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Sample records for therapy modulates eta

  1. Hormone therapy modulates ET(A) mRNA expression in the aorta of ovariectomised New Zealand White rabbits

    DEFF Research Database (Denmark)

    Pedersen, Susan Helene; Nielsen, Lars Bo; Pedersen, Nina Gros

    2009-01-01

    OBJECTIVE: To study the effect of 17beta-estradiol (E(2)) or conjugated equine estrogens (CEE) alone and in combination with norethisterone acetate (NETA) or medroxyprogesterone acetate (MPA) on the endothelin-1 (ET-1) system. METHODS: New Zealand White rabbits were treated with E(2), CEE, E(2......(A) receptor. The effect was maintained with the co-administration of NETA, but not MPA. The differential effects of specific hormone components may explain the variable effects of hormone therapy on the arterial wall....

  2. Aperture modulated arc therapy

    International Nuclear Information System (INIS)

    Crooks, S M; Wu, Xiaodong; Takita, C; Watzich, M; Xing Lei

    2003-01-01

    We show that it is possible to translate an intensity modulated radiation therapy (IMRT) treatment plan and deliver it as a single arc. This technique is referred to in this paper as aperture modulation arc therapy (AMAT). During this arc, the MLC leaves do not conform to the projection of the target PTV and the machine output of the accelerator has a constant value. Dose was calculated using the CORVUS 4.0 IMRT system, which uses a pencil beam dose algorithm, and treatments were delivered using a Varian 2100C/D Clinac. Results are presented for a head and neck and a prostate case, showing the equivalence of the IMRT and the translated AMAT delivery. For a prostate AMAT delivery, coronal plane film dose for the IMRT and AMAT deliveries agreed within 7.19 ± 6.62%. For a meningioma the coronal plane dose distributions were similar to a value of 4.6 ± 6.62%. Dose to the isocentre was measured as being within 2% of the planned value in both cases

  3. Intensity-modulated radiation therapy.

    Science.gov (United States)

    Goffman, Thomas E; Glatstein, Eli

    2002-07-01

    Intensity-modulated radiation therapy (IMRT) is an increasingly popular technical means of tightly focusing the radiation dose around a cancer. As with stereotactic radiotherapy, IMRT uses multiple fields and angles to converge on the target. The potential for total dose escalation and for escalation of daily fraction size to the gross cancer is exciting. The excitement, however, has greatly overshadowed a range of radiobiological and clinical concerns.

  4. Eta mesons in nuclei

    International Nuclear Information System (INIS)

    Liu, L.C.

    1987-01-01

    The possibility of producing eta-mesic nuclei by the use of pions is discussed. If these nuclei are observed experimentally, then the binding energies of the eta in this new nuclear matter can be used to extract accurately the eta-N-N* coupling constant in a nucleus. The framework for these calculations is the coupled channel isobar model

  5. Fan beam intensity modulated proton therapy

    Science.gov (United States)

    Hill, Patrick M.

    A fan beam proton therapy is developed which delivers intensity modulated proton therapy using distal edge tracking. The system may be retrofit onto existing proton therapy gantries without alterations to infrastructure in order to improve treatments through intensity modulation. A novel range and intensity modulation system is designed using acrylic leaves that are inserted or retracted from subsections of the fan beam. Leaf thicknesses are chosen in a base-2 system and motivated in a binary manner. Dose spots from individual beam channels range between 1 and 5 cm. Integrated collimators attempting to limit crosstalk among beam channels are investigated, but found to be inferior to uncollimated beam channel modulators. A treatment planning system performing data manipulation in MATLAB and dose calculation in MCNPX is developed. Beamlet dose is calculated on patient CT data and a fan beam source is manually defined to produce accurate results. An energy deposition tally follows the CT grid, allowing straightforward registration of dose and image data. Simulations of beam channels assume that a beam channel either delivers dose to a distal edge spot or is intensity modulated. A final calculation is performed separately to determine the deliverable dose accounting for all sources of scatter. Treatment plans investigate the effects that varying system parameters have on dose distributions. Beam channel apertures may be as large as 20 mm because the sharp distal falloff characteristic of proton dose provides sufficient intensity modulation to meet dose objectives, even in the presence of coarse lateral resolution. Dose conformity suffers only when treatments are delivered from less than 10 angles. Jaw widths of 1--2 cm produce comparable dose distributions, but a jaw width of 4 cm produces unacceptable target coverage when maintaining critical structure avoidance. Treatment time for a prostate delivery is estimated to be on the order of 10 minutes. Neutron production

  6. Searches for B0 Decays to eta K0, eta eta,eta' eta', eta phi, and eta'phi

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B.

    2006-07-31

    The authors search for B{sup 0} meson decays into two-body combinations of K{sup 0}, {eta}, {eta}', and {phi} mesons in 324 million B{bar B} pairs collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC. They measure the following branching fractions (upper limits at 90% confidence level) in units of 10{sup -6}: {Beta}(B{sup 0} {yields} {eta}K{sup 0}) = 1.8{sub -0.6}{sup +0.7} {+-} 0.1 (< 2.9), {Beta}(B{sup 0} {yields} {eta}{eta}) = 1.1{sub -0.4}{sup +0.5} {+-} 0.1(< 1.8), {Beta}(B{sup 0} {yields} {eta}{phi}) = 0.1 {+-} 0.2 {+-} 0.1(< 0.6), {Beta}(B{sup 0} {yields} {eta}'{phi}) = 0.2{sub -0.3}{sup +0.4} {+-} 0.1(< 1.0), and {Beta}(B{sup 0} {yields} {eta}'{eta}') = 1.0{sub -0.6}{sup +0.8} {+-} 0.1 (< 2.4), where the first error is statistical and the second systematic.

  7. Physics with ETA mesons

    International Nuclear Information System (INIS)

    Liu, Lon-chang.

    1989-01-01

    Since the advent of pion factories, an impressive amount of information about the nuclear dynamics of the Δ(1232) pion- nucleon resonance has been obtained. The study of this isospin-3/2 resonance has greatly benefited from the fact that π/sup /minus//n and π + p systems are pure I = 3/2 states, which couple only to the Δ in the resonance region. Such isospin selectivity of the pion does not exist, however, for the I = 1/2 N* resonances because it is not possible to form a pure I = 1/2 state with a pion and a nucleon. Eta mesons have zero isospin. Consequently, the /eta/N systems are in a pure I = 1/2 state, and /eta/ can be used to tag those N* resonances to which it strongly couples. We will briefly review the πN interaction from the threshold region to c.m. energy √s ≅1600 MeV. We shall see how improved πN data can help the study of πN interactions. I shall discuss what new information about the hadronic interaction can be learned from the study of eta production in pp collisions. The behavior of eta meson in nuclei will be discussed. The interesting question of the quark structure of /eta/(549) and /eta/'(958) will also be discussed within the framework of a simple model. 19 refs., 13 figs

  8. Fan-beam intensity modulated proton therapy.

    Science.gov (United States)

    Hill, Patrick; Westerly, David; Mackie, Thomas

    2013-11-01

    This paper presents a concept for a proton therapy system capable of delivering intensity modulated proton therapy using a fan beam of protons. This system would allow present and future gantry-based facilities to deliver state-of-the-art proton therapy with the greater normal tissue sparing made possible by intensity modulation techniques. A method for producing a divergent fan beam of protons using a pair of electromagnetic quadrupoles is described and particle transport through the quadrupole doublet is simulated using a commercially available software package. To manipulate the fan beam of protons, a modulation device is developed. This modulator inserts or retracts acrylic leaves of varying thickness from subsections of the fan beam. Each subsection, or beam channel, creates what effectively becomes a beam spot within the fan area. Each channel is able to provide 0-255 mm of range shift for its associated beam spot, or stop the beam and act as an intensity modulator. Results of particle transport simulations through the quadrupole system are incorporated into the MCNPX Monte Carlo transport code along with a model of the range and intensity modulation device. Several design parameters were investigated and optimized, culminating in the ability to create topotherapy treatment plans using distal-edge tracking on both phantom and patient datasets. Beam transport calculations show that a pair of electromagnetic quadrupoles can be used to create a divergent fan beam of 200 MeV protons over a distance of 2.1 m. The quadrupole lengths were 30 and 48 cm, respectively, with transverse field gradients less than 20 T/m, which is within the range of water-cooled magnets for the quadrupole radii used. MCNPX simulations of topotherapy treatment plans suggest that, when using the distal edge tracking delivery method, many delivery angles are more important than insisting on narrow beam channel widths in order to obtain conformal target coverage. Overall, the sharp distal

  9. Intensity-modulated arc therapy simplified

    International Nuclear Information System (INIS)

    Wong, Eugene; Chen, Jeff Z.; Greenland, Jonathan

    2002-01-01

    Purpose: We present a treatment planning strategy for intensity-modulated radiation therapy using gantry arcs with dynamic multileaf collimator, previously termed intensity-modulated arc therapy (IMAT). Methods and Materials: The planning strategy is an extension of the photon bar arc and asymmetric arc techniques and is classified into three levels of complexity, with increasing number of gantry arcs. This principle allows us to generalize the analysis of the number of arcs required for intensity modulation for a given treatment site. Using a phantom, we illustrate how the current technique is more flexible than the photon bar arc technique. We then compare plans from our strategy with conventional three-dimensional conformal treatment plans for three sites: prostate (prostate plus seminal vesicles), posterior pharyngeal wall, and chest wall. Results: Our strategy generates superior IMAT treatment plans compared to conventional three-dimensional conformal plans. The IMAT plans spare critical organs well, and the trade-off for simplicity is that the dose uniformity in the target volume may not rival that of true inverse treatment plans. Conclusions: The analyses presented in this paper give a better understanding of IMAT plans. Our strategy is easier to understand and more efficient in generating plans than inverse planning systems; our plans are also simpler to modify, and quality assurance is more intuitive

  10. $\\eta$-metric structures

    OpenAIRE

    Gaba, Yaé Ulrich

    2017-01-01

    In this paper, we discuss recent results about generalized metric spaces and fixed point theory. We introduce the notion of $\\eta$-cone metric spaces, give some topological properties and prove some fixed point theorems for contractive type maps on these spaces. In particular we show that theses $\\eta$-cone metric spaces are natural generalizations of both cone metric spaces and metric type spaces.

  11. The ETA10 supercomputer system

    International Nuclear Information System (INIS)

    Swanson, C.D.

    1987-01-01

    The ETA Systems, Inc. ETA 10 is a next-generation supercomputer featuring multiprocessing, a large hierarchical memory system, high performance input/output, and network support for both batch and interactive processing. Advanced technology used in the ETA 10 includes liquid nitrogen cooled CMOS logic with 20,000 gates per chip, a single printed circuit board for each CPU, and high density static and dynamics MOS memory chips. Software for the ETA 10 includes an underlying kernel that supports multiple user environments, a new ETA FORTRAN compiler with an advanced automatic vectorizer, a multitasking library and debugging tools. Possible developments for future supercomputers from ETA Systems are discussed. (orig.)

  12. A large mixing effect on eta,eta' and iota

    International Nuclear Information System (INIS)

    Kawai, E.

    1983-01-01

    We quantitatively investigate a possible large mixing effect on eta(549), eta'(958) and iota(1440) in a phenomenological way, taking both SU(3) symmetry breaking and gluon intervention into due account. (orig.)

  13. Inverse planning of intensity modulated proton therapy

    International Nuclear Information System (INIS)

    Nill, S.; Oelfke, U.; Bortfeld, T.

    2004-01-01

    A common requirement of radiation therapy is that treatment planning for different radiation modalities is devised on the basis of the same treatment planning system (TPS). The present study presents a novel multi-modal TPS with separate modules for the dose calculation, the optimization engine and the graphical user interface, which allows to integrate different treatment modalities. For heavy-charged particles, both most promising techniques, the distal edge tracking (DET) and the 3-dimensional scanning (3D) technique can be optimized. As a first application, the quality of optimized intensity-modulated treatment plans for photons (IMXT) and protons (IMPT) was analyzed in one clinical case on the basis of the achieved physical dose distributions. A comparison of the proton plans with the photon plans showed no significant improvement in terms of target volume dose, however there was an improvement in terms of organs at risk as well as a clear reduction of the total integral dose. For the DET technique, it is possible to create a treatment plan with almost the same quality of the 3D technique, however with a clearly reduced number (factor of 5) of beam spots as well as a reduced optimization time. Due to its modular design, the system can be easily expanded to more sophisticated dose-calculation algorithms or to modeling of biological effects. (orig.) [de

  14. Single-energy intensity modulated proton therapy

    Science.gov (United States)

    Farace, Paolo; Righetto, Roberto; Cianchetti, Marco

    2015-09-01

    In this note, an intensity modulated proton therapy (IMPT) technique, based on the use of high single-energy (SE-IMPT) pencil beams, is described. The method uses only the highest system energy (226 MeV) and only lateral penumbra to produce dose gradient, as in photon therapy. In the study, after a preliminary analysis of the width of proton pencil beam penumbras at different depths, SE-IMPT was compared with conventional IMPT in a phantom containing titanium inserts and in a patient, affected by a spinal chordoma with fixation rods. It was shown that SE-IMPT has the potential to produce a sharp dose gradient and that it is not affected by the uncertainties produced by metal implants crossed by the proton beams. Moreover, in the chordoma patient, target coverage and organ at risk sparing of the SE-IMPT plan resulted comparable to that of the less reliable conventional IMPT technique. Robustness analysis confirmed that SE-IMPT was not affected by range errors, which can drastically affect the IMPT plan. When accepting a low-dose spread as in modern photon techniques, SE-IMPT could be an option for the treatment of lesions (e.g. cervical bone tumours) where steep dose gradient could improve curability, and where range uncertainty, due for example to the presence of metal implants, hampers conventional IMPT.

  15. Single-energy intensity modulated proton therapy.

    Science.gov (United States)

    Farace, Paolo; Righetto, Roberto; Cianchetti, Marco

    2015-10-07

    In this note, an intensity modulated proton therapy (IMPT) technique, based on the use of high single-energy (SE-IMPT) pencil beams, is described.The method uses only the highest system energy (226 MeV) and only lateral penumbra to produce dose gradient, as in photon therapy. In the study, after a preliminary analysis of the width of proton pencil beam penumbras at different depths, SE-IMPT was compared with conventional IMPT in a phantom containing titanium inserts and in a patient, affected by a spinal chordoma with fixation rods.It was shown that SE-IMPT has the potential to produce a sharp dose gradient and that it is not affected by the uncertainties produced by metal implants crossed by the proton beams. Moreover, in the chordoma patient, target coverage and organ at risk sparing of the SE-IMPT plan resulted comparable to that of the less reliable conventional IMPT technique. Robustness analysis confirmed that SE-IMPT was not affected by range errors, which can drastically affect the IMPT plan.When accepting a low-dose spread as in modern photon techniques, SE-IMPT could be an option for the treatment of lesions (e.g. cervical bone tumours) where steep dose gradient could improve curability, and where range uncertainty, due for example to the presence of metal implants, hampers conventional IMPT.

  16. Single-energy intensity modulated proton therapy

    International Nuclear Information System (INIS)

    Farace, Paolo; Righetto, Roberto; Cianchetti, Marco

    2015-01-01

    In this note, an intensity modulated proton therapy (IMPT) technique, based on the use of high single-energy (SE-IMPT) pencil beams, is described.The method uses only the highest system energy (226 MeV) and only lateral penumbra to produce dose gradient, as in photon therapy. In the study, after a preliminary analysis of the width of proton pencil beam penumbras at different depths, SE-IMPT was compared with conventional IMPT in a phantom containing titanium inserts and in a patient, affected by a spinal chordoma with fixation rods.It was shown that SE-IMPT has the potential to produce a sharp dose gradient and that it is not affected by the uncertainties produced by metal implants crossed by the proton beams. Moreover, in the chordoma patient, target coverage and organ at risk sparing of the SE-IMPT plan resulted comparable to that of the less reliable conventional IMPT technique. Robustness analysis confirmed that SE-IMPT was not affected by range errors, which can drastically affect the IMPT plan.When accepting a low-dose spread as in modern photon techniques, SE-IMPT could be an option for the treatment of lesions (e.g. cervical bone tumours) where steep dose gradient could improve curability, and where range uncertainty, due for example to the presence of metal implants, hampers conventional IMPT. (note)

  17. Dual-gated volumetric modulated arc therapy

    International Nuclear Information System (INIS)

    Fahimian, Benjamin; Wu, Junqing; Wu, Huanmei; Geneser, Sarah; Xing, Lei

    2014-01-01

    Gated Volumetric Modulated Arc Therapy (VMAT) is an emerging radiation therapy modality for treatment of tumors affected by respiratory motion. However, gating significantly prolongs the treatment time, as delivery is only activated during a single respiratory phase. To enhance the efficiency of gated VMAT delivery, a novel dual-gated VMAT (DG-VMAT) technique, in which delivery is executed at both exhale and inhale phases in a given arc rotation, is developed and experimentally evaluated. Arc delivery at two phases is realized by sequentially interleaving control points consisting of MUs, MLC sequences, and angles of VMAT plans generated at the exhale and inhale phases. Dual-gated delivery is initiated when a respiration gating signal enters the exhale window; when the exhale delivery concludes, the beam turns off and the gantry rolls back to the starting position for the inhale window. The process is then repeated until both inhale and exhale arcs are fully delivered. DG-VMAT plan delivery accuracy was assessed using a pinpoint chamber and diode array phantom undergoing programmed motion. DG-VMAT delivery was experimentally implemented through custom XML scripting in Varian’s TrueBeam™ STx Developer Mode. Relative to single gated delivery at exhale, the treatment time was improved by 95.5% for a sinusoidal breathing pattern. The pinpoint chamber dose measurement agreed with the calculated dose within 0.7%. For the DG-VMAT delivery, 97.5% of the diode array measurements passed the 3%/3 mm gamma criterion. The feasibility of DG-VMAT delivery scheme has been experimentally demonstrated for the first time. By leveraging the stability and natural pauses that occur at end-inspiration and end-exhalation, DG-VMAT provides a practical method for enhancing gated delivery efficiency by up to a factor of two

  18. Film Dosimetry for Intensity Modulated Radiation Therapy

    International Nuclear Information System (INIS)

    Benites-Rengifo, J.; Martinez-Davalos, A.; Celis, M.; Larraga, J.

    2004-01-01

    Intensity Modulated Radiation Therapy (IMRT) is an oncology treatment technique that employs non-uniform beam intensities to deliver highly conformal radiation to the targets while minimizing doses to normal tissues and critical organs. A key element for a successful clinical implementation of IMRT is establishing a dosimetric verification process that can ensure that delivered doses are consistent with calculated ones for each patient. To this end we are developing a fast quality control procedure, based on film dosimetry techniques, to be applied to the 6 MV Novalis linear accelerator for IMRT of the Instituto Nacional de Neurologia y Neurocirugia (INNN) in Mexico City. The procedure includes measurements of individual fluence maps for a limited number of fields and dose distributions in 3D using extended dose-range radiographic film. However, the film response to radiation might depend on depth, energy and field size, and therefore compromise the accuracy of measurements. In this work we present a study of the dependence of Kodak EDR2 film's response on the depth, field size and energy, compared with those of Kodak XV2 film. The first aim is to devise a fast and accurate method to determine the calibration curve of film (optical density vs. doses) commonly called a sensitometric curve. This was accomplished by using three types of irradiation techniques: Step-and-shoot, dynamic and static fields

  19. Whole-brain hippocampal sparing radiation therapy: Volume-modulated arc therapy vs intensity-modulated radiation therapy case study

    International Nuclear Information System (INIS)

    Lee, Katrina; Lenards, Nishele; Holson, Janice

    2016-01-01

    The hippocampus is responsible for memory and cognitive function. An ongoing phase II clinical trial suggests that sparing dose to the hippocampus during whole-brain radiation therapy can help preserve a patient's neurocognitive function. Progressive research and advancements in treatment techniques have made treatment planning more sophisticated but beneficial for patients undergoing treatment. The aim of this study is to evaluate and compare hippocampal sparing whole-brain (HS-WB) radiation therapy treatment planning techniques using volume-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). We randomly selected 3 patients to compare different treatment techniques that could be used for reducing dose to the hippocampal region. We created 2 treatment plans, a VMAT and an IMRT, from each patient's data set and planned on the Eclipse 11.0 treatment planning system (TPS). A total of 6 plans (3 IMRT and 3 VMAT) were created and evaluated for this case study. The physician contoured the hippocampus as per the Radiation Therapy Oncology Group (RTOG) 0933 protocol atlas. The organs at risk (OR) were contoured and evaluated for the plan comparison, which included the spinal cord, optic chiasm, the right and left eyes, lenses, and optic nerves. Both treatment plans produced adequate coverage on the planning target volume (PTV) while significantly reducing dose to the hippocampal region. The VMAT treatment plans produced a more homogenous dose distribution throughout the PTV while decreasing the maximum point dose to the target. However, both treatment techniques demonstrated hippocampal sparing when irradiating the whole brain.

  20. Intensity-modulated radiation therapy: dynamic MLC (DMLC) therapy, multisegment therapy and tomotherapy. An example of QA in DMLC therapy

    International Nuclear Information System (INIS)

    Webb, S.

    1998-01-01

    Intensity-modulated radiation therapy will make a quantum leap in tumor control. It is the new radiation therapy for the new millennium. The major methods to achieve IMRT are: 1. Dynamic multileaf collimator (DMLC) therapy, 2. multisegment therapy, and 3. tomotherapy. The principles of these 3 techniques are briefly reviewed. Each technique presents unique QA issues which are outlined. As an example this paper will present the results of a recent new study of an important QA concern in DMLC therapy. (orig.) [de

  1. Radiative decay of the eta-, eta'-mesons in the nonlocal quark model. [eta(eta'). --> gamma gamma. ; eta. -->. pi. /sup +/. pi. /sup -/. gamma. ; eta. -->. pi. /sup 0/2. gamma. ; eta'. -->. rho/sup 0/. gamma. ; eta'. -->. omega gamma. ;. pi. /sup 0/. -->. gamma. e/sup +/e/sup -/; eta(eta'). -->. gamma mu. /sup +/. mu. /sup -/

    Energy Technology Data Exchange (ETDEWEB)

    Efimov, G V; Ivanov, M A; Nogovitsyn, E A [Joint Inst. for Nuclear Research, Dubna (USSR)

    1981-07-01

    P..--> gamma gamma.. (P=..pi../sup 0/, eta, eta'), eta..--> pi../sup +/..pi../sup -/..gamma.., eta..--> pi../sup 0/..gamma gamma.., eta/sup 1/..-->..V..gamma.. (V=rho/sup 0/, ..omega..), p..--> gamma..l/sup +/l/sup -/ (p=..pi../sup 0/, eta, eta') radiation decays are studied for testing the applicability of the non-local quark model for description of the experimental data. The Feynman diagrams of these decays are presented, values of the widths of the Veta..--> gamma gamma.., eta..--> pi../sup +/..pi../sup -/..gamma.., eta..--> pi../sup 0/..gamma gamma.., eta'..--> gamma gamma.., eta'..-->..rho/sup 0/..gamma.., eta'..--> omega gamma.. decays are calculated and given in the form of a table. Calculations are carried out for two values of the eta eta'-crossing angle: THETA=-11 deg and -18 deg. Values of invariant amplitudes of these decays are determined for ..pi../sup 0/..--> gamma..e/sup +/e/sup -/, eta..--> gamma mu../sup +/..mu../sup -/, eta'..--> gamma mu../sup +/..mu../sup -/ decays at THETA=-11 deg and -18 deg. The best agreement with the experimental data is noted to take place at THETA=-11 deg, the determined width of the eta..--> pi../sup 0/..gamma gamma.. decays is underestimated as compared with the experimental one.

  2. SACLAY: Eta mesons at Saturne

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1992-05-15

    Using a nuclear reaction, the new tagged eta meson facility now operating at the French Saturne National Laboratory in Saclay produces eta mesons (together with recoil helium-3 nuclei) by proton bombardment of a deuterium target. The proton beam is extracted from the Saturne synchrotron at 893 MeV, stabilized to 80 keV. This is a scant 1.5 MeV above the reaction threshold and close to the energy where eta production peaks.

  3. SACLAY: Eta mesons at Saturne

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Using a nuclear reaction, the new tagged eta meson facility now operating at the French Saturne National Laboratory in Saclay produces eta mesons (together with recoil helium-3 nuclei) by proton bombardment of a deuterium target. The proton beam is extracted from the Saturne synchrotron at 893 MeV, stabilized to 80 keV. This is a scant 1.5 MeV above the reaction threshold and close to the energy where eta production peaks

  4. A proton beam delivery system for conformal therapy and intensity modulated therapy

    International Nuclear Information System (INIS)

    Yu Qingchang

    2001-01-01

    A scattering proton beam delivery system for conformal therapy and intensity modulated therapy is described. The beam is laterally spread out by a dual-ring double scattering system and collimated by a program-controlled multileaf collimator and patient specific fixed collimators. The proton range is adjusted and modulated by a program controlled binary filter and ridge filters

  5. Whole-brain hippocampal sparing radiation therapy: Volume-modulated arc therapy vs intensity-modulated radiation therapy case study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Katrina, E-mail: Trinabena23@gmail.com; Lenards, Nishele; Holson, Janice

    2016-04-01

    The hippocampus is responsible for memory and cognitive function. An ongoing phase II clinical trial suggests that sparing dose to the hippocampus during whole-brain radiation therapy can help preserve a patient's neurocognitive function. Progressive research and advancements in treatment techniques have made treatment planning more sophisticated but beneficial for patients undergoing treatment. The aim of this study is to evaluate and compare hippocampal sparing whole-brain (HS-WB) radiation therapy treatment planning techniques using volume-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). We randomly selected 3 patients to compare different treatment techniques that could be used for reducing dose to the hippocampal region. We created 2 treatment plans, a VMAT and an IMRT, from each patient's data set and planned on the Eclipse 11.0 treatment planning system (TPS). A total of 6 plans (3 IMRT and 3 VMAT) were created and evaluated for this case study. The physician contoured the hippocampus as per the Radiation Therapy Oncology Group (RTOG) 0933 protocol atlas. The organs at risk (OR) were contoured and evaluated for the plan comparison, which included the spinal cord, optic chiasm, the right and left eyes, lenses, and optic nerves. Both treatment plans produced adequate coverage on the planning target volume (PTV) while significantly reducing dose to the hippocampal region. The VMAT treatment plans produced a more homogenous dose distribution throughout the PTV while decreasing the maximum point dose to the target. However, both treatment techniques demonstrated hippocampal sparing when irradiating the whole brain.

  6. Whole-brain hippocampal sparing radiation therapy: Volume-modulated arc therapy vs intensity-modulated radiation therapy case study.

    Science.gov (United States)

    Lee, Katrina; Lenards, Nishele; Holson, Janice

    2016-01-01

    The hippocampus is responsible for memory and cognitive function. An ongoing phase II clinical trial suggests that sparing dose to the hippocampus during whole-brain radiation therapy can help preserve a patient׳s neurocognitive function. Progressive research and advancements in treatment techniques have made treatment planning more sophisticated but beneficial for patients undergoing treatment. The aim of this study is to evaluate and compare hippocampal sparing whole-brain (HS-WB) radiation therapy treatment planning techniques using volume-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). We randomly selected 3 patients to compare different treatment techniques that could be used for reducing dose to the hippocampal region. We created 2 treatment plans, a VMAT and an IMRT, from each patient׳s data set and planned on the Eclipse 11.0 treatment planning system (TPS). A total of 6 plans (3 IMRT and 3 VMAT) were created and evaluated for this case study. The physician contoured the hippocampus as per the Radiation Therapy Oncology Group (RTOG) 0933 protocol atlas. The organs at risk (OR) were contoured and evaluated for the plan comparison, which included the spinal cord, optic chiasm, the right and left eyes, lenses, and optic nerves. Both treatment plans produced adequate coverage on the planning target volume (PTV) while significantly reducing dose to the hippocampal region. The VMAT treatment plans produced a more homogenous dose distribution throughout the PTV while decreasing the maximum point dose to the target. However, both treatment techniques demonstrated hippocampal sparing when irradiating the whole brain. Copyright © 2016 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  7. Intensity-Modulated Radiation Therapy (IMRT)

    Science.gov (United States)

    ... type your comment or suggestion into the following text box: Comment: E-mail: Area code: Phone no: Thank ... Accelerator Prostate Cancer Treatment Head and Neck Cancer Treatment Introduction to Cancer Therapy (Radiation Oncology) ...

  8. The pitfalls of dosimetric commissioning for intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Tohyama, Naoki; Kodama, Takashi; Hatano, K.

    2013-01-01

    Intensity modulated radiation therapy (IMRT) allows higher radiation dose to be focused to the target volumes while minimizing the dose to OAR. To start of clinical treatment in IMRTvwe must perform commissioning strictly than 3D-conformal radiotherapy (CRT). In this report, pitfalls of dosimetric commissioning for intensity modulated radiation therapy were reviewed. Multileaf collimator (MLC) offsets and MLC transmissions are important parameters in commissioning of RTPS for IMRT. Correction of depth scaling and fluence scaling is necessary for dose measurement using solid phantom. (author)

  9. Vitamin D Signaling Modulators in Cancer Therapy.

    Science.gov (United States)

    Luo, Wei; Johnson, Candace S; Trump, Donald L

    2016-01-01

    The antiproliferative and pro-apoptotic effects of 1α,25-dihydroxycholecalciferol (1,25(OH)2D3, 1,25D3, calcitriol) have been demonstrated in various tumor model systems in vitro and in vivo. However, limited antitumor effects of 1,25D3 have been observed in clinical trials. This may be attributed to a variety of factors including overexpression of the primary 1,25D3 degrading enzyme, CYP24A1, in tumors, which would lead to rapid local inactivation of 1,25D3. An alternative strategy for improving the antitumor activity of 1,25D3 involves the combination with a selective CYP24A1 inhibitor. The validity of this approach is supported by numerous preclinical investigations, which demonstrate that CYP24A1 inhibitors suppress 1,25D3 catabolism in tumor cells and increase the effects of 1,25D3 on gene expression and cell growth. Studies are now required to determine whether selective CYP24A1 inhibitors+1,25D3 can be used safely and effectively in patients. CYP24A1 inhibitors plus 1,25D3 can cause dose-limiting toxicity of vitamin D (hypercalcemia) in some patients. Dexamethasone significantly reduces 1,25D3-mediated hypercalcemia and enhances the antitumor activity of 1,25D3, increases VDR-ligand binding, and increases VDR protein expression. Efforts to dissect the mechanisms responsible for CYP24A1 overexpression and combinational effect of 1,25D3/dexamethasone in tumors are underway. Understanding the cross talk between vitamin D receptor (VDR) and glucocorticoid receptor (GR) signaling axes is of crucial importance to the design of new therapies that include 1,25D3 and dexamethasone. Insights gained from these studies are expected to yield novel strategies to improve the efficacy of 1,25D3 treatment. © 2016 Elsevier Inc. All rights reserved.

  10. Energy and intensity modulated radiation therapy with electrons

    OpenAIRE

    Olofsson, Lennart

    2005-01-01

    In recent years intensity modulated radiation therapy with photons (xIMRT) has gained attention due to its ability to reduce the dose in the tissues close to the tumour volume. However, this technique also results in a large low dose volume. Electron IMRT (eIMRT) has the potential to reduce the integral dose to the patient due to the dose fall off in the electron depth dose curves. This dose fall off makes it possible to modulate the dose distribution in the direction of the beam by selecting...

  11. Splicing modulation therapy in the treatment of genetic diseases

    Directory of Open Access Journals (Sweden)

    Arechavala-Gomeza V

    2014-12-01

    Full Text Available Virginia Arechavala-Gomeza,1 Bernard Khoo,2 Annemieke Aartsma-Rus3 1Neuromuscular Disorders Group, BioCruces Health Research Institute, Barakaldo, Bizkaia, Spain; 2Endocrinology, Division of Medicine, University College London, London, UK; 3Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands All authors contributed equally to this manuscript Abstract: Antisense-mediated splicing modulation is a tool that can be exploited in several ways to provide a potential therapy for rare genetic diseases. This approach is currently being tested in clinical trials for Duchenne muscular dystrophy and spinal muscular atrophy. The present review outlines the versatility of the approach to correct cryptic splicing, modulate alternative splicing, restore the open reading frame, and induce protein knockdown, providing examples of each. Finally, we outline a possible path forward toward the clinical application of this approach for a wide variety of inherited rare diseases. Keywords: splicing, therapy, antisense oligonucleotides, cryptic splicing, alternative splicing

  12. Potential clinical efficacy of intensity-modulated conformal therapy

    International Nuclear Information System (INIS)

    Meeks, Sanford L.; Buatti, John M.; Bova, Francis J.; Friedman, William A.; Mendenhall, William M.; Zlotecki, Robert A.

    1998-01-01

    Purpose: The purpose of this study was to examine the potential benefit of using intensity-modulated conformal therapy for a variety of lesions currently treated with stereotactic radiosurgery or conventional radiotherapy. Methods and Materials: Intensity-modulated conformal treatment plans were generated for small intracranial lesions, as well as head and neck, lung, breast, and prostate cases, using the Peacock Plan[reg] treatment-planning system (Nomos Corporation). For small intracranial lesions, intensity-modulated conformal treatment plans were compared with stereotactic radiosurgery treatment plans generated for patient treatment at the University of Florida Shands Cancer Center. For other sites (head and neck, lung, breast, and prostate), plans generated using the Peacock Plan[reg] were compared with conventional treatment plans, as well as beam's-eye-view conformal treatment plans. Plan comparisons were accomplished through conventional qualitative review of two-dimensional (2D) dose distributions in conjunction with quantitative techniques, such as dose-volume histograms, dosimetric statistics, normal tissue complication probabilities, tumor control probabilities, and objective numerical scoring. Results: For small intracranial lesions, there is little difference between intensity-modulated conformal treatment planning and radiosurgery treatment planning in the conformation of high isodose lines with the target volume. However, stereotactic treatment planning provides a steeper dose gradient outside the target volume and, hence, a lower normal tissue toxicity index. For extracranial sites, objective numerical scores for beam's-eye-view and intensity-modulated conformal planning techniques are superior to scores for conventional treatment plans. The beam's-eye-view planning technique prevents geographic target misses and better excludes healthy tissues from the treatment portal. Compared with scores for the beam's-eye-view planning technique, scores for

  13. Intensity-modulated radiation therapy: first reported treatment in Australasia

    International Nuclear Information System (INIS)

    Corry, J.; Joon, D.L.; Hope, G.; Smylie, J.; Henkul, Z.; Wills, J.; Cramb, J.; Towns, S.; Archer, P.

