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Journal ArticleDOI

Design and Analysis of Novel Focused Hyperthermia Devices

18 Oct 2012-Vol. 48, Iss: 11, pp 3254-3257
TL;DR: In this article, a novel ac and dc magnetic field combined MFH system, targeting the treatment area, is presented to produce an accurately focused magnetic field to abate the tumor cells.
Abstract: Magnetic fluid hyperthermia (MFH) is a promising cancer therapy by virtue of its good depth penetration. As the injected magnetic fluids of MFH are inevitably distributed in the tumor as well as in normal tissues nearby, it is difficult to accurately heat and ablate the targeted tumor without damaging the surrounding healthy tissues. Based on the observation that magnetic nanoparticles are only heated by alternating fields and not by static dc fields, it is possible to exploit such findings in MFH therapy to provide an efficient cure for cancer patients. To avoid unnecessary heating of healthy tissues, a novel system is proposed to set up a dc magnetic field around the tumor target. At the same time, the system creates a field-free region (FFR) with negligible static magnetic field in the target area. The target area can then be fully heated by an alternating field whereas the nearby tissues are not heated. In this paper, a novel ac and dc magnetic field combined MFH system, targeting the treatment area, is presented to produce an accurately focused magnetic field to abate the tumor cells. The proposed method is validated using finite element analysis.
Citations
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Journal ArticleDOI
TL;DR: Previous models for estimating the energy dissipation rates of magnetic nanoparticles in uniform AMFs are extended to provide theoretical predictions of how the selection magnetic field gradient used in MPI can be used to selectively actuate heating by magnetic nanop particles in the low bias field region of the selection magnet field gradient.

42 citations

Book ChapterDOI
01 Jan 2018
TL;DR: This chapter discusses the main biological and physiological effects that are at the basis of the use of heating as an oncological treatment and of the main hyperthermia modalities, and presents a recently proposed criterion for the optimal choice of the working conditions in Magnetic Nanoparticle Hyperthermia.
Abstract: The synergic exploitation of electromagnetic fields and nano-components has led, in the last two decades, to the definition of new therapeutic tools for the treatment of cancer. One of these tools is the Magnetic Nanoparticle Hyperthermia, an emerging hyperthermic treatment where the tumor heating is achieved by accumulating into it magnetic nanoparticles and applying a low frequency magnetic field. Magnetic Nanoparticle Hyperthermia is very attractive thanks to the biocompatibility and low toxicity of the employed magnetic nanoparticles and the possibility of their selective accumulation into the tumor by means of minimally invasive administration routes. Moreover, they exhibit high dissipation capability and the transparency of the human tissues to low frequency magnetic fields allows treating tumors deeply located in the body. For these reasons, Magnetic Nanoparticle Hyperthermia has been extensively investigated, and clinical trials on human patients have been performed since 2003, with encouraging results and reduced side effects, especially concerning brain tumors. In this framework, an important topic is the characterization, both theoretical and experimental, of the properties, particularly the losses, of magnetic nanoparticles. The aim is to identify the nanoparticle parameters (size and shape) and the exposure conditions (magnetic field amplitude and frequency) that maximize the dissipation capability of the magnetic nanoparticles, in order to minimize their concentration in the tumor. However, maximizing the magnetic losses is only one face of the coin: one must also avoid overheating of the healthy tissue surrounding the tumor, due to the eddy currents induced by the applied field. Therefore, one should actually face a more complex constrained optimization problem. This explains in part why the setting of the operative parameters is still based on empirical, possibly over-restrictive, criteria, although the individuation of the actual optimal working conditions is a key point to extend its clinical effectiveness. In this chapter we will prevalently address this last aspect of Magnetic Nanoparticle Hyperthermia. We will begin with an overview of the main biological and physiological effects that are at the basis of the use of heating as an oncological treatment and of the main hyperthermia modalities. Next, we will introduce and discuss Magnetic Nanoparticle Hyperthermia, reporting the main results of its feasibility assessment and of the clinical trials performed up to now. Then, after revising the state of the art and current issues concerning the optimization of the magnetic nanoparticle losses, we will present a recently proposed criterion for the optimal choice of the working conditions in Magnetic Nanoparticle Hyperthermia, critically discussing the reliability of the analytical models on which it is based. Numerical results relative to the challenging and clinically relevant case of brain tumors, obtained by exploiting a 3D realistic model of the human head, will be presented, discussing their significance and practical relevance. Then, exploiting these results, the limits of clinical applicability of Magnetic Nanoparticle Hyperthermia for the treatment of brain tumors in adult patients will be estimated. A discussion on the possible future developments will conclude the chapter.

