Download or read book Optimized Accelerator Based Epithermal Neutron Beams for Boron Neutron Capture Therapy written by Rajat Kudchadker and published by . This book was released on 1996 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: Boron Neutron capture therapy (BNCT) is a form of radiation therapy in which nuclides having a high tendency for capturing thermal neutrons, react by emitting charged particles of short range and leaving essentially no residual radioactivity. If these capture nuclides are selectively introduced into the tumor cells, it is theoretically possible to destroy only the tumor and in the process spare the neighboring healthy tissue. Currently, reactors are the only known source of neutrons being used for BNCT. A number of studies have been done using Monte Carlo computer codes such as MCNP to determine an optimum design of a moderator reflector configuration for an accelerator based neutron source utilizing the Li-7(p, n)Be-7 reaction. To confirm this, benchmark experiments were conducted using both a 2.0 MeV Radio Frequency Quadrupole (RFQ) accelerator and a 2.0 MeV Van de Graaff generator. All previous studies had concluded that 2.5 MeV protons would be optimum, which produces neutron having a maximum energy of 787 keV. For BNCT the desired neutron energies are between 1 eV and nominally 10 keV, i.e. in the epithermal region. These neutrons must hence be moderated to bring them down to the desired energy range. The moderator-reflector assemblies for reactor neutrons or those from 2.5 MeV protons on lithium require a little less than a meter of material to achieve the desired neutron spectrum. This research work focuses on using protons with energies just above the Li-7(p, n)Be-7 reaction threshold. These lower energy protons produce neutrons with a maximum energy of just a few hundred keV requiring much less moderation as compared to the 2.5 MeV proton lithium source. The penalty for the low energy neutron spectrum is the low yield of neutrons per proton as compared to the 2.5 MeV protons on lithium. But, less moderation implies that the patient can be moved closer to the lithium target (neutron source), thus making a more efficient use of the source neutrons. This would partially or wholly compensate for the lower yield per proton. In addition the smaller moderator-reflector assembly would result in less scattering occurring, thereby not degrading the forward directional quality of the beam as much as in current assemblies designed for use with the 2.5 MeV protons on a lithium target.
Download or read book Optimization of an Accelerator based Epithermal Neutron Source for Neutron Capture Therapy written by and published by . This book was released on 2004 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: A modeling investigation was performed to choose moderator material and size for creating optimal epithermal neutron beams for BNCT based on a proton accelerator and the 7Li(p, n)7Be reaction as a neutrons source. An optimal configuration is suggested for the beam shaping assembly made from polytetrafluoroethylene and magnesium fluorine. Results of calculation were experimentally tested and are in good agreement with measurements.
Download or read book Frontiers in Neutron Capture Therapy written by M. Frederick Hawthorne and published by Springer. This book was released on 2013-11-11 with total page 1389 pages. Available in PDF, EPUB and Kindle. Book excerpt: Frontiers in Neutron Capture Therapy contains current research results originally presented at the Eighth International Symposium on Neutron Capture Therapy for Cancer in La Jolla, CA. This comprehensive collection of peer-reviewed manuscripts is showcased in two volumes covering all aspects of the development of this multidisciplinary approach to cancer therapy. Volume I of this work includes clinical results and current progress in treatment planning, neutron sources and dosimetry, while Volume II presents the synthesis, pharmacology and tissue-targeting design of boron compounds, including work on preclinical dosimetry and radiobiology. Intended for researchers and clinicians involved with or interested in new modes of cancer therapy, this volume will also serve as a useful guideline for scientists, students, and practitioners in the field.
Download or read book Neutron Beam Design Development and Performance for Neutron Capture Therapy written by Otto K. Harling and published by Springer Science & Business Media. This book was released on 2013-03-08 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: For this Workshop, the organizers have attempted to invite experts from all known centers which are engaged in neutron beam development for neutron capture therapy. The Workshop was designed around a series of nineteen invited papers which dealt with neutron source design and development and beam characterization and performance. Emphasis was placed on epithermal beams because they offer clinical advantages and are more challenging to implement than thermal beams. Fission reactor sources were the basis for the majority of the papers; however three papers dealt with accelerator neutron sources. An additional three invited papers provided a summary of clinical results of Ncr therapy in Japan between 1968 and 1989 and overviews of clinical considerations for neutron capture therapy and of the status of tumor targeting chemical agents for Ncr. Five contributed poster papers dealing with NCT beam design and performance were also presented. A rapporteurs' paper was prepared after the Workshop to attempt to summarize the major aspects, issues, and conclusions which resulted from this Workshop. Many people contributed to both the smooth functioning of the Workshop and to the preparation of these proceedings. Special thanks are reserved for Ms. Dorothy K.