    2002-01-01

    Intensity-modulated radiation therapy (IMRT) is an exciting new advance in the practice of radiation oncology. It is the use of non-uniform radiation beams to achieve conformal dose distributions. As a result of the high initial capital costs and the time and complexity of planning, IMRT is not yet a widely available clinical treatment option. We describe the process involved in applying this new technology to a case of locally advanced nasopharyngeal cancer. Copyright (2002) Blackwell Science Pty Ltd

  14. Immune-modulating therapy in acute pancreatitis: Fact or fiction

    Science.gov (United States)

    Akinosoglou, Karolina; Gogos, Charalambos

    2014-01-01

    Acute pancreatitis (AP) is one of the most common diseases of the gastrointestinal tract, bearing significant morbidity and mortality worldwide. Current treatment of AP remains unspecific and supportive and is mainly targeted to aggressively prevent systemic complications and organ failure by intensive care. As acute pancreatitis shares an indistinguishable profile of inflammation with sepsis, therapeutic approaches have turned towards modulating the systemic inflammatory response. Targets, among others, have included pro- and anti-inflammatory modulators, cytokines, chemokines, immune cells, adhesive molecules and platelets. Even though, initial results in experimental models have been encouraging, clinical implementation of immune-regulating therapies in acute pancreatitis has had a slow progress. Main reasons include difficulty in clinical translation of experimental data, poor understanding of inflammatory response time-course, flaws in experimental designs, need for multimodal approaches and commercial drawbacks. Whether immune-modulation in acute pancreatitis remains a fact or just fiction remains to be seen in the future. PMID:25386069

  15. The analysis of B-d ->(eta, eta ')l(+)l(-) decays in the standard model

    NARCIS (Netherlands)

    Erkol, G; Turan, G

    We study the differential branching ratio, the branching ratio and the CP-violating asymmetry for the exclusive B-d --> (eta,eta')l(+)l(-) decays in the standard model. We deduce the B-d --> (eta,eta') form factors from the form factors of B --> pi available in the literature, by using the SU(3)(F)

  16. Telekomunikazio-sare eta zerbitzuak: teoria

    OpenAIRE

    Huarte Arrayago, Maider; Saiz Agustín, Purificación; Goirizelaia Ordorika, Iñaki

    2011-01-01

    Helburuak: Testu-liburu honen helburua bikoitza da, 'Telekomunikazio-sare eta zerbitzuak' (2001eko ikasketa-planetako Telekomunikazio Ingeniaritza Teknikoetako 2. mailan irakasten zena) eta 'Telekomunikazio-sare eta zerbitzuak I' (1995eko ikasketa-planetako Telekomunikazio Ingeniaritzako 2. mailan irakasten zena) irakasgaietako ikasleentzat (hortaz, ikasketarako) zein irakasleentzat (hots, irakaskuntzarako) lagungarri izatea. Horregatik, ikasgelan azaldutako kontzeptuen kontsultarako testu-li...

  17. Experiments on eta-meson production

    International Nuclear Information System (INIS)

    Peng, J.C.

    1985-01-01

    Following a review of some highlights of eta-meson characteristics, the status of eta-meson production experiments is reviewed. The physics motivations and first results of two LAMPF experiments on (π,eta) reactions are discussed. Possible future experiments are also discussed. 42 refs., 12 figs., 4 tabs

  18. B meson decays to charmless meson pairs containing eta or eta'

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, : B.

    2009-12-14

    The authors present updated measurements of the branching fractions for B{sup 0} meson decays to {eta}K{sup 0}, {eta}{eta}, {eta}{phi}, {eta}{omega}, {eta}{prime}K{sup 0}, {eta}{prime}{eta}{prime}, {eta}{prime}, {phi}, and {eta}{prime}{omega} and branching fractions and CP-violating charge asymmetries for B{sup +} decays to {eta}{pi}{sup +}, {eta}K{sup +}, {eta}{prime}{pi}{sup +}, and {eta}{prime} K{sup +}. The data represent the full dataset of 467 x 10{sup 6} B{bar B} pairs collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory. Besides large signals for the four charged B decays modes and for B{sup 0} {yields} {eta}{prime}K{sup 0}, they find evidence for three B{sup 0} decays modes at greater than 3.0{sigma} significance. They find {Beta}(B{sup 0} {yields} {eta}K{sup 0}) = (1.15{sub -0.38}{sup +0.43} {+-} 0.09) x 10{sup -6}, {Beta}(B{sup 0} {yields} {eta}{omega}) = (0.94{sub -0.30}{sup +0.35} {+-} 0.09) x 10{sup -6}, and {Beta}(B{sup 0} {yields} {eta}{prime}{omega}) = (1.01{sub -0.38}{sup +0.46} {+-} 0.09) x 10{sup -6}, where the first (second) uncertainty is statistical (systematic). For the B{sup +} {yields} {eta}K{sup +} decay mode, they measure the charge asymmetry {Alpha}{sub ch} (B{sup +} {yields} {eta}K{sup +}) = -0.36 {+-} 0.11 {+-} 0.03.

  19. Optimization approaches to volumetric modulated arc therapy planning

    Energy Technology Data Exchange (ETDEWEB)

    Unkelbach, Jan, E-mail: junkelbach@mgh.harvard.edu; Bortfeld, Thomas; Craft, David [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States); Alber, Markus [Department of Medical Physics and Department of Radiation Oncology, Aarhus University Hospital, Aarhus C DK-8000 (Denmark); Bangert, Mark [Department of Medical Physics in Radiation Oncology, German Cancer Research Center, Heidelberg D-69120 (Germany); Bokrantz, Rasmus [RaySearch Laboratories, Stockholm SE-111 34 (Sweden); Chen, Danny [Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Li, Ruijiang; Xing, Lei [Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States); Men, Chunhua [Department of Research, Elekta, Maryland Heights, Missouri 63043 (United States); Nill, Simeon [Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London SM2 5NG (United Kingdom); Papp, Dávid [Department of Mathematics, North Carolina State University, Raleigh, North Carolina 27695 (United States); Romeijn, Edwin [H. Milton Stewart School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Salari, Ehsan [Department of Industrial and Manufacturing Engineering, Wichita State University, Wichita, Kansas 67260 (United States)

    2015-03-15

    Volumetric modulated arc therapy (VMAT) has found widespread clinical application in recent years. A large number of treatment planning studies have evaluated the potential for VMAT for different disease sites based on the currently available commercial implementations of VMAT planning. In contrast, literature on the underlying mathematical optimization methods used in treatment planning is scarce. VMAT planning represents a challenging large scale optimization problem. In contrast to fluence map optimization in intensity-modulated radiotherapy planning for static beams, VMAT planning represents a nonconvex optimization problem. In this paper, the authors review the state-of-the-art in VMAT planning from an algorithmic perspective. Different approaches to VMAT optimization, including arc sequencing methods, extensions of direct aperture optimization, and direct optimization of leaf trajectories are reviewed. Their advantages and limitations are outlined and recommendations for improvements are discussed.

  20. The ETA systems plans for supercomputers

    International Nuclear Information System (INIS)

    Swanson, C.D.

    1987-01-01

    The ETA Systems, is a class VII supercomputer featuring multiprocessing, a large hierarchical memory system, high performance input/output, and network support for both batch and interactive processing. Advanced technology used in the ETA 10 includes liquid nitrogen cooled CMOS logic with 20,000 gates per chip, a single printed circuit board for each CPU, and high density static and dynamic MOS memory chips. Software for the ETA 10 includes an underlying kernel that supports multiple user environments, a new ETA FORTRAN compiler with an advanced automatic vectorizer, a multitasking library and debugging tools. Possible developments for future supercomputers from ETA Systems are discussed

  1. Linear algebraic methods applied to intensity modulated radiation therapy.

    Science.gov (United States)

    Crooks, S M; Xing, L

    2001-10-01

    Methods of linear algebra are applied to the choice of beam weights for intensity modulated radiation therapy (IMRT). It is shown that the physical interpretation of the beam weights, target homogeneity and ratios of deposited energy can be given in terms of matrix equations and quadratic forms. The methodology of fitting using linear algebra as applied to IMRT is examined. Results are compared with IMRT plans that had been prepared using a commercially available IMRT treatment planning system and previously delivered to cancer patients.

  2. Intensity-modulated radiation therapy clinical evidence and techniques

    CERN Document Server

    Nishimura, Yasumasa

    2015-01-01

    Successful clinical use of intensity-modulated radiation therapy (IMRT) represents a significant advance in radiation oncology. Because IMRT can deliver high-dose radiation to a target with a reduced dose to the surrounding organs, it can improve the local control rate and reduce toxicities associated with radiation therapy. Since IMRT began being used in the mid-1990s, a large volume of clinical evidence of the advantages of IMRT has been collected. However, treatment planning and quality assurance (QA) of IMRT are complicated and difficult for the clinician and the medical physicist. This book, by authors renowned for their expertise in their fields, provides cumulative clinical evidence and appropriate techniques for IMRT for the clinician and the physicist. Part I deals with the foundations and techniques, history, principles, QA, treatment planning, radiobiology and related aspects of IMRT. Part II covers clinical applications with several case studies, describing contouring and dose distribution with cl...

  3. Intensity-Modulated Radiation Therapy for Primary Brain Tumors

    Institute of Scientific and Technical Information of China (English)

    Zhong-min Wang

    2004-01-01

    Radiation therapy has been used to treat primary brain tumors as standard primary and/or adjunctive therapies for decades. It is difficult for conventional radiotherapy to deliver a lethal dose of radiation to the tumors while sparing surrounding normal brain due to complicated structures and multifunction in human brain. With the understanding of radiation physics and computer technology, a number of novel and more precise radiotherapies have been developed in recent years. Intensity modulated radiotherapy (IMRT) is one of these strategies. The use of IMRT in the treatment of primary brain tumors is being increasing nowadays. It shows great promise for some of primary brain tumors and also presents some problems, This review highlights current IMRT in the treatment of mainly primary brain tumors.

  4. Feasibility of a unified approach to intensity-modulated radiation therapy and volume-modulated arc therapy optimization and delivery

    International Nuclear Information System (INIS)

    Hoover, Douglas A.; Chen, Jeff Z.; MacFarlane, Michael; Wong, Eugene; Battista, Jerry J.

    2015-01-01

    Purpose: To study the feasibility of unified intensity-modulated arc therapy (UIMAT) which combines intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) optimization and delivery to produce superior radiation treatment plans, both in terms of dose distribution and efficiency of beam delivery when compared with either VMAT or IMRT alone. Methods: An inverse planning algorithm for UIMAT was prototyped within the PINNACLE treatment planning system (Philips Healthcare). The IMRT and VMAT deliveries are unified within the same arc, with IMRT being delivered at specific gantry angles within the arc. Optimized gantry angles for the IMRT and VMAT phases are assigned automatically by the inverse optimization algorithm. Optimization of the IMRT and VMAT phases is done simultaneously using a direct aperture optimization algorithm. Five treatment plans each for prostate, head and neck, and lung were generated using a unified optimization technique and compared with clinical IMRT or VMAT plans. Delivery verification was performed with an ArcCheck phantom (Sun Nuclear) on a Varian TrueBeam linear accelerator (Varian Medical Systems). Results: In this prototype implementation, the UIMAT plans offered the same target dose coverage while reducing mean doses to organs at risk by 8.4% for head-and-neck cases, 5.7% for lung cases, and 3.5% for prostate cases, compared with the VMAT or IMRT plans. In addition, UIMAT can be delivered with similar efficiency as VMAT. Conclusions: In this proof-of-concept work, a novel radiation therapy optimization and delivery technique that interlaces VMAT or IMRT delivery within the same arc has been demonstrated. Initial results show that unified VMAT/IMRT has the potential to be superior to either standard IMRT or VMAT

  5. Volumetric Modulated Arc Therapy (VMAT) Treatment Planning for Superficial Tumors

    International Nuclear Information System (INIS)

    Zacarias, Albert S.; Brown, Mellonie F.; Mills, Michael D.

    2010-01-01

    The physician's planning objective is often a uniform dose distribution throughout the planning target volume (PTV), including superficial PTVs on or near the surface of a patient's body. Varian's Eclipse treatment planning system uses a progressive resolution optimizer (PRO), version 8.2.23, for RapidArc dynamic multileaf collimator volumetric modulated arc therapy planning. Because the PRO is a fast optimizer, optimization convergence errors (OCEs) produce dose nonuniformity in the superficial area of the PTV. We present a postsurgical cranial case demonstrating the recursive method our clinic uses to produce RapidArc treatment plans. The initial RapidArc treatment plan generated using one 360 o arc resulted in substantial dose nonuniformity in the superficial section of the PTV. We demonstrate the use of multiple arcs to produce improved dose uniformity in this region. We also compare the results of this superficial dose compensation method to the results of a recursive method of dose correction that we developed in-house to correct optimization convergence errors in static intensity-modulated radiation therapy treatment plans. The results show that up to 4 arcs may be necessary to provide uniform dose to the surface of the PTV with the current version of the PRO.

  6. Quality assurance of intensity-modulated radiation therapy.

    Science.gov (United States)

    Palta, Jatinder R; Liu, Chihray; Li, Jonathan G

    2008-01-01

    The current paradigm for the quality assurance (QA) program for intensity-modulated radiation therapy (IMRT) includes QA of the treatment planning system, QA of the delivery system, and patient-specific QA. Although the IMRT treatment planning and delivery system is the same as for conventional three-dimensional conformal radiation therapy, it has more parameters to coordinate and verify. Because of complex beam intensity modulation, each IMRT field often includes many small irregular off-axis fields, resulting in isodose distributions for each IMRT plan that are more conformal than those from conventional treatment plans. Therefore, these features impose a new and more stringent set of QA requirements for IMRT planning and delivery. The generic test procedures to validate dose calculation and delivery accuracy for both treatment planning and IMRT delivery have to be customized for each type of IMRT planning and delivery strategy. The rationale for such an approach is that the overall accuracy of IMRT delivery is incumbent on the piecewise uncertainties in both the planning and delivery processes. The end user must have well-defined evaluation criteria for each element of the planning and delivery process. Such information can potentially be used to determine a priori the accuracy of IMRT planning and delivery.

  7. Quality Assurance of Intensity-Modulated Radiation Therapy

    International Nuclear Information System (INIS)

    Palta, Jatinder R.; Liu, Chihray; Li, Jonathan G.

    2008-01-01

    The current paradigm for the quality assurance (QA) program for intensity-modulated radiation therapy (IMRT) includes QA of the treatment planning system, QA of the delivery system, and patient-specific QA. Although the IMRT treatment planning and delivery system is the same as for conventional three-dimensional conformal radiation therapy, it has more parameters to coordinate and verify. Because of complex beam intensity modulation, each IMRT field often includes many small irregular off-axis fields, resulting in isodose distributions for each IMRT plan that are more conformal than those from conventional treatment plans. Therefore, these features impose a new and more stringent set of QA requirements for IMRT planning and delivery. The generic test procedures to validate dose calculation and delivery accuracy for both treatment planning and IMRT delivery have to be customized for each type of IMRT planning and delivery strategy. The rationale for such an approach is that the overall accuracy of IMRT delivery is incumbent on the piecewise uncertainties in both the planning and delivery processes. The end user must have well-defined evaluation criteria for each element of the planning and delivery process. Such information can potentially be used to determine a priori the accuracy of IMRT planning and delivery

  8. Modulation of EEG Theta Band Signal Complexity by Music Therapy

    Science.gov (United States)

    Bhattacharya, Joydeep; Lee, Eun-Jeong

    The primary goal of this study was to investigate the impact of monochord (MC) sounds, a type of archaic sounds used in music therapy, on the neural complexity of EEG signals obtained from patients undergoing chemotherapy. The secondary goal was to compare the EEG signal complexity values for monochords with those for progressive muscle relaxation (PMR), an alternative therapy for relaxation. Forty cancer patients were randomly allocated to one of the two relaxation groups, MC and PMR, over a period of six months; continuous EEG signals were recorded during the first and last sessions. EEG signals were analyzed by applying signal mode complexity, a measure of complexity of neuronal oscillations. Across sessions, both groups showed a modulation of complexity of beta-2 band (20-29Hz) at midfrontal regions, but only MC group showed a modulation of complexity of theta band (3.5-7.5Hz) at posterior regions. Therefore, the neuronal complexity patterns showed different changes in EEG frequency band specific complexity resulting in two different types of interventions. Moreover, the different neural responses to listening to monochords and PMR were observed after regular relaxation interventions over a short time span.

  9. Intensity Modulated Radiation Therapy. Development of the technique

    International Nuclear Information System (INIS)

    Rafailovici, L.; Alva, R.; Chiozza, J.; Donato, H.; Falomo, S.; Cardiello, C.; Furia, O.; Martinez, A.; Filomia, M.L.; Sansogne, R.; Arbiser, S.; Dosoretz, B.

    2008-01-01

    Full text: Introduction: Intensity Modulated Radiation Therapy (IMRT) is a result of advances in computer sciences that allowed the development of new technology related to planning and radiation therapy. IMRT was developed to homogenize the dose in the target volumes and decrease the dose in the surrounding healthy tissue. Using a software with high calculation capacity a simultaneous irradiation with different doses in a given volume is achieved. IMRT is based on internal planning. Material and methods: 628 patients were treated with IMRT in prostate lesions, head and neck, breast, thorax, abdomen and brain since August 2008. The software for IMRT is the XIO CMS and the accelerator used is a Varian Clinac 6 / 100. IMRT requires a first simulation, where immobilization systems are selected (mats, thermoplastic masks, among others) and the demarcation of the target structures, healthy tissue and dose prescription by a tattoo. Images of CT / MRI are merged when necessary. Once the system made the treatment optimization, this one is regulated by modulators. These are produced by numerical control machines from digital files produced by software. In a second modulation the planned irradiation is checked and tattoo is carried out according with this. We have a strict process of quality assurance to assess the viability of the plan before its implementation. We use the Map Check it possible to compare the dose on the central axis and the distribution in the whole plane regarding to that generated by the planning system. From 03/2008 the virtual simulation process was implemented integrating the described stages. Results and Conclusions: IMRT is a complex technique. The meticulous planning, implementation of process and quality control allows the use of this technique in a reliable and secure way. With IMRT we achieved a high level of dose conformation, less irradiation of healthy tissue, lower rates of complications and the dose escalation for some tumors. (authors) [es

  10. Search for B Meson Decays to eta' eta' K

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B.

    2006-05-05

    The authors describe searches for decays of B mesons to the charmless final states {eta}'{eta}'K. The data consist of 228 million B{bar B} pairs produced in e{sup +}e{sup -} annihilation, collected with the BABAR detector at the Stanford Linear Accelerator Center. The 90% confidence level upper limits for the branching fractions are {Beta}(B{sup 0} {yields} {eta}'{eta}'K{sup 0}) < 31 x 10{sup -6} and {Beta}(B{sup +} {yields} {eta}'{eta}'K{sup +}) < 25 x 10{sup -6}.

  11. Prone Breast Intensity Modulated Radiation Therapy: 5-Year Results

    International Nuclear Information System (INIS)

    Osa, Etin-Osa O.; DeWyngaert, Keith; Roses, Daniel; Speyer, James; Guth, Amber; Axelrod, Deborah; Fenton Kerimian, Maria; Goldberg, Judith D.; Formenti, Silvia C.

    2014-01-01

    Purpose: To report the 5-year results of a technique of prone breast radiation therapy delivered by a regimen of accelerated intensity modulated radiation therapy with a concurrent boost to the tumor bed. Methods and Materials: Between 2003 and 2006, 404 patients with stage I-II breast cancer were prospectively enrolled into 2 consecutive protocols, institutional trials 03-30 and 05-181, that used the same regimen of 40.5 Gy/15 fractions delivered to the index breast over 3 weeks, with a concomitant daily boost to the tumor bed of 0.5 Gy (total dose 48 Gy). All patients were treated after segmental mastectomy and had negative margins and nodal assessment. Patients were set up prone: only if lung or heart volumes were in the field was a supine setup attempted and chosen if found to better spare these organs. Results: Ninety-two percent of patients were treated prone, 8% supine. Seventy-two percent had stage I, 28% stage II invasive breast cancer. In-field lung volume ranged from 0 to 228.27 cm 3 , mean 19.65 cm 3 . In-field heart volume for left breast cancer patients ranged from 0 to 21.24 cm 3 , mean 1.59 cm 3 . There was no heart in the field for right breast cancer patients. At a median follow-up of 5 years, the 5-year cumulative incidence of isolated ipsilateral breast tumor recurrence was 0.82% (95% confidence interval [CI] 0.65%-1.04%). The 5-year cumulative incidence of regional recurrence was 0.53% (95% CI 0.41%-0.69%), and the 5-year overall cumulative death rate was 1.28% (95% CI 0.48%-3.38%). Eighty-two percent (95% CI 77%-85%) of patients judged their final cosmetic result as excellent/good. Conclusions: Prone accelerated intensity modulated radiation therapy with a concomitant boost results in excellent local control and optimal sparing of heart and lung, with good cosmesis. Radiation Therapy Oncology Group protocol 1005, a phase 3, multi-institutional, randomized trial is ongoing and is evaluating the equivalence of a similar dose and fractionation

  12. Prone Breast Intensity Modulated Radiation Therapy: 5-Year Results

    Energy Technology Data Exchange (ETDEWEB)

    Osa, Etin-Osa O.; DeWyngaert, Keith [Department of Radiation Oncology, New York University School of Medicine, New York, New York (United States); Roses, Daniel [Department of Surgery, New York University School of Medicine, New York, New York (United States); Speyer, James [Department of Medical Oncology, New York University School of Medicine, New York, New York (United States); Guth, Amber; Axelrod, Deborah [Department of Surgery, New York University School of Medicine, New York, New York (United States); Fenton Kerimian, Maria [Department of Radiation Oncology, New York University School of Medicine, New York, New York (United States); Goldberg, Judith D. [Department of Population Health, New York University School of Medicine, New York, New York (United States); Formenti, Silvia C., E-mail: Silvia.formenti@nyumc.org [Department of Radiation Oncology, New York University School of Medicine, New York, New York (United States)

    2014-07-15

    Purpose: To report the 5-year results of a technique of prone breast radiation therapy delivered by a regimen of accelerated intensity modulated radiation therapy with a concurrent boost to the tumor bed. Methods and Materials: Between 2003 and 2006, 404 patients with stage I-II breast cancer were prospectively enrolled into 2 consecutive protocols, institutional trials 03-30 and 05-181, that used the same regimen of 40.5 Gy/15 fractions delivered to the index breast over 3 weeks, with a concomitant daily boost to the tumor bed of 0.5 Gy (total dose 48 Gy). All patients were treated after segmental mastectomy and had negative margins and nodal assessment. Patients were set up prone: only if lung or heart volumes were in the field was a supine setup attempted and chosen if found to better spare these organs. Results: Ninety-two percent of patients were treated prone, 8% supine. Seventy-two percent had stage I, 28% stage II invasive breast cancer. In-field lung volume ranged from 0 to 228.27 cm{sup 3}, mean 19.65 cm{sup 3}. In-field heart volume for left breast cancer patients ranged from 0 to 21.24 cm{sup 3}, mean 1.59 cm{sup 3}. There was no heart in the field for right breast cancer patients. At a median follow-up of 5 years, the 5-year cumulative incidence of isolated ipsilateral breast tumor recurrence was 0.82% (95% confidence interval [CI] 0.65%-1.04%). The 5-year cumulative incidence of regional recurrence was 0.53% (95% CI 0.41%-0.69%), and the 5-year overall cumulative death rate was 1.28% (95% CI 0.48%-3.38%). Eighty-two percent (95% CI 77%-85%) of patients judged their final cosmetic result as excellent/good. Conclusions: Prone accelerated intensity modulated radiation therapy with a concomitant boost results in excellent local control and optimal sparing of heart and lung, with good cosmesis. Radiation Therapy Oncology Group protocol 1005, a phase 3, multi-institutional, randomized trial is ongoing and is evaluating the equivalence of a similar dose and

  13. Pancreatic cancer planning: Complex conformal vs modulated therapies

    International Nuclear Information System (INIS)

    Chapman, Katherine L.; Witek, Matthew E.; Chen, Hongyu; Showalter, Timothy N.; Bar-Ad, Voichita; Harrison, Amy S.

    2016-01-01

    To compare the roles of intensity-modulated radiation therapy (IMRT) and volumetric- modulated arc therapy (VMAT) therapy as compared to simple and complex 3-dimensional chemoradiotherpy (3DCRT) planning for resectable and borderline resectable pancreatic cancer. In all, 12 patients who received postoperative radiotherapy (8) or neoadjuvant concurrent chemoradiotherapy (4) were evaluated retrospectively. Radiotherapy planning was performed for 4 treatment techniques: simple 4-field box, complex 5-field 3DCRT, 5 to 6-field IMRT, and single-arc VMAT. All volumes were approved by a single observer in accordance with Radiation Therapy Oncology Group (RTOG) Pancreas Contouring Atlas. Plans included tumor/tumor bed and regional lymph nodes to 45 Gy; with tumor/tumor bed boosted to 50.4 Gy, at least 95% of planning target volume (PTV) received the prescription dose. Dose-volume histograms (DVH) for multiple end points, treatment planning, and delivery time were assessed. Complex 3DCRT, IMRT, and VMAT plans significantly (p < 0.05) decreased mean kidney dose, mean liver dose, liver (V 30 , V 35 ), stomach (D 10 %), stomach (V 45 ), mean right kidney dose, and right kidney (V 15 ) as compared with the simple 4-field plans that are most commonly reported in the literature. IMRT plans resulted in decreased mean liver dose, liver (V 35 ), and left kidney (V 15 , V 18 , V 20 ). VMAT plans decreased small bowel (D 10 %, D 15 %), small bowel (V 35 , V 45 ), stomach (D 10 %, D 15 %), stomach (V 35 , V 45 ), mean liver dose, liver (V 35 ), left kidney (V 15 , V 18 , V 20 ), and right kidney (V 18 , V 20 ). VMAT plans significantly decreased small bowel (D 10 %, D 15 %), left kidney (V 20 ), and stomach (V 45 ) as compared with IMRT plans. Treatment planning and delivery times were most efficient for simple 4-field box and VMAT. Excluding patient setup and imaging, average treatment delivery was within 10 minutes for simple and complex 3DCRT, IMRT, and VMAT treatments. This article

  14. Search for the eta C

    International Nuclear Information System (INIS)

    Garren, L.A.

    1982-01-01

    In an experiment performed at the Alternating Gradient Synchrotron at Brookhaven National Laboratory, we searched for narrow resonances in the reaction pi minus p -> X n, X -> gamma gamma at 13 GeV. We used a double-arm spectrometer with lead glass and scintillation elements. No resonances were observed above mass 2.8 in the gamma-gamma spectrum. The upper limit for the eta c cross section times branching ratio is 23 pb

  15. Current status of intensity-modulated radiation therapy (IMRT)

    International Nuclear Information System (INIS)

    Hatano, Kazuo; Araki, Hitoshi; Sakai, Mitsuhiro

    2007-01-01

    External-beam radiation therapy has been one of the treatment options for prostate cancer. The dose response has been observed for a dose range of 64.8-81 Gy. The problem of external-beam radiotherapy (RT) for prostate cancer is that as the dose increases, adverse effects also increase. Three-dimensional conformal radiation therapy (3D-CRT) has enabled us to treat patients with up to 72-76 Gy to the prostate, with a relatively acceptable risk of late rectal bleeding. Recently, intensity-modulated radiation therapy (IMRT) has been shown to deliver a higher dose to the target with acceptable low rates of rectal and bladder complications. The most important things to keep in mind when using an IMRT technique are that there is a significant trade-off between coverage of the target, avoidance of adjacent critical structures, and the inhomogeneity of the dose within the target. Lastly, even with IMRT, it should be kept in mind that a ''perfect'' plan that creates completely homogeneous coverage of the target volume and zero or small dose to the adjacent organs at risk is not always obtained. Participating in many treatment planning sessions and arranging the beams and beam weights create the best approach to the best IMRT plan. (author)

  16. Clinical implementation and quality assurance for intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Ma, C.-M.; Price, R.; McNeeley, S.; Chen, L.; Li, J.S.; Wang, L.; Ding, M.; Fourkal, E.; Qin, L.

    2002-01-01

    This paper describes the clinical implementation and quality assurance (QA) for intensity-modulated radiation therapy (IMRT) based on the experience at Fox Chase Cancer Center, Philadelphia, USA. We will review our procedures for the clinical implementation of the IMRT technique and the requirements for patient immobilization, target delineation, treatment optimization, beam delivery and system administration. We will discuss the dosimetric requirements and measurement procedures for beam commissioning and dosimetry verification for IMRT. We will examine the details of model-based dose calculation for IMRT treatment planning and the potential problems with such dose calculation algorithms. We will discuss the effect of beam delivery systems on the actual dose distributions received by the patients and the methods to incorporate such effects in the treatment optimization process. We will investigate the use of the Monte Carlo method for dose calculation and treatment verification for IMRT

  17. 3D printed plastics for beam modulation in proton therapy

    International Nuclear Information System (INIS)

    Lindsay, C; Hoehr, C; Kumlin, J; Schaffer, P; Jirasek, A; Lee, R; Martinez, D M

    2015-01-01

    Two 3D printing methods, fused filament fabrication (FFF) and PolyJet™ (PJ) were investigated for suitability in clinical proton therapy (PT) energy modulation. Measurements of printing precision, printed density and mean stopping power are presented. FFF is found to be accurate to 0.1 mm, to contain a void fraction of 13% due to air pockets and to have a mean stopping power dependent on geometry. PJ was found to print accurate to 0.05 mm, with a material density and mean stopping power consistent with solid poly(methyl methacrylate) (PMMA). Both FFF and PJ were found to print significant, sporadic defects associated with sharp edges on the order of 0.2 mm. Site standard PT modulator wheels were printed using both methods. Measured depth-dose profiles with a 74 MeV beam show poor agreement between PMMA and printed FFF wheels. PJ printed wheel depth-dose agreed with PMMA within 1% of treatment dose except for a distal falloff discrepancy of 0.5 mm. (note)

  18. Selective Androgen Receptor Modulators (SARMs) as Function Promoting Therapies

    Science.gov (United States)

    Bhasin, Shalender; Jasuja, Ravi

    2010-01-01

    Purpose of review The last decade has witnessed unprecedented discovery effort to develop selective androgen receptor modulators (SARMs) that improve physical function and bone health without adversely affecting the prostate and cardiovascular outcomes. This review describes the historical evolution, the rationale for SARM development, and the mechanisms of testosterone action and SARM selectivity. Recent Findings While steroidal SARMs have been around since the 1940s, a number of nonsteroidal SARMs that do not serve as substrates for CYP19 aromatase or 5α-reductase, act as full agonists in muscle and bone and as partial agonists in prostate are in development. The differing interactions of steroidal and nonsteroidal compounds with AR contribute to their unique pharmacologic actions. Ligand binding induces specific conformational changes in the ligand binding domain, which could modulate surface topology and protein-protein interactions between AR and coregulators, resulting in tissue-specific gene regulation. Preclinical studies have demonstrated the ability of SARMs to increase muscle and bone mass in preclinical rodent models with varying degree of prostate sparing. Phase I trials of SARMs in humans have reported modest increments in fat-free mass. Summary SARMs hold promise as a new class of function promoting anabolic therapies for a number of clinical indications, including functional limitations associated with aging and chronic disease, frailty, cancer cachexia, and osteoporosis. PMID:19357508

  19. Selective androgen receptor modulators as function promoting therapies.

    Science.gov (United States)

    Bhasin, Shalender; Jasuja, Ravi

    2009-05-01

    The past decade has witnessed an unprecedented discovery effort to develop selective androgen receptor modulators (SARMs) that improve physical function and bone health without adversely affecting the prostate and cardiovascular outcomes. This review describes the historical evolution, the rationale for SARM development, and the mechanisms of testosterone action and SARM selectivity. Although steroidal SARMs have been around since the 1940s, a number of nonsteroidal SARMs that do not serve as substrates for CYP19 aromatase or 5alpha-reductase, act as full agonists in muscle and bone and as partial agonists in prostate are in development. The differing interactions of steroidal and nonsteroidal compounds with androgen receptor (AR) contribute to their unique pharmacologic actions. Ligand binding induces specific conformational changes in the ligand-binding domain, which could modulate surface topology and protein-protein interactions between AR and coregulators, resulting in tissue-specific gene regulation. Preclinical studies have demonstrated the ability of SARMs to increase muscle and bone mass in preclinical rodent models with varying degree of prostate sparing. Phase I trials of SARMs in humans have reported modest increments in fat-free mass. SARMs hold promise as a new class of function promoting anabolic therapies for a number of clinical indications, including functional limitations associated with aging and chronic disease, frailty, cancer cachexia, and osteoporosis.

  20. Volumetric modulated arc therapy: IMRT in a single gantry arc

    International Nuclear Information System (INIS)

    Otto, Karl

    2008-01-01

    In this work a novel plan optimization platform is presented where treatment is delivered efficiently and accurately in a single dynamically modulated arc. Improvements in patient care achieved through image-guided positioning and plan adaptation have resulted in an increase in overall treatment times. Intensity-modulated radiation therapy (IMRT) has also increased treatment time by requiring a larger number of beam directions, increased monitor units (MU), and, in the case of tomotherapy, a slice-by-slice delivery. In order to maintain a similar level of patient throughput it will be necessary to increase the efficiency of treatment delivery. The solution proposed here is a novel aperture-based algorithm for treatment plan optimization where dose is delivered during a single gantry arc of up to 360 deg. The technique is similar to tomotherapy in that a full 360 deg. of beam directions are available for optimization but is fundamentally different in that the entire dose volume is delivered in a single source rotation. The new technique is referred to as volumetric modulated arc therapy (VMAT). Multileaf collimator (MLC) leaf motion and number of MU per degree of gantry rotation is restricted during the optimization so that gantry rotation speed, leaf translation speed, and dose rate maxima do not excessively limit the delivery efficiency. During planning, investigators model continuous gantry motion by a coarse sampling of static gantry positions and fluence maps or MLC aperture shapes. The technique presented here is unique in that gantry and MLC position sampling is progressively increased throughout the optimization. Using the full gantry range will theoretically provide increased flexibility in generating highly conformal treatment plans. In practice, the additional flexibility is somewhat negated by the additional constraints placed on the amount of MLC leaf motion between gantry samples. A series of studies are performed that characterize the relationship

  1. Cardiac Exposure in the Dynamic Conformal Arc Therapy, Intensity-Modulated Radiotherapy and Volumetric Modulated Arc Therapy of Lung Cancer.

    Directory of Open Access Journals (Sweden)

    Xin Ming

    Full Text Available To retrospectively evaluate the cardiac exposure in three cohorts of lung cancer patients treated with dynamic conformal arc therapy (DCAT, intensity-modulated radiotherapy (IMRT, or volumetric modulated arc therapy (VMAT at our institution in the past seven years.A total of 140 lung cancer patients were included in this institutional review board approved study: 25 treated with DCAT, 70 with IMRT and 45 with VMAT. All plans were generated in a same commercial treatment planning system and have been clinically accepted and delivered. The dose distribution to the heart and the effects of tumor laterality, the irradiated heart volume and the beam-to-heart distance on the cardiac exposure were investigated.The mean dose to the heart among all 140 plans was 4.5 Gy. Specifically, the heart received on average 2.3, 5.2 and 4.6 Gy in the DCAT, IMRT and VMAT plans, respectively. The mean heart doses for the left and right lung tumors were 4.1 and 4.8 Gy, respectively. No patients died with evidence of cardiac disease. Three patients (2% with preexisting cardiac condition developed cardiac disease after treatment. Furthermore, the cardiac exposure was found to increase linearly with the irradiated heart volume while decreasing exponentially with the beam-to-heart distance.Compared to old technologies for lung cancer treatment, modern radiotherapy treatment modalities demonstrated better heart sparing. But the heart dose in lung cancer radiotherapy is still higher than that in the radiotherapy of breast cancer and Hodgkin's disease where cardiac complications have been extensively studied. With strong correlations of mean heart dose with beam-to-heart distance and irradiated heart volume, cautions should be exercised to avoid long-term cardiac toxicity in the lung cancer patients undergoing radiotherapy.

