Magnetic Induction Heating of Ferromagnetic Implants for Inducing Localized Hyperthermia in Deep-Seated Tumors

Stauffer, Paul R.; Cetas, Thomas C.; Jones, R. Clark

doi:10.1109/tbme.1984.325334

Cited by 182 publications

(71 citation statements)

References 21 publications

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“…Similarly, energy absorption, and thus background heating, of water and tissue is insignificant in the 350-400 kHz frequency regime. [15] In contrast, when applied to magnetic materials, these fields produce heat as the magnetic dipole of the material aligns with the external field. [16,17] We conjugated a 30 bp DNA to dextran-coated iron oxide nanoparticles and added a complement of 12, 18, or 24 bp linked to a model drug, a fluorophore.…”

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confidence: 99%

Remotely Triggered Release from Magnetic Nanoparticles

et al. 2007

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confidence: 99%

Remotely Triggered Release from Magnetic Nanoparticles

et al. 2007

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“…In order to generate heat, we propose to distribute small 1 mm spherical ferromagnetic particles uniformly throughout the interior of a patient-customized silicone implant that fills the tumor resection cavity. This contrasts with the traditional use of ferromagnetic implant arrays which are highly invasive and require numerous closely spaced interstitial needles or catheters throughout an intact tumor volume (Chin and Stauffer, 1991, Stauffer et al, 1984b, Stauffer et al, 1984a, Mack et al, 1993, Tompkins et al, 1994. That multiple needle implant procedure is time intensive for the surgeon and painful for the patient, and if the spacing is increased from 1.0 towards 1.5 cm for clinical practicality, the ability to achieve homogenous heating within the target volume becomes compromised (Chin and Stauffer, 1991).…”

Section: Discussionmentioning

confidence: 99%

“…One hot source technique that overcomes these issues is the use of external magnetic fields to couple energy non-invasively into implanted ferromagnetic needles or spheres (ferroseeds). This minimally invasive approach has been investigated by numerous groups beginning almost 45 years ago , Burton et al, 1971, Kobayashi et al, 1986, Stauffer et al, 1984a, Mack et al, 1993, Tucker et al, 2000, Stauffer et al, 1984b. When these 1-2 mm diameter ferromagnetic materials are immersed in a sub-megahertz radiofrequency magnetic field, eddy currents are induced on the metal surface.…”

Section: Introductionmentioning

confidence: 99%

Tumor bed brachytherapy for locally advanced laryngeal cancer: a feasibility assessment of combination with ferromagnetic hyperthermia

Stauffer¹,

Vasilchenko²,

Osintsev³

et al. 2016

Biomed. Phys. Eng. Express

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Purpose. To assess the feasibility of adding hyperthermia to an original method of organ-preserving brachytherapy treatment for locally advanced head and neck tumors. Methods and materials. The method involves organ-preserving tumor resection and adjunctive high-dose-rate (HDR) brachytherapy delivered via afterloading catheters. These catheters are embedded in a polymeric implant prepared intraoperatively to fill the resection cavity, allowing precise computer planning of dose distribution in the surrounding at-risk tumor bed tissue. Theoretical and experimental analyzes address the feasibility of heating the tumor bed implant by coupling energy from a 100 kHz magnetic field applied externally into ferromagnetic particles, which are uniformly distributed within the implant. The goal is to combine adjuvant hyperthermia (40 °C-45 °C) to at-risk tissue within 5 mm of the resection cavity for thermal enhancement of radiation and chemotherapy response. Results. A fiveyear relapse free survival rate of 95.8% was obtained for a select group of 48 male patients with T3N0M0 larynx tumors, when combining organ-preserving surgery with HDR brachytherapy from a tumor bed implant. Anticipating the need for additional treatment in patients with more advanced disease, a theoretical analysis demonstrates the ability to heat at-risk tissue up to 10 mm from the surface of an implant filled with magnetically coupled ferromagnetic balls. Using a laboratory induction heating system, it takes just over 2 min to increase the target tissue temperature by 10 °C using a 19% volume fraction of ferromagnetic spheres in a 2 cm diameter silicone implant. Conclusion. The promising clinical results of a 48 patient pilot study demonstrate the feasibility of a new organ sparing treatment for laryngeal cancer. Anticipating the need for additional therapy, theoretical estimations of potential implant heating are confirmed with laboratory experiments, preparing the way for future implementation of a thermobrachytherapy implant approach for organ-sparing treatment of locally advanced laryngeal cancer.

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“…Basic research mainly focused on heat generation by different materials (19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33), thermoseed processing methods (34,35), heating coil designs (36,37), improving uniform temperature distribution (38)(39)(40)(41)(42)(43)(44)(45)(46)(47), and the in vivo effects on animals (12,21,25,28,30,32,33,36,38,41,(48)(49)(50)(51). Clinical research mainly focused on intracranial tumors (52,53), prostate cancer (54)(55)(56)57), and some other tumors …”

Section: Discussionmentioning

confidence: 99%

Feasibility study of high-temperature thermoseed inductive hyperthermia in melanoma treatment

Xia

Li²,

Zhao³

et al. 2011

Oncol Rep

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Abstract. Current treatment modalities for melanoma do not offer satisfactory efficacy. We have developed a new, minimally invasive hyperthermia technology based on radio-frequency hyperthermia. Herein, we investigated the feasibility of using a nickel-copper thermoseed for inductive hyperthermia at a relatively high temperature (46-55˚C). In vitro, the thermoseed showed good thermal effects and effective killing of B16/F10 melanoma cells. Temperatures of 53.1±0.5˚C were achieved for a single thermoseed and 56.5±0.5˚C for two in parallel (spacing 5 mm). No B16/F10 melanoma cells survived with heating time longer than 20 min in the parallel thermoseed group. Magnetic fields or thermoseeds alone did not affect the survival rate of B16/F10 cells (P>0.05). In vivo, B16/F10 melanoma cells were subcutaneously injected into the right axilla of C57BL/6 mice. After the tumors grew to ~11-13 mm, two thermoseeds (spacing 5 mm) were implanted into the tumors and the mice were subjected to an alternating magnetic field (100-250 kHz, 15 kA/m) to induce hyperthermia. The temperature at the center of the tumor reached 46˚C at 5 min and plateaued at 50˚C. Thermoseed treatment produced large necrotic areas, inhibited tumor growth in 60% (6 of 10) of animals and prolonged survival time (P<0.05). Thus, with further optimization and testing, high-temperature thermoseed inductive hyperthermia may have therapeutic potential for melanoma.

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Magnetic Induction Heating of Ferromagnetic Implants for Inducing Localized Hyperthermia in Deep-Seated Tumors

Cited by 182 publications

References 21 publications

Remotely Triggered Release from Magnetic Nanoparticles

Remotely Triggered Release from Magnetic Nanoparticles

Tumor bed brachytherapy for locally advanced laryngeal cancer: a feasibility assessment of combination with ferromagnetic hyperthermia

Feasibility study of high-temperature thermoseed inductive hyperthermia in melanoma treatment

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