Download or read book Accelerator Based Neutron Beams for Neutron Capture Therapy written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The DOE-funded accelerator BNCT program at the Massachusetts Institute of Technology has resulted in the only operating accelerator-based epithermal neutron beam facility capable of generating significant dose rates in the world. With five separate beamlines and two different epithermal neutron beam assemblies installed, we are currently capable of treating patients with rheumatoid arthritis in less than 15 minutes (knee joints) or 4 minutes (finger joints) or irradiating patients with shallow brain tumors to a healthy tissue dose of 12.6 Gy in 3.6 hours. The accelerator, designed by Newton scientific Incorporated, is located in dedicated laboratory space that MIT renovated specifically for this project. The Laboratory for Accelerator Beam Applications consists of an accelerator room, a control room, a shielded radiation vault, and additional laboratory space nearby. In addition to the design, construction and characterization of the tandem electrostatic accelerator, this program also resulted in other significant accomplishments. Assemblies for generating epithermal neutron beams were designed, constructed and experimentally evaluated using mixed-field dosimetry techniques. Strategies for target construction and target cooling were implemented and tested. We demonstrated that the method of submerged jet impingement using water as the coolant is capable of handling power densities of up to 6 x 107 W/m2 with heat transfer coefficients of 106W/m2-K. Experiments with the liquid metal gallium demonstrated its superiority compared with water with little effect on the neutronic properties of the epithermal beam. Monoenergetic proton beams generated using the accelerator were used to evaluate proton RBE as a function of LET and demonstrated a maximum RBE at approximately 30-40 keV/um, a finding consistent with results published by other researchers. We also developed an experimental approach to biological intercomparison of epithermal beams and compared the RBE characteristics of the MIT Reactor M67 clinical beam, The Brookhaven Medical Research Reactor clinical beam (both of which were used in Phase I/II clinical trials of BNCT) and the MIT LABA BNCS beam. Additional research initiated under this program involved an investigation of the potential of BNCT for the prevention of restenosis and the development of accelerator-based fast neutron brachytherapy. A total of 10 student research theses (2 Undergraduate, 4 Masters, and 4 Doctoral) were completed as part of this research program.
Download or read book An Accelerator based Epithermal Photoneutron Source for Boron Neutron Capture Therapy written by and published by . This book was released on 1996 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Boron neutron capture therapy is an experimental binary cancer radiotherapy modality in which a boronated pharmaceutical that preferentially accumulates in malignant tissue is first administered, followed by exposing the tissue in the treatment volume to a thermal neutron field. Current usable beams are reactor-based but a viable alternative is the production of an epithermal neutron beam from an accelerator. Current literature cites various proposed accelerator-based designs, most of which are based on proton beams with beryllium or lithium targets. This dissertation examines the efficacy of a novel approach to BNCT treatments that incorporates an electron linear accelerator in the production of a photoneutron source. This source may help to resolve some of the present concerns associated with accelerator sources, including that of target cooling. The photoneutron production process is discussed as a possible alternate source of neutrons for eventual BNCT treatments for cancer. A conceptual design to produce epithermal photoneutrons by high photons (due to bremsstrahlung) impinging on deuterium targets is presented along with computational and experimental neutron production data. A clinically acceptable filtered epithermal neutron flux on the order of 107 neutrons per second per milliampere of electron current is shown to be obtainable. Additionally, the neutron beam is modified and characterized for BNCT applications by employing two unique moderating materials (an Al/AlF3 composite and a stacked Al/Teflon design) at various incident electron energies.
Download or read book Spectral Tailoring for Boron Neutron Capture Therapy written by Victor Alexander Nievaart and published by IOS Press. This book was released on 2007 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the first clinical trials on Boron Neutron Capture Therapy in the 1950s, BNCT research has been mainly focussed on the treatment of (deep-seated) brain tumours, in particular, glioblastoma multiforme. Promising work to treat other cancers at other locations and even other diseases are in progress. Therefore, the chemists, medical doctors, physicists and biologists involved in BNCT are not only continuing to investigate and improve the (brain) clinical results, but are also investigating the new applications in BNCT. The work presented in this thesis is in the field of physics and deals, from three different viewpoints, with obtaining the optimal source neutron energy to optimise BNCT. The optimal source neutron energy is defined such as to obtain as many as possible (n, a)-absorptions due to 10B in the tumours and as low as possible total neutron dose in the healthy tissues and organs at risk
Download or read book The Design of an Intense Accelerator based Epithermal Neutron Beam Prototype for BNCT Using Near threshold Reactions written by Charles Leon Lee and published by . This book was released on 1998 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Design of an Accelerator based Epithermal Neutron Beam for Boron Neuton Capture Therapy written by Xiao-Lin Zhou and published by . This book was released on 1990 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Neutron Capture Therapy written by Wolfgang A.G. Sauerwein and published by Springer Science & Business Media. This book was released on 2012-11-05 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutron capture therapy (NCT) is based on the ability of the non-radioactive isotope boron-10 to capture thermal neutrons with very high probability and immediately to release heavy particles with a path length of one cell diameter, which in principle allows for tumor cell-selective high-LET particle radiotherapy. This book provides a comprehensive summary of the progress made in NCT in recent years. Individual sections cover all important aspects, including neutron sources, boron chemistry, drugs for NCT, dosimetry, and radiation biology. The use of NCT in a variety of malignancies and also some non-malignant diseases is extensively discussed. NCT is clearly shown to be a promising modality at the threshold of wider clinical application. All of the chapters are written by experienced specialists in language that will be readily understood by all participating disciplines.
