Download or read book Applicators and Methods to Achieve Precise Spatial Control of the Treatment Zone During Microwave Ablation written by Austin Pfannenstiel and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Cancer is a large and growing societal concern. According to the World Health Organization, one in five men and one in six women worldwide will develop cancer during their lifetime. However, some patients cannot be treated with established therapeutic modalities such as surgery, radiation, or chemotherapy because of challenges with performing these complex procedures for some tumors, the potential for complication due to other medical conditions, and/or dose limiting toxicities. Thermal ablation offers a low-cost, minimally invasive therapy that can be used to treat tumors, usually as an outpatient procedure. Of the possible thermal ablation energy modalities, microwave ablation (MWA) is gaining increasing clinical adoption due to its ability to rapidly heat large volumes of tissue, radiate through charred or other high impedance tissues, and avoid expensive and cumbersome ancillary equipment. However, a significant problem limiting MWA technologies is that the growth of the thermal treatment zone cannot be precisely targeted or visualized in real time and it is therefore extremely difficult to reliably ensure the entire tumor is fully treated without also causing unintended thermal injury to adjacent critical anatomy. This limitation leaves doctors with a difficult choice of risking undertreatment and disease recurrence or risking overtreatment and damage to critical healthy anatomy that may cause pain or life-threatening complications. The fundamental technical barrier to precise targeting, and therefore to broader MWA clinical acceptance is that all currently available MWA systems can only produce a roughly spherical, ellipsoidal, or teardrop-shaped treatment zone centered on the axis near the tip of the applicator, which is not suitable for treating tumors with irregular shapes or those located near critical anatomy. This dissertation focuses on the development of a MWA applicator and methods to achieve precise spatial control of the treatment zone during microwave ablation in diverse tissue targets. A 14-gauge directional MWA (DMWA) applicator design is presented which would allow the physician to instead place the applicator alongside the tumor and direct heat towards the target and away from nearby sensitive tissues. DMWA may also be used with multiple applicators to "bracket" the tumor and clinical margin to enable a procedure with less chance of complications and disease recurrence, or applied on the surface of a target aiming inward in an even less-invasive non-penetrating approach. Coupled electromagnetic-bioheat transfer computational models were used for design and simulation of this DMWA applicator. Proof-of-concept applicators were evaluated in ex vivo liver at 60, 80, and 100 W generator settings for 3, 5 and 10 minutes (n=4 per combination) and in vivo tissue at 80 and 100 W generator settings for 5 or 10 minutes (n=2 or 3 per combination). Mean ex vivo ablation forward depth was 8-15.5 mm. No backward heating was observed at 60 W, 3-5 minutes; directivity (the ratio of forward ablation depth to backward ablation depth) was 4.7-11.0 for the other power and time combinations. In vivo ablation forward depth was 10.3-11.5 mm and directivity was 11.5-16.1. No visible or microscopic thermal damage to non-target tissues in direct contact with the back side of the applicator was observed. As the resulting thermal treatment zone from MWA is comprised of regions exposed to direct electromagnetic heating as well as regions indirectly heated by thermal conduction from the temperature gradients created during thermal ablation, using excessive treatment power or duration during a DMWA procedure may still result in undesired heating of non-target sectors through the thermally conductive surrounding tissues. A method is presented to cycle microwave power on and off to allow blood perfusion in the surrounding tissue to cool the margins of the treatment zone and improve the directivity of the DMWA procedure. Coupled electromagnetic-bioheat transfer computational models were used to evaluate equivalent energy delivery power pulsing protocols with periods of 5, 10, or 20 seconds, duty cycles of 50, 75, or 100%, and a 100 W generator power setting. A 10 second period, 70% duty cycle, 80 W generator setting power pulsing protocol in ex vivo liver showed a 51.7% reduction in the backward ablation depth, a 2.3% increase in the forward ablation depth, and a 115.2% increase in the directivity ratio. A 10 second period, 70% duty cycle, 100 W generator setting power pulsing protocol in in vivo liver showed a 40.1% reduction in the backward ablation depth, a 1.0% reduction in the forward ablation depth, and a 59.6% increase in the directivity ratio. Once many common types of cancer metastasize, a common site to which they spread is bone. Should cancer form