Thermoablation of malignant kidney tumors using magnetic nanoparticles: an in vivo feasibility study in a rabbit model.
The objective of this study was to assess the technical feasibility of CT-guided magnetic thermoablation for the treatment of malignant kidney tumors in a VX2 tumor rabbit model. VX2 tumors were implanted into the kidneys of five rabbits and allowed to grow for 2 weeks. After preinterventional CT perfusion imaging, CT-guided injection of superparamagnetic iron oxide particles (300 microl) was performed, followed by exposure of the animals to an alternating electromagnetic field for 15 min (approximately 0.32 kA/m). Then animals underwent CT perfusion imaging again. Afterward, animals were sacrificed and kidneys were dissected for macroscopic and histological evaluation. Changes in perfusion before and after exposure to the alternating magnetic field were analyzed. In one animal no tumor growth could be detected so the animal was used for optimization of the ablation procedure including injection technique and peri-interventional cross-sectional imaging (CT, MRI). After image-guided intratumoral injection of ferrofluids, the depiction of nanoparticle distribution by CT correlated well with macroscopic evaluation of the dissected kidneys. MRI was limited due to severe susceptibility artefacts. Postinterventional CT perfusion imaging revealed a perfusion deficiency around the ferrofluid deposits. Histological workup showed different zones of thermal damage adjacent to the ferrofluid deposits. In conclusion, CT-guided magnetic thermoablation of malignant kidney tumors is technically feasible in an animal model and results in a perfusion deficiency indicating tumor necrosis as depicted by CT perfusion imaging and shown in histological evaluation.
Applied Medical Engineering, Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University, Aachen, Germany. bruners@hia.rwth-aachen.de
Philipp
P
Bruners
Till
T
Braunschweig
Michael
M
Hodenius
Hubertus
H
Pietsch
Tobias
T
Penzkofer
Martin
M
Baumann
Rolf W
RW
Günther
Thomas
T
Schmitz-Rode
Andreas H
AH
Mahnken
D000818:Animals; D004195:Disease Models, Animal; D005240:Feasibility Studies; D005290:Ferric Compounds / Q000627:therapeutic use*; D006979:Hyperthermia, Induced / Q000379:methods*; D007680:Kidney Neoplasms / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D055909:Magnetic Field Therapy / Q000379:methods*; D008297:Male; D053768:Metal Nanoparticles / Q000627:therapeutic use*; D009336:Necrosis / Q000473:pathology; D011817:Rabbits; D014057:Tomography, X-Ray Computed
D005290:Ferric Compounds; C000499:ferric oxide