Download or read book Accelerator based Neutron Source for Boron Neutron Capture Therapy BNCT and Method written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A source for boron neutron capture therapy (BNCT) comprises a body of photoneutron emitter that includes heavy water and is closely surrounded in heat-imparting relationship by target material; one or more electron linear accelerators for supplying electron radiation having energy of substantially 2 to 10 MeV and for impinging such radiation on the target material, whereby photoneutrons are produced and heat is absorbed from the target material by the body of photoneutron emitter. The heavy water is circulated through a cooling arrangement to remove heat. A tank, desirably cylindrical or spherical, contains the heavy water, and a desired number of the electron accelerators circumferentially surround the tank and the target material as preferably made up of thin plates of metallic tungsten. Neutrons generated within the tank are passed through a surrounding region containing neutron filtering and moderating materials and through neutron delimiting structure to produce a beam or beams of epithermal neutrons normally having a minimum flux intensity level of 1.0.times. 10.sup. 9 neutrons per square centimeter per second. Such beam or beams of epithermal neutrons are passed through gamma ray attenuating material to provide the required epithermal neutrons for BNCT use.
Download or read book Clinical Requirements and Accelerator Concepts for BNCT written by and published by . This book was released on 1997 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accelerator-based neutron sources are an attractive alternative to nuclear reactors for providing epithermal neutron beams for Boron Neutron Capture Therapy. Based on clinical requirements and neutronics modeling the use of proton and deuteron induced reactions in 7Li and 9Be targets has been compared. Excellent epithermal neutron beams can be produced via the 7Li(p, n)7Be reaction at proton energies of (approximately)2.5 MeV. An electrostatic quadrupole accelerator and a lithium target, which can deliver and handle 2.5 MeV protons at beam currents up to 50 mA, are under development for an accelerator-based BNCT facility at the Lawrence Berkeley National Laboratory.
Download or read book Optimal Neutron Source Beam Shaping Assembly for Boron Neutron Capture Therapy written by and published by . This book was released on 2003 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: There were three objectives to this project: (1) The development of the 2-D Swan code for the optimization of the nuclear design of facilities for medical applications of radiation, radiation shields, blankets of accelerator-driven systems, fusion facilities, etc. (2) Identification of the maximum beam quality that can be obtained for Boron Neutron Capture Therapy (BNCT) from different reactor-, and accelerator-based neutron sources. The optimal beam-shaping assembly (BSA) design for each neutron source was also to e obtained. (3) Feasibility assessment of a new neutron source for NCT and other medical and industrial applications. This source consists of a state-of-the-art proton or deuteron accelerator driving and inherently safe, proliferation resistant, small subcritical fission assembly.
Download or read book Design And Construction Of Accelerator Based Boron Neutron Capture Therapy Facility With Multiple Treatment Rooms At Southern Tohoku BNCT Research Center written by Takahiro Kato and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Purpose; To describe the design and construction of an accelerator-based boron neutron capture therapy (AB-BNCT) facility with multiple treatment rooms at the Southern Tohoku BNCT Research Center (STBRC).Materials and Methods; AB-BNCT system at the STBRC is equipped with a cyclotron-based epithermal neutron source (C-BENS), which consists of a cyclotron accelerator (HM-30), a beryllium neutron production target, and a beam shaping assembly (BSA). We developed a remote patient transport system (RPTS) for workers to reduce the work time in the treatment room under the condition of remaining activities just after an irradiation. We studied the feasibility of this system and carefully designed optimum layout to realize patient flow and workflow efficiently.Results; We designed the upside-down Y shaped beamline configuration, in which HM-30 and two treatment rooms are assumed to be located on a top and bottoms, respectively. To reduce the activities caused by thermal neutron, BSA is surrounded by LiF-loaded polyethylene blocks and low-activation concrete. The measured out-of-field thermal and fast neutron dose profiles were in good agreement with calculated ones using MCNPX. It was also confirmed that the RPTS could be operated up to 9 m apart from the RPTS without any problems. Conclusion; We successfully established the environment of BNCT as one of the division of general hospital without sense of incongruity in comparison of environment of conventional radiotherapy. The AB-BNCT system described in this study confirmed to specifications and is being used for BNCT in a hospital.