  2. Mass loss from Eta Carinae

    International Nuclear Information System (INIS)

    Andriesse, C.D.; Viotti, R.

    1979-01-01

    This high luminosity (5x10 6 solar luminosity) star since 1840 is losing mass at the rate of 7.5x10 -2 solar masses per year. The large mass loss could be the result of vibrational instabilities produced in the CNO hydrogen burning phase of a very massive (160 solar masses) star. The presence of high excitation lines in the ultraviolet spectrum of Eta Car suggests the idea of a hot zone excited by dissipation of the supersonic turbulent flow. (Auth.)

  3. Searches for Charmless Decays B0 --> eta omega, B0 --> eta K0, B+ --> eta rho+, and B+ --> eta' pi+

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B

    2004-08-13

    The authors report results for measurements of the decay branching fractions of B{sup 0} to the charmless final states {eta}{omega} and {eta}K{sup 0}, and of B{sup +} to {eta}{rho}{sup +} and {eta}'{pi}{sup +}. None of these decays have been observed definitively. Measurements of the related decays B{sup +} --> {eta}K{sup +}, B{sup +} --> {eta}{pi}{sup +}, and B --> {eta}'K were published recently. Charmless decays with kaons are usually expected to be dominated by b --> s loop (''penguin'') transitions, while b --> u tree transitions are typically larger for the decays with pions and {rho} mesons. However the B --> {eta}K decays are especially interesting since they are suppressed relative to the abundant B --> {eta}'K decays due to destructive interference between two penguin amplitudes. The CKM-suppressed b --> u amplitudes may interfere significantly with penguin amplitudes, possibly leading to large direct CP violation in B{sup +} --> {eta}{rho}{sup +} and B{sup +} --> {eta}'{pi}{sup +}; numerical estimates are available in a few cases. The authors search for such direct CP violation by measuring the charge asymmetry A{sub ch} {equivalent_to} ({Gamma}{sup -} - {Gamma}{sup +})/({Gamma}{sup -} + {Gamma}{sup +}) in the rates {Gamma}{sup {+-}} = {Gamma}(B{sup {+-}} --> f{sup {+-}}), for each observed charged final state f{sup {+-}}. Charmless B decays are becoming useful to test the accuracy of theoretical predictions. Phenomenological fits to the branching fractions and charge asymmetries can be used to understand the importance of tree and penguin contributions and may provide sensitivity to the CKM angle {gamma}.

  4. Pancreatic cancer planning: Complex conformal vs modulated therapies

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, Katherine L. [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States); Witek, Matthew E. [Department of Radiation Oncology, University of Wisconsin School of Medicine School of Medicine and Public Health, Madison, WI (United States); Chen, Hongyu [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States); Showalter, Timothy N. [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States); Bar-Ad, Voichita [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States); Harrison, Amy S., E-mail: amy.harrison@jefferson.edu [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States)

    2016-07-01

    To compare the roles of intensity-modulated radiation therapy (IMRT) and volumetric- modulated arc therapy (VMAT) therapy as compared to simple and complex 3-dimensional chemoradiotherpy (3DCRT) planning for resectable and borderline resectable pancreatic cancer. In all, 12 patients who received postoperative radiotherapy (8) or neoadjuvant concurrent chemoradiotherapy (4) were evaluated retrospectively. Radiotherapy planning was performed for 4 treatment techniques: simple 4-field box, complex 5-field 3DCRT, 5 to 6-field IMRT, and single-arc VMAT. All volumes were approved by a single observer in accordance with Radiation Therapy Oncology Group (RTOG) Pancreas Contouring Atlas. Plans included tumor/tumor bed and regional lymph nodes to 45 Gy; with tumor/tumor bed boosted to 50.4 Gy, at least 95% of planning target volume (PTV) received the prescription dose. Dose-volume histograms (DVH) for multiple end points, treatment planning, and delivery time were assessed. Complex 3DCRT, IMRT, and VMAT plans significantly (p < 0.05) decreased mean kidney dose, mean liver dose, liver (V{sub 30}, V{sub 35}), stomach (D{sub 10}%), stomach (V{sub 45}), mean right kidney dose, and right kidney (V{sub 15}) as compared with the simple 4-field plans that are most commonly reported in the literature. IMRT plans resulted in decreased mean liver dose, liver (V{sub 35}), and left kidney (V{sub 15}, V{sub 18}, V{sub 20}). VMAT plans decreased small bowel (D{sub 10}%, D{sub 15}%), small bowel (V{sub 35}, V{sub 45}), stomach (D{sub 10}%, D{sub 15}%), stomach (V{sub 35}, V{sub 45}), mean liver dose, liver (V{sub 35}), left kidney (V{sub 15}, V{sub 18}, V{sub 20}), and right kidney (V{sub 18}, V{sub 20}). VMAT plans significantly decreased small bowel (D{sub 10}%, D{sub 15}%), left kidney (V{sub 20}), and stomach (V{sub 45}) as compared with IMRT plans. Treatment planning and delivery times were most efficient for simple 4-field box and VMAT. Excluding patient setup and imaging, average

  5. Radiative decays of eta-eta'-mesons in quark nonlocal model

    International Nuclear Information System (INIS)

    Efimov, G.V.; Ivanov, M.A.; Nogovitsyn, E.A.

    1980-01-01

    Leading radiative decays of eta, eta'-mesons (P→γγ, P=π 0 ,eta,eta', eta→π + π - γ, eta→π 0 γγ, eta'→Vsub(γ)(V=rho 0 , ω)) are decribed within a quark nonlocal model. Decay widths and electromagnetic form factors for the P→γl + l - decay are calculated. Calculations are performed for two mixing angles (THETA=-11 deg and THETA=-18 deg). For the case when THETA=-11 deg good agreement with experiment is achieved

  6. A comprehensive formulation for volumetric modulated arc therapy planning

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dan; Lyu, Qihui; Ruan, Dan; O’Connor, Daniel; Low, Daniel A.; Sheng, Ke, E-mail: ksheng@mednet.ucla.edu [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California 90024 (United States)

    2016-07-15

    Purpose: Volumetric modulated arc therapy (VMAT) is a widely employed radiation therapy technique, showing comparable dosimetry to static beam intensity modulated radiation therapy (IMRT) with reduced monitor units and treatment time. However, the current VMAT optimization has various greedy heuristics employed for an empirical solution, which jeopardizes plan consistency and quality. The authors introduce a novel direct aperture optimization method for VMAT to overcome these limitations. Methods: The comprehensive VMAT (comVMAT) planning was formulated as an optimization problem with an L2-norm fidelity term to penalize the difference between the optimized dose and the prescribed dose, as well as an anisotropic total variation term to promote piecewise continuity in the fluence maps, preparing it for direct aperture optimization. A level set function was used to describe the aperture shapes and the difference between aperture shapes at adjacent angles was penalized to control MLC motion range. A proximal-class optimization solver was adopted to solve the large scale optimization problem, and an alternating optimization strategy was implemented to solve the fluence intensity and aperture shapes simultaneously. Single arc comVMAT plans, utilizing 180 beams with 2° angular resolution, were generated for a glioblastoma multiforme case, a lung (LNG) case, and two head and neck cases—one with three PTVs (H&N{sub 3PTV}) and one with foue PTVs (H&N{sub 4PTV})—to test the efficacy. The plans were optimized using an alternating optimization strategy. The plans were compared against the clinical VMAT (clnVMAT) plans utilizing two overlapping coplanar arcs for treatment. Results: The optimization of the comVMAT plans had converged within 600 iterations of the block minimization algorithm. comVMAT plans were able to consistently reduce the dose to all organs-at-risk (OARs) as compared to the clnVMAT plans. On average, comVMAT plans reduced the max and mean OAR dose by 6

  7. Radiative decay of the eta-, eta'-mesons in the nonlocal quark model

    International Nuclear Information System (INIS)

    Efimov, G.V.; Ivanov, M.A.; Nogovitsyn, E.A.

    1981-01-01

    P→γγ (P=π 0 , eta, eta'), eta→π + π - γ, eta→π 0 γγ, eta 1 →Vγ (V=rho 0 , ω), p→γl + l - (p=π 0 , eta, eta') radiation decays are studied for testing the applicability of the non-local quark model for description of the experimental data. The Feynman diagrams of these decays are presented, values of the widths of the Veta→γγ, eta→π + π - γ, eta→π 0 γγ, eta'→γγ, eta'→rho 0 γ, eta'→ωγ decays are calculated and given in the form of a table. Calculations are carried out for two values of the eta eta'-crossing angle: THETA=-11 deg and -18 deg. Values of invariant amplitudes of these decays are determined for π 0 →γe + e - , eta→γμ + μ - , eta'→γμ + μ - decays at THETA=-11 deg and -18 deg. The best agreement with the experimental data is noted to take place at THETA=-11 deg, the determined width of the eta→π 0 γγ decays is underestimated as compared with the experimental one [ru

  8. A measurement of the eta' spin parity

    International Nuclear Information System (INIS)

    Cerrada, M.; Wagner, F.; Chaloupka, V.; Hemingway, R.J.; Holmgren, S.O.; Losty, M.J.; Loverre, P.F.; Marzano, F.; Blokzijl, R.; Jongejans, B.; Massaro, G.G.G.; Schotanus, D.J.; Tiecke, H.G.; Timmermans, J.J.M.; Foster, B.; McDowell, W.L.

    1977-01-01

    The spin parity of the eta'(958) is studied in the reaction K - p→eta'Λ at 4.2 GeV/c, using bubble chamber data with a statistical sensitivity of 128 events/μb. The data unambiguously prefer the 0 - assignment. (Auth.)

  9. A measurement of the eta ' spin parity

    CERN Document Server

    Cerrada, M; Chaloupka, V; Foster, B; Hemingway, R J; Holmgren, S O; Jongejans, B; Losty, Michael J; Loverre, P F; Marzano, F; Massaro, G G G; McDowell, W L; Schotanus, D J; Tiecke, H G; Timmermans, J; Wagner, F

    1977-01-01

    The spin parity of the eta '(958) is studied in the reaction K/sup -/p to eta ' Lambda at 4.2 GeV/c, using bubble chamber data with a statistical sensitivity of 128 events/ mu b. The data unambiguously prefer the 0/sup -/ assignment. (18 refs).

  10. Automatic interactive optimization for volumetric modulated arc therapy planning

    International Nuclear Information System (INIS)

    Tol, Jim P; Dahele, Max; Peltola, Jarkko; Nord, Janne; Slotman, Ben J; Verbakel, Wilko FAR

    2015-01-01

    Intensity modulated radiotherapy treatment planning for sites with many different organs-at-risk (OAR) is complex and labor-intensive, making it hard to obtain consistent plan quality. With the aim of addressing this, we developed a program (automatic interactive optimizer, AIO) designed to automate the manual interactive process for the Eclipse treatment planning system. We describe AIO and present initial evaluation data. Our current institutional volumetric modulated arc therapy (RapidArc) planning approach for head and neck tumors places 3-4 adjustable OAR optimization objectives along the dose-volume histogram (DVH) curve that is displayed in the optimization window. AIO scans this window and uses color-coding to differentiate between the DVH-lines, allowing it to automatically adjust the location of the optimization objectives frequently and in a more consistent fashion. We compared RapidArc AIO plans (using 9 optimization objectives per OAR) with the clinical plans of 10 patients, and evaluated optimal AIO settings. AIO consistency was tested by replanning a single patient 5 times. Average V95&V107 of the boost planning target volume (PTV) and V95 of the elective PTV differed by ≤0.5%, while average elective PTV V107 improved by 1.5%. Averaged over all patients, AIO reduced mean doses to individual salivary structures by 0.9-1.6Gy and provided mean dose reductions of 5.6Gy and 3.9Gy to the composite swallowing structures and oral cavity, respectively. Re-running AIO five times, resulted in the aforementioned parameters differing by less than 3%. Using the same planning strategy as manually optimized head and neck plans, AIO can automate the interactive Eclipse treatment planning process and deliver dosimetric improvements over existing clinical plans

  11. Ultrasound-based guidance of intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Fung, Albert Y.C.; Ayyangar, Komanduri M.; Djajaputra, David; Nehru, Ramasamy M.; Enke, Charles A.

    2006-01-01

    In ultrasound-guided intensity-modulated radiation therapy (IMRT) of prostate cancer, ultrasound imaging ascertains the anatomical position of patients during x-ray therapy delivery. The ultrasound transducers are made of piezoelectric ceramics. The same crystal is used for both ultrasound production and reception. Three-dimensional (3D) ultrasound devices capture and correlate series of 2-dimensional (2D) B-mode images. The transducers are often arranged in a convex array for focusing. Lower frequency reaches greater depth, but results in low resolution. For clear image, some gel is usually applied between the probe and the skin contact surface. For prostate positioning, axial and sagittal scans are performed, and the volume contours from computed tomography (CT) planning are superimposed on the ultrasound images obtained before radiation delivery at the linear accelerator. The planning volumes are then overlaid on the ultrasound images and adjusted until they match. The computer automatically deduces the offset necessary to move the patient so that the treatment area is in the correct location. The couch is translated as needed. The currently available commercial equipment can attain a positional accuracy of 1-2 mm. Commercial manufacturer designs differ in the detection of probe coordinates relative to the isocenter. Some use a position-sensing robotic arm, while others have infrared light-emitting diodes or pattern-recognition software with charge-couple-device cameras. Commissioning includes testing of image quality and positional accuracy. Ultrasound is mainly used in prostate positioning. Data for 7825 daily fractions of 234 prostate patients indicated average 3D inter-fractional displacement of about 7.8 mm. There was no perceivable trend of shift over time. Scatter plots showed slight prevalence toward superior-posterior directions. Uncertainties of ultrasound guidance included tissue inhomogeneities, speckle noise, probe pressure, and inter

  12. A comprehensive dosimetric study of pancreatic cancer treatment using three-dimensional conformal radiation therapy (3DCRT), intensity-modulated radiation therapy (IMRT), volumetric-modulated radiation therapy (VMAT), and passive-scattering and modulated-scanning proton therapy (PT)

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Xuanfeng; Dionisi, Francesco; Tang, Shikui; Ingram, Mark; Hung, Chun-Yu; Prionas, Evangelos; Lichtenwalner, Phil; Butterwick, Ian; Zhai, Huifang; Yin, Lingshu; Lin, Haibo; Kassaee, Alireza; Avery, Stephen, E-mail: stephen.avery@uphs.upenn.edu

    2014-07-01

    With traditional photon therapy to treat large postoperative pancreatic target volume, it often leads to poor tolerance of the therapy delivered and may contribute to interrupted treatment course. This study was performed to evaluate the potential advantage of using passive-scattering (PS) and modulated-scanning (MS) proton therapy (PT) to reduce normal tissue exposure in postoperative pancreatic cancer treatment. A total of 11 patients with postoperative pancreatic cancer who had been previously treated with PS PT in University of Pennsylvania Roberts Proton Therapy Center from 2010 to 2013 were identified. The clinical target volume (CTV) includes the pancreatic tumor bed as well as the adjacent high-risk nodal areas. Internal (iCTV) was generated from 4-dimensional (4D) computed tomography (CT), taking into account target motion from breathing cycle. Three-field and 4-field 3D conformal radiation therapy (3DCRT), 5-field intensity-modulated radiation therapy, 2-arc volumetric-modulated radiation therapy, and 2-field PS and MS PT were created on the patients’ average CT. All the plans delivered 50.4 Gy to the planning target volume (PTV). Overall, 98% of PTV was covered by 95% of the prescription dose and 99% of iCTV received 98% prescription dose. The results show that all the proton plans offer significant lower doses to the left kidney (mean and V{sub 18} {sub Gy}), stomach (mean and V{sub 20} {sub Gy}), and cord (maximum dose) compared with all the photon plans, except 3-field 3DCRT in cord maximum dose. In addition, MS PT also provides lower doses to the right kidney (mean and V{sub 18} {sub Gy}), liver (mean dose), total bowel (V{sub 20} {sub Gy} and mean dose), and small bowel (V{sub 15} {sub Gy} absolute volume ratio) compared with all the photon plans and PS PT. The dosimetric advantage of PT points to the possibility of treating tumor bed and comprehensive nodal areas while providing a more tolerable treatment course that could be used for dose

  13. A comprehensive dosimetric study of pancreatic cancer treatment using three-dimensional conformal radiation therapy (3DCRT), intensity-modulated radiation therapy (IMRT), volumetric-modulated radiation therapy (VMAT), and passive-scattering and modulated-scanning proton therapy (PT)

    International Nuclear Information System (INIS)

    Ding, Xuanfeng; Dionisi, Francesco; Tang, Shikui; Ingram, Mark; Hung, Chun-Yu; Prionas, Evangelos; Lichtenwalner, Phil; Butterwick, Ian; Zhai, Huifang; Yin, Lingshu; Lin, Haibo; Kassaee, Alireza; Avery, Stephen

    2014-01-01

    With traditional photon therapy to treat large postoperative pancreatic target volume, it often leads to poor tolerance of the therapy delivered and may contribute to interrupted treatment course. This study was performed to evaluate the potential advantage of using passive-scattering (PS) and modulated-scanning (MS) proton therapy (PT) to reduce normal tissue exposure in postoperative pancreatic cancer treatment. A total of 11 patients with postoperative pancreatic cancer who had been previously treated with PS PT in University of Pennsylvania Roberts Proton Therapy Center from 2010 to 2013 were identified. The clinical target volume (CTV) includes the pancreatic tumor bed as well as the adjacent high-risk nodal areas. Internal (iCTV) was generated from 4-dimensional (4D) computed tomography (CT), taking into account target motion from breathing cycle. Three-field and 4-field 3D conformal radiation therapy (3DCRT), 5-field intensity-modulated radiation therapy, 2-arc volumetric-modulated radiation therapy, and 2-field PS and MS PT were created on the patients’ average CT. All the plans delivered 50.4 Gy to the planning target volume (PTV). Overall, 98% of PTV was covered by 95% of the prescription dose and 99% of iCTV received 98% prescription dose. The results show that all the proton plans offer significant lower doses to the left kidney (mean and V 18 Gy ), stomach (mean and V 20 Gy ), and cord (maximum dose) compared with all the photon plans, except 3-field 3DCRT in cord maximum dose. In addition, MS PT also provides lower doses to the right kidney (mean and V 18 Gy ), liver (mean dose), total bowel (V 20 Gy and mean dose), and small bowel (V 15 Gy absolute volume ratio) compared with all the photon plans and PS PT. The dosimetric advantage of PT points to the possibility of treating tumor bed and comprehensive nodal areas while providing a more tolerable treatment course that could be used for dose escalation and combining with radiosensitizing

  14. Dosimetric verification of the intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Zou Huawei; Jia Mingxuan; Wu Rong; Xiao Fuda; Dong Xiaoqi

    2004-01-01

    Objective: To discuss the methods of the dosimetric verification in the intensity-modulated radiation therapy (IMRT) and insure correct execution of the IMRT planning in the clinical practice. Methods: The CMSFOCUS9200 inverse planning system was used to provide optimized 5-field IMRT treatment plans for the patients. A phantom was made from true water-equivalent material. The doses of the interesting points and isodose distributions of the interesting planes in the phantom were calculated using patients' treatment plan. The phantom was placed on the couch of the accelerator and was irradiated using the phantom's treatment planning data. The doses of interesting points were measured using a 0.23 cc chamber and the isodose distributions of interesting planes were measured using RIT 113 film dosimetry system in the phantom. The results were compared with those from calculation in planning system for verification. Results: The doses and isodose distributions measured by the chamber and the film were consistent with those predicted by the planning. The error between the measured dose and calculated dose in the interesting points was less than 3%. Conclusion: The dosimetric verification of IMRT is a reliable measure in the course of its implementation. (authors)

  15. Intensity-Modulated Radiation Therapy in Childhood Ependymoma

    International Nuclear Information System (INIS)

    Schroeder, Thomas M.; Chintagumpala, Murali; Okcu, M. Fatih; Chiu, J. Kam; Teh, Bin S.; Woo, Shiao Y.; Paulino, Arnold C.

    2008-01-01

    Purpose: To determine the patterns of failure after intensity-modulated radiation therapy (IMRT) for localized intracranial ependymoma. Methods and Materials: From 1994 to 2005, 22 children with pathologically proven, localized, intracranial ependymoma were treated with adjuvant IMRT. Of the patients, 12 (55%) had an infratentorial tumor and 14 (64%) had anaplastic histology. Five patients had a subtotal resection (STR), as evidenced by postoperative magnetic resonance imaging. The clinical target volume encompassed the tumor bed and any residual disease plus margin (median dose 54 Gy). Median follow-up for surviving patients was 39.8 months. Results: The 3-year overall survival rate was 87% ± 9%. The 3-year local control rate was 68% ± 12%. There were six local recurrences, all in the high-dose region of the treatment field. Median time to recurrence was 21.7 months. Of the 5 STR patients, 4 experienced recurrence and 3 died. Patients with a gross total resection had significantly better local control (p = 0.024) and overall survival (p = 0.008) than those with an STR. At last follow-up, no patient had developed visual loss, brain necrosis, myelitis, or a second malignancy. Conclusions: Treatment with IMRT provides local control and survival rates comparable with those in historic publications using larger treatment volumes. All failures were within the high-dose region, suggesting that IMRT does not diminish local control. The degree of surgical resection was shown to be significant for local control and survival

  16. Study of $\\eta-\\eta'$ mixing from measurement of $B^0_{(s)}\\to J/\\psi\\eta^{(')}$ decay rates

    CERN Document Server

    Aaij, Roel; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bertolin, Alessandro; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Brown, Henry; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casanova Mohr, Raimon; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew Christopher; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gastaldi, Ugo; Gauld, Rhorry; Gavardi, Laura; Gazzoni, Giulio; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, V.V.; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lowdon, Peter; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Otto, Adam; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Polikarpov, Sergey; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skillicorn, Ian; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Todd, Jacob; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wiedner, Dirk; Wilkinson, Guy; Wilkinson, Michael; Williams, Matthew; Williams, Mike; Wilschut, Hans; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang

    2015-01-01

    A study of $B^0$and $B^0_s$ meson decays into $J/\\psi\\eta$ and $J/\\psi\\eta^{\\prime}$ final states is performed using a data set of proton-proton collisions at centre-of-mass energies of 7 and 8TeV, collected by the LHCb experiment and corresponding to 3.0fb$^{-1}$ of integrated luminosity. The decay $B^0 \\rightarrow J/\\psi \\eta^{\\prime}$ is observed for the first time. The following ratios of branching fractions are measured: $ \\frac{\\mathcal{B}(B^0 \\rightarrow J/\\psi \\eta^{\\prime})}{\\mathcal{B}(B^0_s \\rightarrow J/\\psi \\eta^{\\prime})} = (2.28\\pm0.65\\,(stat)\\,\\pm0.10\\,(syst)\\,\\pm0.13\\,(f_{s}/f_{d}))\\times10^{-2},$ $ \\frac{\\mathcal{B}(B^0 \\rightarrow J/\\psi \\eta)}{\\mathcal{B}(B^0_s \\rightarrow J/\\psi \\eta)} = (1.85\\pm0.61\\,(stat)\\,\\pm0.09\\,(syst)\\,\\pm0.11\\,(f_{s}/f_{d}))\\times10^{-2},$ where the third uncertainty is related to the present knowledge of $f_{s}/f_{d}$, the ratio between the probabilities for a $b$ quark to form a $B^0_s$ or $B^0$ meson. The branching fraction ratios are used to determine the para...

  17. Eta Carinae: A Demanding Mistress

    Science.gov (United States)

    Gull, Theodore

    2012-01-01

    In the 1840's a southern star, Eta Argus, brightened to rival Sirius for nearly a decade, then faded. Today, we see the Homunculus, an hourglass figure with tutu, a dusty shell exceeding 12 solar masses expanding outward at 500 km/s. Many observers have systematically studied the massive binary total shrouded by interacting winds and its ejecta. More recently 3-D wind-wind collision models have begun to explain the extended structures resolved by Hubble Space Telescope. Now Herschel Space Observatory infrared scans are revealing wind interaction emissions and complex molecules left over from the dust that formed out of gas originally overabundant in nitrogen and greatly-depleted in oxygen and carbon. Many questions remain to be answered: What is the dust that formed in the 1840s event? What are the end states of the two massive companions ... SN, GRB, Hypernova? and When

  18. Choreographing Couch and Collimator in Volumetric Modulated Arc Therapy

    International Nuclear Information System (INIS)

    Yang Yingli; Zhang Pengpeng; Happersett, Laura; Xiong Jianping; Yang Jie; Chan, Maria; Beal, Kathryn; Mageras, Gig; Hunt, Margie

    2011-01-01

    Purpose: To design and optimize trajectory-based, noncoplanar subarcs for volumetric modulated arc therapy (VMAT) deliverable on both Varian TrueBEAM system and traditional accelerators; and to investigate their potential advantages for treating central nervous system (CNS) tumors. Methods and Materials: To guide the computerized selection of beam trajectories consisting of simultaneous couch, gantry, and collimator motion, a score function was implemented to estimate the geometric overlap between targets and organs at risk for each couch/gantry angle combination. An initial set of beam orientations is obtained as a function of couch and gantry angle, according to a minimum search of the score function excluding zones of collision. This set is grouped into multiple continuous and extended subarcs subject to mechanical limitations using a hierarchical clustering algorithm. After determination of couch/gantry trajectories, a principal component analysis finds the collimator angle at each beam orientation that minimizes residual target-organ at risk overlaps. An in-house VMAT optimization algorithm determines the optimal multileaf collimator position and monitor units for control points within each subarc. A retrospective study of 10 CNS patients compares the proposed method of VMAT trajectory with dynamic gantry, leaves, couch, and collimator motion (Tra-VMAT); a standard noncoplanar VMAT with no couch/collimator motion within subarcs (Std-VMAT); and noncoplanar intensity-modulated radiotherapy (IMRT) plans that were clinically used. Results: Tra-VMAT provided improved target dose conformality and lowered maximum dose to brainstem, optic nerves, and chiasm by 7.7%, 1.1%, 2.3%, and 1.7%, respectively, compared with Std-VMAT. Tra-VMAT provided higher planning target volume minimum dose and reduced maximum dose to chiasm, optic nerves, and cochlea by 6.2%, 1.3%, 6.3%, and 8.4%, respectively, and reduced cochlea mean dose by 8.7%, compared with IMRT. Tra-VMAT averaged

  19. Linear energy transfer incorporated intensity modulated proton therapy optimization

    Science.gov (United States)

    Cao, Wenhua; Khabazian, Azin; Yepes, Pablo P.; Lim, Gino; Poenisch, Falk; Grosshans, David R.; Mohan, Radhe

    2018-01-01

    The purpose of this study was to investigate the feasibility of incorporating linear energy transfer (LET) into the optimization of intensity modulated proton therapy (IMPT) plans. Because increased LET correlates with increased biological effectiveness of protons, high LETs in target volumes and low LETs in critical structures and normal tissues are preferred in an IMPT plan. However, if not explicitly incorporated into the optimization criteria, different IMPT plans may yield similar physical dose distributions but greatly different LET, specifically dose-averaged LET, distributions. Conventionally, the IMPT optimization criteria (or cost function) only includes dose-based objectives in which the relative biological effectiveness (RBE) is assumed to have a constant value of 1.1. In this study, we added LET-based objectives for maximizing LET in target volumes and minimizing LET in critical structures and normal tissues. Due to the fractional programming nature of the resulting model, we used a variable reformulation approach so that the optimization process is computationally equivalent to conventional IMPT optimization. In this study, five brain tumor patients who had been treated with proton therapy at our institution were selected. Two plans were created for each patient based on the proposed LET-incorporated optimization (LETOpt) and the conventional dose-based optimization (DoseOpt). The optimized plans were compared in terms of both dose (assuming a constant RBE of 1.1 as adopted in clinical practice) and LET. Both optimization approaches were able to generate comparable dose distributions. The LET-incorporated optimization achieved not only pronounced reduction of LET values in critical organs, such as brainstem and optic chiasm, but also increased LET in target volumes, compared to the conventional dose-based optimization. However, on occasion, there was a need to tradeoff the acceptability of dose and LET distributions. Our conclusion is that the

  20. Iterative regularization in intensity-modulated radiation therapy optimization

    International Nuclear Information System (INIS)

    Carlsson, Fredrik; Forsgren, Anders

    2006-01-01

    A common way to solve intensity-modulated radiation therapy (IMRT) optimization problems is to use a beamlet-based approach. The approach is usually employed in a three-step manner: first a beamlet-weight optimization problem is solved, then the fluence profiles are converted into step-and-shoot segments, and finally postoptimization of the segment weights is performed. A drawback of beamlet-based approaches is that beamlet-weight optimization problems are ill-conditioned and have to be regularized in order to produce smooth fluence profiles that are suitable for conversion. The purpose of this paper is twofold: first, to explain the suitability of solving beamlet-based IMRT problems by a BFGS quasi-Newton sequential quadratic programming method with diagonal initial Hessian estimate, and second, to empirically show that beamlet-weight optimization problems should be solved in relatively few iterations when using this optimization method. The explanation of the suitability is based on viewing the optimization method as an iterative regularization method. In iterative regularization, the optimization problem is solved approximately by iterating long enough to obtain a solution close to the optimal one, but terminating before too much noise occurs. Iterative regularization requires an optimization method that initially proceeds in smooth directions and makes rapid initial progress. Solving ten beamlet-based IMRT problems with dose-volume objectives and bounds on the beamlet-weights, we find that the considered optimization method fulfills the requirements for performing iterative regularization. After segment-weight optimization, the treatments obtained using 35 beamlet-weight iterations outperform the treatments obtained using 100 beamlet-weight iterations, both in terms of objective value and of target uniformity. We conclude that iterating too long may in fact deteriorate the quality of the deliverable plan

  1. Ultrafast treatment plan optimization for volumetric modulated arc therapy (VMAT).

    Science.gov (United States)

    Men, Chunhua; Romeijn, H Edwin; Jia, Xun; Jiang, Steve B

    2010-11-01

    To develop a novel aperture-based algorithm for volumetric modulated are therapy (VMAT) treatment plan optimization with high quality and high efficiency. The VMAT optimization problem is formulated as a large-scale convex programming problem solved by a column generation approach. The authors consider a cost function consisting two terms, the first enforcing a desired dose distribution and the second guaranteeing a smooth dose rate variation between successive gantry angles. A gantry rotation is discretized into 180 beam angles and for each beam angle, only one MLC aperture is allowed. The apertures are generated one by one in a sequential way. At each iteration of the column generation method, a deliverable MLC aperture is generated for one of the unoccupied beam angles by solving a subproblem with the consideration of MLC mechanic constraints. A subsequent master problem is then solved to determine the dose rate at all currently generated apertures by minimizing the cost function. When all 180 beam angles are occupied, the optimization completes, yielding a set of deliverable apertures and associated dose rates that produce a high quality plan. The algorithm was preliminarily tested on five prostate and five head-and-neck clinical cases, each with one full gantry rotation without any couch/collimator rotations. High quality VMAT plans have been generated for all ten cases with extremely high efficiency. It takes only 5-8 min on CPU (MATLAB code on an Intel Xeon 2.27 GHz CPU) and 18-31 s on GPU (CUDA code on an NVIDIA Tesla C1060 GPU card) to generate such plans. The authors have developed an aperture-based VMAT optimization algorithm which can generate clinically deliverable high quality treatment plans at very high efficiency.

  2. Quality assurance of patients for intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Yoon, Sang Min; Yi, Byong Yong; Choi, Eun Kyung; Kim, Jong Hoon; Ahn, Seung Do; Lee, Sang Wook

    2002-01-01

    To establish and verify the proper and the practical IMRT (intensity-modulated radiation therapy) patient QA (Quality Assurance). An IMRT QA which consists of 3 steps and 16 items were designed and examined the validity of the program by applying to 9 patients, 12 IMRT cases of various sites. The three step QA program consists of RTP related QA, treatment information flow QA, and a treatment delivery QA procedure. The evaluation of organ constraints, the validity of the point dose, and the dose distribution are major issues in the RTP related QA procedure. The leaf sequence file generation, the evaluation of the MLC control file, the comparison of the dry run film, and the IMRT field simulate image were included in the treatment information flow procedure QA. The patient setup QA, the verification of the IMRT treatment fields to the patients, and the examination of the data in the Record and Verify system make up the treatment delivery QA procedure. The point dose measurement results of 10 cases showed good agreement with the RTP calculation within 3%. One case showed more than a 3% difference and the other case showed more than 5%, which was out side the tolerance level. We could not find any differences of more than 2 mm between the RTP leaf sequence and the dry run film. Film dosimetry and the dose distribution from the phantom plan showed the same tendency, but quantitative analysis was not possible because of the film dosimetry nature. No error had been found from the MLC control file and one mis-registration case was found before treatment. This study shows the usefulness and the necessity of the IMRT patient QA program. The whole procedure of this program should be performed, especially by institutions that have just started to accumulate experience. But, the program is too complex and time consuming. Therefore, we propose practical and essential QA items for institutions in which the IMRT is performed as a routine procedure

  3. Intensity Modulated Radiation Therapy With Dose Painting to Treat Rhabdomyosarcoma

    International Nuclear Information System (INIS)

    Yang, Joanna C.; Dharmarajan, Kavita V.; Wexler, Leonard H.; La Quaglia, Michael P.; Happersett, Laura; Wolden, Suzanne L.

    2012-01-01

    Purpose: To examine local control and patterns of failure in rhabdomyosarcoma patients treated with intensity modulated radiation therapy (RT) with dose painting (DP-IMRT). Patients and Methods: A total of 41 patients underwent DP-IMRT with chemotherapy for definitive treatment. Nineteen also underwent surgery with or without intraoperative RT. Fifty-six percent had alveolar histologic features. The median interval from beginning chemotherapy to RT was 17 weeks (range, 4-25). Very young children who underwent second-look procedures with or without intraoperative RT received reduced doses of 24-36 Gy in 1.4-1.8-Gy fractions. Young adults received 50.4 Gy to the primary tumor and lower doses of 36 Gy in 1.8-Gy fractions to at-risk lymph node chains. Results: With 22 months of median follow-up, the actuarial local control rate was 90%. Patients aged ≤7 years who received reduced overall and fractional doses had 100% local control, and young adults had 79% (P=.07) local control. Three local failures were identified in young adults whose primary target volumes had received 50.4 Gy in 1.8-Gy fractions. Conclusions: DP-IMRT with lower fractional and cumulative doses is feasible for very young children after second-look procedures with or without intraoperative RT. DP-IMRT is also feasible in adolescents and young adults with aggressive disease who would benefit from prophylactic RT to high-risk lymph node chains, although dose escalation might be warranted for improved local control. With limited follow-up, it appears that DP-IMRT produces local control rates comparable to those of sequential IMRT in patients with rhabdomyosarcoma.

