Optimal microwave source distributions for heating off-center tumors in spheres of high water content tissue

Rappaport, Carey M.; Pereira, J. G.

doi:10.1109/22.159640

Cited by 6 publications

(5 citation statements)

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“…A number of publications are available on the subject (55)(56)(57)(58)(59). Hyperthermia, however, will not been reviewed in this paper.…”

Section: Biological Effectsmentioning

confidence: 95%

“…The evacuation of the ions must take place against the concentration gradient. It is supported by the enzyme ATP-ase, or calcium pump, which acquires the necessary energy by dissociating adenosine ftiphosphate (ATP) molecules (2) Recendy, microscopic effects of signals of mobile telephony GSM and DECT on voltage-dependent membrane channels have been analyzed by computer simulation (58) . The theory is based on Markov finite-state models.…”

Section: Interaction Of Microwave Fields With the Nervous System(57"6mentioning

confidence: 99%

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Biological Effects and Medical Applications

Rosen

Vorst

1997

27th European Microwave Conference, 1997

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ABSTRACI RF/microwaves applications in medicine, particularly in cardiology, urology and surgery are described. Several of the applications have gained worldwide acceptance and are presendy used to treat human subjects, while others are curndy being researched and developed. To develop medical applications using RF/Microwaves, known and new biological effects are being thoroughly investigated. The effect of electromagnetic fields on biological materials and systems have been of particular interest RF/MICROWAVES APPLICATIONS IN MEDICINE INTRODUCTI0NThe use of RE/microwaves in therapeutic medicine has increased dramatically in the last few years. RF and microwave therapies for cancer in humans are well documented, and are presently used in many cancer centers. RF treatments for supraventricular arrhythmias, and more recently for ventricular tachycardia (VT) are currently employed by major hospitals. RF/microwaves are also used in human subjects for the treatnent of benign prostatic hyperplasia (BPH), and have gained international approval, including approval by the United States Food and Drug Administration (FDA). Despite these advances, considerable efforts are being expended on the improvement of such medical device technology.Furthermore, new modalities such as microwave enhanced liposuction, microwave ablation, RF/microwaves for the enhancement of drug absorption and microwave wound sterilizaton are continually being researched. In this paper we specifically adress the advances in the area of RE/microwave ablation, RF/microwave treatment of benign prostatic hyperplasia, microwave balloon angioplasty and two new areas of investigation: microwave enhanced liposuction and microwave anastomoses. RF/MICROWAVE ABLATION (115)Cardiac arrhythmias can result from a variety of clinical conditions, but at their root is an abnormal focus, or pathway, of electrical activity. Abnormal sources of electrical activity most commonly occur at or above the AV-node, and are thus deened supraventricular tachy-arrhythmias. Altematively, abnormal ventricular foci cause ventricular tachycardia. The presence of abnormal conduction pathways can also result in an uncontrolled cycling of electrical activity resulting from retrograde signal conduction through the myocardium (re-entry tachy-arrhytmnias). Re-entry can occur within the AVnode (AVNRT), or via accessory conduction pathways (AP). Regardless of the specific etiology, once the source of the arrhythmia has been identified, destruction of the abnormal cardiac tissue is curative. Various energy forms have been used to create such localized tissue injury, including direct current (DC), radio-frequency (RF), and microwave energy.The clinical use of DC ablation dates back to 1982. An electrode catheter is placed at the desired location, and a DC shock is applied. Although complete ablation occurs in up to 65% of patients, DC ablation is fraught with complications. Hypotension, perforation, cardiac tamponade, embolization, pericarditis, and ventricular tachy-arrhythmias have been reported ...

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“…A number of publications are available on the subject (55)(56)(57)(58)(59). Hyperthermia, however, will not been reviewed in this paper.…”

Section: Biological Effectsmentioning

confidence: 95%

Section: Interaction Of Microwave Fields With the Nervous System(57"6mentioning

confidence: 99%

Biological Effects and Medical Applications

Rosen

Vorst

1997

27th European Microwave Conference, 1997

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“…Dielectric polarization is a rather complicated phenomenon [4]. It may be due to a variety of mechanisms, which can be summarized here only briefly.…”

Section: Electric Field and Flux Densitymentioning

confidence: 99%

“…Numerous publications are available on the subject, with [1][2][3][4][5] as examples. More recently, however, other subjects have received as much attention, in particular EM energy absorption in human subjects, especially in the human head and neck [6], interaction of microwaves with the nervous system [7], influence of the fields of mobilophony on membrane channels [8], and molecular effects [9].…”

