International Journal of Hematology and Oncology 2019, Vol 29, Num 4 Page(s): 210-218
Evaluation of Chemokine Receptor-4 Expression by 68Ga – Pentixafor PET/CT in Patients with Multiple Myeloma

Elgin OZKAN1, Cigdem SOYDAL1, Ugur SAHIN2, Meral BEKSAC2, Cemaleddin OZTURK2, Sinem Civriz BOZDAG2, Pervin TOPCUOGLU2, Saskia KROPF3, Hans-Jürgen WESTER4, Ozlem Nuriye KUCUK1

1Ankara University Faculty of Medicine, Department of Nuclear Medicine, Ankara, TURKEY
2Ankara University Faculty of Medicine, Department of Haematology, Ankara, TURKEY
3Scintomics GmbH, Fürstenfeldbruck, GERMANY
4Pharmaceutical Radiochemistry, Technische Universität München, Munich, GERMANY

Keywords: Multiple myeloma, Chemokine receptors, 68Ga-Pentixafor
The aim of this study to demonstrate and compare the CXCR4 expression by means of 68Ga-Pentixafor PET/CT in patients with multiple myeloma with standard clinical parameters and 18F-FDG PET/CT findings. Twenty-four (17 women, 7 men; mean age: 58.9±12.7) multiple myeloma patients who had undergone 18F-FDG PET/CT imaging to evaluate the disease activity were included in the study. 68Ga-Pentixafor PET/CT imaging was performed within an average period of 12 days after initial 18F-FDG PET/CT imaging. 68Ga-Pentixafor PET and 18F-FDG PET/CT revealed focal pathological lesions in 13/24 (54%) and 16/24 (67%) patients, respectively. In 19/24 patients, both tracers showed concordant findings (CXCR4+ and FDG+ in 12 patients; CXCR4- and FDG- in 7patients). In the remaining 5 patients, findings were discordant. The number of focal lesions identified by means of 68Ga-Pentixafor and 18FFDG were 89 (44%) and 113 (56%), respectively. 68Ga-Pentixafor PET/CT showed more lesions in 2/12 (17%) patients, whereas 18F-FDG PET/CT was proved to be superior in 7/12 (58%) patients. In the remaining 3/12 (25%) patients, both tracers detected an equal number of lesions. There was no significant difference in appendicular and axial skeletal and extramedullary distribution ratios for both PET/CT examinations (p> 0.05). There was no statistically significant correlations between the 68Ga-Pentixafor PET/CT and 18F-FDG PET/CT positivity and disease activity, MM subtype, ISS phase, light chain disease, beta2microglobulin, albumin, creatinine, LDH, FLC and M protein levels in during scans. 68Ga-Pentixafor PET/CT cannot replace 18F-FDG PET/CT for diagnostic imaging of patients with multiple myeloma, 68Ga-PET/CT seem to be a valuable probe for patient stratification in the context of CXCR4-targeted radioligand therapy.