Theranostics 2019; 9(12):3653-3658. doi:10.7150/thno.31032
Prospective non-invasive evaluation of CXCR4 expression for the diagnosis of MALT lymphoma using [68Ga]Ga-Pentixafor-PET/MRI
1. Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Austria;
2. Ludwig Boltzmann Institute Applied Diagnostics, Vienna, Austria.
3. Scintomics GmbH, Garching, Germany.
4. Department of Internal Medicine I, Division of Oncology, Medical University of Vienna, Austria.
5. Department of Biomedical Imaging and Image-guided Therapy, Division of General and Paediatric Radiology, Medical University of Vienna, Austria;
6. Christian-Doppler Laboratory for Applied Metabolomics, Division of Nuclear Medicine, Medical University of Vienna, Austria.
7. Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY.
Haug AR, Leisser A, Wadsak W, Mitterhauser M, Pfaff S, Kropf S, Wester HJ, Hacker M, Hartenbach M, Kiesewetter-Wiederkehr B, Raderer M, Mayerhoefer ME. Prospective non-invasive evaluation of CXCR4 expression for the diagnosis of MALT lymphoma using [68Ga]Ga-Pentixafor-PET/MRI. Theranostics 2019; 9(12):3653-3658. doi:10.7150/thno.31032. Available from http://www.thno.org/v09p3653.htm
MALT lymphomas express the chemokine receptor CXCR4 on a regular basis, and [68Ga]Ga-Pentixafor-PET has been shown to quantify CXCR4 expression non-invasively. We, therefore, aimed to evaluate [68Ga]Ga-Pentixafor-PET/MRI for the non-invasive assessment of MALT lymphomas.
Methods: We included 36 MALT lymphoma patients, who had not undergone previous systemic or radiation therapy, in our prospective, IRB-approved, proof-of-concept study. Involved anatomic regions were the orbit (n=14), stomach (n=10), lungs (n=5), and other sites (soft-tissues n=3; adrenal gland, tonsils, parotid gland, and urinary bladder n=1, respectively). MRI sequences included an axial 2-point Dixon T1 VIBE SPAIR 3D sequence for PET attenuation correction; a coronal T2 HASTE sequence; and an axial echo-planar imaging SPAIR-based diffusion-weighted sequence (DWI) obtained during free-breathing (b-values, 50 and 800), with corresponding ADC (apparent diffusion coefficient) maps.
Results: In 33/36 patients, there were MALT lymphomas with an increased uptake of [68Ga]Ga-Pentixafor; all current lymphoma manifestations showed an increased uptake and, accordingly, were positive on the PET/MRI. The remaining three patients had undergone surgery for their orbital MALT lymphomas prior to PET/MRI. Mean SUVmax was 8.6 ± 4.7, mean SUVmean was 4.7 ± 1.8, and mean SUVpeak was 8.0 ± 4.2. The mean SUVmax of the liver was 1.8, and the mean tumor-to-liver ratio was 2.9 ± 2.0. There were no significant differences in SUVmax (P=0.22), SUVmean (P=0.53), SUVpeak (P=0.29), or SUVt/l (P=0.92) between the four anatomic regions (orbit, stomach, lungs, other). The mean tumor volume was 146 ± 499.
Conclusions: Our results thus indicate that [68Ga]Ga-Pentixafor-PET is feasible for the assessment of MALT lymphomas, with a good tumor-to-background ratio in terms of radiotracer uptake.
Keywords: MALT lymphoma, PET, CXCR4, [68Ga]-Pentixafor, PET/MRI