  4. THE ENVIRONMENTAL TECHNOLOGIES ACCEPTANCE (ETA) PROGRAM

    International Nuclear Information System (INIS)

    Behr-Andres, Christina B.

    2001-01-01

    The Environmental Technologies Acceptance (ETA) Program at the Energy and Environmental Research Center (EERC) is intended to advance the development, commercial acceptance, and timely deployment of selected private sector technologies for the cleanup of sites in the nuclear defense complex as well as the greater market. As shown in Table 1, this cooperative agreement funded by the National Energy Technology Laboratory (NETL) consists of three tasks: Technology Selection, Technology Development, and Technology Verification. As currently conceived, the ETA will address the needs of as many technologies as appropriate under its current 3-year term. This report covers activities during the first 6 months of the 3-year ETA program

  5. Accuracy of Real-time Couch Tracking During 3-dimensional Conformal Radiation Therapy, Intensity Modulated Radiation Therapy, and Volumetric Modulated Arc Therapy for Prostate Cancer

    International Nuclear Information System (INIS)

    Wilbert, Juergen; Baier, Kurt; Hermann, Christian; Flentje, Michael; Guckenberger, Matthias

    2013-01-01

    Purpose: To evaluate the accuracy of real-time couch tracking for prostate cancer. Methods and Materials: Intrafractional motion trajectories of 15 prostate cancer patients were the basis for this phantom study; prostate motion had been monitored with the Calypso System. An industrial robot moved a phantom along these trajectories, motion was detected via an infrared camera system, and the robotic HexaPOD couch was used for real-time counter-steering. Residual phantom motion during real-time tracking was measured with the infrared camera system. Film dosimetry was performed during delivery of 3-dimensional conformal radiation therapy (3D-CRT), step-and-shoot intensity modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT). Results: Motion of the prostate was largest in the anterior–posterior direction, with systematic (∑) and random (σ) errors of 2.3 mm and 2.9 mm, respectively; the prostate was outside a threshold of 5 mm (3D vector) for 25.0%±19.8% of treatment time. Real-time tracking reduced prostate motion to ∑=0.01 mm and σ = 0.55 mm in the anterior–posterior direction; the prostate remained within a 1-mm and 5-mm threshold for 93.9%±4.6% and 99.7%±0.4% of the time, respectively. Without real-time tracking, pass rates based on a γ index of 2%/2 mm in film dosimetry ranged between 66% and 72% for 3D-CRT, IMRT, and VMAT, on average. Real-time tracking increased pass rates to minimum 98% on average for 3D-CRT, IMRT, and VMAT. Conclusions: Real-time couch tracking resulted in submillimeter accuracy for prostate cancer, which transferred into high dosimetric accuracy independently of whether 3D-CRT, IMRT, or VMAT was used.

  6. Intrafraction Motion in Stereotactic Body Radiation Therapy for Non-Small Cell Lung Cancer: Intensity Modulated Radiation Therapy Versus Volumetric Modulated Arc Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Maddalena M.G.; Peulen, Heike M.U.; Belderbos, Josè S.A.; Sonke, Jan-Jakob, E-mail: j.sonke@nki.nl

    2016-06-01

    Purpose: Stereotactic body radiation therapy (SBRT) for early-stage inoperable non-small cell lung cancer (NSCLC) patients delivers high doses that require high-precision treatment. Typically, image guidance is used to minimize day-to-day target displacement, but intrafraction position variability is often not corrected. Currently, volumetric modulated arc therapy (VMAT) is replacing intensity modulated radiation therapy (IMRT) in many departments because of its shorter delivery time. This study aimed to evaluate whether intrafraction variation in VMAT patients is reduced in comparison with patients treated with IMRT. Methods and Materials: NSCLC patients (197 IMRT and 112 VMAT) treated with a frameless SBRT technique to a prescribed dose of 3 × 18 Gy were evaluated. Image guidance for both techniques was identical: pretreatment cone beam computed tomography (CBCT) (CBCT{sub precorr}) for setup correction followed immediately before treatment by postcorrection CBCT (CBCT{sub postcorr}) for verification. Then, after either a noncoplanar IMRT technique or a VMAT technique, a posttreatment (CBCT{sub postRT}) scan was acquired. The CBCT{sub postRT} and CBCT{sub postcorr} scans were then used to evaluate intrafraction motion. Treatment delivery times, systematic (Σ) and random (σ) intrafraction variations, and associated planning target volume (PTV) margins were calculated. Results: The median treatment delivery time was significantly reduced by 20 minutes (range, 32-12 minutes) using VMAT compared with noncoplanar IMRT. Intrafraction tumor motion was significantly larger for IMRT in all directions up to 0.5 mm systematic (Σ) and 0.7 mm random (σ). The required PTV margins for IMRT and VMAT differed by less than 0.3 mm. Conclusion: VMAT-based SBRT for NSCLC was associated with significantly shorter delivery times and correspondingly smaller intrafraction motion compared with noncoplanar IMRT. However, the impact on the required PTV margin was small.

  7. Powers of Eta from Fay's identities

    Czech Academy of Sciences Publication Activity Database

    Zuevsky, Alexander

    2016-01-01

    Roč. 11, č. 19 (2016), s. 135-141 ISSN 1822-511X Institutional support: RVO:67985840 Keywords : modular forms * Fay's trisecant identities * $eta$-function Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics

  8. Measurements of the branching fractions of the singly Cabibbo-suppressed decays D-0 -> omega eta, eta(()'())pi(0) and eta(()'())eta

    NARCIS (Netherlands)

    Ablikim, M.; Achasov, M.N.; Ahmed, S.; Albrecht, M.; Amoroso, A.; An, F. F.; An, Q.; Haddadi, Z.; Kalantar-Nayestanaki, N.; Kavatsyuk, M.; Löhner, H.; Messchendorp, J. G.; Tiemens, M.

    2018-01-01

    By analyzing a data sample of 2.93 fb(-1) collected at root s = 3.773 GeV with the BESIII detector operated at the BEPCII storage rings, we measure the branching fractions B(D-0 -> omega eta) = (2.15 +/- 0.17(stat) +/- 0.15(sys)) x 10(-3), B(D-0 ->eta pi(0)) = (0.58 +/- 0.05(stat) +/- 0.05(sys)) x

  9. Dose verification for respiratory-gated volumetric modulated arc therapy

    Energy Technology Data Exchange (ETDEWEB)

    Qian Jianguo; Xing Lei; Liu Wu; Luxton, Gary, E-mail: gluxton@stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305 (United States)

    2011-08-07

    A novel commercial medical linac system (TrueBeam(TM), Varian Medical Systems, Palo Alto, CA) allows respiratory-gated volumetric modulated arc therapy (VMAT), a new modality for treating moving tumors with high precision and improved accuracy by allowing for regular motion associated with a patient's breathing during VMAT delivery. The purpose of this work is to adapt a previously-developed dose reconstruction technique to evaluate the fidelity of VMAT treatment during gated delivery under clinic-relevant periodic motion related to patient breathing. A Varian TrueBeam system was used in this study. VMAT plans were created for three patients with lung or pancreas tumors. Conventional 6 and 15 MV beams with flattening filter and high-dose-rate 10 MV beams with no flattening filter were used in these plans. Each patient plan was delivered to a phantom first without gating and then with gating for three simulated respiratory periods (3, 4.5 and 6 s). Using the adapted log-file-based dose reconstruction procedure supplemented with ion chamber array (Seven29(TM), PTW, Freiburg, Germany) measurements, the delivered dose was used to evaluate the fidelity of gated VMAT delivery. Comparison of Seven29 measurements with and without gating showed good agreement with gamma-index passing rates above 99% for 1%/1 mm dose accuracy/distance-to-agreement criteria. With original plans as reference, gamma-index passing rates were 100% for the reconstituted plans (1%/1 mm criteria) and 93.5-100% for gated Seven29 measurements (3%/3 mm criteria). In the presence of leaf error deliberately introduced into the gated delivery of a pancreas patient plan, both dose reconstruction and Seven29 measurement consistently indicated substantial dosimetric differences from the original plan. In summary, a dose reconstruction procedure was demonstrated for evaluating the accuracy of respiratory-gated VMAT delivery. This technique showed that under clinical operation, the TrueBeam system

  10. Comparative analysis of 60Co intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Fox, Christopher; Romeijn, H Edwin; Lynch, Bart; Dempsey, James F; Men, Chunhua; Aleman, Dionne M

    2008-01-01

    In this study, we perform a scientific comparative analysis of using 60 Co beams in intensity-modulated radiation therapy (IMRT). In particular, we evaluate the treatment plan quality obtained with (i) 6 MV, 18 MV and 60 Co IMRT; (ii) different numbers of static multileaf collimator (MLC) delivered 60 Co beams and (iii) a helical tomotherapy 60 Co beam geometry. We employ a convex fluence map optimization (FMO) model, which allows for the comparison of plan quality between different beam energies and configurations for a given case. A total of 25 clinical patient cases that each contain volumetric CT studies, primary and secondary delineated targets, and contoured structures were studied: 5 head-and-neck (H and N), 5 prostate, 5 central nervous system (CNS), 5 breast and 5 lung cases. The DICOM plan data were anonymized and exported to the University of Florida optimized radiation therapy (UFORT) treatment planning system. The FMO problem was solved for each case for 5-71 equidistant beams as well as a helical geometry for H and N, prostate, CNS and lung cases, and for 3-7 equidistant beams in the upper hemisphere for breast cases, all with 6 MV, 18 MV and 60 Co dose models. In all cases, 95% of the target volumes received at least the prescribed dose with clinical sparing criteria for critical organs being met for all structures that were not wholly or partially contained within the target volume. Improvements in critical organ sparing were found with an increasing number of equidistant 60 Co beams, yet were marginal above 9 beams for H and N, prostate, CNS and lung. Breast cases produced similar plans for 3-7 beams. A helical 60 Co beam geometry achieved similar plan quality as static plans with 11 equidistant 60 Co beams. Furthermore, 18 MV plans were initially found not to provide the same target coverage as 6 MV and 60 Co plans; however, adjusting the trade-offs in the optimization model allowed equivalent target coverage for 18 MV. For plans with comparable

  11. ETA-II accelerator upgrades

    International Nuclear Information System (INIS)

    Nilson, D.G.; Deadrick, F.J.; Hibbs, S.M.; Sampayan, S.E.; Petersen, D.E.

    1991-09-01

    We discuss recent improvements to the ETA-II linear induction electron accelerator. The accelerator's cells have been carefully reconditioned to raise the maximum accelerating gap voltage from approximately 100 kV to 125 kV. Insulators of Rexolite plastic in a new ''zero-gap'' arrangement replaced the alumina originals after several alternative materials were investigated. A new multi-cable current feed system will be used to eliminate pulse reflection interactions encountered in earlier experiments. Improved alignment fixtures have been installed to help minimize beam perturbation due to poorly aligned intercell magnets between 10-cell groups. A stretched wire alignment technique (SWAT) has been utilized to enhance overall magnetic alignment, and to characterize irreducible alignment errors. These changes are in conjunction with an expansion of the accelerator from a 20-cell to a 60-cell configuration. When completed, the upgraded accelerator is expected to deliver 2.5 kA of electron beam current at 7.5 MeV in bursts of up to fifty 70-ns pulses at a 5-kHz repetition rate. A 5.5-meter-long wiggler will convert the energy into 3-GW microwave pulses at 140 GHz for plasma heating experiments in the Microwave Tokamak Experiment (MTX)

  12. Characteristics of the ETA gun

    International Nuclear Information System (INIS)

    Paul, A.C.; Neil, V.K.; Craig, G.D.; Fessenden, T.J.

    1981-01-01

    The Experimental Test Accelerator (ETA) is a linear induction device consisting of a 2.5-MV electron gun and ten 0.25-MV accelerating units designed to produce a 10-kA beam of electrons at 5 MeV. Calculations with the computer code EBQ as well as experimental measurements indicate that the current produced by the gun is limited by two phenomena. The first arises from the variation of particle energy with time during the pulse. Only particles with energy within a limited range can be transported by the focusing coils in the gun: therefore the variation of the gun's output current with time is determined by the coil settings. The second effect results from a collective interaction at sufficiently large current to cause a virtual cathode to form a few centimeters past the extraction grid. Operation in this regime results in greatly increased beam emittance and poor beam transport through the accelerator. Results of the code calculations are compared with experimental data and found to be in good agreement. (author)

  13. Eta Carinae - A Demanding Mistress

    Science.gov (United States)

    Gull, Theodore R.

    2011-01-01

    Over the past 15 years, a number of observers and modelers have increasingly focused on this massive system that is approaching its end stage, a supernova? a hypernova? When? The discovery by Augusto Damineli that Eta Carinae had a 5.5-year period proved timely as the newly-installed STIS was primed to observe its properties in the visible and ultraviolet. Initial observations occurred on January 1998, and through multiple programs, including the multi-cycle Hubble Treasury program, have sampled changes across two cycles. Now a multi-cycle program, focused on mapping variations in the extended wind-wind collision zones through early 2015, will test 3-D models of the interacting winds. In parallel, studies have been accomplished in X-rays with RXTE and CHANDRA, now in the far infrared with Herschel and from the ground with VLT. Each new observation is helping to peel back the veil of mystery on this massive binary system, but also opening up more questions to be answered. Timely inclusion of laboratory studies and models have greatly enhanced the observational results. We will summarize the latest results including submitted papers and very recent results with Herschel.

  14. Design and application of 3D-printed stepless beam modulators in proton therapy

    Science.gov (United States)

    Lindsay, C.; Kumlin, J.; Martinez, D. M.; Jirasek, A.; Hoehr, C.

    2016-06-01

    A new method for the design of stepless beam modulators for proton therapy is described and verified. Simulations of the classic designs are compared against the stepless method for various modulation widths which are clinically applicable in proton eye therapy. Three modulator wheels were printed using a Stratasys Objet30 3D printer. The resulting depth dose distributions showed improved uniformity over the classic stepped designs. Simulated results imply a possible improvement in distal penumbra width; however, more accurate measurements are needed to fully verify this effect. Lastly, simulations were done to model bio-equivalence to Co-60 cell kill. A wheel was successfully designed to flatten this metric.

  15. Comparison of volumetric modulated arc therapy and intensity modulated radiation therapy for whole brain hippocampal sparing treatment plans based on radiobiological modeling

    Directory of Open Access Journals (Sweden)

    Ethan Kendall

    2018-01-01

    Full Text Available Introduction: In this article, we report the results of our investigation on comparison of radiobiological aspects of treatment plans with linear accelerator-based intensity-modulated radiation therapy and volumetric-modulated arc therapy for patients having hippocampal avoidance whole-brain radiation therapy. Materials and Methods: In this retrospective study using the dose-volume histogram, we calculated and compared biophysical indices of equivalent uniform dose, tumor control probability, and normal tissue complication probability (NTCP for 15 whole-brain radiotherapy patients. Results and Discussions: Dose-response models for tumors and critical structures were separated into two groups: mechanistic and empirical. Mechanistic models formulate mathematically with describable relationships while empirical models fit data through empirical observations to appropriately determine parameters giving results agreeable to those given by mechanistic models. Conclusions: Techniques applied in this manuscript could be applied to any other organs or types of cancer to evaluate treatment plans based on radiobiological modeling.

  16. Measurement of CP asymmetries in D-+/- -> eta 'pi(+/-) and D-S(+/-) -> eta 'pi(+/-) decays

    NARCIS (Netherlands)

    Dufour, L.; Mulder, M; Onderwater, C. J. G.; Pellegrino, A.; Tolk, S.; van Veghel, M.

    2017-01-01

    A search for CP violation in D-+/- -> eta 'pi(+/-) and D-S(+/-) -> eta 'pi(+/-) decays is performed using proton-proton collision data, corresponding to an integrated luminosity of 3 fb(-1), recorded by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The measured CP-violating charge

  17. Stereotactic body radiation therapy planning with duodenal sparing using volumetric-modulated arc therapy vs intensity-modulated radiation therapy in locally advanced pancreatic cancer: A dosimetric analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rachit; Wild, Aaron T.; Ziegler, Mark A.; Hooker, Ted K.; Dah, Samson D.; Tran, Phuoc T.; Kang, Jun; Smith, Koren; Zeng, Jing [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, 401N. Broadway, Weinberg Suite 1440, Baltimore, MD 21231 (United States); Pawlik, Timothy M. [Department of Surgery, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Tryggestad, Erik [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, 401N. Broadway, Weinberg Suite 1440, Baltimore, MD 21231 (United States); Ford, Eric [Department of Radiation Oncology, Fred Hutchinson Cancer Center, University of Washington, Seattle, WA (United States); Herman, Joseph M., E-mail: jherma15@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, 401N. Broadway, Weinberg Suite 1440, Baltimore, MD 21231 (United States)

    2013-10-01

    Stereotactic body radiation therapy (SBRT) achieves excellent local control for locally advanced pancreatic cancer (LAPC), but may increase late duodenal toxicity. Volumetric-modulated arc therapy (VMAT) delivers intensity-modulated radiation therapy (IMRT) with a rotating gantry rather than multiple fixed beams. This study dosimetrically evaluates the feasibility of implementing duodenal constraints for SBRT using VMAT vs IMRT. Non–duodenal sparing (NS) and duodenal-sparing (DS) VMAT and IMRT plans delivering 25 Gy in 1 fraction were generated for 15 patients with LAPC. DS plans were constrained to duodenal D{sub max} of<30 Gy at any point. VMAT used 1 360° coplanar arc with 4° spacing between control points, whereas IMRT used 9 coplanar beams with fixed gantry positions at 40° angles. Dosimetric parameters for target volumes and organs at risk were compared for DS planning vs NS planning and VMAT vs IMRT using paired-sample Wilcoxon signed rank tests. Both DS VMAT and DS IMRT achieved significantly reduced duodenal D{sub mean}, D{sub max}, D{sub 1cc}, D{sub 4%}, and V{sub 20} {sub Gy} compared with NS plans (all p≤0.002). DS constraints compromised target coverage for IMRT as demonstrated by reduced V{sub 95%} (p = 0.01) and D{sub mean} (p = 0.02), but not for VMAT. DS constraints resulted in increased dose to right kidney, spinal cord, stomach, and liver for VMAT. Direct comparison of DS VMAT and DS IMRT revealed that VMAT was superior in sparing the left kidney (p<0.001) and the spinal cord (p<0.001), whereas IMRT was superior in sparing the stomach (p = 0.05) and the liver (p = 0.003). DS VMAT required 21% fewer monitor units (p<0.001) and delivered treatment 2.4 minutes faster (p<0.001) than DS IMRT. Implementing DS constraints during SBRT planning for LAPC can significantly reduce duodenal point or volumetric dose parameters for both VMAT and IMRT. The primary consequence of implementing DS constraints for VMAT is increased dose to other organs at

  18. RADIATION THERAPY COMMUNICATION-REIRRADIATION OF A NASAL TUMOR IN A BRACHYCEPHALIC DOG USING INTENSITY MODULATED RADIATION THERAPY.

    Science.gov (United States)

    Rancilio, Nicholas J; Custead, Michelle R; Poulson, Jean M

    2016-09-01

    A 5-year-old spayed female Shih Tzu was referred for evaluation of a nasal transitional carcinoma. A total lifetime dose of 117 Gy was delivered to the intranasal mass in three courses over nearly 2 years using fractionated intensity modulated radiation therapy (IMRT) to spare normal tissues. Clinically significant late normal tissue side effects were limited to bilaterally diminished tear production. The patient died of metastatic disease progression 694 days after completion of radiation therapy course 1. This case demonstrates that retreatment with radiation therapy to high lifetime doses for recurrent local disease may be well tolerated with IMRT. © 2016 American College of Veterinary Radiology.

  19. Delivery confirmation of bolus electron conformal therapy combined with intensity modulated x-ray therapy

    International Nuclear Information System (INIS)

    Kavanaugh, James A.; Hogstrom, Kenneth R.; Fontenot, Jonas P.; Henkelmann, Gregory; Chu, Connel; Carver, Robert A.

    2013-01-01

    Purpose: The purpose of this study was to demonstrate that a bolus electron conformal therapy (ECT) dose plan and a mixed beam plan, composed of an intensity modulated x-ray therapy (IMXT) dose plan optimized on top of the bolus ECT plan, can be accurately delivered. Methods: Calculated dose distributions were compared with measured dose distributions for parotid and chest wall (CW) bolus ECT and mixed beam plans, each simulated in a cylindrical polystyrene phantom that allowed film dose measurements. Bolus ECT plans were created for both parotid and CW PTVs (planning target volumes) using 20 and 16 MeV beams, respectively, whose 90% dose surface conformed to the PTV. Mixed beam plans consisted of an IMXT dose plan optimized on top of the bolus ECT dose plan. The bolus ECT, IMXT, and mixed beam dose distributions were measured using radiographic films in five transverse and one sagittal planes for a total of 36 measurement conditions. Corrections for film dose response, effects of edge-on photon irradiation, and effects of irregular phantom optical properties on the Cerenkov component of the film signal resulted in high precision measurements. Data set consistency was verified by agreement of depth dose at the intersections of the sagittal plane with the five measured transverse planes. For these same depth doses, results for the mixed beam plan agreed with the sum of the individual depth doses for the bolus ECT and IMXT plans. The six mean measured planar dose distributions were compared with those calculated by the treatment planning system for all modalities. Dose agreement was assessed using the 4% dose difference and 0.2 cm distance to agreement. Results: For the combined high-dose region and low-dose region, pass rates for the parotid and CW plans were 98.7% and 96.2%, respectively, for the bolus ECT plans and 97.9% and 97.4%, respectively, for the mixed beam plans. For the high-dose gradient region, pass rates for the parotid and CW plans were 93.1% and 94

  20. Measurement of Branching Fractions and Charge Asymmetries in B Meson Decays to eta(prime)K*, eta(prime)rho, and eta pi

    CERN Document Server

    Ford, W

    2003-01-01

    The present preliminary measurements of branching fractions and charge asymmetries for the B meson decays B -> eta(prime) K*, B -> eta(prime)rho, and B sup + -> eta(prime)pi sup +. The data were recorded with the BABAR detector at PEP-II and correspond to 89 x 10 sup 6 B(bar B) pairs produced in e sup + e sup - annihilation through the UPSILON(4S) resonance. They find the branching fractions BETA(B sup 0 -> eta K* sup 0) = (19.0 sub - sub 2 sub . sub 1 sup + sup 2 sup . sup 2 +- 1.3) x 10 sup - sup 6 , BETA(B sup + -> eta K* sup +) = (25.7 sub - sub 3 sub . sub 6 sup + sup 3 sup . sup 8 +- 1.8) x 10 sup - sup 6 with 90% confidence, and BETA(B sup + -> eta(prime)pi sup +) = (2.8 sub - sub 1 sub . sub 0 sup + sup 1 sup . sup 3 +- 0.3) x 10 sup - sup 6 ( eta(prime)K* sup 0) eta(prime)K* sup +) < 12 x 10 sup - sup 6. The time-integrated charge asymmetries are A sub c sub h (eta K* sup 0) = +0.03 +- 0.11 +- 0.02, A sub c sub h (eta K* sup +) = +0.15 +- 0.14 +- 0.02, and A sub c sub h (eta rho sup +) = +0.06 +-...

  1. Eta-expansion does The Trick

    DEFF Research Database (Denmark)

    Danvy, Olivier; Malmkjær, Karoline; Palsberg, Jens

    1996-01-01

    Partial-evaluation folklore has it that massaging one's source programs can make them specialize better. In Jones, Gomard, and Sestoft's recent textbook, a whole chapter is dedicated to listing such “binding-time improvements”: nonstandard use of continuation-passing style, eta-expansion, and a p......Partial-evaluation folklore has it that massaging one's source programs can make them specialize better. In Jones, Gomard, and Sestoft's recent textbook, a whole chapter is dedicated to listing such “binding-time improvements”: nonstandard use of continuation-passing style, eta...... across dynamic case expressions. This requirement precisely accounts for the nonstandard use of continuation-passing style encountered in partial evaluation. Eta-expansion thus acts as a uniform binding-time coercion between values and contexts, be they of function type, product type, or disjoint...

  2. Volumetric modulated arc therapy for lung stereotactic radiation therapy can achieve high local control rates.

    Science.gov (United States)

    Yamashita, Hideomi; Haga, Akihiro; Takahashi, Wataru; Takenaka, Ryousuke; Imae, Toshikazu; Takenaka, Shigeharu; Nakagawa, Keiichi

    2014-11-11

    The aim of this study was to report the outcome of primary or metastatic lung cancer patients undergoing volumetric modulated arc therapy for stereotactic body radiation therapy (VMAT-SBRT). From October 2010 to December 2013, consecutive 67 lung cancer patients received single-arc VMAT-SBRT using an Elekta-synergy system. All patients were treated with an abdominal compressor. The gross tumor volumes were contoured on 10 respiratory phases computed tomography (CT) datasets from 4-dimensional (4D) CT and merged into internal target volumes (ITVs). The planning target volume (PTV) margin was isotropically taken as 5 mm. Treatment was performed with a D95 prescription of 50 Gy (43 cases) or 55 Gy (12 cases) in 4 fractions for peripheral tumor or 56 Gy in 7 fractions (12 cases) for central tumor. Among the 67 patients, the median age was 73 years (range, 59-95 years). Of the patients, male was 72% and female 28%. The median Karnofsky performance status was 90-100% in 39 cases (58%) and 80-90% in 20 cases (30%). The median follow-up was 267 days (range, 40-1162 days). Tissue diagnosis was performed in 41 patients (61%). There were T1 primary lung tumor in 42 patients (T1a in 28 patients, T1b in 14 patients), T2 in 6 patients, three T3 in 3 patients, and metastatic lung tumor in 16 patients. The median mean lung dose was 6.87 Gy (range, 2.5-15 Gy). Six patients (9%) developed radiation pneumonitis required by steroid administration. Actuarial local control rate were 100% and 100% at 1 year, 92% and 75% at 2 years, and 92% and 75% at 3 years in primary and metastatic lung cancer, respectively (p =0.59). Overall survival rate was 83% and 84% at 1 year, 76% and 53% at 2 years, and 46% and 20% at 3 years in primary and metastatic lung cancer, respectively (p =0.12). Use of VMAT-based delivery of SBRT in primary in metastatic lung tumors demonstrates high local control rates and low risk of normal tissue complications.

  3. Volumetric modulated arc therapy for lung stereotactic radiation therapy can achieve high local control rates

    International Nuclear Information System (INIS)

    Yamashita, Hideomi; Haga, Akihiro; Takahashi, Wataru; Takenaka, Ryousuke; Imae, Toshikazu; Takenaka, Shigeharu; Nakagawa, Keiichi

    2014-01-01

    The aim of this study was to report the outcome of primary or metastatic lung cancer patients undergoing volumetric modulated arc therapy for stereotactic body radiation therapy (VMAT-SBRT). From October 2010 to December 2013, consecutive 67 lung cancer patients received single-arc VMAT-SBRT using an Elekta-synergy system. All patients were treated with an abdominal compressor. The gross tumor volumes were contoured on 10 respiratory phases computed tomography (CT) datasets from 4-dimensional (4D) CT and merged into internal target volumes (ITVs). The planning target volume (PTV) margin was isotropically taken as 5 mm. Treatment was performed with a D95 prescription of 50 Gy (43 cases) or 55 Gy (12 cases) in 4 fractions for peripheral tumor or 56 Gy in 7 fractions (12 cases) for central tumor. Among the 67 patients, the median age was 73 years (range, 59–95 years). Of the patients, male was 72% and female 28%. The median Karnofsky performance status was 90-100% in 39 cases (58%) and 80-90% in 20 cases (30%). The median follow-up was 267 days (range, 40–1162 days). Tissue diagnosis was performed in 41 patients (61%). There were T1 primary lung tumor in 42 patients (T1a in 28 patients, T1b in 14 patients), T2 in 6 patients, three T3 in 3 patients, and metastatic lung tumor in 16 patients. The median mean lung dose was 6.87 Gy (range, 2.5-15 Gy). Six patients (9%) developed radiation pneumonitis required by steroid administration. Actuarial local control rate were 100% and 100% at 1 year, 92% and 75% at 2 years, and 92% and 75% at 3 years in primary and metastatic lung cancer, respectively (p = 0.59). Overall survival rate was 83% and 84% at 1 year, 76% and 53% at 2 years, and 46% and 20% at 3 years in primary and metastatic lung cancer, respectively (p = 0.12). Use of VMAT-based delivery of SBRT in primary in metastatic lung tumors demonstrates high local control rates and low risk of normal tissue complications

  4. Biological-based optimization and volumetric modulated arc therapy delivery for stereotactic body radiation therapy

    International Nuclear Information System (INIS)

    Diot, Quentin; Kavanagh, Brian; Timmerman, Robert; Miften, Moyed

    2012-01-01

    Purpose: To describe biological-based optimization and Monte Carlo (MC) dose calculation-based treatment planning for volumetric modulated arc therapy (VMAT) delivery of stereotactic body radiation therapy (SBRT) in lung, liver, and prostate patients. Methods: Optimization strategies and VMAT planning parameters using a biological-based optimization MC planning system were analyzed for 24 SBRT patients. Patients received a median dose of 45 Gy [range, 34-54 Gy] for lung tumors in 1-5 fxs and a median dose of 52 Gy [range, 48-60 Gy] for liver tumors in 3-6 fxs. Prostate patients received a fractional dose of 10 Gy in 5 fxs. Biological-cost functions were used for plan optimization, and its dosimetric quality was evaluated using the conformity index (CI), the conformation number (CN), the ratio of the volume receiving 50% of the prescription dose over the planning target volume (Rx/PTV50). The quality and efficiency of the delivery were assessed according to measured quality assurance (QA) passing rates and delivery times. For each disease site, one patient was replanned using physical cost function and compared to the corresponding biological plan. Results: Median CI, CN, and Rx/PTV50 for all 24 patients were 1.13 (1.02-1.28), 0.79 (0.70-0.88), and 5.3 (3.1-10.8), respectively. The median delivery rate for all patients was 410 MU/min with a maximum possible rate of 480 MU/min (85%). Median QA passing rate was 96.7%, and it did not significantly vary with the tumor site. Conclusions: VMAT delivery of SBRT plans optimized using biological-motivated cost-functions result in highly conformal dose distributions. Plans offer shorter treatment-time benefits and provide efficient dose delivery without compromising the plan conformity for tumors in the prostate, lung, and liver, thereby improving patient comfort and clinical throughput. The short delivery times minimize the risk of patient setup and intrafraction motion errors often associated with long SBRT treatment

  5. Comparison of dose-volume histograms for Tomo therapy, linear accelerator-based 3D conformal radiation therapy, and intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Ji, Youn-Sang; Dong, Kyung-Rae; Kim, Chang-Bok; Choi, Seong-Kwan; Chung, Woon-Kwan; Lee, Jong-Woong

    2011-01-01

    Highlights: → Evaluation of DVH from 3D CRT, IMRT and Tomo therapy was conducted for tumor therapy. → The doses of GTV and CTV were compared using DVHs from 3D CRT, IMRT and Tomo therapy. → The GTV was higher when Tomo therapy was used, while the doses of critical organ were low. → They said that Tomo therapy satisfied the goal of radiation therapy more than the others. - Abstract: Evaluation of dose-volume histograms from three-dimensional conformal radiation therapy (3D CRT), intensity-modulated radiation therapy (IMRT), and Tomo therapy was conducted. These three modalities are among the diverse treatment systems available for tumor therapy. Three patients who received tumor therapy for a malignant oligodendroglioma in the cranium, nasopharyngeal carcinoma in the cervical neck, and prostate cancer in the pelvis were selected as study subjects. Therapy plans were made for the three patients before dose-volume histograms were obtained. The doses of the gross tumor volume (GTV) and the clinical target volume (CTV) were compared using the dose-volume histograms obtained from the LINAC-based 3D CRT, IMRT planning station (Varian Eclipse-Varian, version 8.1), and Tomo therapy planning station. In addition, the doses of critical organs in the cranium, cervix, and pelvis that should be protected were compared. The GTV was higher when Tomo therapy was used compared to 3D CRT and the LINAC-based IMRT, while the doses of critical organ tissues that required protection were low. These results demonstrated that Tomo therapy satisfied the ultimate goal of radiation therapy more than the other therapies.

  6. Inclusive eta production at large transverse momenta

    International Nuclear Information System (INIS)

    Donaldson, G.J.; Gordon, H.A.; Lai, K.; Stumer, I.; Barnes, A.V.; Mellema, D.J.; Tollestrup, A.V.; Walker, R.L.; Dahl, O.; Johnson, R.; Ogawa, A.; Pripstein, M.; Shannon, S.

    1978-01-01

    We have measured the ratio of inclusive production of eta to π 0 at transverse momenta above 1.5 GeV/c. Results are presented for various meson and proton beams with momenta of 100, 200, and 300 GeV/c incident upon a hydrogen target. The eta/π 0 production ratio is found to be independent of incident beam momentum and of the transverse and longitudinal momenta of production. The ratio for pion- and proton-induced reactions is 0.44 +- 0.05; for kaons, it is 0.74 +- 0.12

  7. Host modulation therapeutics in periodontics: role as an adjunctive periodontal therapy.

    Science.gov (United States)

    Shinwari, Muhammad Saad; Tanwir, Farzeen; Hyder, Pakiza Raza; Bin Saeed, Muhammad Humza

    2014-09-01

    Host Modulation Therapy (HMT) is a treatment concept that reduces tissue destruction and stabilizes or even regenerates inflammatory tissue by modifying host response factors. It has been used for treating osteoporosis and arthritis for several decades. However, its use in dentistry has only been recently reported. The objective of this article is to present a review of the various literatures available on HMT and also its role as adjunct therapy in periodontics. For identifying studies for this review, a PUBMED search was carried out in 2013 for all articles published till December 2012. The search was restricted to English language publications only. Longitudinal prospective and retrospective studies were included in the search. The key words used were: Host Modulation Therapy; Sub antimicrobial dose doxycycline and Non-Surgical Periodontal Therapy. The main outcomes sought were host modulation therapeutics in periodontics. Exclusion criteria included cross sectional studies, short case series as well as studies with short follow-up periods. There is a paucity of literature on HMT in periodontics although the only drug approved by United States Food and Drug Administration (FDA) is a subantimicrobial dose of doxycycline (SDD) with highly predictable results as a host modulating agent in periodontal diseases and also an effective adjunctive therapy in various diseases of periodontium. However, more randomized controlled trials are needed to obtain clinical guidelines on the usage of other host modulating agents as adjunct as well as definite therapy for periodontal diseases. SDD is an effective adjunct therapy when used in dosage of 20mg twice daily for minimum 3 months duration in various periodontal diseases with predictable clinical outcomes. It is also recommended that future clinical research on anti cytokine drugs, chemically modified tetracycline and other HMT agents should be conducted so that new drugs are available with highly predictable results.