Section: Introductionmentioning

confidence: 99%

Biological Effects

2005

RF/Microwave Interaction With Biological Tissues

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PREFACEvariety of effects are described and discussed; they include those on the nervous system, the brain and spinal cord, the blood-brain barrier, cells and membranes, effects at the molecular level, influence of drugs, and effects due to extremely low frequency components of signal modulation. Thermal considerations, related to absorption, are the subject of a significant part of this chapter. The possibility of nonthermal effects is also discussed. This leads to a discussion on radiation hazards and exposure standards.Chapter 4 is devoted to thermal therapy. Thermotherapy has been used as medical treatment in, for example, rheumatism and muscle diseases. In this chapter, the reader will find a description of applicators and an extensive discussion on the foundation of dielectric heating and inductive heating as well as a variety of technological information. Hyperthermia is also discussed as a noninvasive method, and practical thermometry methods are described.Recently, electromagnetic (EM) environments have become very complex because of the wide and rapid spread of a number of electric or electronic devices, including recent progress and the increase in use in the area of cellular telephony. As a countermeasure, wave absorbers are being used for protecting biological and medical environments, and knowledge about these absorbers has become important. In Chapter 5, we investigate materials for EM wave absorbers, both from a theoretical and an application point of view. Special attention is paid to ferrite absorbers, for which it has long been a challenge to develop an EM wave absorber at the desired matching frequency. The chapter ends with the description of a method for improving the distribution of RF fields in a small room.Chapter 6 begins with some of the fundamental aspects of major components used in RF/microwave delivery systems for therapeutic applications. The authors have chosen to detail the research done on the subject of cardiac ablation. The chapter also covers new ideas and research done on the use of RF/microwaves in the development of future measurement techniques, such as blood perfusion, for example, and the use of microwaves in therapeutic applications. New inventions would reduce further the need for surgical or invasive procedures, substituting noninvasive and minimally invasive techniques.The authors acknowledge the enthusiastic help received during the preparation of the manuscript.Andre Vander Vorst acknowledges the numerous conversations he has had over the years with two past doctoral students, D. Vanhoenacker-Janvier on a variety of microwave issues, more specifically microwave propagation, and Benoît Stockbroeckx about exposure measurements and radiation hazards. The stimulating environment created by some Ph.D. students is also acknowledged, especially Jian Teng, who participated in the investigation of the effect of microwaves on the nervous system of rabbits, and Dirk Adang, who in 2004 started a one-year epidemiological study on rats exposed to microwaves. This author also be...

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“…The means of linear accelerator in tumor therapy are amplified because of it is a source of high power radio and Microwave radiation. The question is that in the last years for the tumor therapy the radio frequency and RF/Microwave methods are prevalent and these using increased in the many tumor therapy centers [3][4][5]. At the action of the radiation in the series of cases so called latent injuries of macromolecule are arises.…”

Section: Proton-microwave Therapymentioning

confidence: 99%

Proton-microwave therapy

Oksuzyan

Ivanyan²

PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268)

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The new method of tumor therapy is proposed: joining up of proton (photon) and microwave methods. The combined tumor therapy gives the possibility of simultaneous influence on the albumen molecules (tissue cells) in vivo of RF/Microwave and proton (photon) radiation. Such an influence must be made not only synchronous but coherent as well. In this case the effectiveness will depend on the relative phase between the proton bunches sequence or photons, radiated tissue and radio frequency oscillations, with the help of which this bunches were formed and accelerated in accelerator. The proposed combined proton + RF/Microwave therapy method gives the possibility of simultaneously (with proton or photon) and coherent influence on the tissue cells, in the wide microwave range, included mm-range. It may be provided by multiplication of the accelerating field frequency by n. It is necessary to mention, that the additional MW therapy is able to decrease the proton (photon) radiation dose for patients, because of appeared centers of the devitalisation of tumor tissue may be explored due to MW action (already without proton or photon radiation), i.e. it possible to obtain the more spare therapy method. The Linac of YerPhI synchrotron at energy 75MeV, in which it was proposed to establish the proton linear accelerator, at 12MeV is the likely accelerator for carryint out this method of tumor therapy. PROTON-MICROWAVE THERAPYA creation of Proton Therapy Complex (PTC) is proposed on the base of Yerevan Electron Synchrotron. Proton acceleration will be made in the ring of electron synchrotron from the injection energy of 12MeV up to the 250MeV energy. However the proton tumor therapy in range of middle and high energy (70-250MeV) will be much more effectively in case of combination of the traditional and new methods of therapy. Such a combination is used already in the world practice of the tumor therapy. The reference on the electron and photon therapy combined method is given in work [1] (see p.21). The electrons in energy range of 5-25MeV were used.In case of proton therapy the energy range choosing is made more exact, because of the pronons have more hight factor of Relative Biologycal Effectivity {RBE), thus for the every case of the tumor it is necessary to choose an according voxel field for proton and tissue interaction. It is making with the help of special scattering and scanning arrangements ([1], pp. 408-414 Let's consider now the means of acting electron linear accelerator of YerPhY at energy 75 MeV, in which was proposed to establish the proton linear accelerator at 12MeV. The depth of proton running with the such energy may be calculated on the base of the date of linear energy transfer (LET)

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Optimal microwave source distributions for heating off-center tumors in spheres of high water content tissue

Cited by 6 publications

References 4 publications

Biological Effects and Medical Applications

Biological Effects and Medical Applications

Biological Effects

Proton-microwave therapy

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