12 citations

Book ChapterDOI
01 Jan 2019
TL;DR: In this paper, the authors introduce and discuss the emerging field of image-guided thermal therapy using magnetic particle imaging (MPI) and magnetic fluid hyperthermia (MFH), where the heat dissipated from the MNPs in the presence of an alternating magnetic field is used to treat cancer.
Abstract: Magnetic nanoparticles (MNPs) find applications in magnetic fluid hyperthermia (MFH), where the heat dissipated from the MNPs in the presence of an alternating magnetic field is used to treat cancer. However, upon systemic delivery MNPs are also readily phagocytosed by liver and spleen macrophages, leading to accumulation in these organs and thus resulting in nonspecific heating and damage to these healthy organs during MFH. A potential solution to this problem is using magnetic field gradients such as those used in magnetic particle imaging (MPI), a tracer imaging technology which makes the use of MNP's nonlinear magnetization response to a scanned field gradient to obtain the MNP distribution. The field gradient of MPI can be used to localize the region where MNPs dissipate heat, whereas its imaging capability can be utilized for real-time thermal therapy. In this chapter, we introduce and discuss this emerging field of image-guided thermal therapy using MPI and MFH.

8 citations

Journal ArticleDOI
TL;DR: The conditions for controlling the FFR based on the magnetic properties of the MNPs were theoretically calculated and verified through experiments and a new method for the quantitative generation and control of FFR for selective heat treatment was proposed.
Abstract: Magnetic hyperthermia using magnetic nano particles (MNPs) is a very innovative method for application in cancer therapy. However, the heat generated by MNPs can destroy normal cells, which necessitates localized heat treatment methods to minimize the damage inflicted by magnetic hyperthermia. One such method involves the use of a field-free region (FFR). In this paper, the conditions for controlling the FFR based on the magnetic properties of the MNPs were theoretically calculated and verified through experiments. The strength of the gradient magnetic field for controlling the FFR was determined by the relationship between the nanoparticle size, the magnetizing condition, and the temperature change depending on the strength of the AMF. Based on this, a new method for the quantitative generation and control of FFR for selective heat treatment was proposed. We tested the selective heating and temperature control by controlling the FFR. We observed the changing dimension of FFR and heat distribution of MNPs according to changes in the gradient field. When we used 9.56 nm sized MNPs and controlled the distance between two magnets, the area of FFR varied from a minimum of 7.41 cm2 to a maximum of 26.24 cm2. In addition, the temperature increase varied from approximately 5 to 45 K when the FFR was controlled using an AMF operating at 12 kA/m and 207 kHz. We hope our findings will be a crucial consideration in system design and potentially in effective cancer therapy.

7 citations


Cites methods from "Design and Analysis of Novel Focuse..."

  • ...proposed the use of an FFR to focus the heating and controlled its size by using a set of six DC coils [29]....

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Journal ArticleDOI
01 Jun 2020
TL;DR: In this article, the authors proposed a radiofrequency (RF) radiating system for highly focused hyperthermia with magnetic nanoparticles, where a coil was designed to focus the magnetic field at the frequency that maximizes the heat release from the chosen nanoparticles.
Abstract: In this paper, we propose a radiofrequency (RF) radiating system for highly focused hyperthermia with magnetic nanoparticles. We first designed a coil able to focus the magnetic field at the frequency (around 340 kHz) that maximizes the heat release from the chosen nanoparticles. Then, through an electromagnetic software based on the Method of Moments (MoM), we performed numerical simulations of the coil that resulted in excellent agreement with the experimental measurements conducted at the workbench on a fabricated prototype. After that, a radiating system consisting of the coil, a high-power radiofrequency signal generator, and a set of magnetic nanoparticles have been set up. We carried out several experimental trials with different samples of magnetic nanoparticles in order to demonstrate the focusing property of the proposed system. The results we obtained suggested that a careful design of the radiating system could pave the way towards more efficient and safer magnetic hyperthermia treatments in clinical applications.