in the vertebral bodies, the resulting tumor growth can cause significant pain and neurological problems including paralysis. Due to the proximity of a significant amount of critical anatomy, including the spinal cord and other nerves, treating these tumors can be exceedingly challenging. DMWA may offer the ability to provide enough spatial control of the ablation zone to attempt more palliative treatments of vertebral tumors in proximity to critical nerves and the spinal cord. However, there is limited published literature describing the interactions of microwave energy in bone tissues in detail; of specific importance is the degree of microwave absorption/transmission in bone tissue relative to tissues types that would comprise metastatic disease and how that may affect the resultant size and shape of the resultant treatment zone. Presented are three-dimensional simulations of spinal DMWA treatment zones based on coupled electromagnetic-bioheat transfer computational models with tissue domains that mimic the anatomical dimensions and the biophysical properties of each different type of tissue, including cortical bone, cancellous bone, spinal cord, cartilage, and metastatic and primary tumor. DMWA experimental ablations at 80 or 120 W generator settings for 3.5 or 5 minutes with two fiber optic temperature sensors in ex vivo vertebrae showed a temperature rise of 33.5 - 63.2 °C in the vertebral body 9.5 mm from the DMWA applicator (T1) and a temperature rise of 10.8 - 32.3 °C in the spinal canal 2.5 mm from the backside of the applicator (T2). A computational model with static bone tissue biophysical properties was able to predict the temperature change in the forward direction within 3 - 7% and in the backward direction within 11 - 37% of the experimental observation. This computational model was further modified to include tissue-specific perfusion values and demonstrated two DMWA applicators operated at 80 W generator setting for 5 minutes could heat the entirety of a 2 cm metastatic tumor in the vertebral body to ablative temperature (55 °C) without exceeding 45 °C in the spinal canal.
Download or read book Approaches for Improved Precision of Microwave Thermal Therapy written by Brogan McWilliams and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal therapies employing interstitial microwave applicators for hyperthermia or ablation are in clinical use for treatment of cancer and benign disease in various organs. However, treatment of targets in proximity to critical structures with currently available devices is risky due to unfocused deposition of energy into tissue. For successful treatment, complete thermal coverage of the tumor and margin of surrounding healthy tissue must be achieved, while precluding damage to critical structures. This thesis investigates two approaches to increase precision of microwave thermal therapy. Chapter 2 investigates a novel coaxial antenna design for microwave ablation (MWA) employing a hemi-cylinderical reflector to achieve a directional heating pattern. A proof of concept antenna with an S11 of -29 dB at 2.45 GHz was used in ex vivo experiments to characterize the antennas' heating pattern with varying input power and geometry of the reflector. Ablation zones up to 20 mm radially were observed in the forward direction, with minimal heating (less than 4 mm) behind the reflector. Chapter 3 investigates the use of magnetic nanoparticles (MNP) of varying size and geometry for enhancing microwave tissue heating. A conventional dipole, operating at 2.45 GHz and radiating 15 W, was inserted into a 20 mm radius sphere of distributed MNPs and heating measurements were taken 5 mm, 10 mm, and 15 mm radially away. A heating rate of 0.08°C/s was observed at 10 mm, an increase of 2-4 times that of the control measurement. These approaches provide strong potential for improving spatial control of tissue heating with interstitial and catheter-based microwave antennas.
Download or read book Microwave Ablation Treatment of Solid Tumors written by Ping Liang and published by Springer. This book was released on 2014-11-17 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microwave ablation is a simple, affordable, and highly precise technique. After its successful application in treating liver tumors, it is now widely used to combat renal tumors, adrenal tumors, thyroid nodes, uterine fibroids and other solid tumors. This book presents 40 successful cases of treating these diseases. A series of picture before treatment, after treatment and from different angles is provided for each kind of tumor treatment. In each chapter, step by step operative techniques and illustrations are included. This book also examines CT, NMR and ultrasonography to evaluate the effect of microwave ablation. Editor Ping Liang, is the Director and Professor at Dept. of Interventional Ultrasound, General Hospital of PLA, Beijing, China. Editor Xiaoling Yu is Professor and Chief physician, Editor Jie Yu is Associate Chief physician at the same department.
