2026-06-30T03:03:41Zhttps://repisalud.isciii.es/rest/oai/request

oai:repisalud.isciii.es:20.500.12105/93262024-09-27T09:09:36Zcom_20.500.12105_19604com_20.500.12105_2051col_20.500.12105_19605

00925njm 22002777a 4500 dc Mason, Christian A author Kossatz, Susanne author Carter, Lukas M author Pirovano, Giacomo author Brand, Christian author Guru, Navjot author Perez-Medina, Carlos author Lewis, Jason S author Mulder, Willem J M author Reiner, Thomas author 2020-03 The immune function within the tumor microenvironment has become a prominent therapeutic target, with tumor-associated macrophages (TAMs) playing a critical role in immune suppression. We propose an 89Zr-labeled high-density lipoprotein (89Zr-HDL) nanotracer as a means of monitoring response to immunotherapy. Methods: Female MMTV-PyMT mice were treated with pexidartinib, a colony-stimulating factor 1 receptor (CSF1R) inhibitor, to reduce TAM density. The accumulation of 89Zr-HDL within the tumor was assessed using PET/CT imaging and autoradiography, whereas TAM burden was determined using immunofluorescence. Results: A significant reduction in 89Zr-HDL accumulation was observed in PET/CT images, with 2.9% ± 0.3% and 3.7% ± 0.2% injected dose/g for the pexidartinib- and vehicle-treated mice, respectively. This reduction was corroborated ex vivo and correlated with decreased TAM density. Conclusion: These results support the potential use of 89Zr-HDL nanoparticles as a PET tracer to quickly monitor the response to CSF1R inhibitors and other therapeutic strategies targeting TAMs. J Nucl Med. 2020; 61(3):433-436 10.2967/jnumed.119.230466 1535-5667 0161-5505 Journal of nuclear medicine : official publication, Society of Nuclear Medicine 31420495 http://hdl.handle.net/20.500.12105/9326 CSF1R inhibitor HDL PET/CT imaging Immunotherapy Tumor-associated macrophages An 89Zr-HDL PET Tracer Monitors Response to a CSF1R Inhibitor