The application of magnetic particle imaging in targeted cancer treatments

Introduction: In 2005, a completely new quantitative imaging method called magnetic particle imaging (MPI) was introduced, which uses the nonlinear re-magnetization behavior of magnetic nanoparticles (MNp) to determine their local concentration. This article aims to introduce MPI and its applications to the Iranian scientific community. Then quantitative drug release, as one of the clinical applications of MPI, is discussed.Description: MPI relies on the response of MNp, which can be used as tracers for medical imaging, to an alternating magnetic field. It provides a unique combination of features including high sensitivity, spatial and temporal resolution, inherent quantitative and no ionizing radiation; which makes it a promising method for several clinical applications. Apply MPI by using drug-loaded MNp would enable tracking the biodistribution of the drug. In the main article, the properties of usable MNp in MPI are introduced.Discussion and Conclusion: MPI is well suited for applications that can use tracer materials flowing in the blood stream for a certain amount of time including diagnosis and assessment of cardiovascular disease. The other applications of MPI are in oncology, sentinel lymph node imaging, hyperthermia, cell labeling and tracking, gastrointestinal imaging and lung imaging. Furthermore, specific ligands can be loaded on MNp for targeted imaging as well as chemotherapeutic drugs for targeted therapy. Furthermore, drug release has been monitored using imaging modalities including optical imaging, photoacoustic imaging and magnetic resonance imaging (MRI). However, the penetration depth of optical imaging and photoacoustic imaging in biological tissues is limited. Also, MRI is not linearly quantitative and intrinsic/background signals can convolute drug distribution signals, making it generally unsuitable for quantitative clinical measures of drug release. MPI is likely an ideal imaging modality to monitor drug release because it offers large imaging depths and a linearly quantifiable signal, high sensitivity, low magnetic fields, and real-time imaging capability.