6 citations


Cites background from "Design and Analysis of Novel Focuse..."

  • ...Thus, different works have been proposed to face this issue [23], [25]....

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References
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BookDOI
01 Jan 1997
TL;DR: Preparation and Modification of Biodegradable Magnetic Particles: Preparation and Application of Monosized magnetic Particles in Selective Cell Separation and Applications in Molecular Biology and Drug Delivery and Radionuclide Therapy.
Abstract: Preparation and Modification of Biodegradable Magnetic Particles: Preparation and Application of Monosized Magnetic Particles in Selective Cell Separation W.S. Prestvik, et al. Characterization of Magnetic Particles: Intravenously Injected Particles: Surface Properties and Interaction with Blood Proteins - The Key Determining the Organ Distribution R.H. Muller, et al. Applications in Cell Separation and Analysis: Physics of the Magnetic Cell Sorting M. Zborowski. Applications in Molecular Biology: Magnetic Separation in Molecular Biology M. Bosnes, et al. Biomedical Applications of Magnetic Carriers: Overview of Magnetic Separations Used in Biochemical and Biotechnological Applications I. Safarik, M. Safarikova. Drug Delivery and Radionuclide Therapy: Targeting Magnetic Microspheres to Brain Tumors S.K. Pulfer, J.M. Gallo. MRI-Contrast Agents: Magnetic Nanoparticles as Contrast Agents for MR Imaging: An Overview J.W. Bulte, R.A. Brooks. Hyperthermia: Magnetic Fluid Hyperthermia (MFH) A. Jordan, et al. 36 Additional Articles. Index.

984 citations

Journal ArticleDOI
TL;DR: Magnetic mediated hyperthermia (MMH) as discussed by the authors is a well-known treatment for cancer, which consists of the localization of magnetic particles or seeds within tumour tissue followed by exposure to an externally applied alternating magnetic field to cause them to heat.
Abstract: The use of hyperthermia in the treatment of cancers is appealing because, as a physical therapy, hyperthermia would have far fewer restrictive side effects than chemotherapy and radiotherapy, and it could be used in combination with these therapies. However, the currently available modalities of hyperthermia are often limited by their inability to selectively target tumour tissue and, hence, they carry a high risk of collateral organ damage or they deposit heat in a very localized manner which can result in under-treatment of a tumour. Magnetically mediated hyperthermia (MMH) has the potential to address these shortcomings. MMH consists of the localization of magnetic particles or seeds within tumour tissue followed by exposure to an externally applied alternating magnetic field to cause them to heat. Since this concept was introduced (over 40 years ago), MMH has evolved into four general sub-classes: arterial embolization hyperthermia (AEH), direct injection hyperthermia (DIH), intracellular hyperthermia...