  8. Conformal radiation therapy with or without intensity modulation in the treatment of localized prostate cancer

    International Nuclear Information System (INIS)

    Maingon, P.; Truc, G.; Bosset, M.; Peignaux, K.; Ammor, A.; Bolla, M.

    2005-01-01

    Conformal radiation therapy has now to be considered as a standard treatment of localized prostatic adenocarcinomas. Using conformational methods and intensity modulated radiation therapy requires a rigorous approach for their implementation in routine, focused on the reproducibility of the treatment, target volume definitions, dosimetry, quality control, setup positioning. In order to offer to the largest number of patients high-dose treatment, the clinicians must integrate as prognostic factors accurate definition of microscopic extension as well as the tolerance threshold of critical organs. High-dose delivery is expected to be most efficient in intermediary risks and locally advanced diseases. Intensity modulated radiation therapy is specifically dedicated to dose escalation. Perfect knowledge of classical constraints of conformal radiation therapy is required. Using such an approach in routine needs a learning curve including the physicists and a specific quality assurance program. (author)

  9. The Role of Descending Modulation in Manual Therapy and Its Analgesic Implications: A Narrative Review

    Directory of Open Access Journals (Sweden)

    Andrew D. Vigotsky

    2015-01-01

    Full Text Available Manual therapy has long been a component of physical rehabilitation programs, especially to treat those in pain. The mechanisms of manual therapy, however, are not fully understood, and it has been suggested that its pain modulatory effects are of neurophysiological origin and may be mediated by the descending modulatory circuit. Therefore, the purpose of this review is to examine the neurophysiological response to different types of manual therapy, in order to better understand the neurophysiological mechanisms behind each therapy’s analgesic effects. It is concluded that different forms of manual therapy elicit analgesic effects via different mechanisms, and nearly all therapies appear to be at least partially mediated by descending modulation. Additionally, future avenues of mechanistic research pertaining to manual therapy are discussed.

  10. Modulation of the tumor vasculature and oxygenation to improve therapy

    DEFF Research Database (Denmark)

    Siemann, Dietmar W; Horsman, Michael R

    2015-01-01

    The tumor microenvironment is increasingly recognized as a major factor influencing the success of therapeutic treatments and has become a key focus for cancer research. The progressive growth of a tumor results in an inability of normal tissue blood vessels to oxygenate and provide sufficient...... important are the functional consequences experienced by the tumor cells residing in such environments: adaptation to hypoxia, cell quiescence, modulation of transporters and critical signaling molecules, immune escape, and enhanced metastatic potential. Together these factors lead to therapeutic barriers...

  11. Texture analysis on the fluence map to evaluate the degree of modulation for volumetric modulated arc therapy

    International Nuclear Information System (INIS)

    Park, So-Yeon; Kim, Il Han; Ye, Sung-Joon; Carlson, Joel

    2014-01-01

    Purpose: Texture analysis on fluence maps was performed to evaluate the degree of modulation for volumetric modulated arc therapy (VMAT) plans. Methods: A total of six textural features including angular second moment, inverse difference moment, contrast, variance, correlation, and entropy were calculated for fluence maps generated from 20 prostate and 20 head and neck VMAT plans. For each of the textural features, particular displacement distances (d) of 1, 5, and 10 were adopted. To investigate the deliverability of each VMAT plan, gamma passing rates of pretreatment quality assurance, and differences in modulating parameters such as multileaf collimator (MLC) positions, gantry angles, and monitor units at each control point between VMAT plans and dynamic log files registered by the Linac control system during delivery were acquired. Furthermore, differences between the original VMAT plan and the plan reconstructed from the dynamic log files were also investigated. To test the performance of the textural features as indicators for the modulation degree of VMAT plans, Spearman’s rank correlation coefficients (r s ) with the plan deliverability were calculated. For comparison purposes, conventional modulation indices for VMAT including the modulation complexity score for VMAT, leaf travel modulation complexity score, and modulation index supporting station parameter optimized radiation therapy (MI SPORT ) were calculated, and their correlations were analyzed in the same way. Results: There was no particular textural feature which always showed superior correlations with every type of plan deliverability. Considering the results comprehensively, contrast (d = 1) and variance (d = 1) generally showed considerable correlations with every type of plan deliverability. These textural features always showed higher correlations to the plan deliverability than did the conventional modulation indices, except in the case of modulating parameter differences. The r s values

  12. Texture analysis on the fluence map to evaluate the degree of modulation for volumetric modulated arc therapy

    Energy Technology Data Exchange (ETDEWEB)

    Park, So-Yeon [Department of Radiation Oncology, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744 (Korea, Republic of); Biomedical Research Institute, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Kim, Il Han [Department of Radiation Oncology, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744 (Korea, Republic of); Biomedical Research Institute, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Department of Radiation Oncology, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Ye, Sung-Joon [Department of Radiation Oncology, Seoul National University Hospital, Seoul 110-744, (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744 (Korea, Republic of); Biomedical Research Institute, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Seoul National University Graduate School of Convergence Science and Technology, Suwon 433-270 (Korea, Republic of); Carlson, Joel [Biomedical Research Institute, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Seoul National University Graduate School of Convergence Science and Technology, Suwon 433-270 (Korea, Republic of); and others

    2014-11-01

    Purpose: Texture analysis on fluence maps was performed to evaluate the degree of modulation for volumetric modulated arc therapy (VMAT) plans. Methods: A total of six textural features including angular second moment, inverse difference moment, contrast, variance, correlation, and entropy were calculated for fluence maps generated from 20 prostate and 20 head and neck VMAT plans. For each of the textural features, particular displacement distances (d) of 1, 5, and 10 were adopted. To investigate the deliverability of each VMAT plan, gamma passing rates of pretreatment quality assurance, and differences in modulating parameters such as multileaf collimator (MLC) positions, gantry angles, and monitor units at each control point between VMAT plans and dynamic log files registered by the Linac control system during delivery were acquired. Furthermore, differences between the original VMAT plan and the plan reconstructed from the dynamic log files were also investigated. To test the performance of the textural features as indicators for the modulation degree of VMAT plans, Spearman’s rank correlation coefficients (r{sub s}) with the plan deliverability were calculated. For comparison purposes, conventional modulation indices for VMAT including the modulation complexity score for VMAT, leaf travel modulation complexity score, and modulation index supporting station parameter optimized radiation therapy (MI{sub SPORT}) were calculated, and their correlations were analyzed in the same way. Results: There was no particular textural feature which always showed superior correlations with every type of plan deliverability. Considering the results comprehensively, contrast (d = 1) and variance (d = 1) generally showed considerable correlations with every type of plan deliverability. These textural features always showed higher correlations to the plan deliverability than did the conventional modulation indices, except in the case of modulating parameter differences. The r

  13. Understanding eta' → etaππ and allied processes despite Adler zeros

    International Nuclear Information System (INIS)

    Santhanam, I.; Chakrabarty, S.; Mitra, A.N.

    1979-01-01

    With use of the (hitherto obscure) negative-parity meson matrix N/sub +/ of partial symmetry, an eta' → etaππ amplitude, explicitly satisfying the Adler conditions, has been constructed within the relativistic quark pair-creation model without any adjustable parameters. The model yields a total eta' width of 388 keV and etaππ, rho 0 γ, and γγ branching ratios of 68.0%, 29.9%, and 1.88%, all in excellent agreement with data. The same model gives the π-π scattering lengths as m/sub π/a 0 =0.19, m/sub π/a 2 =-0.08

  14. The survival analysis on localized prostate cancer treated with neoadjuvant endocrine therapy followed by intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Gao Hong; Li Gaofeng; Wu Qinhong; Li Xuenan; Zhong Qiuzi; Xu Yonggang

    2010-01-01

    Objective: To retrospectively investigate clinical outcomes and prognostic factors in localized prostate cancer treated with neoadjuvant endocrine therapy followed by intensity modulated radiotherapy (IMRT). Methods: Between March 2003 and October 2008, 54 localized prostate cancer treated by IMRT were recruited. All patients had received endocrine therapy before IMRT. The endocrine therapy included surgical castration or medical castration in combination with antiandrogens. The target of IMRT was the prostate and seminal vesicles with or without pelvis. The biochemical failure was defined according to the phoenix definition. By using the risk grouping standard proposed by D'Amico, patients were divided into three groups: low-risk group (n = 5), intermediate-risk group (n = 12), and high-risk group (n = 37). Kaplan-Meier method was used to calculate the overall survival rate. Prognostic factors were analyzed by univariate and multiple Cox regression analysis. Results: The follow-up rate was 98%. The number of patients under follow-up was 39 at 3 years and 25 at 5 years. Potential prognostic factors, including risk groups, mode of endocrine therapy, time of endocrine therapy, phoenix grouping before IMRT, the prostate specific antigen doubling time (PSADT) before radiotherapy, PSA value before IMRT, interval of endocrine therapy and IMRT, irradiation region, and irradiation dose were analyzed by survival analysis. In univariate analysis, time of endocrine therapy (75 % vs 95 %, χ 2 = 6. 45, P = 0. 011), phoenix grouping before IMRT (87% vs 96%, χ 2 = 4. 36, P = 0. 037), interval of endocrine therapy and IMRT (80% vs 95%, χ 2 = 11.60, P= 0. 001), irradiation dose (75% vs 91%, χ 2 =5.92, P= 0. 015) were statistically significant prognostic factors for 3 - year overall survival , and risk groups (85 vs 53 vs 29, χ 2 = 6. 40, P =0. 041) and PSADT before IMRT (62 vs 120, U =24. 50, P =0. 003) were significant factors for the median survival time. In the multiple Cox

  15. Hispaania ei usu ETA rahupakkumisse / Heiki Suurkask

    Index Scriptorium Estoniae

    Suurkask, Heiki, 1972-

    2004-01-01

    Baski terrorirühmitus kutsus uut peaministrit Jose Luis Rodriguez Zapaterot dialoogile, hiljuti valimised võitnud Sotsialistlik Töölispartei teatas vastuseks, et ETA on terroristlik rühmitus ja selle avaldustele tähelepanu ei osutata. Vt. samas: Vaherahule järgnes terrorilaine

  16. Eta-Expansion Does The Trick

    DEFF Research Database (Denmark)

    Danvy, Olivier; Malmkjær, Karoline; Palsberg, Jens

    1996-01-01

    -sum type. For the latter case, it enables “The Trick.” In this article, we extend Gomard and Jones' partial evaluator for the &lgr;-calculus, &lgr;-Mix, with products and disjoint sums; we point out how eta-expansion for (finite) disjoint sums enable The Trick; we generalize our earlier work by identifying...

  17. Eta-Expansion Does The Trick

    DEFF Research Database (Denmark)

    Danvy, Olivier; Malmkjær, Karoline; Palsberg, Jens

    1995-01-01

    -sum type. For the latter case, it enables “The Trick.” In this article, we extend Gomard and Jones' partial evaluator for the &lgr;-calculus, &lgr;-Mix, with products and disjoint sums; we point out how eta-expansion for (finite) disjoint sums enable The Trick; we generalize our earlier work by identifying...

  18. The cusp effect in {eta}'{yields}{eta}{pi}{pi} decays

    Energy Technology Data Exchange (ETDEWEB)

    Kubis, Bastian; Schneider, Sebastian P. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Bonn (Germany)

    2009-08-15

    Strong final-state interactions create a pronounced cusp in {eta}'{yields}{eta}{pi}{sup 0}{pi}{sup 0} decays. We adapt and generalize the non-relativistic effective field theory framework developed for the extraction of {pi}{pi} scattering lengths from K{yields}3{pi} decays to this case. The cusp effect is predicted to have an effect of more than 8% on the decay spectrum below the {pi}{sup +}{pi}{sup -} threshold. (orig.)

  19. Search for the Lambda(0)(b) -> Lambda eta ' and Lambda(0)(b) -> Lambda eta decays with the LHCb detector

    NARCIS (Netherlands)

    Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Cartelle, P. Alvarez; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Gutierrez, O. Aquines; Archilli, F.; d'Argent, P.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Onderwater, C. J. G.; Pellegrino, A.; Tolk, S.

    2015-01-01

    A search is performed for the as yet unobserved baryonic Lambda(0)(b) -> Lambda eta' and Lambda(0)(b) -> Lambda eta decays with 3 fb(-1) of proton-proton collision data recorded by the LHCb experiment. The B-0 -> K-s(0)eta' decay is used as a normalisation channel. No significant signal is observed

  20. Carcinoma of the anal canal: Intensity modulated radiation therapy (IMRT) versus three-dimensional conformal radiation therapy (3DCRT)

    OpenAIRE

    Sale, Charlotte; Moloney, Phillip; Mathlum, Maitham

    2013-01-01

    Introduction Patients with anal canal carcinoma treated with standard conformal radiotherapy frequently experience severe acute and late toxicity reactions to the treatment area. Roohipour et al. (Dis Colon Rectum 2008; 51: 147–53) stated a patient's tolerance of chemoradiation to be an important prediction of treatment success. A new intensity modulated radiation therapy (IMRT) technique for anal carcinoma cases has been developed at the Andrew Love Cancer Centre aimed at reducing radiation ...

  1. Head and neck intensity modulated radiation therapy leads to an increase of opportunistic oral pathogens

    NARCIS (Netherlands)

    Schuurhuis, Jennifer M.; Stokman, Monique A.; Witjes, Max J. H.; Langendijk, Johannes A.; van Winkelhoff, Arie J.; Vissink, Arjan; Spijkervet, Frederik K. L.

    Objectives: The introduction of intensity modulated radiation therapy (IMRT) has led to new possibilities in the treatment of head and neck cancer (HNC). Limited information is available on how this more advanced radiation technique affects the oral microflora. In a prospective study we assessed the

  2. Programmable segmented volumetric modulated arc therapy for respiratory coordination in pancreatic cancer

    International Nuclear Information System (INIS)

    Wu, Jian-Kuen; Wu, Chien-Jang; Cheng, Jason Chia-Hsien

    2012-01-01

    We programmably divided long-arc volumetric modulated arc therapy (VMAT) into split short arcs, each taking less than 30 s for respiratory coordination. The VMAT plans of five pancreatic cancer patients were modified; the short-arc plans had negligible dose differences and satisfied the 3%/3-mm gamma index on a MapCHECK-2 device.

  3. Visceral Blood Flow Modulation: Potential Therapy for Morbid Obesity

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Tyler J., E-mail: tjharris@gmail.com [University of California, Los Angeles, Department of Vascular and Interventional Radiology (United States); Murphy, Timothy P.; Jay, Bryan S. [Rhode Island Hospital, Brown University, Department of Diagnostic Imaging, Vascular Disease Research Center (United States); Hampson, Christopher O.; Zafar, Abdul M. [University of Texas Health Science Center at San Antonio, Department of Radiology (United States)

    2013-06-15

    We present this preliminary investigation into the safety and feasibility of endovascular therapy for morbid obesity in a swine model. A flow-limiting, balloon-expandable covered stent was placed in the superior mesenteric artery of three Yorkshire swine after femoral arterial cutdown. The pigs were monitored for between 15 and 51 days after the procedure and then killed, with weights obtained at 2-week increments. In the two pigs in which the stent was flow limiting, a reduced rate of weight gain (0.42 and 0.53 kg/day) was observed relative to the third pig (0.69 kg/day), associated with temporary food aversion and signs of mesenteric ischemia in one pig.

  4. Visceral Blood Flow Modulation: Potential Therapy for Morbid Obesity

    International Nuclear Information System (INIS)

    Harris, Tyler J.; Murphy, Timothy P.; Jay, Bryan S.; Hampson, Christopher O.; Zafar, Abdul M.

    2013-01-01

    We present this preliminary investigation into the safety and feasibility of endovascular therapy for morbid obesity in a swine model. A flow-limiting, balloon-expandable covered stent was placed in the superior mesenteric artery of three Yorkshire swine after femoral arterial cutdown. The pigs were monitored for between 15 and 51 days after the procedure and then killed, with weights obtained at 2-week increments. In the two pigs in which the stent was flow limiting, a reduced rate of weight gain (0.42 and 0.53 kg/day) was observed relative to the third pig (0.69 kg/day), associated with temporary food aversion and signs of mesenteric ischemia in one pig.

  5. Some Comments on the Decays of eta (550)

    Science.gov (United States)

    Veltman, M.; Yellin, J.

    1966-07-01

    Various decay modes of the {eta}(500) are discussed. The relations, through SU{sub 3} and the Gell-Mann, Sharp, Wagner model, between the {eta}-decay modes and the modes {eta} {yields} {pi}{pi}{gamma), {pi}{sup 0} {yields} {gamma}{gamma} are investigated taking into account {eta}-{eta}{sup *} mixing. The present experimental values for the neutral branching ratios plus the shape of the {eta} {yields} {pi}{sup +}{pi}{sup {minus}}{pi}{sup 0} Dalitz plot are shown to require a 25% {vert_bar}{Delta}{rvec I}{vert_bar} = 3 contribution to the {eta} {yields} 3{pi} amplitude. The connection between a possible charge asymmetry in {eta} {yields} {pi}{sup +}{pi}{sup {minus}}{pi}{sup 0} and the branching ratio {Gamma}{sub {eta} {yields} {pi}{sup 0}e{sup +}e{sup {minus}}}/{Gamma}{sub {eta}}{sup all} is investigated in the framework of a model proposed earlier by several authors. It is shown that there is no conflict between the existing data and this model. The Dalitz plot distribution of {eta} {yields} {pi}{sup +}{pi}{sup {minus}}{pi}{sup 0} is discussed under various assumptions about the properties of the interaction responsible for the decay. (auth)

  6. Intensity-modulated radiation therapy: overlapping co-axial modulated fields

    International Nuclear Information System (INIS)

    Metcalfe, P; Tangboonduangjit, P; White, P

    2004-01-01

    The Varian multi-leaf collimator has a 14.5 cm leaf extension limit from each carriage. This means the target volumes in the head and neck region are sometimes too wide for standard width-modulated fields to provide adequate dose coverage. A solution is to set up asymmetric co-axial overlapping fields. This protects the MLC carriage while in return the MLC provides modulated dose blending in the field overlap region. Planar dose maps for coincident fields from the Pinnacle radiotherapy treatment planning system are compared with planar dose maps reconstructed from radiographic film and electronic portal images. The film and portal images show small leaf-jaw matchlines at each field overlap border. Linear profiles taken across each image show that the observed leaf-jaw matchlines from the accelerator images are not accounted for by the treatment planning system. Dose difference between film reconstructed electronic portal images and planning system are about 2.5 cGy in a modulated field at d max . While the magnitude of the dose differences are small improved round end leaf modelling combined with a finer dose calculation grid may minimize the discrepancy between calculated and delivered dose

  7. Cardiovascular disease: primary prevention, disease modulation and regenerative therapy.

    LENUS (Irish Health Repository)

    Sultan, Sherif

    2012-10-01

    Cardiovascular primary prevention and regeneration programs are the contemporary frontiers in functional metabolic vascular medicine. This novel science perspective harnesses our inherent ability to modulate the interface between specialized gene receptors and bioavailable nutrients in what is labeled as the nutrient-gene interaction. By mimicking a natural process through the conveyance of highly absorbable receptor specific nutrients, it is feasible to accelerate cell repair and optimize mitochondrial function, thereby achieving cardiovascular cure. We performed a comprehensive review of PubMed, EMBASE and Cochrane Review databases for articles relating to cardiovascular regenerative medicine, nutrigenomics and primary prevention, with the aim of harmonizing their roles within contemporary clinical practice. We searched in particular for large-scale randomized controlled trials on contemporary cardiovascular pharmacotherapies and their specific adverse effects on metabolic pathways which feature prominently in cardiovascular regenerative programs, such as nitric oxide and glucose metabolism. Scientific research on \\'cardiovascular-free\\' centenarians delineated that low sugar and low insulin are consistent findings. As we age, our insulin level increases. Those who can decelerate the rapidity of this process are prompting their cardiovascular rejuvenation. It is beginning to dawn on some clinicians that contemporary treatments are not only failing to impact on our most prevalent diseases, but they may be causing more damage than good. Primary prevention programs are crucial elements for a better outcome. Cardiovascular primary prevention and regeneration programs have enhanced clinical efficacy and quality of life and complement our conventional endovascular practice.

  8. Oral contraceptive therapy modulates hemispheric asymmetry in spatial attention.

    Science.gov (United States)

    Cicinelli, Ettore; De Tommaso, Marina; Cianci, Antonio; Colacurci, Nicola; Rella, Leonarda; Loiudice, Luisa; Cicinelli, Maria Vittoria; Livrea, Paolo

    2011-12-01

    Functional cerebral asymmetries (FCAs) are known to fluctuate across the menstrual cycle. The visual line-bisection task administered to normally cycling women showed different patterns of the interhemispheric interactions during menses and the midluteal cycle phase. However, the contribution of estrogens and progestins hormones to this phenomenon is still unclear. The aim of our study was to show a variation of FCAs in women administered oral contraceptives (OCs) using the visual line-bisection task. Visual line-bisection task with three horizontal lines was administered to 36 healthy women taking a 21-day OC. Twenty-nine patients were right handed. The task was administered during OC intake (day 10) and at the end of the pill-free period. The right-handed women showed a significant leftward bias of veridical center on the first and third lines during OC intake compared with an opposite rightward bias during the pill-free period. The same phenomenon of contralateral deviation was observed in left-handed women on day 10 of OC intake. The results of this study confirm a hormonal modulation on interhemispheric interaction and suggest that OCs may improve the interhemispheric interaction reducing FCAs compared with the low hormone level period. This opens new insights in OC prescription and choice of administration schedule in order to improve cognitive performances. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Intensity-modulated radiation therapy for anal carcinoma

    International Nuclear Information System (INIS)

    Peiffert, D.; Moreau-Claeys, M.V.; Tournier-Rangeard, L.; Huger, S.; Marchesi, V.

    2011-01-01

    Anal canal carcinoma are highly curable by irradiation, combined with chemotherapy in locally advanced disease, with preservation of sphincter function. The clinical target volume for the nodes is extended, often including the inguinal nodes, which is not usual for other pelvic tumours. Acute and late effects are correlated with the volume and dose delivered to organs at risk, i. e. small bowel, bladder and increased by concomitant chemotherapy. Intensity modulated irradiation (IMRT) makes it possible to optimize the dose distribution in this 'complex U shaped' volume, while maintaining the dose distribution for the target volumes. The conversion from conformal irradiation to IMRT necessitates good knowledge of the definition and skills to delineate target volumes and organs at risk, including new volumes needed to optimize the dose distribution. Dosimetric and clinical benefits of IMRT are described, based on early descriptions and evidence-based publication. The growing development of IMRT in anal canal radiotherapy must be encouraged, and long-term benefits should be soon published. Radiation oncologists should precisely learn IMRT recommendations before starting the technique, and evaluate its early and late results for adverse effects, but also for long-term tumour control. (authors)

  10. Intensity Modulated Proton Therapy Versus Intensity Modulated Photon Radiation Therapy for Oropharyngeal Cancer: First Comparative Results of Patient-Reported Outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Sio, Terence T. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Oncology, Mayo Clinic, Scottsdale, Arizona (United States); Lin, Huei-Kai; Shi, Qiuling [Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Gunn, G. Brandon [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Cleeland, Charles S. [Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Lee, J. Jack; Hernandez, Mike [Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Blanchard, Pierre; Thaker, Nikhil G.; Phan, Jack; Rosenthal, David I.; Garden, Adam S.; Morrison, William H.; Fuller, C. David [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Mendoza, Tito R. [Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Mohan, Radhe [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Wang, Xin Shelley [Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Frank, Steven J., E-mail: sjfrank@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2016-07-15

    Purpose: We hypothesized that patients with oropharyngeal cancer treated with intensity modulated proton therapy (IMPT) would have lower symptom burdens, as measured by patient-reported outcome (PRO) surveys, than patients treated with intensity modulated photon therapy (IMRT). Methods and Materials: Patients were treated for oropharyngeal cancer from 2006 to 2015 through prospective registries with concurrent chemotherapy and IMPT or chemotherapy and IMRT and completed the MD Anderson Symptom Inventory for Head and Neck Cancer (MDASI-HN) module at various times before treatment (baseline), during treatment (acute phase), within the first 3 months after treatment (subacute phase), and afterward (chronic phase). Individual symptoms and the top 5 and top 11 most severe symptoms were summarized and compared between the radiation therapy modalities. Results: PRO data were collected and analyzed from 35 patients treated with chemotherapy and IMPT and from 46 treated with chemotherapy and IMRT. The baseline symptom burdens were similar between both groups. The overall top 5 symptoms were food taste problems (mean score 4.91 on a 0-10 scale), dry mouth (4.49), swallowing/chewing difficulties (4.26), lack of appetite (4.08), and fatigue (4.00). Among the top 11 symptoms, changes in taste and appetite during the subacute and chronic phases favored IMPT (all P<.048). No differences in symptom burden were detected between modalities during the acute and chronic phases by top-11 symptom scoring. During the subacute phase, the mean (±standard deviation) top 5 MDASI scores were 5.15 ± 2.66 for IMPT versus 6.58 ± 1.98 for IMRT (P=.013). Conclusions: According to the MDASI-HN, symptom burden was lower among the IMPT patients than among the IMRT patients during the subacute recovery phase after treatment. A prospective randomized clinical trial is underway to define the value of IMPT for the management of head and neck tumors.

  11. Intensity Modulated Proton Therapy Versus Intensity Modulated Photon Radiation Therapy for Oropharyngeal Cancer: First Comparative Results of Patient-Reported Outcomes

    International Nuclear Information System (INIS)

    Sio, Terence T.; Lin, Huei-Kai; Shi, Qiuling; Gunn, G. Brandon; Cleeland, Charles S.; Lee, J. Jack; Hernandez, Mike; Blanchard, Pierre; Thaker, Nikhil G.; Phan, Jack; Rosenthal, David I.; Garden, Adam S.; Morrison, William H.; Fuller, C. David; Mendoza, Tito R.; Mohan, Radhe; Wang, Xin Shelley; Frank, Steven J.

    2016-01-01

    Purpose: We hypothesized that patients with oropharyngeal cancer treated with intensity modulated proton therapy (IMPT) would have lower symptom burdens, as measured by patient-reported outcome (PRO) surveys, than patients treated with intensity modulated photon therapy (IMRT). Methods and Materials: Patients were treated for oropharyngeal cancer from 2006 to 2015 through prospective registries with concurrent chemotherapy and IMPT or chemotherapy and IMRT and completed the MD Anderson Symptom Inventory for Head and Neck Cancer (MDASI-HN) module at various times before treatment (baseline), during treatment (acute phase), within the first 3 months after treatment (subacute phase), and afterward (chronic phase). Individual symptoms and the top 5 and top 11 most severe symptoms were summarized and compared between the radiation therapy modalities. Results: PRO data were collected and analyzed from 35 patients treated with chemotherapy and IMPT and from 46 treated with chemotherapy and IMRT. The baseline symptom burdens were similar between both groups. The overall top 5 symptoms were food taste problems (mean score 4.91 on a 0-10 scale), dry mouth (4.49), swallowing/chewing difficulties (4.26), lack of appetite (4.08), and fatigue (4.00). Among the top 11 symptoms, changes in taste and appetite during the subacute and chronic phases favored IMPT (all P<.048). No differences in symptom burden were detected between modalities during the acute and chronic phases by top-11 symptom scoring. During the subacute phase, the mean (±standard deviation) top 5 MDASI scores were 5.15 ± 2.66 for IMPT versus 6.58 ± 1.98 for IMRT (P=.013). Conclusions: According to the MDASI-HN, symptom burden was lower among the IMPT patients than among the IMRT patients during the subacute recovery phase after treatment. A prospective randomized clinical trial is underway to define the value of IMPT for the management of head and neck tumors.

  12. Volumetric Modulated Arc Therapy for Spine Radiosurgery: Superior Treatment Planning and Delivery Compared to Static Beam Intensity Modulated Radiotherapy.

    Science.gov (United States)

    Zach, Leor; Tsvang, Lev; Alezra, Dror; Ben Ayun, Maoz; Harel, Ran

    2016-01-01

    Spine stereotactic radiosurgery (SRS) delivers an accurate and efficient high radiation dose to vertebral metastases in 1-5 fractions. We aimed to compare volumetric modulated arc therapy (VMAT) to static beam intensity modulated radiotherapy (IMRT) for spine SRS. Ten spine lesions of previously treated SRS patients were planned retrospectively using both IMRT and VMAT with a prescribed dose of 16 Gy to 100% of the planning target volume (PTV). The plans were compared for conformity, homogeneity, treatment delivery time, and safety (spinal cord dose). All evaluated parameters favored the VMAT plan over the IMRT plans. D min in the IMRT was significantly lower than in the VMAT plan (7.65 Gy/10.88 Gy, p DSC) was found to be significantly better for the VMAT plans compared to the IMRT plans (0.77/0.58, resp., p  value < 0.01), and an almost 50% reduction in the net treatment time was calculated for the VMAT compared to the IMRT plans (6.73 min/12.96 min, p < 0.001). In our report, VMAT provides better conformity, homogeneity, and safety profile. The shorter treatment time is a major advantage and not only provides convenience to the painful patient but also contributes to the precision of this high dose radiation therapy.

  13. Volumetric Modulated Arc Therapy for Spine Radiosurgery: Superior Treatment Planning and Delivery Compared to Static Beam Intensity Modulated Radiotherapy

    Directory of Open Access Journals (Sweden)

    Leor Zach

    2016-01-01

    Full Text Available Purpose. Spine stereotactic radiosurgery (SRS delivers an accurate and efficient high radiation dose to vertebral metastases in 1–5 fractions. We aimed to compare volumetric modulated arc therapy (VMAT to static beam intensity modulated radiotherapy (IMRT for spine SRS. Methods and Materials. Ten spine lesions of previously treated SRS patients were planned retrospectively using both IMRT and VMAT with a prescribed dose of 16 Gy to 100% of the planning target volume (PTV. The plans were compared for conformity, homogeneity, treatment delivery time, and safety (spinal cord dose. Results. All evaluated parameters favored the VMAT plan over the IMRT plans. Dmin in the IMRT was significantly lower than in the VMAT plan (7.65 Gy/10.88 Gy, p<0.001, the Dice Similarity Coefficient (DSC was found to be significantly better for the VMAT plans compared to the IMRT plans (0.77/0.58, resp., p  value<0.01, and an almost 50% reduction in the net treatment time was calculated for the VMAT compared to the IMRT plans (6.73 min/12.96 min, p<0.001. Conclusions. In our report, VMAT provides better conformity, homogeneity, and safety profile. The shorter treatment time is a major advantage and not only provides convenience to the painful patient but also contributes to the precision of this high dose radiation therapy.

  14. Chiral symmetry and eta, eta' → 3π decays. Grand unified theories

    International Nuclear Information System (INIS)

    Roiesnel, C.

    1982-11-01

    Two different topics related to symmetry breaking are discussed. First the eta, eta' → 3π decays are presented. The amplitudes eta, eta' → 3π are calculated with the square root threshold singularity induced by the strong pion-pion final state interaction properly taken into account. It is shown that the eta' → 3π decay rate depends sensitively upon an improved treatment of the pseudoscalar nonet mass matrix. Then symmetry-breaking effects in grand unified theories are discussed. The threshold effects in a spontaneously broken gauge theory are studied. In particular a computation of the symmetry-breaking effects in the SU(5) grand unified theory including those of the breaking of SU(2)xU(1) is presented. As an application a precise value of the superheavy gauge boson mass Mx is given. It is possible in SU(5) to define a natural effective weak angle theta w(μ) for any scale μ, below as well as above Mw, and the predicted curve for sin 2 theta w(μ) is given [fr

  15. Search for tau decays to the eta meson

    International Nuclear Information System (INIS)

    Skwarnicki, T.

    1987-12-01

    Using a sample of 530,000 tau leptons collected by the Crystal Ball experiment at the e + e - storage ring DORIS II, we have searched for tau decays to the eta meson. No eta signal is found in the inclusive analysis, tau → eta X, of 1-prong decays, leading to the upper limits, BR(tau - → nu π - eta) - → π - π 0 eta) - → nu π - π 0 π 0 eta) - → nu π - eta eta) - → nu π - eta and tau - → nu π - π 0 eta, are also not found in the exclusive analyses, while BR(tau - → nu π - π 0 ) = (22.7 +- 0.9 +- 3.0)% and BR(tau - → nu π - π 0 π 0 ) = (7.0 +- 0.7 +- 1.4)% are measured in accord with the expectations. The hadronic final state, π - π 0 π 0 , is reconstructed in tau decays for the first time. The results are preliminary. 21 refs., 10 figs

  16. THE ETA-MESON PHOTOPRODUCTION ON PROTON

    Czech Academy of Sciences Publication Activity Database

    Donoval, Jan; Bydžovský, Petr

    2011-01-01

    Roč. 26, 3-4 (2011), s. 645-646 ISSN 0217-751X. [11th International Workshop on Meson Production , Properties and Interaction. Krakow, 10.06.2010-15.06.2010] R&D Projects: GA ČR GA202/08/0984 Institutional research plan: CEZ:AV0Z10480505 Keywords : Eta-meson photoproduction * form factors * nucleon resonances Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.053, year: 2011

  17. Eta-Expansion Does The Trick

    DEFF Research Database (Denmark)

    Danvy, Olivier; Malmkjær, Karoline; Palsberg, Jens

    1995-01-01

    Partial-evaluation folklore has it that massaging one's source programs can make them specialize better. In Jones, Gomard, and Sestoft's recent textbook, a whole chapter is dedicated to listing such “binding-time improvements”: nonstandard use of continuation-passing style, eta-expansion, and a p......Partial-evaluation folklore has it that massaging one's source programs can make them specialize better. In Jones, Gomard, and Sestoft's recent textbook, a whole chapter is dedicated to listing such “binding-time improvements”: nonstandard use of continuation-passing style, eta...... across dynamic case expressions. This requirement precisely accounts for the nonstandard use of continuation-passing style encountered in partial evaluation. Eta-expansion thus acts as a uniform binding-time coercion between values and contexts, be they of function type, product type, or disjoint......-expansion, and a popular transformation called “The Trick.” We provide a unified view of these binding-time improvements, from a typing perspective. Just as a proper treatment of product values in partial evaluation requires partially static values, a proper treatment of disjoint sums requires moving static contexts...

  18. Comparison of testicular dose delivered by intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) in patients with prostate cancer

    International Nuclear Information System (INIS)

    Martin, Jeffrey M.; Handorf, Elizabeth A.; Price, Robert A.; Cherian, George; Buyyounouski, Mark K.; Chen, David Y.; Kutikov, Alexander; Johnson, Matthew E.; Ma, Chung-Ming Charlie; Horwitz, Eric M.

