Combining magnetic particle imaging and magnetic fluid hyperthermia in a theranostic platform

Hensley, Daniel; Tay, Zhi Wei; Dhavalikar, Rohan; Zheng, Bo; Goodwill, Patrick; Rinaldi, Carlos; Conolly, Steven M.

doi:10.1088/1361-6560/aa5601

Cited by 132 publications

(109 citation statements)

References 61 publications

(92 reference statements)

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“…As such, MPI shows excellent promise for clinical applications such as angiography (Haegele et al 2012; Salamon et al 2016), stem cell tracking and vitality assessment (Fidler et al 2015; Them et al 2016; Zheng, Vazin, et al 2015; Zheng, von See, et al 2016), brain perfusion (Orendorff et al 2016), lung perfusion (Zhou et al 2016),lung ventilation (Nishimoto et al 2015), cancer imaging (E. Yu et al 2016), and localized hyperthermia (Murase, Aoki, et al 2015; Hensley et al 2016). …”

Section: Introductionmentioning

confidence: 99%

The relaxation wall: experimental limits to improving MPI spatial resolution by increasing nanoparticle core size

Tay

Hensley

Vreeland³

et al. 2017

Biomed. Phys. Eng. Express

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Magnetic Particle Imaging (MPI) is a promising new tracer modality with zero attenuation in tissue, high contrast and sensitivity, and an excellent safety profile. However, the spatial resolution of MPI is currently around 1 mm in small animal scanners. Especially considering tradeoffs when scaling up MPI scanning systems to human size, this resolution needs to be improved for clinical applications such as angiography and brain perfusion. One method to improve spatial resolution is to increase the magnetic core size of the superparamagnetic nanoparticle tracers. The Langevin model of superparamagnetism predicts a cubic improvement of spatial resolution with magnetic core diameter. However, prior work has shown that the finite temporal response, or magnetic relaxation, of the tracer increases with magnetic core diameter and eventually leads to blurring in the MPI image. Here we perform the first wide ranging study of 5 core sizes between 18–32 nm with experimental quantification of the spatial resolution of each. Our results show that increasing magnetic relaxation with core size eventually opposes the expected Langevin behavior, causing spatial resolution to stop improving after 25 nm. Different MPI excitation strategies were experimentally investigated to mitigate the effect of magnetic relaxation. The results show that magnetic relaxation could not be fully mitigated for the larger core sizes and the cubic resolution improvement predicted by the Langevin was not achieved. This suggests that magnetic relaxation is a significant and unsolved barrier to achieving the high spatial resolutions predicted by the Langevin model for large core size SPIOs.

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Section: Introductionmentioning

confidence: 99%

The relaxation wall: experimental limits to improving MPI spatial resolution by increasing nanoparticle core size

Tay

Hensley

Vreeland³

et al. 2017

Biomed. Phys. Eng. Express

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“…More specific image-guided treatment of the actual cancer tissue is highly desirable. Using MPI to precisely determine the location of SPIO before heating may overcome these limitations through an image-guided theranostic platform (Figure 7)[55–57]. To proof this, localization of thermal damage and therapy was validated with luciferase activity and histological assessment [55].…”

Section: Spios As Mpi Tracersmentioning

confidence: 99%

Superparamagnetic iron oxides as MPI tracers: A primer and review of early applications

Bulte

2019

Advanced Drug Delivery Reviews

157

123

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Magnetic particle imaging (MPI) has recently emerged as a non-invasive, whole body imaging technique that detects superparamagnetic iron oxide (SPIO) nanoparticles similar as those used in magnetic resonance imaging (MRI). Based on tracer “hot spot” detection instead of providing contrast on MRI scans, MPI has already proven to be truly quantitative. Without the presence of endogenous background signal, MPI can also be used in certain tissues where the endogenous MRI signal is too low to provide contrast. After an introduction to the history and simplified principles of MPI, this review focuses on early MPI applications including MPI cell tracking, multiplexed MPI, perfusion and tumor MPI, lung MPI, functional MPI, and MPI-guided hyperthermia. While it is too early to tell if MPI will become a mainstay imaging technique with the (theoretical) sensitivity that it promises, and if it can successfully compete with SPIO-based 1H MRI and perfluorocarbon-based 19F MRI, it provides unprecedented opportunities for exploring new nanoparticle-based imaging applications.

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“…For clinical translation, the MRI and CT methods are attractive in that they are already routinely available worldwide, whereas while MPI is a promising emerging modality [25], it has a long way to go before it might become established in clinical settings. Regarding MRI versus CT, at first sight it might seem that MRI would be the natural modality to use, given that it is very sensitive to iron oxide nanoparticles, some of which are or have been used as intravenous T 1 and T 2 Ã contrast agents [26].…”

Section: Factors Affecting the Dispersion Of Magnetic Nanoparticles Imentioning

confidence: 99%

Commentary on the clinical and preclinical dosage limits of interstitially administered magnetic fluids for therapeutic hyperthermia based on current practice and efficacy models

Southern¹,

Pankhurst²

2017

International Journal of Hyperthermia

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We offer a critique of what constitutes a suitable dosage limit, in both clinical and preclinical studies, for interstitially administered magnetic nanoparticles in order to enable therapeutic hyperthermia under the action of an externally applied alternating magnetic field. We approach this first from the perspective of the currently approved clinical dosages of magnetic nanoparticles in the fields of MRI contrast enhancement, sentinel node detection, iron replacement therapy and magnetic thermoablation. We compare this to a simple analytical model of the achievable hyperthermia temperature rise in both humans and animals based on the interstitially administered dose, the heating and dispersion characteristics of the injected fluid, and the strength and frequency of the applied magnetic field. We show that under appropriately chosen conditions a therapeutic temperature rise is achievable in clinically relevant situations. We also show that in such cases it may paradoxically be harder to achieve the same therapeutic temperature rise in a preclinical model. We comment on the implications for the evidence-based translation of hyperthermia based interventions from the laboratory to the clinic.

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Combining magnetic particle imaging and magnetic fluid hyperthermia in a theranostic platform

Cited by 132 publications

References 61 publications

The relaxation wall: experimental limits to improving MPI spatial resolution by increasing nanoparticle core size

The relaxation wall: experimental limits to improving MPI spatial resolution by increasing nanoparticle core size

Superparamagnetic iron oxides as MPI tracers: A primer and review of early applications

Commentary on the clinical and preclinical dosage limits of interstitially administered magnetic fluids for therapeutic hyperthermia based on current practice and efficacy models

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