Download or read book Analysis of Accelerator Based Neutron Spectra for BNCT Using Proton Recoil Spectroscopy written by and published by . This book was released on 1998 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Boron Neutron Capture Therapy (BNCT) is a promising binary treatment modality for high-grade primary brain tumors (glioblastoma multiforme, GM) and other cancers. BNCT employs a boron-10 containing compound that preferentially accumulates in the cancer cells in the brain. Upon neutron capture by 1°B energetic alpha particles and triton released at the absorption site kill the cancer cell. In order to gain penetration depth in the brain Fairchild proposed, for this purpose, the use of energetic epithermal neutrons at about 10 keV. Phase 1/2 clinical trials of BNCT for GM are underway at the Brookhaven Medical Research Reactor (BMRR) and at the MIT Reactor, using these nuclear reactors as the source for epithermal neutrons. In light of the limitations of new reactor installations, e.g. cost, safety and licensing, and limited capability for modulating the reactor based neutron beam energy spectra, alternative neutron sources are being contemplated for wider implementation of this modality in a hospital environment. For example, accelerator based neutron sources offer the possibility of tailoring the neutron beams, in terms of improved depth-dose distributions, to the individual and offer, with relative ease, the capability of modifying the neutron beam energy and port size. In previous work new concepts for compact accelerator/target configuration were published. In this work, using the Van de Graaff accelerator the authors have explored different materials for filtering and reflecting neutron beams produced by irradiating a thick Li target with 1.8 to 2.5 MeV proton beams. However, since the yield and the maximum neutron energy emerging from the Li-7(p, n)Be-7 reaction increase with increase in the proton beam energy, there is a need for optimization of the proton energy versus filter and shielding requirements to obtain the desired epithermal neutron beam. The MCNP-4A computer code was used for the initial design studies that were verified with benchmark experiments using a proton recoil spectroscopy detection system. Comparison was also made between in phantom 1°BF3 readings made at the BMRR and those made at the RARAF accelerator facility.
Download or read book OPTIMIZATION OF THE EPITHERMAL NEUTRON BEAM FOR BORON NEUTRON CAPTURE THERAPY AT THE BROOKHAVEN MEDICAL RESEARCH REACTOR written by and published by . This book was released on 2002 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clinical trials of Boron Neutron Capture Therapy for patients with malignant brain tumor had been carried out for half a decade, using an epithermal neutron beam at the Brookhaven's Medical Reactor. The decision to permanently close this reactor in 2000 cut short the efforts to implement a new conceptual design to optimize this beam in preparation for use with possible new protocols. Details of the conceptual design to produce a higher intensity, more forward-directed neutron beam with less contamination from gamma rays, fast and thermal neutrons are presented here for their potential applicability to other reactor facilities. Monte Carlo calculations were used to predict the flux and absorbed dose produced by the proposed design. The results were benchmarked by the dose rate and flux measurements taken at the facility then in use.
Download or read book Target Studies for Accelerator based Boron Neutron Capture Therapy written by and published by . This book was released on 1996 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two new concepts, NIFTI and DISCOS, are described. These concepts enable the efficient production of epithermal neutrons for BNCT (Boron Neutron Capture Therapy) medical treatment, utilizing a low current, low energy proton beam impacting on a lithium target. The NIFTI concept uses an iron layer that strongly impedes the transmission of neutrons with energies above 24 KeV. Lower energy neutrons readily pass through this iron ''filter'', which has a deep ''window'' in its scattering cross section at 24 KeV. The DISCOS concept uses a rapidly rotating, high g disc to create a series of thin ((approximately) 1 micron thickness) liquid lithium targets in the form of continuous films through which the proton beam passes. The average energy lost by a proton as it passes through a single target is small, approximately 10 KeV. Between the targets, the proton beam is reaccelerated by an applied DC electric field. The DISCOS approach enables the accelerator -- target facility to operate with a beam energy only slightly above the threshold value for neutron production -- resulting in an output beam of low-energy epithermal neutrons -- while achieving a high yield of neutrons per milliamp of proton beam current.