    2015-01-01

    A small decrease in testosterone level has been documented after prostate irradiation, possibly owing to the incidental dose to the testes. Testicular doses from prostate external beam radiation plans with either intensity-modulated radiation therapy (IMRT) or volumetric-modulated arc therapy (VMAT) were calculated to investigate any difference. Testicles were contoured for 16 patients being treated for localized prostate cancer. For each patient, 2 plans were created: 1 with IMRT and 1 with VMAT. No specific attempt was made to reduce testicular dose. Minimum, maximum, and mean doses to the testicles were recorded for each plan. Of the 16 patients, 4 received a total dose of 7800 cGy to the prostate alone, 7 received 8000 cGy to the prostate alone, and 5 received 8000 cGy to the prostate and pelvic lymph nodes. The mean (range) of testicular dose with an IMRT plan was 54.7 cGy (21.1 to 91.9) and 59.0 cGy (25.1 to 93.4) with a VMAT plan. In 12 cases, the mean VMAT dose was higher than the mean IMRT dose, with a mean difference of 4.3 cGy (p = 0.019). There was a small but statistically significant increase in mean testicular dose delivered by VMAT compared with IMRT. Despite this, it unlikely that there is a clinically meaningful difference in testicular doses from either modality

  19. Comparison of testicular dose delivered by intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) in patients with prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Jeffrey M. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Handorf, Elizabeth A. [Department of Biostatistics, Fox Chase Cancer Center, Philadelphia, PA (United States); Price, Robert A.; Cherian, George [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Buyyounouski, Mark K. [Department of Radiation Oncology, Stanford University, Stanford, CA (United States); Chen, David Y.; Kutikov, Alexander [Department of Urologic Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Johnson, Matthew E.; Ma, Chung-Ming Charlie [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Horwitz, Eric M., E-mail: eric.horwitz@fccc.edu [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States)

    2015-10-01

    A small decrease in testosterone level has been documented after prostate irradiation, possibly owing to the incidental dose to the testes. Testicular doses from prostate external beam radiation plans with either intensity-modulated radiation therapy (IMRT) or volumetric-modulated arc therapy (VMAT) were calculated to investigate any difference. Testicles were contoured for 16 patients being treated for localized prostate cancer. For each patient, 2 plans were created: 1 with IMRT and 1 with VMAT. No specific attempt was made to reduce testicular dose. Minimum, maximum, and mean doses to the testicles were recorded for each plan. Of the 16 patients, 4 received a total dose of 7800 cGy to the prostate alone, 7 received 8000 cGy to the prostate alone, and 5 received 8000 cGy to the prostate and pelvic lymph nodes. The mean (range) of testicular dose with an IMRT plan was 54.7 cGy (21.1 to 91.9) and 59.0 cGy (25.1 to 93.4) with a VMAT plan. In 12 cases, the mean VMAT dose was higher than the mean IMRT dose, with a mean difference of 4.3 cGy (p = 0.019). There was a small but statistically significant increase in mean testicular dose delivered by VMAT compared with IMRT. Despite this, it unlikely that there is a clinically meaningful difference in testicular doses from either modality.

  20. Radiation-Induced Cancers From Modern Radiotherapy Techniques: Intensity-Modulated Radiotherapy Versus Proton Therapy

    International Nuclear Information System (INIS)

    Yoon, Myonggeun; Ahn, Sung Hwan; Kim, Jinsung; Shin, Dong Ho; Park, Sung Yong; Lee, Se Byeong; Shin, Kyung Hwan; Cho, Kwan Ho

    2010-01-01

    Purpose: To assess and compare secondary cancer risk resulting from intensity-modulated radiotherapy (IMRT) and proton therapy in patients with prostate and head-and-neck cancer. Methods and Materials: Intensity-modulated radiotherapy and proton therapy in the scattering mode were planned for 5 prostate caner patients and 5 head-and-neck cancer patients. The secondary doses during irradiation were measured using ion chamber and CR-39 detectors for IMRT and proton therapy, respectively. Organ-specific radiation-induced cancer risk was estimated by applying organ equivalent dose to dose distributions. Results: The average secondary doses of proton therapy for prostate cancer patients, measured 20-60cm from the isocenter, ranged from 0.4 mSv/Gy to 0.1 mSv/Gy. The average secondary doses of IMRT for prostate patients, however, ranged between 3 mSv/Gy and 1 mSv/Gy, approximately one order of magnitude higher than for proton therapy. Although the average secondary doses of IMRT were higher than those of proton therapy for head-and-neck cancers, these differences were not significant. Organ equivalent dose calculations showed that, for prostate cancer patients, the risk of secondary cancers in out-of-field organs, such as the stomach, lungs, and thyroid, was at least 5 times higher for IMRT than for proton therapy, whereas the difference was lower for head-and-neck cancer patients. Conclusions: Comparisons of organ-specific organ equivalent dose showed that the estimated secondary cancer risk using scattering mode in proton therapy is either significantly lower than the cases in IMRT treatment or, at least, does not exceed the risk induced by conventional IMRT treatment.

  1. Intensity-modulated radiation therapy: a review with a physics perspective.

    Science.gov (United States)

    Cho, Byungchul

    2018-03-01

    Intensity-modulated radiation therapy (IMRT) has been considered the most successful development in radiation oncology since the introduction of computed tomography into treatment planning that enabled three-dimensional conformal radiotherapy in 1980s. More than three decades have passed since the concept of inverse planning was first introduced in 1982, and IMRT has become the most important and common modality in radiation therapy. This review will present developments in inverse IMRT treatment planning and IMRT delivery using multileaf collimators, along with the associated key concepts. Other relevant issues and future perspectives are also presented.

  2. Zinc therapy on children with Psoriasis modulates trace elements in serum and tissue

    International Nuclear Information System (INIS)

    El-Said, S. A.

    2013-01-01

    This study illustrates the effect of zinc therapy on some trace elements in either serum and skin which has been done on twenty patients with psoriasis with age range between 4 -13 years. They were under medical treatment with 5 milligram; oral zinc sulfate for 12 weeks. A significant increase in both serum and tissue copper and iron levels was detected by atomic absorption spectrophotometer . In addition, a significant decrease in both serum and tissue calcium and magnesium in psoriatic patients. It has been concluded that zinc therapy could be valuable through modulation of copper, calcium, iron and magnesium in psoriatic patients.

  3. Comparison study of intensity modulated arc therapy using single or multiple arcs to intensity modulated radiation therapy for high-risk prostate cancer

    International Nuclear Information System (INIS)

    Ashamalla, Hani; Tejwani, Ajay; Parameritis, Loannis; Swamy, Uma; Luo, Pei Ching; Guirguis, Adel; Lavaf, Amir

    2013-01-01

    Intensity modulated arc therapy (IMAT) is a form of intensity modulated radiation therapy (IMRT) that delivers dose in single or multiple arcs. We compared IMRT plans versus single-arc field (1ARC) and multi-arc fields (3ARC) IMAT plans in high-risk prostate cancer. Sixteen patients were studied. Prostate (PTV P ), right pelvic (PTV RtLN ) and left pelvic lymph nodes (PTV LtLN ), and organs at risk were contoured. PTVP, PTV RtLN , and PTV LtLN received 50.40 Gy followed by a boost to PTV B of 28.80 Gy. Three plans were per patient generated: IMRT, 1ARC, and 3ARC. We recorded the dose to the PTV, the mean dose (D MEAN ) to the organs at risk, and volume covered by the 50% isodose. Efficiency was evaluated by monitor units (MU) and beam on time (BOT). Conformity index (CI), Paddick gradient index, and homogeneity index (HI) were also calculated. Average Radiation Therapy Oncology Group CI was 1.17, 1.20, and 1.15 for IMRT, 1ARC, and 3ARC, respectively. The plans' HI were within 1% of each other. The D MEAN of bladder was within 2% of each other. The rectum D MEAN in IMRT plans was 10% lower dose than the arc plans (p < 0.0001). The GI of the 3ARC was superior to IMRT by 27.4% (p = 0.006). The average MU was highest in the IMRT plans (1686) versus 1ARC (575) versus 3ARC (1079). The average BOT was 6 minutes for IMRT compared to 1.3 and 2.9 for 1ARC and 3ARC IMAT (p < 0.05). For high-risk prostate cancer, IMAT may offer a favorable dose gradient profile, conformity, MU and BOT compared to IMRT.

  4. Results of the quality control treatments plans in volume arc therapy modulated for thirty treated patients

    International Nuclear Information System (INIS)

    Fenoglietto, P.; Ailleres, N.; Simeon, S.; Santoro, L.; Dubois, J.B.; Azria, D.

    2009-01-01

    The intensity modulated radiotherapy (I.M.R.T.) provided by voluminal arc therapy was implemented at the Val d'Aurelle regional center against cancer in november 2008. In May 2009 more than 30 patients have benefited from this technique in our institution and for each of them, the dosimetry planing has been checked under the accelerator before the treatment. The analysis of these results of measures under accelerators equipped of 120 leave collimators and for optimizations realised with the Rapid-arc computer code from Varian. The issue of a treatment in intensity modulation by voluminal arc therapy gives satisfying results falling within the range of those previously found in conventional I.M.R.T.. Besides, the quality control is faster because of lesser number of beams to verify. (N.C.)

  5. Study of $\\eta$ and $\\eta'$ Production in $\\overline{n}p$ Annihilations

    CERN Document Server

    Filippi, A; Botta, E; Bressani, Tullio; Calvo, D; Costa, S; D'Isep, F; Feliciello, A; Iazzi, F; Marcello, S; Minetti, B; Mirfakhraee, N; Balestra, F; Bussa, M P; Busso, L; Cerello, P G; Denisov, O Yu; Garfagnini, R; Grasso, A; Maggiora, A; Panzarasa, A; Panzieri, D; Tosello, F; Bertin, A; Bruschi, M; Capponi, M; De Castro, S; Donà, R; Galli, D; Giacobbe, B; Marconi, U; Massa, I; Piccinini, M; Poli, M; Semprini-Cesari, N; Spighi, R; Vagnoni, V M; Vecchi, S; Villa, M; Vitale, A; Zoccoli, A; Bianconi, A; Bonomi, G; Lodi-Rizzini, E; Venturelli, L; Zenoni, A; Cicalò, C; Masoni, A; Mauro, S; Puddu, G; Serci, S; Usai, G L; Gorchakov, O E; Prakhov, S N; Rozhdestvensky, A M; Sapozhnikov, M G; Tretyak, V I; Gianotti, P; Guaraldo, C; Lanaro, A; Lucherini, V; Petrascu, C; Ableev, V G; Vannucci, Luigi; Vedovato, G; Bendiscioli, G; Filippini, V; Fontana, A; Montagna, P; Rotondi, A; Salvini, P; Tessaro, S

    1999-01-01

    The annihilation fractions and cross sections for the np annihilation reaction in flight (~50-400 MeV/c) into eta pi /sup +/ and eta ' pi /sup +/ final states have been measured. The first ones follow the trend expected for P wave annihilations. From the ratios of the yields an evaluation of the pseudoscalar mixing angle in the standard form is possible. The value found shows that for pseudoscalar meson production from P wave the quark line rule is not grossly violated. (22 refs).

  6. Further study of eta'→μ+μ-γ decay

    International Nuclear Information System (INIS)

    Dzhelyadin, R.I.; Golovkin, S.V.; Kakauridze, D.V.

    1980-01-01

    The study of rare electromagnetic decay eta'→μ + μ - γ has been continued. The μ + μ - γ effective mass spectrum is presented. The branching ratio BR(eta'→μ + μ - γ)=(8.9+-2.4)x10 -5 , has been measured. The eta' meson electromagnetic form-factor has been defined. The experimental results are in agreement with the vector dominance model

  7. Comparative analysis of volumetric-modulated arc therapy and intensity-modulated radiotherapy for base of tongue cancer

    International Nuclear Information System (INIS)

    Nithya, L.; Arulraj, Kumar; Rathinamuthu, Sasikumar; Pandey, Manish Bhushan; Nambi Raj, N. Arunai

    2014-01-01

    The aim of this study was to compare the various dosimetric parameters of dynamic multileaf collimator (MLC) intensity modulated radiation therapy (IMRT) plans with volumetric modulated arc therapy (VMAT) plans for base of tongue cases. All plans were done in Monaco planning system for Elekta synergy linear accelerator with 80 MLC. IMRT plans were planned with nine stationary beams, and VMAT plans were done for 360° arc with single arc or dual arc. The dose to the planning target volumes (PTV) for 70, 63, and 56 Gy was compared. The dose to 95, 98, and 50% volume of PTV were analyzed. The homogeneity index (HI) and the conformity index (CI) of the PTV 70 were also analyzed. IMRT and VMAT plan showed similar dose coverage, HI, and CI. Maximum dose and dose to 1-cc volume of spinal cord, planning risk volume (PRV) cord, and brain stem were compared. IMRT plan and VMAT plan showed similar results except for the 1 cc of PRV cord that received slightly higher dose in VMAT plan. Mean dose and dose to 50% volume of right and left parotid glands were analyzed. VMAT plan gave better sparing of parotid glands than IMRT. In normal tissue dose analyses VMAT was better than IMRT. The number of monitor units (MU) required for delivering the good quality of the plan and the time required to deliver the plan for IMRT and VMAT were compared. The number of MUs for VMAT was higher than that of IMRT plans. However, the delivery time was reduced by a factor of two for VMAT compared with IMRT. VMAT plans yielded good quality of the plan compared with IMRT, resulting in reduced treatment time and improved efficiency for base of tongue cases. (author)

  8. Comparative analysis of volumetric-modulated arc therapy and intensity-modulated radiotherapy for base of tongue cancer

    Directory of Open Access Journals (Sweden)

    L Nithya

    2014-01-01

    Full Text Available The aim of this study was to compare the various dosimetric parameters of dynamic multileaf collimator (MLC intensity modulated radiation therapy (IMRT plans with volumetric modulated arc therapy (VMAT plans for base of tongue cases. All plans were done in Monaco planning system for Elekta synergy linear accelerator with 80 MLC. IMRT plans were planned with nine stationary beams, and VMAT plans were done for 360° arc with single arc or dual arc. The dose to the planning target volumes (PTV for 70, 63, and 56 Gy was compared. The dose to 95, 98, and 50% volume of PTV were analyzed. The homogeneity index (HI and the conformity index (CI of the PTV 70 were also analyzed. IMRT and VMAT plan showed similar dose coverage, HI, and CI. Maximum dose and dose to 1-cc volume of spinal cord, planning risk volume (PRV cord, and brain stem were compared. IMRT plan and VMAT plan showed similar results except for the 1 cc of PRV cord that received slightly higher dose in VMAT plan. Mean dose and dose to 50% volume of right and left parotid glands were analyzed. VMAT plan gave better sparing of parotid glands than IMRT. In normal tissue dose analyses VMAT was better than IMRT. The number of monitor units (MU required for delivering the good quality of the plan and the time required to deliver the plan for IMRT and VMAT were compared. The number of MUs for VMAT was higher than that of IMRT plans. However, the delivery time was reduced by a factor of two for VMAT compared with IMRT. VMAT plans yielded good quality of the plan compared with IMRT, resulting in reduced treatment time and improved efficiency for base of tongue cases.

  9. Imidazoles and benzimidazoles as tubulin-modulators for anti-cancer therapy.

    Science.gov (United States)

    Torres, Fernando C; García-Rubiño, M Eugenia; Lozano-López, César; Kawano, Daniel F; Eifler-Lima, Vera L; von Poser, Gilsane L; Campos, Joaquín M

    2015-01-01

    Imidazoles and benzimidazoles are privileged heterocyclic bioactive compounds used with success in the clinical practice of innumerous diseases. Although there are many advancements in cancer therapy, microtubules remain as one of the few macromolecular targets validated for planning active anti-cancer compounds, and the design of drugs that modulate microtubule dynamics in unknown sites of tubulin is one of the goals of the medicinal chemistry. The discussion of the role of new and commercially available imidazole and benzimidazole derivatives as tubulin modulators is scattered throughout scientific literature, and indicates that these compounds have a tubulin modulation mechanism different from that of tubulin modulators clinically available, such as paclitaxel, docetaxel, vincristine and vinblastine. In fact, recent literature indicates that these derivatives inhibit microtubule formation binding to the colchicine site, present good pharmacokinetic properties and are capable of overcoming multidrug resistance in many cell lines. The understanding of the mechanisms involved in the imidazoles/benzimidazoles modulation of microtubule dynamics is very important to develop new strategies to overcome the resistance to anti-cancer drugs and to discover new biomarkers and targets for cancer chemotherapy.

  10. Observation of the $B^0_s\\to\\eta'\\eta'$ decay

    CERN Document Server

    AUTHOR|(CDS)2075808; Adeva, Bernardo; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Bel, Lennaert; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bertolin, Alessandro; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casanova Mohr, Raimon; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cavallero, Giovanni; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferrari, Fabio; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gastaldi, Ugo; Gauld, Rhorry; Gavardi, Laura; Gazzoni, Giulio; Geraci, Angelo; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, Vladimir; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Kenzie, Matthew; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lowdon, Peter; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Manning, Peter Michael; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Mitzel, Dominik Stefan; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Osorio Rodrigues, Bruno; Otalora Goicochea, Juan Martin; Otto, Adam; Owen, Patrick; Oyanguren, Maria Aranzazu; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Pescatore, Luca; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Quagliani, Renato; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skillicorn, Ian; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Sterpka, Christopher Francis; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Todd, Jacob; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Trabelsi, Karim; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viana Barbosa, Joao Vitor; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wiedner, Dirk; Wilkinson, Guy; Wilkinson, Michael; Williams, Matthew; Williams, Mike; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang

    2015-01-01

    The first observation of the $B^0_s\\to\\eta'\\eta'$ decay is reported. The study is based on a sample of proton-proton collisions corresponding to $3.0$ ${\\rm fb^{-1}}$ of integrated luminosity collected with the LHCb detector. The significance of the signal is $6.4$ standard deviations. The branching fraction is measured to be $[3.31 \\pm 0.64\\,{\\rm (stat)} \\pm 0.28\\,{\\rm (syst)} \\pm 0.12\\,{\\rm (norm)}]\\times10^{-5}$, where the third uncertainty comes from the $B^{\\pm}\\to\\eta' K^{\\pm}$ branching fraction that is used as a normalisation. In addition, the charge asymmetries of $B^{\\pm}\\to\\eta' K^{\\pm}$ and $B^{\\pm}\\to\\phi K^{\\pm}$, which are control channels, are measured to be $(-0.2 \\pm1.3)\\%$ and $(+1.7\\pm1.3)\\%$, respectively. All results are consistent with theoretical expectations.

  11. Verification of dosimetric commissioning accuracy of intensity modulated radiation therapy and volumetric modulated arc therapy delivery using task Group-119 guidelines

    Directory of Open Access Journals (Sweden)

    Karunakaran Kaviarasu

    2017-01-01

    Full Text Available Aim: The purpose of this study is to verify the accuracy of the commissioning of intensity-modulated radiation therapy (IMRT and volumetric-modulated arc therapy (VMAT based on the recommendation of the American Association of Physicists in Medicine Task Group 119 (TG-119. Materials and Methods: TG-119 proposes a set of clinical test cases to verify the accuracy of IMRT planning and delivery system. For these test cases, we generated two sets of treatment plans, the first plan using 7–9 IMRT fields and a second plan utilizing two-arc VMAT technique for both 6 MV and 15 MV photon beams. The template plans of TG-119 were optimized and calculated by Varian Eclipse Treatment Planning System (version 13.5. Dose prescription and planning objectives were set according to the TG-119 goals. The point dose (mean dose to the contoured chamber volume at the specified positions/locations was measured using compact (CC-13 ion chamber. The composite planar dose was measured with IMatriXX Evaluation 2D array with OmniPro IMRT Software (version 1.7b. The per-field relative gamma was measured using electronic portal imaging device in a way similar to the routine pretreatment patient-specific quality assurance. Results: Our planning results are compared with the TG-119 data. Point dose and fluence comparison data where within the acceptable confident limit. Conclusion: From the obtained data in this study, we conclude that the commissioning of IMRT and VMAT delivery were found within the limits of TG-119.

  12. Verification of Dosimetric Commissioning Accuracy of Intensity Modulated Radiation Therapy and Volumetric Modulated Arc Therapy Delivery using Task Group-119 Guidelines.

    Science.gov (United States)

    Kaviarasu, Karunakaran; Nambi Raj, N Arunai; Hamid, Misba; Giri Babu, A Ananda; Sreenivas, Lingampally; Murthy, Kammari Krishna

    2017-01-01

    The purpose of this study is to verify the accuracy of the commissioning of intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) based on the recommendation of the American Association of Physicists in Medicine Task Group 119 (TG-119). TG-119 proposes a set of clinical test cases to verify the accuracy of IMRT planning and delivery system. For these test cases, we generated two sets of treatment plans, the first plan using 7-9 IMRT fields and a second plan utilizing two-arc VMAT technique for both 6 MV and 15 MV photon beams. The template plans of TG-119 were optimized and calculated by Varian Eclipse Treatment Planning System (version 13.5). Dose prescription and planning objectives were set according to the TG-119 goals. The point dose (mean dose to the contoured chamber volume) at the specified positions/locations was measured using compact (CC-13) ion chamber. The composite planar dose was measured with IMatriXX Evaluation 2D array with OmniPro IMRT Software (version 1.7b). The per-field relative gamma was measured using electronic portal imaging device in a way similar to the routine pretreatment patient-specific quality assurance. Our planning results are compared with the TG-119 data. Point dose and fluence comparison data where within the acceptable confident limit. From the obtained data in this study, we conclude that the commissioning of IMRT and VMAT delivery were found within the limits of TG-119.

  13. 76 FR 12760 - Comment Request for Information Collection for Report ETA 902, Disaster Unemployment Assistance...

    Science.gov (United States)

    2011-03-08

    ... Collection for Report ETA 902, Disaster Unemployment Assistance Activities (OMB Control No. 1205- 0051... soliciting comments concerning the proposed extension of the ETA 902, Disaster Unemployment [email protected] . SUPPLEMENTARY INFORMATION: I. Background The ETA 902 Report, Disaster Unemployment...

  14. Some considerations concerning volume-modulated arc therapy: a stepping stone towards a general theory

    International Nuclear Information System (INIS)

    Webb, S; McQuaid, D

    2009-01-01

    In this paper it is formally shown that the dynamic multileaf collimator (MLC) IMRT delivery technique remains valid if the MLC is supported on a 1D moving platform. It is also shown that, in such circumstances, it is always time preferable to deliver overlapping modulating fields as a single swept field rather than as separate fields. The most general formulism is presented and then related to simpler equations in limiting cases. The paper explains in detail how a 'small-arc approximation' can be invoked to relate the 1D linear theory to the MLC-on-moving-platform-(gantry) delivery technique involving rotation therapy and known as volume-modulated arc therapy (VMAT). It is explained how volume-modulated arc therapy delivered with open unmodulated fields and which can deliver conformal dose distributions can be interpreted as an IMRT delivery. The (Elekta adopted) term VMAT will be used in a generic sense to include a similar (Varian) method known as RapidArc. Approximate expressions are derived for the 'amount of modulation' possible in a VMAT delivery. This paper does not discuss the actual VMAT planning but gives an insight at a deep level into VMAT delivery. No universal theory of VMAT is known in the sense that there is no theory that can predict precisely the performance of a VMAT delivery in terms of the free parameters available (variable gantry speed, variable fluence-delivery rate, set of MLC shapes, MLC orientation, number of arcs, coplanarity versus non-coplanarity, etc). This is in stark contrast to the situation with several other IMRT delivery techniques where such theoretical analyses are known. In this paper we do not provide such a theory; the material presented is a stepping stone on the path towards this.

  15. Eta Products and Theta Series Identities

    CERN Document Server

    Kohler, Gunter

    2011-01-01

    This monograph deals with products of Dedekind's eta function, with Hecke theta series on quadratic number fields, and with "Eisenstein series." The author brings to the public the large number of identities that have been discovered over the past 20 years, the majority of which have not been published elsewhere. This book will be of interest to graduate students and scholars in the field of number theory and, in particular, modular forms. It is not an introductory text in this field. Nevertheless, some theoretical background material is presented that is important for understanding

  16. Rare decays of neutral π and eta

    International Nuclear Information System (INIS)

    Poutissou, J.M.

    1983-09-01

    The decays of the pseudoscalar neutral mesons π degree and eta degree have provided a test of fundamental principles. The main branch, π degree → 2γ, was investigated in the late 60's in the context of current algebra and the decay rate calculated from the singular triangle diagram is in excellent agreement with experiment. Rare leptonic decays of the neutral pseudoscalar mesons are of interest because of the information they reveal about neutral currents or other exotic interactions between leptons and quarks. The author discusses recent information on the π degree → e + e - decay

  17. Bladder radiotherapy treatment: A retrospective comparison of 3-dimensional conformal radiotherapy, intensity-modulated radiation therapy, and volumetric-modulated arc therapy plans

    Energy Technology Data Exchange (ETDEWEB)

    Pasciuti, Katia, E-mail: k.pasciuti@virgilio.it [Department of Radiotherapy Physics, Royal Free Hospital, London (United Kingdom); Kuthpady, Shrinivas [Department of Radiotherapy, Royal Free Hospital, London (United Kingdom); Anderson, Anne; Best, Bronagh [Department of Radiotherapy Physics, Royal Free Hospital, London (United Kingdom); Waqar, Saleem; Chowdhury, Subhra [Department of Radiotherapy, Royal Free Hospital, London (United Kingdom)

    2017-04-01

    To examine tumor's and organ's response when different radiotherapy plan techniques are used. Ten patients with confirmed bladder tumors were first treated using 3-dimensional conformal radiotherapy (3DCRT) and subsequently the original plans were re-optimized using the intensity-modulated radiation treatment (IMRT) and volumetric-modulated arc therapy (VMAT)-techniques. Targets coverage in terms of conformity and homogeneity index, TCP, and organs' dose limits, including integral dose analysis were evaluated. In addition, MUs and treatment delivery times were compared. Better minimum target coverage (1.3%) was observed in VMAT plans when compared to 3DCRT and IMRT ones confirmed by a statistically significant conformity index (CI) results. Large differences were observed among techniques in integral dose results of the femoral heads. Even if no statistically significant differences were reported in rectum and tissue, a large amount of energy deposition was observed in 3DCRT plans. In any case, VMAT plans provided better organs and tissue sparing confirmed also by the normal tissue complication probability (NTCP) analysis as well as a better tumor control probability (TCP) result. Our analysis showed better overall results in planning using VMAT techniques. Furthermore, a total time reduction in treatment observed among techniques including gantry and collimator rotation could encourage using the more recent one, reducing target movements and patient discomfort.

  18. Indications for the decays D/sub s//sup +-/ → eta π/sup +-/ and D/sub s//sup +-/ → eta' π/sup +-/

    International Nuclear Information System (INIS)

    Wormser, G.

    1987-11-01

    A search for D/sub s//sup +-/ decays into eta π/sup +-/ and eta' π/sup +-/ has been performed by the MarkII collaboration at the PEP e + e - storage ring. Eta particles are reconstructed by their γγ decay mode. The eta fragmentation has been measured and found to be in good agreement with the Lund model prediction. Eta' production has been measured for the first time in e + e - high energy annihilation. Good indications are found for both decay modes D/sub s//sup +-/ → eta π/sup +-/ and D/sub s//sup +-/ → eta' π/sup +-/

  19. Clinical Outcomes of Intensity-Modulated Pelvic Radiation Therapy for Carcinoma of the Cervix

    International Nuclear Information System (INIS)

    Hasselle, Michael D.; Rose, Brent S.; Kochanski, Joel D.; Nath, Sameer K.; Bafana, Rounak; Yashar, Catheryn M.; Hasan, Yasmin; Roeske, John C.; Mundt, Arno J.; Mell, Loren K.

    2011-01-01

    Purpose: To evaluate disease outcomes and toxicity in cervical cancer patients treated with pelvic intensity-modulated radiation therapy (IMRT). Methods and Materials: We included all patients with Stage I-IVA cervical carcinoma treated with IMRT at three different institutions from 2000-2007. Patients treated with extended field or conventional techniques were excluded. Intensity-modulated radiation therapy plans were designed to deliver 45 Gy in 1.8-Gy daily fractions to the planning target volume while minimizing dose to the bowel, bladder, and rectum. Toxicity was graded according to the Radiation Therapy Oncology Group system. Overall survival and disease-free survival were estimated by use of the Kaplan-Meier method. Pelvic failure, distant failure, and late toxicity were estimated by use of cumulative incidence functions. Results: The study included 111 patients. Of these, 22 were treated with postoperative IMRT, 8 with IMRT followed by intracavitary brachytherapy and adjuvant hysterectomy, and 81 with IMRT followed by planned intracavitary brachytherapy. Of the patients, 63 had Stage I-IIA disease and 48 had Stage IIB-IVA disease. The median follow-up time was 27 months. The 3-year overall survival rate and the disease-free survival rate were 78% (95% confidence interval [CI], 68-88%) and 69% (95% CI, 59-81%), respectively. The 3-year pelvic failure rate and the distant failure rate were 14% (95% CI, 6-22%) and 17% (95% CI, 8-25%), respectively. Estimates of acute and late Grade 3 toxicity or higher were 2% (95% CI, 0-7%) and 7% (95% CI, 2-13%), respectively. Conclusions: Intensity-modulated radiation therapy is associated with low toxicity and favorable outcomes, supporting its safety and efficacy for cervical cancer. Prospective clinical trials are needed to evaluate the comparative efficacy of IMRT vs. conventional techniques.

  20. ETA chemistry experience and assessment on CPP in Korea

    International Nuclear Information System (INIS)

    Park, K.K.; Lee, J.B.; Yoon, S.W.

    2002-01-01

    To reduce FAC of carbon steel in secondary system, water treatment chemistry was converted to ETA at Kori unit 1. Full scale tests to choose the optimum concentration of ETA were conducted and the evaluation after one cycle operation with ETA was also performed. Optimum concentration of ETA in final feed water was determined as 1.8 ppm. At this condition, iron concentration was reduced by 69.8% in final feed water and 69.7% in heater drain compared to ammonia-AVT. The amount of sludge removed from each steam generator was 11.3 kg, which was 88.2% lower than that of ammonia-AVT. With successful results of Kori unit 1, Applications of ETA were extended to other PWRs. Iron transport was found to be reduced significantly. Also, the output of electric power increased by 9 MWe at Young-Kwang unit 1. However, fouling of ion exchange resin in CPP was appeared. ETA appears to have a solvent function in the initial stage of ETA chemistry. Resin was restored when the fouling was removed with hot water and sodium bicarbonates. In particular, the MR type anion resin may be effective in resistance to fouling when ETA-chemistry is used. (authors)

  1. {pi}{eta} pair hard electroproduction and exotic hybrid mesons

    Energy Technology Data Exchange (ETDEWEB)

    Anikin, I.V. [LPT, Universite Paris-Sud, 91405-Orsay, France, UMR 8627 du CNRS (France); BLTP, JINR, 141980 Dubna (Russian Federation); CPHT, Ecole Polytechnique, 91128 Palaiseau, France, UMR 7644 du CNRS (France); Pire, B. [CPHT, Ecole Polytechnique, 91128 Palaiseau, France, UMR 7644 du CNRS (France); Szymanowski, L. [Soltan Institute for Nuclear Studies, Warsaw (Poland) and Univ. de Liege, B-4000 Liege (Belgium); Teryaev, O.V. [BLTP, JINR, 141980 Dubna (Russian Federation); Wallon, S. [LPT, Universite Paris-Sud, 91405-Orsay, France, UMR 8627 du CNRS (France)

    2005-06-13

    We show that hard electroproduction is a promising way to study exotic hybrid mesons, in particular through the hybrid decay channel H->{pi}{eta}. We discuss the {pi}{eta} generalized distribution amplitude, calculate the production amplitude and propose a forward-backward asymmetry as a signal for the hybrid meson production.

  2. Software Users Manual (SUM): Extended Testability Analysis (ETA) Tool

    Science.gov (United States)

    Maul, William A.; Fulton, Christopher E.

    2011-01-01

    This software user manual describes the implementation and use the Extended Testability Analysis (ETA) Tool. The ETA Tool is a software program that augments the analysis and reporting capabilities of a commercial-off-the-shelf (COTS) testability analysis software package called the Testability Engineering And Maintenance System (TEAMS) Designer. An initial diagnostic assessment is performed by the TEAMS Designer software using a qualitative, directed-graph model of the system being analyzed. The ETA Tool utilizes system design information captured within the diagnostic model and testability analysis output from the TEAMS Designer software to create a series of six reports for various system engineering needs. The ETA Tool allows the user to perform additional studies on the testability analysis results by determining the detection sensitivity to the loss of certain sensors or tests. The ETA Tool was developed to support design and development of the NASA Ares I Crew Launch Vehicle. The diagnostic analysis provided by the ETA Tool was proven to be valuable system engineering output that provided consistency in the verification of system engineering requirements. This software user manual provides a description of each output report generated by the ETA Tool. The manual also describes the example diagnostic model and supporting documentation - also provided with the ETA Tool software release package - that were used to generate the reports presented in the manual

  3. Ikerketaz gizarte langintzan: Sorburuak, kopuruak eta aburuak

    Directory of Open Access Journals (Sweden)

    Kontxesi Berrio-Otxoa Otxoa de Angiozar

    2011-06-01

    Full Text Available Normal 0 21 false false false ES X-NONE X-NONE Artikulu honek jasotzen ditu gizarte langintzaren arloan ikerlanaren beharraz arduratu diren egile esanguratsuek gizarte langintzako ikerketari emandako definizioak. Bidenabar, gizarte langintzaren hastapenetan beste jakintza arloekin uztartuta egindako ikerketek izandako garrantzia ere azaltzen zaigu. Ikerketari buruzko aipuekin batera, ohartarazten zaigu ikerketa modu ezberdinetan ulertu izan dela gizarte langintzaren eremuan; eta horren harira, gizarte langileen jardunean ikerketak duen presentzia aztertu ondoren, egun ere, era ezberdinetan ulertu eta kategorizatzearen inguruko hausnarketa egiten du egileak. This article covers the different definitions of research in social work built up by the more significant authors who have worried about the need for doing research work on social work. At the same time, it show us the importance of combined research with other areas of knowledge that took place at the begginings of Social Work discipline. Moreover, the article worns us about the diferent ways that research has been understood in relation with social work and it points out the presence and importance of research in social worker´s daily work. Finally, the author offers us her reflexions on the different ways that research is understood and categorized nowadays.

  4. Treatment planning, optimization, and beam delivery technqiues for intensity modulated proton therapy

    Science.gov (United States)

    Sengbusch, Evan R.

    , beamlet weight, the number of delivered beamlets, and the number of delivery angles. These methods are evaluated via treatment planning studies including left-sided whole breast irradiation, lung stereotactic body radiotherapy, nasopharyngeal carcinoma, and whole brain radiotherapy with hippocampal avoidance. Improvements in efficiency and efficacy relative to traditional proton therapy and intensity modulated photon radiation therapy are discussed.

