythemia, n = 2 polycythemia vera) and 5 controls underwent 68Ga-Pentixafor-PET/CT. Imaging findings were compared with immunohistochemical stainings, laboratory data and splenic volume. Results: 68Ga-Pentixafor-PET/CT was visually positive in 12/12 patients and CXCR4 target specificity could be confirmed by immunohistochemical staining. A significantly higher tracer uptake could be detected in the bone marrow of MPN patients (SUVmean 6.45±2.34 vs. 4.44±1.24). Dynamic changes of CXCR4 expression determined by 68Ga-Pentixafor-PET/CT corresponded with treatment response. Conclusion: 68Ga-Pentixafor-PET/CT represents a novel diagnostic tool to non-invasively detect and quantify the extent of disease involvement in MPNs.