Download or read book Antenna and System Design for Controlled Delivery of Microwave Thermal Ablation written by Hojjatollah Fallahi and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Microwave ablation is an established minimally invasive modality for thermal ablation of unresectable tumors and other diseases. The goal of a microwave ablation procedure is to deliver microwave power in a manner localized to the targeted tissue, with the objective of raising the target tissue to ablative temperatures (~60 °C). Engineering efforts in microwave applicator design have largely been focused on the design of microwave antennas that yield large, near-spherical ablation zones, and can fit within rigid needles or flexible catheters. These efforts have led to significant progress in the development and clinical application of microwave ablation systems, particularly for treating tumors in the liver and other highly vascular organs. However, currently available applicator designs are ill-suited to treating targets of diverse shapes and sizes. Furthermore, there are a lack of non-imaging-based techniques for monitoring the transient progression of the ablation zone as a means for providing feedback to the physician. This dissertation presents the design, implementation, and experimental evaluation of microwave ablation antennas for site-specific therapeutic applications with these issues in mind. A deployable 915 MHz loop antenna is presented, providing a minimally-invasive approach for thermal ablation of the endometrial lining of the uterus for treatment of heavy menstrual bleeding. The antenna incorporates a radiating loop, which can be deployed to adjustable shapes within the uterine cavity, and a passive element, to enable thermal ablation, to 5.7-9.6 mm depth, of uterine cavities ranging in size from 4-6.5 cm in length and 2.5-4.5 cm in width. Electromagnetic-bioheat transfer simulations were employed for design optimization of the antennas, and proof-of-concept applicators were fabricated and extensively evaluated in ex vivo tissue. Finally, feasibility of using the broadband antenna reflection coefficient for monitoring the ablation progress during the course of ablation was evaluated. Experimental studies demonstrated a shift in antenna resonant frequency of 50 MHz correlated with complete ablation. For treatment of 1-2 cm spherical targets, water-cooled monopole antennas operating at 2.45 and 5.8 GHz were designed and experimentally evaluated in ex vivo tissue. The technical feasibility of using these applicators for treating 1-2 cm diameter benign adrenal adenomas was demonstrated. These studies demonstrated the potential of using minimally-invasive microwave ablation applicators for treatment of hypertension caused by benign aldosterone producing adenomas. Since tissue dielectric properties have been observed to change substantially at elevated temperatures, knowledge of the temperature-dependence of tissue dielectric properties may provide a means for estimating treatment state from changes in antenna reflection coefficient during a procedure. The broadband dielectric properties of bovine liver, an established tissue for experimental characterization of microwave ablation applicators, were measured from room temperature to ablative temperatures. The measured dielectric data were fit to a parametric model using piecewise linear functions, providing a means for readily incorporating these data into computational models. These data represent the first report of changes in broadband dielectric properties of liver tissue at ablative temperatures and should help enable additional studies in ablation system development.
Download or read book Spine Intervention An Issue of Neuroimaging Clinics of North America written by Majid Khan and published by Elsevier Health Sciences. This book was released on 2019-11-12 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This issue of Neuroimaging Clinics of North America focuses on Spine Intervention and is edited by Dr. Majid Khan. Articles will include: The Spine: Embryology and anatomy; Osteoporosis and tumoral spine involvement: Overview and diagnosis; Hot and cold spine tumor ablations; Vertebral compression fractures treatment with cement augmentation procedures; Sacral fractures and sacroplasty; Conventional image guided procedures for painful spine; Advanced image guided procedures for painful spine; Image guided percutaneous treatment of lumbar stenosis and disc degeneration; Overview, diagnosis and treatment of spinal CSF leak; Overview, diagnosis and treatment of Spine vascular malformation; Rapid onsite evaluation (ROSE) for spine biopsies; and more!
