In vivo monitoring of magnetic nanoparticle quantity in tumor bearing mice by multichannel magnetorelaxometry for thermal ablation studies

Abstract

Event Abstract Back to Event In vivo monitoring of magnetic nanoparticle quantity in tumor bearing mice by multichannel magnetorelaxometry for thermal ablation studies Heike Richter1*, Melanie Kettering2, Frank Wiekhorst1, Olaf Kosch1, Uwe Steinhoff1, Kay Schwarz1, Peter Zirpel1, Ingrid Hilger2 and Lutz Trahms1 1 Physikalisch-Technische Bundesanstalt, Germany 2 University Hospital, Institute of Diagnostic and Interventional Radiology, Germany In magnetic thermal ablation, superparamagnetic iron oxide nanoparticles (MNP) that are accumulated in a tumor are exposed to an externally applied alternating magnetic field and generate heat, thereby inactivating cancer cells with minimal side-effects to the normal tissue. The intratumoral quantity of MNP needs to be thoroughly controlled to govern adequate heat production in the carcinoma region. Here, we investigate the capability of magnetorelaxometry (MRX) for the in vivo quantification of MNP accumulation in the tumor region and, moreover, the feasibility of non-invasive, non-contact monitoring the MNP uptake in freely moving SCID-conscious mice. We examined a BT-474 adenocarcinoma bearing mouse, which previously got an intratumoral injection of MNP (fluidMAG-D, chemicell GmbH, Berlin) followed by a thermal ablation treatment 24h after MNP injection. Using a 304-multichannel biomagnetic SQUID system in a magnetically shielded room, we performed MRX measurements of the mouse in the pre and post phase of thermal ablation. The mouse was magnetized using a Helmholtz coil (d 85 cm) with a magnetic field of 1.0 mT. The relaxation of the magnetic moment of MNP after switching off the magnetic field was measured for 90 s. We present results of a magnetic dipole model fit applying a Levenberg-Marquardt algorithm. In the presence of motion, it was therewith feasible to obtain position and magnitude of the magnetic moment and hence to quantify the nanoparticle accumulation in the mouse. The findings of our methodical study demonstrate that magnetorelaxometry is well-suited to monitor quantitatively the MNP accumulation without anesthesia before and after cancer therapy by magnetic heating, being an important precondition for treatment success. Conference: Biomag 2010 - 17th International Conference on Biomagnetism , Dubrovnik, Croatia, 28 Mar - 1 Apr, 2010. Presentation Type: Poster Presentation Topic: Nanoparticles, Biosusceptometry and Effects of Magnetic Fields Citation: Richter H, Kettering M, Wiekhorst F, Kosch O, Steinhoff U, Schwarz K, Zirpel P, Hilger I and Trahms L (2010). In vivo monitoring of magnetic nanoparticle quantity in tumor bearing mice by multichannel magnetorelaxometry for thermal ablation studies. Front. Neurosci. Conference Abstract: Biomag 2010 - 17th International Conference on Biomagnetism . doi: 10.3389/conf.fnins.2010.06.00391 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 08 Apr 2010; Published Online: 08 Apr 2010. * Correspondence: Heike Richter, Physikalisch-Technische Bundesanstalt, Berlin, Germany, heike.richter@ptb.de Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Heike Richter Melanie Kettering Frank Wiekhorst Olaf Kosch Uwe Steinhoff Kay Schwarz Peter Zirpel Ingrid Hilger Lutz Trahms Google Heike Richter Melanie Kettering Frank Wiekhorst Olaf Kosch Uwe Steinhoff Kay Schwarz Peter Zirpel Ingrid Hilger Lutz Trahms Google Scholar Heike Richter Melanie Kettering Frank Wiekhorst Olaf Kosch Uwe Steinhoff Kay Schwarz Peter Zirpel Ingrid Hilger Lutz Trahms PubMed Heike Richter Melanie Kettering Frank Wiekhorst Olaf Kosch Uwe Steinhoff Kay Schwarz Peter Zirpel Ingrid Hilger Lutz Trahms Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.