Edwin Lok, Olivia Liang, Monika Haack, Eric T Wong
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引用次数: 0
Abstract
Purpose: Tumor Treating Fields (TTFields) are delivered by transducer arrays applied to scalp or body surface for treatment of multiple malignancies. Dermatologic complications are thought to be related to hydrogel situated between the electrodes and scalp or skin to facilitate electric field penetration. High intensity of TTFields on these surfaces may also be a contributing factor. We explored conductivity changes in the hydrogel and skin to improve TTFields coverage and penetration.
Methods: Magnetic resonance imaging datasets from 12 glioblastoma patients and attenuation-corrected positron emission tomography-computed tomography datasets from 3 non-small cell lung and 2 ovarian carcinoma patients were used to segment anatomic structures. Finite element mesh models were generated and solved for distribution of applied electric fields, rate of energy deposition, and current density at the gross tumor volume (GTV) and clinical target volume (CTV). Electric field-volume, specific absorption rate-volume, and current density-volume histograms were generated, by which plan quality metrics were used to evaluate relative differences in field coverage between models at various hydrogel and skin conductivities.
Results: By varying conductivity of hydrogel, TTFields coverage at GTV or CTV increased up to 0.5 S/m for head and 1.0 S/m for thorax and pelvis models, and no additional increase was observed beyond these saturation points. Although scalp hotspots increased or decreased by +1.5%, -0.1%, and -0.9% in E5%, SAR5%, and CD5%, the skin hotspots increased by as much as +23.5%, +45.7%, and +20.6%, respectively. When altering conductivity of the entire scalp, TTFields coverage peaked near 1 S/m at the GTV or CTV for the head models. TTFields coverage in both the GTV and scalp increased up to 1 S/m for the head models but plateaued thereafter. Contouring under the scalp increased scalp hotspots by +316% in E5% at 1 S/m compared to altering the conductivity of the entire scalp. GTV hotspots decreased by +17% in E5% at 1 S/m.
Conclusion: TTFields delivery can be modulated by the conductivity of hydrogel and scalp/skin at the transducer-scalp or transducer-skin interface. Optimizing this aspect of TTFields delivery may increase tumor control while minimizing toxicity at the scalp or skin.
期刊介绍：
The translation of new discoveries in medicine to clinical routine has never been easy. During the second half of the last century, thanks to the progress in chemistry, biochemistry and pharmacology, we have seen the development and the application of a large number of drugs and devices aimed at the treatment of symptoms, blocking unwanted pathways and, in the case of infectious diseases, fighting the micro-organisms responsible. However, we are facing, today, a dramatic change in the therapeutic approach to pathologies and diseases. Indeed, the challenge of the present and the next decade is to fully restore the physiological status of the diseased organism and to completely regenerate tissue and organs when they are so seriously affected that treatments cannot be limited to the repression of symptoms or to the repair of damage. This is being made possible thanks to the major developments made in basic cell and molecular biology, including stem cell science, growth factor delivery, gene isolation and transfection, the advances in bioengineering and nanotechnology, including development of new biomaterials, biofabrication technologies and use of bioreactors, and the big improvements in diagnostic tools and imaging of cells, tissues and organs.
In today`s world, an enhancement of communication between multidisciplinary experts, together with the promotion of joint projects and close collaborations among scientists, engineers, industry people, regulatory agencies and physicians are absolute requirements for the success of any attempt to develop and clinically apply a new biological therapy or an innovative device involving the collective use of biomaterials, cells and/or bioactive molecules. “Frontiers in Bioengineering and Biotechnology” aspires to be a forum for all people involved in the process by bridging the gap too often existing between a discovery in the basic sciences and its clinical application.
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