Download or read book MRI Guided Focused Ultrasound Surgery written by Ferenc A. Jolesz and published by CRC Press. This book was released on 2007-09-26 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: MRI-Guided Focused Ultrasound Surgery will be the first publication on this new technology, and will present a variety of current and future clinical applications in tumor ablation treatment. This source helps surgeons and specialists evaluate, analyze, and utilize MRI-guided focused ultrasound surgery - bridging the gap between phase 3 clinical tr
Download or read book Thermal Treatment of Tissue written by and published by . This book was released on 2007 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radiofrequency Ablation for Small Hepatocellular Carcinoma written by Minshan Chen and published by Springer. This book was released on 2015-11-26 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive guide to the treatment of small hepatocellular carcinoma (sHCC) using a minimally invasive technique: radiofrequency ablation (RFA). RFA has emerged as a new treatment modality and become the main modality of locoregional therapy. Extensive clinical research indicates that RFA is as effective as surgical resection for sHCC, and it has the advantage of being less invasive. However, the outcomes after RFA are largely dependent on the operators’ experience- known as the “learning curve”. This book presents the characteristics of sHCC and discusses why sHCC is the best candidate for RFA. Then it introduces all the commercially available RFA systems, and their working principles, advantages, disadvantages and so on. It goes on to demonstrate how to perform RFA under the guidance of ultrasound, CT, laparoscopy, or during open operation. Finally, it discusses the radiologic assessment and follow‐up after RFA, as well as adjuvant therapies and clinical trials on RFA. The authors are experts from the fields of pathology, radiology, surgery, and gastroenterology, as well as manufacturers. With this book, readers gain have a clear idea of when and how to do RFA. It aims to standardize and generalize the procedure of RFA, which will be very helpful in improving the outcome of RFA for sHCC.
Download or read book Spine Radiosurgery written by Peter Gerszten and published by Thieme. This book was released on 2015-08-19 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spine Radiosurgery, Second Edition , is a comprehensive text that includes discussions of the latest devices, treatment planning techniques, target definition, and patient selection in this specialty. Written by leading experts in the fields of neurosurgery, radiation oncology, and medical physics, this book is the definitive reference for clinical applications of state-of-the-art radiosurgery of the spine. Key Features: Six new chapters on such topics as histopathological examination of spinal lesions, minimally invasive techniques, and treatment of spinal chordomas More than 100 full-color illustrations demonstrate key concepts Discussion of new treatments for metastatic spine disease and spinal cord compression This book is a must-have resource for clinicians, fellows, and residents in neurosurgery and radiation oncology. Spine surgeons, orthopaedists, medical physicists, and oncologists at all levels will also benefit from the wealth of information provided.
Download or read book Tumor Ablation written by Eric van Sonnenberg and published by Springer Science & Business Media. This book was released on 2008-09-08 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is an enormous sense of excitement in the communities of cancer research and cancer care as we move into the middle third of the ?rst decade of the 21st century. For the ?rst time,there is a true sense of c- ?dence that the tools provided by the human genome project will enable cancer researchers to crack the code of genomic abnormalities that allow tumor cells to live within the body and provide highly speci?c, virtually non-toxic therapies for the eradication,or at least ?rm control of human cancers. There is also good reason to hope that these same lines of inquiry will yield better tests for screening, early detection, and prev- tion of progression beyond curability. While these developments provide a legitimate basis for much op- mism, many patients will continue to develop cancers and suffer from their debilitating effects, even as research moves ahead. For these in- viduals, it is imperative that the cancer ?eld make the best possible use of the tools available to provide present day cancer patients with the best chances for cure, effective palliation, or, at the very least, relief from symptoms caused by acute intercurrent complications of cancer. A modality that has emerged as a very useful approach to at least some of these goals is tumor ablation by the use of physical or physiochemical approaches.
Download or read book Lung Cancer written by Henry S. Park and published by BoD – Books on Demand. This book was released on 2021-06-02 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lung cancer continues to be the leading cause of cancer mortality worldwide among both men and women. Recent advances in prevention, screening and management in the past decade have led to significant improvements in survival and quality of life. Local treatments like minimally invasive surgery, radiotherapy, and image-guided ablation have contributed to improving the effectiveness and tolerability of potentially curative treatments in early-stage, locally advanced, and oligometastatic/oligoprogressive disease. Chemotherapy, targeted therapy, immunotherapy, and palliative local therapy options have expanded rapidly, with new regimens showing improved outcomes even for those with widely metastatic disease. This book comprehensively reviews the evidence that has driven personalized medicine, based on a variety of multidisciplinary perspectives by international lung cancer experts.