522 citations

Journal ArticleDOI
TL;DR: Percutaneous radiofrequency ablation yields high proportions of sustained complete responses in properly selected patients with pulmonary malignancies, and is associated with acceptable morbidity.
Abstract: Summary Background Radiofrequency ablation is an accepted treatment for non-surgical patients with liver cancer. The purpose of this study was to identify the feasibility, safety, and effectiveness of percutaneous radiofrequency ablation of malignant lung tumours. Methods Between July 1, 2001, and Dec 10, 2005, a series of 106 patients with 183 lung tumours that were 3·5 cm in diameter or smaller (mean 1·7 cm [SD 1·3]) were enrolled in a prospective, intention-to-treat, single-arm, multicentre clinical trial from seven centres in Europe, the USA, and Australia. Proof of malignancy was obtained by biopsy in all patients. Diagnoses included non-small-cell lung cancer (NSCLC) in 33 patients, metastasis from colorectal carcinoma in 53 patients, and metastasis from other primary malignancies in 20 patients. All patients were considered by the treating physician to be unsuitable for surgery and unfit for radiotherapy or chemotherapy. Patients underwent radiofrequency ablation in accordance with standard rules for CT-guided lung biopsy and were then followed for up to 2 years. Primary endpoints were technical success (defined as correct placement of the ablation device into all tumour targets with completion of the planned ablation protocol), safety (including identification of treatment-related complications and changes in pulmonary function), and confirmed complete response of tumours (according to modified Response Evaluation Criteria in Solid Tumors). Secondary endpoints were overall survival, cancer-specific survival, and quality of life. This trial is registered with ClinicalTrials.gov, number NCT00690703. Findings Correct placement of the ablation device into the target tumour with completion of the planned treatment protocol was feasible in 105 (99%) of 106 patients. The technical failure in one patient was caused by the inability to place the device inside a small tumour. No procedure-related deaths occurred in any of the 137 ablation procedures. Major complications consisted of pneumothorax (n=27) or pleural effusion (n=4), which needed drainage. No significant worsening of pulmonary function was noted. A confirmed complete response of target tumours lasting at least 1 year was shown in 75 (88%) of 85 assessable patients. No differences in response were noted between patients with NSCLC or lung metastases. Overall survival was 70% (95% CI 51–83%) at 1 year and 48% (30–65%) at 2 years in patients with NSCLC, 89% (76–95%) at 1 year and 66% (53–79%) at 2 years in patients with colorectal metastases, and 92% (65–99%) at 1 year and 64% (43–82%) at 2 years in patients with other metastases. Cancer-specific survival was 92% (78–98%) at 1 year and 73% (54–86%) at 2 years in patients with NSCLC, 91% (78–96%) at 1 year and 68% (54–80%) at 2 years in patients with colorectal metastases, and 93% (67–99%) at 1 year and 67% (48–84%) at 2 years in patients with other metastases. Patients with stage I NSCLC (n=13) had a 2-year overall survival of 75% (45–92%) and a 2-year cancer-specific survival of 92% (66–99%). Interpretation Percutaneous radiofrequency ablation yields high proportions of sustained complete responses in properly selected patients with pulmonary malignancies, and is associated with acceptable morbidity. Randomised controlled trials comparing radiofrequency ablation with standard non-surgical treatment options are warranted. Funding Angiodynamics (Queensbury, NY, USA).

476 citations


"Design and Analysis of Novel Focuse..." refers background in this paper

  • ...Although there are a wealth of methods to induce hyperthermia for cancer treatment, including the use of ultrasound, radio-frequency capacitance (10–100 MHz) and microwave (above 300 MHz), each technique has its own limitations [5]–[7]....

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Journal ArticleDOI
TL;DR: In this article, superparamagnetic ferrite nanocrystals of approximately 10 nm were formed within the gel network by bridging anionic bis(ethylhexyl) sodium sulfosuccinate reverse micelles.

142 citations


"Design and Analysis of Novel Focuse..." refers background in this paper

  • ...therapy by virtue of its good depth penetration [8]....

    [...]

Journal ArticleDOI
TL;DR: Although randomized controlled trials comparing RFA and MCT for hepatic ablation are lacking, a review of presently available data supports that MCT may be optimal when larger necrosis zones and/or ablation of multiple lesions are the objectives.
Abstract: Background Surgical resection of malignant hepatic tumors has been demonstrated to increase overall survival; however, the majority of patients are not candidates for resection. For patients with unresectable tumors, various chemical and thermal ablation modalities have been developed. microwave coagulation therapy (MCT) is one such thermal ablation modality and the purpose of this review is to evaluate the presently available data for MCT and assess the level of evidence to support its clinical use. Methods This review is limited to published studies in the English literature including at least 30 patients per study with MCT for hepatocellular cancer (HCC) or colorectal hepatic metastasis (CRHM). Patterns of local recurrence, complications and survival outcome of MCT ablation are presented and discussed including assessment of Asian experience using the 2.4 GHZ device and American experience using the 914 MHZ device. Conclusions Although randomized controlled trials comparing RFA and MCT for hepatic ablation are lacking, our review (based on level 2 data) supports that MCT may be optimal when larger necrosis zones and/or ablation of multiple lesions are the objectives. The data support that the potential procedural advantage(s) noted for ablation of CRHM and HCC >3 cm, is not supported for HCC

120 citations