  5. Volumetric modulated arc therapy for spine SBRT patients to reduce treatment time and intrafractional motion

    Directory of Open Access Journals (Sweden)

    Ahmad Amoush

    2015-01-01

    Full Text Available Volumetric modulated arc therapy (VMAT is an efficient technique to reduce the treatment time and intrafractional motion to treat spine patients presented with severe back pain. Five patients treated with spine stereotactic body radiation therapy (SBRT using 9 beams intensity modulated radiation therapy (IMRT were retrospectively selected for this study. The patients were replanned using two arcs VMAT technique. The average mean dose was 104% ± 1.2% and 104.1% ± 1.0% in IMRT and VMAT, respectively (p = 0.9. Accordingly, the average conformal index (CI was 1.3 ± 0.1 and 1.5 ± 0.3, respectively (p = 0.5. The average dose gradient (DG distance was 1.5 ± 0.1 cm and 1.4 ± 0.1 cm, respectively (p = 0.3. The average spinal cord maximum dose was 11.6 ± 1.0 Gy and 11.8 ± 1.1 Gy (p = 0.8 and V10Gy was 7.4 ± 1.4 cc and 8.6 ± 1.7 cc (p = 0.4 for IMRT and VMAT, respectively. Accordingly, the average number of monitor units (MUs was 6771.7 ± 1323.3 MU and 3978 ± 576.7 MU respectively (p = 0.02. The use of VMAT for spine SBRT patients with severe back pain can reduce the treatment time and intrafractional motion.

  6. SU-E-T-449: Hippocampal Sparing Radiotherapy Using Intensity Modulated Radiotherapy and Volumetric Modulated Arc Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Moon, S [Korea University, Seoul (Korea, Republic of); Kyung Hee University Hospital at Gangdong, Gangdong-gu (Korea, Republic of); Kim, D; Chung, W [Kyung Hee University Hospital at Gangdong, Gangdong-gu (Korea, Republic of); Yoon, M [Korea University, Seoul (Korea, Republic of)

    2015-06-15

    Purpose: The hippocampus sparing during the cranial irradiation has become interesting because it may mitigate radiation-induced neurocognitive toxicity. Herein we report our preliminary study for sparing the hippocampus with and without tilling condition for patient with brain metastases. Methods: Ten patients previously treated with whole brain were reviewed. Five patients tilted the head to around 30 degrees and others were treated without tilting. Treatment plans of linear accelerator (Linac)-based volumetric modulated arc therapy (VMAT) and intensity modulated radiotherapy (IMRT) were generated for prescription dose of 30 Gy in 15 fractions. Hippocampal avoidance regions were created with 5-mm volumetric expansion around the hippocampus. Whole brain, hippocampus and hippocampal avoidance volume were 1372cm3, 6cm3 and 30cm3 and hippocampal avoidance volume was 2.2% of the whole brain planned target volume in average. Organs at risk (OARs) are hippocampus, eyes, lens, and cochleae. Coverage index (CVI), conformity index (CI), homogeneity index (HI) and mean dose to OARs were used to compare dose characteristic of tilted and non-tilted cases. Results: In IMRT, when CI, CVI and HI of whole brain were 0.88, 0.09 and 0.98 in both tilted and non-tilted cases, absorbed dose of hippocampal avoidance volume in tilted cases were 10% lower than non-tilted cases. Doses in other OARs such as eyes, lens, and cochleae were also decreased about 20% when tilting the head. When CI, HI and CVI in VMAT were 0.9, 0.08 and 0.99, the dose-decreased ratio of OARs in both with and without tilting cases were almost the same with IMRT. But absolute dose of hippocampal avoidance volume in VMAT was 30% lower than IMRT. Conclusion: This study confirms that dose to hippocampus decreases if patients tilt the head. When treating the whole brain with head tilted, patients can acquire the same successful treatment Result and also preserve their valuable memory.

  7. Quantitative comparison of volumetric modulated arc therapy and intensity modulated radiotherapy plan quality in sino-nasal cancer

    International Nuclear Information System (INIS)

    Sankaralingam, Marimuthu; Glegg, Martin; Smith, Suzanne; James, Allan; Rizwanullah, Mohammed

    2012-01-01

    The aim of this study was to compare various dosimetric parameters of dynamic mlc intensity modulated radiotherapy (IMRT) plans with volumetric modulated arc therapy (VMAT) plans for sino-nasal cancers, which are rare and complex tumors to treat with radiotherapy. IMRT using five fields, coplanar in the sagittal plane and VMAT employing two coplanar arc plans were created for five patients. The plans were assessed by comparing Conformity Index and Sigma Index (dose homogeneity) in the Planning Target Volume (PTV) and through comparison of dose-volume characteristics to the following organs at risk (OARs): Spinal cord, brainstem, eye, ipsilateral and contralateral optic nerve and the volume of brain receiving 10% of the prescribed dose (V 10% ). The total monitor units required to deliver the plan were also compared. Conformity Index was found to be superior in VMAT plans for three patients and in IMRT plans for two patients. Dose homogeneity within the PTV was better with VMAT plans for all five cases. The mean difference in Sigma Index was 0.68%. There was no significant difference in dose between IMRT and VMAT plans for any of the OARs assessed in these patients. The monitor units were significantly reduced in the VMAT plan in comparison to the IMRT plan for four out of five patients, with mean reduction of 66%. It was found in this study that for the treatment of sino-nasal cancer, VMAT produced minimal, and statistically insignificant improvement in dose homogeneity within the PTV when compared with IMRT. VMAT plans were delivered using significantly fewer monitor units. We conclude in this study that VMAT does not offer significant improvement of treatment for sino-nasal cancer over the existing IMRT techniques, but the findings may change with a larger sample of patients in this rare condition. (author)

  8. Trends in intensity modulated radiation therapy use for locally advanced rectal cancer at National Comprehensive Cancer Network centers

    OpenAIRE

    Marsha Reyngold, MD, PhD; Joyce Niland, PhD; Anna ter Veer, MS; Tanios Bekaii-Saab, MD; Lily Lai, MD; Joshua E. Meyer, MD; Steven J. Nurkin, MD, MS; Deborah Schrag, MD, MPH; John M. Skibber, MD, FACS; Al B. Benson, MD; Martin R. Weiser, MD; Christopher H. Crane, MD; Karyn A. Goodman, MD, MS

    2018-01-01

    Purpose: Intensity modulated radiation therapy (IMRT) has been rapidly incorporated into clinical practice because of its technological advantages over 3-dimensional conformal radiation therapy (CRT). We characterized trends in IMRT utilization in trimodality treatment of locally advanced rectal cancer at National Comprehensive Cancer Network cancer centers between 2005 and 2011. Methods and materials: Using the prospective National Comprehensive Cancer Network Colorectal Cancer Database, ...

  9. Prostate Stereotactic Ablative Radiation Therapy Using Volumetric Modulated Arc Therapy to Dominant Intraprostatic Lesions

    International Nuclear Information System (INIS)

    Murray, Louise J.; Lilley, John; Thompson, Christopher M.; Cosgrove, Vivian; Mason, Josh; Sykes, Jonathan; Franks, Kevin; Sebag-Montefiore, David; Henry, Ann M.

    2014-01-01

    Purpose: To investigate boosting dominant intraprostatic lesions (DILs) in the context of stereotactic ablative radiation therapy (SABR) and to examine the impact on tumor control probability (TCP) and normal tissue complication probability (NTCP). Methods and Materials: Ten prostate datasets were selected. DILs were defined using T2-weighted, dynamic contrast-enhanced and diffusion-weighted magnetic resonance imaging. Four plans were produced for each dataset: (1) no boost to DILs; (2) boost to DILs, no seminal vesicles in prescription; (3) boost to DILs, proximal seminal vesicles (proxSV) prescribed intermediate dose; and (4) boost to DILs, proxSV prescribed higher dose. The prostate planning target volume (PTV) prescription was 42.7 Gy in 7 fractions. DILs were initially prescribed 115% of the PTV Prostate prescription, and PTV DIL prescriptions were increased in 5% increments until organ-at-risk constraints were reached. TCP and NTCP calculations used the LQ-Poisson Marsden, and Lyman-Kutcher-Burman models respectively. Results: When treating the prostate alone, the median PTV DIL prescription was 125% (range: 110%-140%) of the PTV Prostate prescription. Median PTV DIL D50% was 55.1 Gy (range: 49.6-62.6 Gy). The same PTV DIL prescriptions and similar PTV DIL median doses were possible when including the proxSV within the prescription. TCP depended on prostate α/β ratio and was highest with an α/β ratio = 1.5 Gy, where the additional TCP benefit of DIL boosting was least. Rectal NTCP increased with DIL boosting and was considered unacceptably high in 5 cases, which, when replanned with an emphasis on reducing maximum dose to 0.5 cm 3 of rectum (Dmax 0.5cc ), as well as meeting existing constraints, resulted in considerable rectal NTCP reductions. Conclusions: Boosting DILs in the context of SABR is technically feasible but should be approached with caution. If this therapy is adopted, strict rectal constraints are required including Dmax 0.5cc . If

  10. Endometrial changes from short-term therapy with CDB-4124, a selective progesterone receptor modulator.

    Science.gov (United States)

    Ioffe, Olga B; Zaino, Richard J; Mutter, George L

    2009-03-01

    Selective progesterone receptor modulators are a class of drugs with progesterone antagonist activity that may confer therapeutic benefit for reproductive disorders in premenopausal women. Endometrial structure, which is dynamically controlled by circulating sex hormones, is likely to be perturbed by progesterone receptor modulators through their progesterone antagonist properties. We examined endometrial histology in 58 premenopausal women treated with the progesterone receptor modulator CDB-4124 (also known as Proellex) for endometriosis or uterine leiomyomata in two clinical trials. Endometrial biopsies obtained after 3 or 6 months with doses of 12.5, 25, or 50 mg daily oral CDB-4124 were reviewed independently by three pathologists. Consensus diagnoses using the World Health Organization hyperplasia scoring system, comments on specific histologic features, and clinical annotation were collected and analyzed. The majority of the endometrial biopsies (103 of 174 biopsies) contained histologic changes that are not seen during normal menstrual cycles. The histology of CDB-4124-treated patients was generally inactive or atrophic, and less frequently, proliferative or secretory, superimposed upon which were novel changes including formation of cystically dilated glands, and secretory changes coexisting with mitoses and apoptotic bodies. With increasing treatment dose and duration, the cysts became predominant and their lining inactive or atrophic. Cystic glands in the CDB-4124-treated subjects correlated with increased endometrial thickness by ultrasound. None of the CDB-4124-treated patients developed endometrial carcinoma or hyperplasia while on therapy. CDB-4124 therapy for 3-6 months produces histologic changes that are sufficiently novel that they might easily be misinterpreted by pathologists, particularly as disordered proliferative or hyperplastic endometrium. Knowledge of the constellation of endometrial changes associated with this agent and other

  11. Radiochromic film in the dosimetric verification of intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Zhou Yingjuan; Huang Shaomin; Deng Xiaowu

    2007-01-01

    Objective: Objective To investigate the dose-response behavior of a new type of radio- chromic film( GAFCHROMIC EBT) and explore the clinical application means and precision of dosage measurement, which can be applied for: (1) plan-specific dosimetric verification for intensity modulated radiation therapy, (2) to simplify the process of quality assurance using traditional radiographic film dosimetric system and (3) to establish a more reliable, more efficient dosimetric verification system for intensity modulated radiation therapy. Methods: (1) The step wedge calibration technique was used to calibrate EBT radiochromic film and EDR2 radiographic film. The dose characteristics, the measurement consistency and the quality assurance process between the two methods were compared. (2) The in-phantom dose-measurement based verification technique has been adopted. Respectively, EBT film and EDR2 film were used to measure the same dose plane of IMRT treatment plans. The results of the dose map, dose profiles and iso- dose curves were compared with those calculated by CORVUS treatment planning system to evaluate the function of EBT film for dosimetric verification for intensity modulated radiation therapy. Results: (1) Over the external beam dosimetric range of 0-500 cGy, EBT/VXR-16 and EDR2/VXR-16 film dosimetric system had the same measurement consistency with the measurement variability less then 0.70%. The mean measurement variability of these two systems was 0.37% and 0.68%, respectively. The former proved to be the superior modality at measurement consistency, reliability, and efficiency over dynamic clinical dose range , furthermore, its quality assurance showed less process than the latter. (2) The dosimetric verification of IMRT plane measured with EBT film was quite similar to that with EDR2 film which was processed under strict quality control. In a plane of the phantom, the maximal dose deviation off axis between EBT film measurement and the TPS calculation was

  12. Evaluation of a mixed beam therapy for post-mastectomy breast cancer patients: bolus electron conformal therapy combined with intensity modulated photon radiotherapy and volumetric modulated photon arc therapy.

    Science.gov (United States)

    Zhang, Rui; Heins, David; Sanders, Mary; Guo, Beibei; Hogstrom, Kenneth

    2018-05-10

    The purpose of this study was to assess the potential benefits and limitations of a mixed beam therapy, which combined bolus electron conformal therapy (BECT) with intensity modulated photon radiotherapy (IMRT) and volumetric modulated photon arc therapy (VMAT), for left-sided post-mastectomy breast cancer patients. Mixed beam treatment plans were produced for nine post-mastectomy radiotherapy (PMRT) patients previously treated at our clinic with VMAT alone. The mixed beam plans consisted of 40 Gy to the chest wall area using BECT, 40 Gy to the supraclavicular area using parallel opposed IMRT, and 10 Gy to the total planning target volume (PTV) by optimizing VMAT on top of the BECT+IMRT dose distribution. The treatment plans were created in a commercial treatment planning system (TPS), and all plans were evaluated based on PTV coverage, dose homogeneity index (DHI), conformity index (CI), dose to organs at risk (OARs), normal tissue complication probability (NTCP), and secondary cancer complication probability (SCCP). The standard VMAT alone planning technique was used as the reference for comparison. Both techniques produced clinically acceptable PMRT plans but with a few significant differences: VMAT showed significantly better CI (0.70 vs. 0.53, p 0.5 cm and volume of tissue between the distal PTV surface and heart or lung approximately > 250 cm 3 ) between distal PTV surface and lung may benefit the most from mixed beam therapy. This work has demonstrated that mixed beam therapy (BECT+IMRT : VMAT = 4 : 1) produces clinically acceptable plans having reduced OAR doses and risks of side effects compared with VMAT. Even though VMAT alone produces more homogenous and conformal dose distributions, mixed beam therapy remains as a viable option for treating post-mastectomy patients, possibly leading to reduced normal tissue complications. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. Hypolipidemic therapy modulates expression of apolipoprotein B (APOB) epitopes on low density lipoproteins (LDL)

    International Nuclear Information System (INIS)

    Kleinman, Y.; Schonfeld, g.; Oshry, Y.; Gevish, d.; Eisenberg, S.

    1986-01-01

    LDL of untreated hypertriglyceridemic (HTG) patients are smaller and enriched in triglycerides and proteins compared with normal LDL. HTG-LDL also bind defectively to the LDL receptor of cultured human fibroblasts. These defects are reversible by hypolipidemic therapy. The authors tested the hypothesis that LDL binding to cells may be altered by modulation of apoB epitopes on the surface of LDL. Fasting plasma samples were obtained from 5 HTG patients before and three weeks after bezafibrate therapy when mean triglyceride levels were 436 and 157 mg/dl, respectively (p 50 values of LDL with Mab B1B3 fell from 6.0 to 3.2 μg LDL protein (p 50 did not change with Mab D7.1. Thus, the improved interaction of LDL is related to the altered disposition of apoB on LDL

  14. Modulation of porcine biotransformation enzymes by anthelmintic therapy with fenbendazole and flubendazole.

    Science.gov (United States)

    Savlík, M; Fimanová, K; Szotáková, B; Lamka, J; Skálová, L

    2006-06-01

    Fenbendazole (FEN) and flubendazole (FLU) are benzimidazole anthelmintics often used in pig management for the control of nematodoses. The in vivo study presented here was designed to test the influence of FLU and FEN on cytochrome P4501A and other cytochrome P450 (CYP) isoforms, UDP-glucuronosyl transferase and several carbonyl reducing enzymes. The results indicated that FEN (in a single therapeutic dose as well as in repeated therapeutic doses) caused significant induction of pig CYP1A, while FLU did not show an inductive effect towards this isoform. Some of the other hepatic and intestinal biotransformation enzymes that were assayed were moderately influenced by FEN or FLU. Strong CYP1A induction following FEN therapy in pigs may negatively affect the efficacy and pharmacokinetics of FEN itself or other simultaneously or consecutively administered drugs. From the perspective of biotransformation enzyme modulation, FLU would appear to be a more convenient anthelmintic therapy of pigs than FEN.

  15. A Florescence Detection Module for Photodynamic Therapy Optimization by Measuring the Concentration of Photo sensitizer

    International Nuclear Information System (INIS)

    Serrano Navarro, Joel; Stolik Isakina, Suren; La Rosa Vazquez, Jose M. de; Valor Reed, Alma

    2016-01-01

    In the present work, a portable fluorescence detection system designed and built for dosimetry control applications in Photodynamic Therapy is presented. The system excites the used photo sensitizer drug with a modulated laser light source and subsequently measures the radiance of the emitted fluorescent light. Since the fluorescent radiance is directly related to the photosensitizers concentration, this measurement allows for real-time monitoring of the photo sensitizer concentration in the treated tissue. The system is thought to permit adjusting the therapeutic regime in order to optimize the expected therapy results. In the developed system, a synchronous detection technique is employed to recover the fluorescence signals embedded in noisy backgrounds and lit environments. A scanning probe with a 405 nm diode laser is used to excite the photo sensitizer, while a detection wavelength range from 590 nm to 700 nm has been implemented. (Author)

  16. Two-Body B Meson Decays to {eta} and {eta}{sup '} : Observation of B {yields} {eta}K{sup *}

    Energy Technology Data Exchange (ETDEWEB)

    Richichi, S. J. [University of Oklahoma, Norman, Oklahoma 73019 (United States); Severini, H. [University of Oklahoma, Norman, Oklahoma 73019 (United States); Skubic, P. [University of Oklahoma, Norman, Oklahoma 73019 (United States); Undrus, A. [University of Oklahoma, Norman, Oklahoma 73019 (United States); Chen, S. [Purdue University, West Lafayette, Indiana 47907 (United States); Fast, J. [Purdue University, West Lafayette, Indiana 47907 (United States); Hinson, J. W. [Purdue University, West Lafayette, Indiana 47907 (United States); Lee, J. [Purdue University, West Lafayette, Indiana 47907 (United States); Menon, N. [Purdue University, West Lafayette, Indiana 47907 (United States); Miller, D. H. [Purdue University, West Lafayette, Indiana 47907 (United States)] (and others)

    2000-07-17

    In a sample of 19x10{sup 6} produced B mesons, we have observed the decays B{yields}{eta}K{sup *} and improved our previous measurements of B{yields}{eta}{sup '}K . The branching fractions we measure for these decay modes are B(B{sup +}{yields}{eta}K{sup *+}) =(26.4{sup +9.6}{sub -8.2}{+-}3.3)x 10{sup -6} , B(B{sup 0}{yields}{eta}K{sup *0}) =(13.8{sup +5.5}{sub -4.6}{+-}1.6)x 10{sup -6} , B(B{sup +}{yields}{eta}{sup '} K{sup +})=(80{sup +10}{sub -9}{+-} 7)x10{sup -6} , and B(B{sup 0}{yields}{eta}{sup '} K{sup 0})=(89{sup +18}{sub -16}{+-} 9)x10{sup -6} . We have searched with comparable sensitivity for related decays and report upper limits for these branching fractions. (c) 2000 The American Physical Society.

  17. TH-AB-BRB-01: Trajectory Modulated Arc Therapy: Application to Partial Breast Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hristov, D. [Stanford University Cancer Center (United States)

    2016-06-15

    Current state-of-the art digital C-arm medical linear accelerators are capable of delivering radiation treatments with high level of automation, which affords coordinated motions of gantry, couch, and multileaf collimator (MLC) with dose rate modulations. The new machine capacity has shown the potential to bring substantially improved radiation dosimetry and/or delivery efficiency to many challenging diseases. Combining an integrated beam orientation optimization algorithm with automated machine navigation, markedly improved dose conformity has been achieved using 4ρ therapy. Trajectory modulated radiation therapy (TMAT) can be used to deliver highly conformal dose to partial breast or to carve complex dose distribution for therapy involving extended volumes such as total marrow and total lymph node treatment. Dynamic electron arc radiotherapy (DEAR) not only overcomes the deficiencies of conventional electron therapy in dose conformity and homogeneity but also achieves so without patient-specific shields. The combination of MLC and couch tracking provides improved motion management of thoracic and abdominal tumors. A substantial body of work has been done in these technological advances for clinical translation. The proposed symposium will provide a timely review of these exciting opportunities. Learning Objectives: Recognize the potential of using digitally controlled linacs for clinically significant improvements in delivered dose distributions for various treatment sites. Identify existing approaches to treatment planning, optimization and delivery for treatment techniques utilizing the advanced functions of digital linacs and venues for further development and improvement. Understand methods for testing and validating delivery system performance. Identify tools available on current delivery systems for implementation and control for such treatments. Obtain the update in clinical applications, trials and regulatory approval. K. Sheng, NIH U19AI067769, NIH R43

  18. TH-AB-BRB-01: Trajectory Modulated Arc Therapy: Application to Partial Breast Irradiation

    International Nuclear Information System (INIS)

    Hristov, D.

    2016-01-01

    Current state-of-the art digital C-arm medical linear accelerators are capable of delivering radiation treatments with high level of automation, which affords coordinated motions of gantry, couch, and multileaf collimator (MLC) with dose rate modulations. The new machine capacity has shown the potential to bring substantially improved radiation dosimetry and/or delivery efficiency to many challenging diseases. Combining an integrated beam orientation optimization algorithm with automated machine navigation, markedly improved dose conformity has been achieved using 4ρ therapy. Trajectory modulated radiation therapy (TMAT) can be used to deliver highly conformal dose to partial breast or to carve complex dose distribution for therapy involving extended volumes such as total marrow and total lymph node treatment. Dynamic electron arc radiotherapy (DEAR) not only overcomes the deficiencies of conventional electron therapy in dose conformity and homogeneity but also achieves so without patient-specific shields. The combination of MLC and couch tracking provides improved motion management of thoracic and abdominal tumors. A substantial body of work has been done in these technological advances for clinical translation. The proposed symposium will provide a timely review of these exciting opportunities. Learning Objectives: Recognize the potential of using digitally controlled linacs for clinically significant improvements in delivered dose distributions for various treatment sites. Identify existing approaches to treatment planning, optimization and delivery for treatment techniques utilizing the advanced functions of digital linacs and venues for further development and improvement. Understand methods for testing and validating delivery system performance. Identify tools available on current delivery systems for implementation and control for such treatments. Obtain the update in clinical applications, trials and regulatory approval. K. Sheng, NIH U19AI067769, NIH R43

  19. Carcinoma of the anal canal: Intensity modulated radiation therapy (IMRT) versus three-dimensional conformal radiation therapy (3DCRT)

    Science.gov (United States)

    Sale, Charlotte; Moloney, Phillip; Mathlum, Maitham

    2013-01-01

    Introduction Patients with anal canal carcinoma treated with standard conformal radiotherapy frequently experience severe acute and late toxicity reactions to the treatment area. Roohipour et al. (Dis Colon Rectum 2008; 51: 147–53) stated a patient's tolerance of chemoradiation to be an important prediction of treatment success. A new intensity modulated radiation therapy (IMRT) technique for anal carcinoma cases has been developed at the Andrew Love Cancer Centre aimed at reducing radiation to surrounding healthy tissue. Methods A same-subject repeated measures design was used for this study, where five anal carcinoma cases at the Andrew Love Cancer Centre were selected. Conformal and IMRT plans were generated and dosimetric evaluations were performed. Each plan was prescribed a total of 54 Gray (Gy) over a course of 30 fractions to the primary site. Results The IMRT plans resulted in improved dosimetry to the planning target volume (PTV) and reduction in radiation to the critical structures (bladder, external genitalia and femoral heads). Statistically there was no difference between the IMRT and conformal plans in the dose to the small and large bowel; however, the bowel IMRT dose–volume histogram (DVH) doses were consistently lower. Conclusion The IMRT plans were superior to the conformal plans with improved dose conformity and reduced radiation to the surrounding healthy tissue. Anecdotally it was found that patients tolerated the IMRT treatment better than the three-dimensional (3D) conformal radiation therapy. This study describes and compares the planning techniques. PMID:26229623

  20. Carcinoma of the anal canal: Intensity modulated radiation therapy (IMRT) versus three-dimensional conformal radiation therapy (3DCRT)

    International Nuclear Information System (INIS)

    Sale, Charlotte; Moloney, Phillip; Mathlum, Maitham

    2013-01-01

    Patients with anal canal carcinoma treated with standard conformal radiotherapy frequently experience severe acute and late toxicity reactions to the treatment area. Roohipour et al. (Dis Colon Rectum 2008; 51: 147–53) stated a patient's tolerance of chemoradiation to be an important prediction of treatment success. A new intensity modulated radiation therapy (IMRT) technique for anal carcinoma cases has been developed at the Andrew Love Cancer Centre aimed at reducing radiation to surrounding healthy tissue. A same-subject repeated measures design was used for this study, where five anal carcinoma cases at the Andrew Love Cancer Centre were selected. Conformal and IMRT plans were generated and dosimetric evaluations were performed. Each plan was prescribed a total of 54 Gray (Gy) over a course of 30 fractions to the primary site. The IMRT plans resulted in improved dosimetry to the planning target volume (PTV) and reduction in radiation to the critical structures (bladder, external genitalia and femoral heads). Statistically there was no difference between the IMRT and conformal plans in the dose to the small and large bowel; however, the bowel IMRT dose–volume histogram (DVH) doses were consistently lower. The IMRT plans were superior to the conformal plans with improved dose conformity and reduced radiation to the surrounding healthy tissue. Anecdotally it was found that patients tolerated the IMRT treatment better than the three-dimensional (3D) conformal radiation therapy. This study describes and compares the planning techniques

  1. Carcinoma of the anal canal: Intensity modulated radiation therapy (IMRT) versus three-dimensional conformal radiation therapy (3DCRT).

    Science.gov (United States)

    Sale, Charlotte; Moloney, Phillip; Mathlum, Maitham

    2013-12-01

    Patients with anal canal carcinoma treated with standard conformal radiotherapy frequently experience severe acute and late toxicity reactions to the treatment area. Roohipour et al. (Dis Colon Rectum 2008; 51: 147-53) stated a patient's tolerance of chemoradiation to be an important prediction of treatment success. A new intensity modulated radiation therapy (IMRT) technique for anal carcinoma cases has been developed at the Andrew Love Cancer Centre aimed at reducing radiation to surrounding healthy tissue. A same-subject repeated measures design was used for this study, where five anal carcinoma cases at the Andrew Love Cancer Centre were selected. Conformal and IMRT plans were generated and dosimetric evaluations were performed. Each plan was prescribed a total of 54 Gray (Gy) over a course of 30 fractions to the primary site. The IMRT plans resulted in improved dosimetry to the planning target volume (PTV) and reduction in radiation to the critical structures (bladder, external genitalia and femoral heads). Statistically there was no difference between the IMRT and conformal plans in the dose to the small and large bowel; however, the bowel IMRT dose-volume histogram (DVH) doses were consistently lower. The IMRT plans were superior to the conformal plans with improved dose conformity and reduced radiation to the surrounding healthy tissue. Anecdotally it was found that patients tolerated the IMRT treatment better than the three-dimensional (3D) conformal radiation therapy. This study describes and compares the planning techniques.

  2. Carcinoma of the anal canal: Intensity modulated radiation therapy (IMRT) versus three-dimensional conformal radiation therapy (3DCRT)

    Energy Technology Data Exchange (ETDEWEB)

    Sale, Charlotte; Moloney, Phillip; Mathlum, Maitham [Andrew Love Cancer Centre, Geelong Hospital, Geelong, Victoria (Australia)

    2013-12-15

    Patients with anal canal carcinoma treated with standard conformal radiotherapy frequently experience severe acute and late toxicity reactions to the treatment area. Roohipour et al. (Dis Colon Rectum 2008; 51: 147–53) stated a patient's tolerance of chemoradiation to be an important prediction of treatment success. A new intensity modulated radiation therapy (IMRT) technique for anal carcinoma cases has been developed at the Andrew Love Cancer Centre aimed at reducing radiation to surrounding healthy tissue. A same-subject repeated measures design was used for this study, where five anal carcinoma cases at the Andrew Love Cancer Centre were selected. Conformal and IMRT plans were generated and dosimetric evaluations were performed. Each plan was prescribed a total of 54 Gray (Gy) over a course of 30 fractions to the primary site. The IMRT plans resulted in improved dosimetry to the planning target volume (PTV) and reduction in radiation to the critical structures (bladder, external genitalia and femoral heads). Statistically there was no difference between the IMRT and conformal plans in the dose to the small and large bowel; however, the bowel IMRT dose–volume histogram (DVH) doses were consistently lower. The IMRT plans were superior to the conformal plans with improved dose conformity and reduced radiation to the surrounding healthy tissue. Anecdotally it was found that patients tolerated the IMRT treatment better than the three-dimensional (3D) conformal radiation therapy. This study describes and compares the planning techniques.

  3. Automated Volumetric Modulated Arc Therapy Treatment Planning for Stage III Lung Cancer: How Does It Compare With Intensity-Modulated Radio Therapy?

    Energy Technology Data Exchange (ETDEWEB)

    Quan, Enzhuo M. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Chang, Joe Y.; Liao Zhongxing [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Xia Tingyi [Department of Radiation Oncology, Beijing 301 Hospital, Beijing (China); Yuan Zhiyong [Department of Radiation Oncology, Tianjin Medical University Cancer Hospital and Institute, Tianjin (China); Liu Hui [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Oncology, Zhongshan University Hospital, Guangzhou (China); Li, Xiaoqiang; Wages, Cody A.; Mohan, Radhe [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhang Xiaodong, E-mail: xizhang@mdanderson.org [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2012-09-01

    Purpose: To compare the quality of volumetric modulated arc therapy (VMAT) or intensity-modulated radiation therapy (IMRT) plans generated by an automated inverse planning system with that of dosimetrist-generated IMRT treatment plans for patients with stage III lung cancer. Methods and Materials: Two groups of 8 patients with stage III lung cancer were randomly selected. For group 1, the dosimetrists spent their best effort in designing IMRT plans to compete with the automated inverse planning system (mdaccAutoPlan); for group 2, the dosimetrists were not in competition and spent their regular effort. Five experienced radiation oncologists independently blind-reviewed and ranked the three plans for each patient: a rank of 1 was the best and 3 was the worst. Dosimetric measures were also performed to quantitatively evaluate the three types of plans. Results: Blind rankings from different oncologists were generally consistent. For group 1, the auto-VMAT, auto-IMRT, and manual IMRT plans received average ranks of 1.6, 2.13, and 2.18, respectively. The auto-VMAT plans in group 1 had 10% higher planning tumor volume (PTV) conformality and 24% lower esophagus V70 (the volume receiving 70 Gy or more) than the manual IMRT plans; they also resulted in more than 20% higher complication-free tumor control probability (P+) than either type of IMRT plans. The auto- and manual IMRT plans in this group yielded generally comparable dosimetric measures. For group 2, the auto-VMAT, auto-IMRT, and manual IMRT plans received average ranks of 1.55, 1.75, and 2.75, respectively. Compared to the manual IMRT plans in this group, the auto-VMAT plans and auto-IMRT plans showed, respectively, 17% and 14% higher PTV dose conformality, 8% and 17% lower mean lung dose, 17% and 26% lower mean heart dose, and 36% and 23% higher P+. Conclusions: mdaccAutoPlan is capable of generating high-quality VMAT and IMRT treatment plans for stage III lung cancer. Manual IMRT plans could achieve quality

  4. Automated Volumetric Modulated Arc Therapy Treatment Planning for Stage III Lung Cancer: How Does It Compare With Intensity-Modulated Radio Therapy?

    International Nuclear Information System (INIS)

    Quan, Enzhuo M.; Chang, Joe Y.; Liao Zhongxing; Xia Tingyi; Yuan Zhiyong; Liu Hui; Li, Xiaoqiang; Wages, Cody A.; Mohan, Radhe; Zhang Xiaodong

    2012-01-01

    Purpose: To compare the quality of volumetric modulated arc therapy (VMAT) or intensity-modulated radiation therapy (IMRT) plans generated by an automated inverse planning system with that of dosimetrist-generated IMRT treatment plans for patients with stage III lung cancer. Methods and Materials: Two groups of 8 patients with stage III lung cancer were randomly selected. For group 1, the dosimetrists spent their best effort in designing IMRT plans to compete with the automated inverse planning system (mdaccAutoPlan); for group 2, the dosimetrists were not in competition and spent their regular effort. Five experienced radiation oncologists independently blind-reviewed and ranked the three plans for each patient: a rank of 1 was the best and 3 was the worst. Dosimetric measures were also performed to quantitatively evaluate the three types of plans. Results: Blind rankings from different oncologists were generally consistent. For group 1, the auto-VMAT, auto-IMRT, and manual IMRT plans received average ranks of 1.6, 2.13, and 2.18, respectively. The auto-VMAT plans in group 1 had 10% higher planning tumor volume (PTV) conformality and 24% lower esophagus V70 (the volume receiving 70 Gy or more) than the manual IMRT plans; they also resulted in more than 20% higher complication-free tumor control probability (P+) than either type of IMRT plans. The auto- and manual IMRT plans in this group yielded generally comparable dosimetric measures. For group 2, the auto-VMAT, auto-IMRT, and manual IMRT plans received average ranks of 1.55, 1.75, and 2.75, respectively. Compared to the manual IMRT plans in this group, the auto-VMAT plans and auto-IMRT plans showed, respectively, 17% and 14% higher PTV dose conformality, 8% and 17% lower mean lung dose, 17% and 26% lower mean heart dose, and 36% and 23% higher P+. Conclusions: mdaccAutoPlan is capable of generating high-quality VMAT and IMRT treatment plans for stage III lung cancer. Manual IMRT plans could achieve quality

  5. Modulating Cytotoxic Effector Functions by Fc Engineering to Improve Cancer Therapy.

    Science.gov (United States)

    Kellner, Christian; Otte, Anna; Cappuzzello, Elisa; Klausz, Katja; Peipp, Matthias

    2017-09-01

    In the last two decades, monoclonal antibodies have revolutionized the therapy of cancer patients. Although antibody therapy has continuously been improved, still a significant number of patients do not benefit from antibody therapy. Therefore, rational optimization of the antibody molecule by Fc engineering represents a major area of translational research to further improve this potent therapeutic option. Monoclonal antibodies are able to trigger a variety of effector mechanisms. Especially Fc-mediated effector functions such as antibody-dependent cell-mediated cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), and complement- dependent cytotoxicity (CDC) are considered important in antibody therapy of cancer. Novel mechanistic insights into the action of monoclonal antibodies allowed the development of various Fc engineering approaches to modulate antibodies' effector functions. Strategies in modifying the Fc glycosylation profile (Fc glyco-engineering) or approaches in engineering the protein backbone (Fc protein engineering) have been intensively evaluated. In the current review, Fc engineering strategies resulting in improved ADCC, ADCP and CDC activity are summarized and discussed.