Download or read book Physical Properties of Tissues written by Francis Duck and published by Academic Press. This book was released on 2013-10-22 with total page 357 pages. Available in PDF, EPUB and Kindle. Book excerpt: This unique reference book describes quantitatively the measured and predicted values of all the physical properties of mammalian tissue. Reported measurements are thoroughly documented and are complemented by a range of empirical mathematical models which describe the observed physical behavior of tissue.**Intended as a broad-ranging reference, this volume gives the bioengineer, physicist, radiologist, or physiologist access to a literature which may not be known in detail. It will also be of value for those concerned with the study of a range of environmental radiation hazards. Most extensive compilation of values of physical properties of tissue**Presents data for thermal, optical, ultrasonic, mechanical, x-ray, electrical, and magnetic resonance properties**Comprehensive bibliography
Download or read book Physics of Thermal Therapy written by Eduardo Moros and published by Taylor & Francis. This book was released on 2016-04-19 with total page 375 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of thermal therapy has been growing tenaciously in the last few decades. The application of heat to living tissues, from mild hyperthermia to high-temperature thermal ablation, has produced a host of well-documented genetic, cellular, and physiological responses that are being researched intensely for medical applications, particularly fo
Download or read book Laser induced Interstitial Thermotherapy written by Gerhard J. Müller and published by SPIE Press. This book was released on 1995 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Clinical Aspects of Electroporation written by Stephen T. Kee and published by Springer Science & Business Media. This book was released on 2011-04-06 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electroporation is the forefront in tumor ablation. This book presents the basic principles and clinical applications of electroporation, including the latest research results and patient data. A comprehensive approach to the basic science behind the development of this ground-breaking technique and its introduction into clinical practice, the book discusses the entire spectrum of currently available reversible treatments, the emerging irreversible applications, and their impact on patient care. Clinical Aspects of Electroporation is the first book intended for clinicians on this extremely important and rapidly developing field.
Download or read book CT and MR Guided Interventions in Radiology written by Andreas H. Mahnken and published by Springer Science & Business Media. This book was released on 2013-05-14 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interventional radiology is an indispensable and still expanding area of modern medicine that encompasses numerous diagnostic and therapeutic procedures. The revised and extended second edition of this volume covers a broad range of non-vascular interventions guided by CT or MR imaging. Indications, materials, techniques, and results are all carefully discussed. A particularly comprehensive section is devoted to interventional oncology as the most rapidly growing branch of interventional radiology. In addition, detailed information is provided that will assist in establishing and developing an interventional service. This richly illustrated book will be a most valuable source of information and guidance for all radiologists who deal with non-vascular procedures.
Download or read book Theranostics and Image Guided Drug Delivery written by Maya Thanou and published by Royal Society of Chemistry. This book was released on 2018-01-02 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular imaging of drugs or drug carriers is a valuable tool that can provide important information on spatiotemporal distribution of drugs, allowing improved drug distribution at target sites. Chemically labelled drugs can be used to both diagnose and treat diseases. This book introduces the topic of image guided drug delivery and covers the latest imaging techniques and developments in theranostics, highlighting the interdisciplinary nature of this field as well as its translational ability. These technologies and techniques hold potential for individualised, safer therapies. The book introduces the chemistry behind labelling drugs or drug carriers for imaging. It then discusses current scientific progress in the discovery and development of theranostic agents as well as the latest advances in triggered drug delivery. Novel imaging techniques that can be combined with therapeutics are presented, as well as results and findings from early clinical trials. This text will provide postgraduates and researchers in various disciplines associated with drug discovery, including chemistry, device engineering, oncology, neurology, cardiology, imaging, and nanoscience, an overview of this important field where several disciplines have been combined to improve treatments. Readers will be introduced to techniques that can be translated to the clinic and be applied widely.