  6. Intensity-modulated proton therapy, volumetric-modulated arc therapy, and 3D conformal radiotherapy in anaplastic astrocytoma and glioblastoma. A dosimetric comparison

    Energy Technology Data Exchange (ETDEWEB)

    Adeberg, S.; Debus, J. [Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg (Germany); Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg (Germany); University Hospital Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); German Cancer Research Center (DKFZ), Clinical Cooperation Unit Radiation Oncology, Heidelberg (Germany); Harrabi, S.B.; Bougatf, N.; Rieber, J.; Koerber, S.A.; Herfarth, K.; Rieken, S. [Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg (Germany); Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg (Germany); University Hospital Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); Bernhardt, D.; Syed, M.; Sprave, T.; Mohr, A. [Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg (Germany); University Hospital Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); Abdollahi, A. [University Hospital Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); Haberer, T. [Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg (Germany); Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg (Germany); Combs, S.E. [Technische Universitaet Muenchen, Department of Radiation Oncology, Muenchen (Germany); Helmholtz Zentrum Muenchen, Institut fuer Innovative Radiotherapie (iRT), Department of Radiation Sciences (DRS), Neuherberg (Germany)

    2016-11-15

    The prognosis for high-grade glioma (HGG) patients is poor; thus, treatment-related side effects need to be minimized to conserve quality of life and functionality. Advanced techniques such as proton radiation therapy (PRT) and volumetric-modulated arc therapy (VMAT) may potentially further reduce the frequency and severity of radiogenic impairment. We retrospectively assessed 12 HGG patients who had undergone postoperative intensity-modulated proton therapy (IMPT). VMAT and 3D conformal radiotherapy (3D-CRT) plans were generated and optimized for comparison after contouring crucial neuronal structures important for neurogenesis and neurocognitive function. Integral dose (ID), homogeneity index (HI), and inhomogeneity coefficient (IC) were calculated from dose statistics. Toxicity data were evaluated. Target volume coverage was comparable for all three modalities. Compared to 3D-CRT and VMAT, PRT showed statistically significant reductions (p < 0.05) in mean dose to whole brain (-20.2 %, -22.7 %); supratentorial (-14.2 %, -20,8 %) and infratentorial (-91.0 %, -77.0 %) regions; brainstem (-67.6 %, -28.1 %); pituitary gland (-52.9 %, -52.5 %); contralateral hippocampus (-98.9 %, -98.7 %); and contralateral subventricular zone (-62.7 %, -66.7 %, respectively). Fatigue (91.7 %), radiation dermatitis (75.0 %), focal alopecia (100.0 %), nausea (41.7 %), cephalgia (58.3 %), and transient cerebral edema (16.7 %) were the most common acute toxicities. Essential dose reduction while maintaining equal target volume coverage was observed using PRT, particularly in contralaterally located critical neuronal structures, areas of neurogenesis, and structures of neurocognitive functions. These findings were supported by preliminary clinical results confirming the safety and feasibility of PRT in HGG. (orig.) [German] Die Prognose bei ''High-grade''-Gliomen (HGG) ist infaust. Gerade bei diesen Patienten sollten therapieassoziierte Nebenwirkungen minimiert werden

  7. Dosimetric comparison of intensity modulated radiation, Proton beam therapy and proton arc therapy for para-aortic lymph node tumor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Hoon [Dept. of Radiation Oncology, Konyang University Hospital. Daejeon (Korea, Republic of)

    2014-12-15

    To test feasibility of proton arc therapy (PAT) in the treatment of para-aortic lymph node tumor and compare its dosimetric properties with advanced radiotherapy techniques such as intensity modulated radiation therapy (IMRT) and conventional 3D conformal proton beam therapy (PBT). The treatment plans for para-aortic lymph node tumor were planned for 9 patients treated at our institution using IMRT, PBT, and PAT. Feasibility test and dosimetric evaluation were based on comparisons of dose volume histograms (DVHs) which reveal mean dose, D{sub 30%}, D{sub 60%}, D{sub 90%}, V{sub 30%}, V{sub 60%}, V{sub 90}%, organ equivalent doses (OEDs), normal tissue complication probability (NTCP), homogeneity index (HI) and conformity index (CI). The average doses delivered by PAT to the liver, kidney, small bowel, duodenum, stomach were 7.6%, 3%, 17.3%, 26.7%, and 14.4%, of the prescription dose (PD), respectively, which is higher than the doses delivered by IMRT (0.4%, 7.2%, 14.2%, 15.9%, and 12.8%, respectively) and PBT (4.9%, 0.5%, 14.12%, 16.1% 9.9%, respectively). The average homogeneity index and conformity index of tumor using PAT were 12.1 and 1.21, respectively which were much better than IMRT (21.5 and 1.47, respectively) and comparable to PBT (13.1 and 1.23, respectively). The result shows that both NTCP and OED of PAT are generally lower than IMRT and PBT. This study demonstrates that PAT is better in target conformity and homogeneity than IMRT and PBT but worse than IMRT and PBT for most of dosimetric factor which indicate that PAT is not recommended for the treatment of para-aortic lymph node tumor.

  8. Imaging Changes in Pediatric Intracranial Ependymoma Patients Treated With Proton Beam Radiation Therapy Compared to Intensity Modulated Radiation Therapy

    International Nuclear Information System (INIS)

    Gunther, Jillian R.; Sato, Mariko; Chintagumpala, Murali; Ketonen, Leena; Jones, Jeremy Y.; Allen, Pamela K.; Paulino, Arnold C.; Okcu, M. Fatih; Su, Jack M.; Weinberg, Jeffrey; Boehling, Nicholas S.; Khatua, Soumen; Adesina, Adekunle; Dauser, Robert; Whitehead, William E.; Mahajan, Anita

    2015-01-01

    Purpose: The clinical significance of magnetic resonance imaging (MRI) changes after radiation therapy (RT) in children with ependymoma is not well defined. We compared imaging changes following proton beam radiation therapy (PBRT) to those after photon-based intensity modulated RT (IMRT). Methods and Materials: Seventy-two patients with nonmetastatic intracranial ependymoma who received postoperative RT (37 PBRT, 35 IMRT) were analyzed retrospectively. MRI images were reviewed by 2 neuroradiologists. Results: Sixteen PBRT patients (43%) developed postradiation MRI changes at 3.8 months (median) with resolution by 6.1 months. Six IMRT patients (17%) developed changes at 5.3 months (median) with 8.3 months to resolution. Mean age at radiation was 4.4 and 6.9 years for PBRT and IMRT, respectively (P=.06). Age at diagnosis (>3 years) and time of radiation (≥3 years) was associated with fewer imaging changes on univariate analysis (odds ratio [OR]: 0.35, P=.048; OR: 0.36, P=.05). PBRT (compared to IMRT) was associated with more frequent imaging changes, both on univariate (OR: 3.68, P=.019) and multivariate (OR: 3.89, P=.024) analyses. Seven (3 IMRT, 4 PBRT) of 22 patients with changes had symptoms requiring intervention. Most patients were treated with steroids; some PBRT patients also received bevacizumab and hyperbaric oxygen therapy. None of the IMRT patients had lasting deficits, but 2 patients died from recurrent disease. Three PBRT patients had persistent neurological deficits, and 1 child died secondarily to complications from radiation necrosis. Conclusions: Postradiation MRI changes are more common with PBRT and in patients less than 3 years of age at diagnosis and treatment. It is difficult to predict causes for development of imaging changes that progress to clinical significance. These changes are usually self-limiting, but some require medical intervention, especially those involving the brainstem

  9. Outcome of three-dimensional conformal radiation therapy and intensity-modulated radiation therapy for inoperable locally advanced pancreatic cancer

    International Nuclear Information System (INIS)

    Lu Ningning; Jin Jing; Li Yexiong; Yu Zihao; Liu Xinfan; Wang Weihu; Wang Shulian; Song Yongwen; Liu Yuping

    2009-01-01

    Objective: To evaluate the outcome of radiotherapy for locally advanced pancreatic cancer. Methods: From January 2000 to December 2007, 41 patients with inoperable locally advanced (stage III) pancreatic cancer were treated with three-dimensional conformal radiation therapy(3DCRT) or intensity-modulated radiation therapy (IMRT). Among these patients, 30 received concurrent radio-chemo-therapy. Results: The median survival time(MST) and 1-year overall survival were 9.2 months and 23%. Patients with pretreatment KPS ≥ 80, no regional lymph nodes metastasis, and CR/PR after radiotherapy had better prognosis. The corresponding MSTs were 11.1 months vs 5.8 months (χ 2 =7.50, P=0.006), 10.8 months vs 6.5 months(χ 2 =5.67, P=0.017), and 19.5 months vs 9.1 months (χ 2 =7.28, P=0.007), respectively. Concurrent radio-chemotherapy tended to improve the overall survival(χ 2 =3.25, P=0.072). After radiotherapy, 18 patients had clinical benefit response, mainly being abdominal pain relief. Neither grade 4 hematologic nor grade 3 non-hematologic toxicities were observed. Conclusions: For patients with locally advanced pancreatic cancer, both 3DCRT and IMRT are effective in alleviation of disease-related symptoms. Patients with better performance status before treatment, no regional lymph nodes metastasis, and better response to radiotherapy may have better prognosis. Concurrent radio-chemotherapy trend to improve overall survival when compared with radiotherapy alone. (authors)

  10. Intensity modulated radiation therapy using laser-accelerated protons: a Monte Carlo dosimetric study

    International Nuclear Information System (INIS)

    Fourkal, E; Li, J S; Xiong, W; Nahum, A; Ma, C-M

    2003-01-01

    In this paper we present Monte Carlo studies of intensity modulated radiation therapy using laser-accelerated proton beams. Laser-accelerated protons coming out of a solid high-density target have broad energy and angular spectra leading to dose distributions that cannot be directly used for therapeutic applications. Through the introduction of a spectrometer-like particle selection system that delivers small pencil beams of protons with desired energy spectra it is feasible to use laser-accelerated protons for intensity modulated radiotherapy. The method presented in this paper is a three-dimensional modulation in which the proton energy spectrum and intensity of each individual beamlet are modulated to yield a homogeneous dose in both the longitudinal and lateral directions. As an evaluation of the efficacy of this method, it has been applied to two prostate cases using a variety of beam arrangements. We have performed a comparison study between intensity modulated photon plans and those for laser-accelerated protons. For identical beam arrangements and the same optimization parameters, proton plans exhibit superior coverage of the target and sparing of neighbouring critical structures. Dose-volume histogram analysis of the resulting dose distributions shows up to 50% reduction of dose to the critical structures. As the number of fields is decreased, the proton modality exhibits a better preservation of the optimization requirements on the target and critical structures. It is shown that for a two-beam arrangement (parallel-opposed) it is possible to achieve both superior target coverage with 5% dose inhomogeneity within the target and excellent sparing of surrounding tissue

  11. High gain free electron laser at ETA

    International Nuclear Information System (INIS)

    Orzechowski, T.J.; Prosnitz, D.; Halbach, K.

    1983-01-01

    A single pass, tapered electron wiggler and associated beam transport has been constructed at the Experimental Test Accelerator (ETA) at Lawrence Livermore National Laboratory (LLNL). The system is designed to transport 1 kA of 4.5 MeV electrons with an emittance of 30 millirad-cm. The planar wiggler is provided by a pulsed electromagnet. The interaction region is an oversized rectangular waveguide. Quadrupole fields stabilize the beam in the plane parallel to the wiggler field. The 3 meter long wiggler has a 9.8 cm period. The Free Electron Laser (FEL) will serve as an amplifier for input frequencies of 35 GHz and 140 GHz. The facility is designed to produce better than 500 Megawatts peak power

  12. Structure and mechanism of human DNA polymerase [eta

    Energy Technology Data Exchange (ETDEWEB)

    Biertümpfel, Christian; Zhao, Ye; Kondo, Yuji; Ramón-Maiques, Santiago; Gregory, Mark; Lee, Jae Young; Masutani, Chikahide; Lehmann, Alan R.; Hanaoka, Fumio; Yang, Wei (Sussex); (NIH); (Gakushuin); (Osaka)

    2010-11-03

    The variant form of the human syndrome xeroderma pigmentosum (XPV) is caused by a deficiency in DNA polymerase {eta} (Pol{eta}), a DNA polymerase that enables replication through ultraviolet-induced pyrimidine dimers. Here we report high-resolution crystal structures of human Pol{eta} at four consecutive steps during DNA synthesis through cis-syn cyclobutane thymine dimers. Pol{eta} acts like a 'molecular splint' to stabilize damaged DNA in a normal B-form conformation. An enlarged active site accommodates the thymine dimer with excellent stereochemistry for two-metal ion catalysis. Two residues conserved among Pol{eta} orthologues form specific hydrogen bonds with the lesion and the incoming nucleotide to assist translesion synthesis. On the basis of the structures, eight Pol{eta} missense mutations causing XPV can be rationalized as undermining the molecular splint or perturbing the active-site alignment. The structures also provide an insight into the role of Pol{eta} in replicating through D loop and DNA fragile sites.

  13. Validation of intensity modulated radiation therapy patient plans with portal images

    International Nuclear Information System (INIS)

    Delpon, G.; Warren, S.; Mahe, D.; Gaudaire, S.; Lisbona, A.

    2007-01-01

    The goal of this study was to show the feasibility of step and shoot intensity-modulated radiation therapy pre-treatment quality control for patients using the electronic portal imaging device (iViewGT) fitted on a Sli+ linac (Elekta Oncology Systems, Crawley, UK) instead of radiographic films. Since the beginning of intensity-modulated radiation therapy treatments, the dosimetric quality control necessary before treating each new patient has been a time-consuming and therefore costly obligation. In order to fully develop this technique, it seems absolutely essential to reduce the cost of these controls, especially the linac time. Up to now, verification of the relative dosimetry field by field has been achieved by acquiring radiographic films in the isocenter plane and comparing them to the results of the XiO planning system (Computerized Medical Systems, Missouri, USA) using RIT113 v4.1 software (Radiological Imaging Technology, Colorado, USA). A qualitative and quantitative evaluation was realised for every field of every patient. A quick and simple procedure was put into place to be able to make the same verifications using portal images. This new technique is not a modification of the overall methodology of analysis. The results achieved by comparing the measurement with the electronic portal imaging device and the calculation with the treatment planning system were in line with those achieved with the films for all indicators we studied (isodoses, horizontal and vertical dose profiles and gamma index). (authors)

  14. Genome-wide RNAi Screening to Identify Host Factors That Modulate Oncolytic Virus Therapy.

    Science.gov (United States)

    Allan, Kristina J; Mahoney, Douglas J; Baird, Stephen D; Lefebvre, Charles A; Stojdl, David F

    2018-04-03

    High-throughput genome-wide RNAi (RNA interference) screening technology has been widely used for discovering host factors that impact virus replication. Here we present the application of this technology to uncovering host targets that specifically modulate the replication of Maraba virus, an oncolytic rhabdovirus, and vaccinia virus with the goal of enhancing therapy. While the protocol has been tested for use with oncolytic Maraba virus and oncolytic vaccinia virus, this approach is applicable to other oncolytic viruses and can also be utilized for identifying host targets that modulate virus replication in mammalian cells in general. This protocol describes the development and validation of an assay for high-throughput RNAi screening in mammalian cells, the key considerations and preparation steps important for conducting a primary high-throughput RNAi screen, and a step-by-step guide for conducting a primary high-throughput RNAi screen; in addition, it broadly outlines the methods for conducting secondary screen validation and tertiary validation studies. The benefit of high-throughput RNAi screening is that it allows one to catalogue, in an extensive and unbiased fashion, host factors that modulate any aspect of virus replication for which one can develop an in vitro assay such as infectivity, burst size, and cytotoxicity. It has the power to uncover biotherapeutic targets unforeseen based on current knowledge.

  15. Linear Energy Transfer-Guided Optimization in Intensity Modulated Proton Therapy: Feasibility Study and Clinical Potential

    Energy Technology Data Exchange (ETDEWEB)

    Giantsoudi, Drosoula, E-mail: dgiantsoudi@partners.org [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Grassberger, Clemens; Craft, David; Niemierko, Andrzej; Trofimov, Alexei; Paganetti, Harald [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States)

    2013-09-01

    Purpose: To investigate the feasibility and potential clinical benefit of linear energy transfer (LET) guided plan optimization in intensity modulated proton therapy (IMPT). Methods and Materials: A multicriteria optimization (MCO) module was used to generate a series of Pareto-optimal IMPT base plans (BPs), corresponding to defined objectives, for 5 patients with head-and-neck cancer and 2 with pancreatic cancer. A Monte Carlo platform was used to calculate dose and LET distributions for each BP. A custom-designed MCO navigation module allowed the user to interpolate between BPs to produce deliverable Pareto-optimal solutions. Differences among the BPs were evaluated for each patient, based on dose–volume and LET–volume histograms and 3-dimensional distributions. An LET-based relative biological effectiveness (RBE) model was used to evaluate the potential clinical benefit when navigating the space of Pareto-optimal BPs. Results: The mean LET values for the target varied up to 30% among the BPs for the head-and-neck patients and up to 14% for the pancreatic cancer patients. Variations were more prominent in organs at risk (OARs), where mean LET values differed by a factor of up to 2 among the BPs for the same patient. An inverse relation between dose and LET distributions for the OARs was typically observed. Accounting for LET-dependent variable RBE values, a potential improvement on RBE-weighted dose of up to 40%, averaged over several structures under study, was noticed during MCO navigation. Conclusions: We present a novel strategy for optimizing proton therapy to maximize dose-averaged LET in tumor targets while simultaneously minimizing dose-averaged LET in normal tissue structures. MCO BPs show substantial LET variations, leading to potentially significant differences in RBE-weighted doses. Pareto-surface navigation, using both dose and LET distributions for guidance, provides the means for evaluating a large variety of deliverable plans and aids in

  16. A comparison of three optimization algorithms for intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Pflugfelder, D.; Wilkens, J.J.; Nill, S.; Oelfke, U.

    2008-01-01

    In intensity modulated treatment techniques, the modulation of each treatment field is obtained using an optimization algorithm. Multiple optimization algorithms have been proposed in the literature, e.g. steepest descent, conjugate gradient, quasi-Newton methods to name a few. The standard optimization algorithm in our in-house inverse planning tool KonRad is a quasi-Newton algorithm. Although this algorithm yields good results, it also has some drawbacks. Thus we implemented an improved optimization algorithm based on the limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) routine. In this paper the improved optimization algorithm is described. To compare the two algorithms, several treatment plans are optimized using both algorithms. This included photon (IMRT) as well as proton (IMPT) intensity modulated therapy treatment plans. To present the results in a larger context the widely used conjugate gradient algorithm was also included into this comparison. On average, the improved optimization algorithm was six times faster to reach the same objective function value. However, it resulted not only in an acceleration of the optimization. Due to the faster convergence, the improved optimization algorithm usually terminates the optimization process at a lower objective function value. The average of the observed improvement in the objective function value was 37%. This improvement is clearly visible in the corresponding dose-volume-histograms. The benefit of the improved optimization algorithm is particularly pronounced in proton therapy plans. The conjugate gradient algorithm ranked in between the other two algorithms with an average speedup factor of two and an average improvement of the objective function value of 30%. (orig.)

  17. Linear Energy Transfer-Guided Optimization in Intensity Modulated Proton Therapy: Feasibility Study and Clinical Potential

    International Nuclear Information System (INIS)

    Giantsoudi, Drosoula; Grassberger, Clemens; Craft, David; Niemierko, Andrzej; Trofimov, Alexei; Paganetti, Harald

    2013-01-01

    Purpose: To investigate the feasibility and potential clinical benefit of linear energy transfer (LET) guided plan optimization in intensity modulated proton therapy (IMPT). Methods and Materials: A multicriteria optimization (MCO) module was used to generate a series of Pareto-optimal IMPT base plans (BPs), corresponding to defined objectives, for 5 patients with head-and-neck cancer and 2 with pancreatic cancer. A Monte Carlo platform was used to calculate dose and LET distributions for each BP. A custom-designed MCO navigation module allowed the user to interpolate between BPs to produce deliverable Pareto-optimal solutions. Differences among the BPs were evaluated for each patient, based on dose–volume and LET–volume histograms and 3-dimensional distributions. An LET-based relative biological effectiveness (RBE) model was used to evaluate the potential clinical benefit when navigating the space of Pareto-optimal BPs. Results: The mean LET values for the target varied up to 30% among the BPs for the head-and-neck patients and up to 14% for the pancreatic cancer patients. Variations were more prominent in organs at risk (OARs), where mean LET values differed by a factor of up to 2 among the BPs for the same patient. An inverse relation between dose and LET distributions for the OARs was typically observed. Accounting for LET-dependent variable RBE values, a potential improvement on RBE-weighted dose of up to 40%, averaged over several structures under study, was noticed during MCO navigation. Conclusions: We present a novel strategy for optimizing proton therapy to maximize dose-averaged LET in tumor targets while simultaneously minimizing dose-averaged LET in normal tissue structures. MCO BPs show substantial LET variations, leading to potentially significant differences in RBE-weighted doses. Pareto-surface navigation, using both dose and LET distributions for guidance, provides the means for evaluating a large variety of deliverable plans and aids in

  18. Electromagnetic corrections in {eta}{yields}3{pi} decays

    Energy Technology Data Exchange (ETDEWEB)

    Ditsche, Christoph; Kubis, Bastian [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Bonn (Germany); Meissner, Ulf G. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Bonn (Germany); Forschungszentrum Juelich, Institut fuer Kernphysik (Theorie), Institute for Advanced Simulations, and Juelich Center for Hadron Physics, Juelich (Germany)

    2009-03-15

    We re-evaluate the electromagnetic corrections to {eta}{yields}3{pi} decays at next-to-leading order in the chiral expansion, arguing that effects of order e{sup 2}(m{sub u}-m{sub d}) disregarded so far are not negligible compared to other contributions of order e {sup 2} times a light-quark mass. Despite the appearance of the Coulomb pole in {eta}{yields}{pi}{sup +}{pi}{sup -}{pi}{sup 0} and cusps in {eta}{yields}3{pi}{sup 0}, the overall corrections remain small. (orig.)

  19. Sensitivity of intensity modulated proton therapy plans to changes in patient weight

    International Nuclear Information System (INIS)

    Albertini, Francesca; Bolsi, Alessandra; Lomax, Antony J.; Rutz, Hans Peter; Timmerman, Beate; Goitein, Gudrun

    2008-01-01

    Purpose: A retrospective study to investigate the sensitivity of intensity modulated proton therapy (IMPT) to changes in body weight occurring during the course of radiotherapy for patients treated in the sacral region. Materials and methods: During therapy, important weight gain and loss were observed for two patients treated to para-spinal tumors, which resulted in both patients being re-scanned and re-planned. Both patients were treated as part of their therapy, with a narrow-angle IMPT (NA-IMPT) plan delivering a 'dose hole' around the cauda equina (CE), which was mainly formed through modulation of Bragg peaks in depth. To investigate the impact of these weight changes on the proton range and delivered dose, the nominal fields were re-calculated on the new CT data sets. Results were analyzed by comparing these new plans with those originally delivered and by calculating changes in range and delivered doses in target volumes and normal tissues. Results: Maximum differences in proton range in the CE region of up to +8 mm and -13 mm, respectively, for the patient who gained weight and for the patient who lost weight, increased the maximum dose to the CE by only 2%. This indicates that both IMPT plans were relatively insensitive to substantial range uncertainties. Even greater differences in range (16 mm) in the planning target volume only slightly affected its dose homogeneity (differences in V 90% of 6% in the worst case). Nevertheless, some large undesired local dose differences were observed. Conclusions: We demonstrated, that, at least for the two analyzed cases, NA-IMPT plans are less sensitive to weight variations than one may expect. Still, we would advise to calculate new plans in case of substantial change in weight for patients treated in the sacral region, primarily due to the presence of new hot/cold area

  20. Spinal cordd biological safety comparison of intensity modulated radiotherapy and conventional radiation therapy

    International Nuclear Information System (INIS)

    Xilinbaoleri; Xu Wanlong; Chen Gang; Liu Hao; Wang Ruozheng; Bai Jingping

    2010-01-01

    Objective: To compare the spine intensity modulated radiation therapy (IMRT) and the conventional radiation therapy on the beagle spinal cord neurons, in order to prove the biological safety of IMRT of the spinal cord. Methods: Twelve selected purebred beagles were randomly divided into 2 groups. A beagle clinical model of tumor was mimiced in the ninth and tenth thoracic vertebrae. Then the beagles were irradiated by 2 different models of intensity modulated radiotherapy and conventional radiation therapy, with the total irradiation doses of 50 and 70 Gy. The samples of spinal cord were taken out from the same position of the nine and tenth thoracic vertebrae at the third month after radiation.All the samples were observed by the electron microscope, and the Fas and HSP70 expression in spinal cord neurons were evaluated by immunohistochemistry method. Terminal deoxynucleatidyl transferase mediated dUTP nick and labeling (TUNEL) technique was used to examine the apoptotic cells in the spinal cord. Results: The neurons in the spinal cord of IMRT group were mainly reversible injury, and those in the conventional radiation therapy were mainly apoptosis. Compared with the conventional radiation therapy group [50 Gy group, (7.3 ± 1.1)%; 70 Gy group, (11.3 ± 1.4)%], the apoptosis rate of the spinal cord neurons of the intensity modulated radiotherapy group [50 Gy group, (1.2 ± 0.7)%; 70 Gy group (2.5 ± 0.8)%] was much lower[(50 Gy group, t=0.022, P<0.05; 70 Gy group, t=0.017, P<0.05)]. The expression levels of Fas in the IMPT group (50 Gy group, 4.6 ± 0.8; 70 Gy group, 7.4 ± 1.1) were also much lowerthan those in the other group (50 Gy group, 15.1 ± 6.4; 70 Gy group, 19.3 ± 7.6. 50 Gy group, t=0.231, P<0.05; 70 Gy group, t=0.457, P<0.05), while the expression levels of HSP70 in the IMPT group (50 Gy group, 9.1 ± 0.8; 70 Gy group, 7.3 ± 1.4)were much higher than those in the conventional radiation therapy group (50 Gy group, 2.1 ± 0.9; 70 Gy group, 1.7 ± 0

  1. A 4 MV flattening filter-free beam: commissioning and application to conformal therapy and volumetric modulated arc therapy

    International Nuclear Information System (INIS)

    Stevens, S W; Rosser, K E; Bedford, J L

    2011-01-01

    Recent studies have indicated that radiotherapy treatments undertaken on a flattening filter-free (FFF) linear accelerator have a number of advantages over treatments undertaken on a conventional linear accelerator. In addition, 4 MV photon beams may give improved isodose coverage for some treatment volumes at air/tissue interfaces, compared to when utilizing the clinical standard of 6 MV photons. In order to investigate these benefits, FFF beams were established on an Elekta Beam Modulator linear accelerator for 4 MV photons. Commissioning beam data were obtained for open and wedged fields. The measured data were then imported into a treatment planning system and a beam model was commissioned. The beam model was optimized to improve dose calculations at shallow, clinically relevant depths. Following verification, the beam model was utilized in a treatment planning study, including volumetric modulated arc therapy, for a selection of lung, breast/chest wall and larynx patients. Increased dose rates of around 800 MU min -1 were recorded for open fields (relative to 320 MU min -1 for filtered open fields) and reduced head scatter was inferred from output factor measurements. Good agreement between planned and delivered dose was observed in verification of treatment plans. The planning study indicated that with a FFF beam, equivalent (and in some cases improved) isodose profiles could be achieved for small lung and larynx treatment volumes relative to 4 MV filtered treatments. Furthermore, FFF treatments with wedges could be replicated using open fields together with an 'effective wedge' technique and isocentre shift. Clinical feasibility of a FFF beam was therefore demonstrated, with beam modelling, treatment planning and verification being successfully accomplished.

  2. Realization of fluence field modulated CT on a clinical TomoTherapy megavoltage CT system

    International Nuclear Information System (INIS)

    Szczykutowicz, Timothy P; Hermus, James; Geurts, Mark; Smilowitz, Jennifer

    2015-01-01

    The multi-leaf collimator (MLC) assembly present on TomoTherapy (Accuray, Madison WI) radiation therapy (RT) and mega voltage CT machines is well suited to perform fluence field modulated CT (FFMCT). In addition, there is a demand in the RT environment for FFMCT imaging techniques, specifically volume of interest (VOI) imaging.A clinical TomoTherapy machine was programmed to perform VOI. Four different size ROIs were placed at varying distances from isocenter. Projections intersecting the VOI received ‘full dose’ while those not intersecting the VOI received 30% of the dose (i.e. the incident fluence for non VOI projections was 30% of the incident fluence for projections intersecting the VOI). Additional scans without fluence field modulation were acquired at ‘full’ and 30% dose. The noise (pixel standard deviation) and mean CT number were measured inside the VOI region and compared between the three scans. Dose maps were generated using a dedicated TomoTherapy treatment planning dose calculator.The VOI-FFMCT technique produced an image noise 1.05, 1.00, 1.03, and 1.05 times higher than the ‘full dose’ scan for ROI sizes of 10 cm, 13 cm, 10 cm, and 6 cm respectively within the VOI region. The VOI-FFMCT technique required a total imaging dose equal to 0.61, 0.69, 0.60, and 0.50 times the ‘full dose’ acquisition dose for ROI sizes of 10 cm, 13 cm, 10 cm, and 6 cm respectively within the VOI region.Noise levels can be almost unchanged within clinically relevant VOIs sizes for RT applications while the integral imaging dose to the patient can be decreased, and/or the image quality in RT can be dramatically increased with no change in dose relative to non-FFMCT RT imaging. The ability to shift dose away from regions unimportant for clinical evaluation in order to improve image quality or reduce imaging dose has been demonstrated. This paper demonstrates that FFMCT can be performed using the MLC on a clinical TomoTherapy machine for the

  3. Intensity-modulated radiation therapy to bilateral lower limb extremities concurrently: a planning case study

    Energy Technology Data Exchange (ETDEWEB)

    Fitzgerald, Emma, E-mail: emmafitz1390@gmail.com; Miles, Wesley; Fenton, Paul; Frantzis, Jim [Radiation Oncology, Epworth HealthCare, Victoria (Australia)

    2014-09-15

    Non-melanomatous skin cancers represent 80% of all newly diagnosed cancers in Australia with basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) being the most common. A previously healthy 71-year-old woman presented with widespread and tender superficial skin cancers on the lower bilateral limbs. External beam radiation therapy through the use of intensity-modulated radiation therapy (IMRT) was employed as the treatment modality of choice as this technique provides conformal dose distribution to a three-dimensional treatment volume while reducing toxicity to surrounding tissues. The patient was prescribed a dose of 60 Gy to the planning target volume (PTV) with 1.0 cm bolus over the ventral surface of each limb. The beam arrangement consisted of six treatment fields that avoided entry and exit through the contralateral limb. The treatment plans met the International Commission on Radiation Units and Measurements (ICRU) guidelines and produced highly conformal dosimetric results. Skin toxicity was measured against the National Cancer Institute: Common Terminology Criteria for Adverse Events (NCI: CTCAE) version 3. A well-tolerated treatment was delivered with excellent results given the initial extent of the disease. This case study has demonstrated the feasibility and effectiveness of IMRT for skin cancers as an alternative to surgery and traditional superficial radiation therapy, utilising a complex PTV of the extremities for patients with similar presentations.

  4. Improved Outcomes with Intensity Modulated Radiation Therapy Combined with Temozolomide for Newly Diagnosed Glioblastoma Multiforme

    Directory of Open Access Journals (Sweden)

    Noel J. Aherne

    2014-01-01

    Full Text Available Purpose. Glioblastoma multiforme (GBM is optimally treated by maximal debulking followed by combined chemoradiation. Intensity modulated radiation therapy (IMRT is gaining widespread acceptance in other tumour sites, although evidence to support its use over three-dimensional conformal radiation therapy (3DCRT in the treatment of gliomas is currently lacking. We examined the survival outcomes for patients with GBM treated with IMRT and Temozolomide. Methods and Materials. In all, 31 patients with GBM were treated with IMRT and 23 of these received chemoradiation with Temozolomide. We correlated survival outcomes with patient functional status, extent of surgery, radiation dose, and use of chemotherapy. Results. Median survival for all patients was 11.3 months, with a median survival of 7.2 months for patients receiving 40.05 Gray (Gy and a median survival of 17.4 months for patients receiving 60 Gy. Conclusions. We report one of the few series of IMRT in patients with GBM. In our group, median survival for those receiving 60 Gy with Temozolomide compared favourably to the combined therapy arm of the largest randomised trial of chemoradiation versus radiation to date (17.4 months versus 14.6 months. We propose that IMRT should be considered as an alternative to 3DCRT for patients with GBM.

  5. Improved outcomes with intensity modulated radiation therapy combined with temozolomide for newly diagnosed glioblastoma multiforme.

    Science.gov (United States)

    Aherne, Noel J; Benjamin, Linus C; Horsley, Patrick J; Silva, Thomaz; Wilcox, Shea; Amalaseelan, Julan; Dwyer, Patrick; Tahir, Abdul M R; Hill, Jacques; Last, Andrew; Hansen, Carmen; McLachlan, Craig S; Lee, Yvonne L; McKay, Michael J; Shakespeare, Thomas P

    2014-01-01

    Purpose. Glioblastoma multiforme (GBM) is optimally treated by maximal debulking followed by combined chemoradiation. Intensity modulated radiation therapy (IMRT) is gaining widespread acceptance in other tumour sites, although evidence to support its use over three-dimensional conformal radiation therapy (3DCRT) in the treatment of gliomas is currently lacking. We examined the survival outcomes for patients with GBM treated with IMRT and Temozolomide. Methods and Materials. In all, 31 patients with GBM were treated with IMRT and 23 of these received chemoradiation with Temozolomide. We correlated survival outcomes with patient functional status, extent of surgery, radiation dose, and use of chemotherapy. Results. Median survival for all patients was 11.3 months, with a median survival of 7.2 months for patients receiving 40.05 Gray (Gy) and a median survival of 17.4 months for patients receiving 60 Gy. Conclusions. We report one of the few series of IMRT in patients with GBM. In our group, median survival for those receiving 60 Gy with Temozolomide compared favourably to the combined therapy arm of the largest randomised trial of chemoradiation versus radiation to date (17.4 months versus 14.6 months). We propose that IMRT should be considered as an alternative to 3DCRT for patients with GBM.

  6. Salivary gland function of nasopharyngeal cancer patients treated by simultaneous modulated accelerated radiation therapy

    International Nuclear Information System (INIS)

    Zhang Qi; Li Huanbin; Wang Ling

    2007-01-01

    The work was to study protective effect of simultaneous modulated accelerated radiation therapy (SMART) on salivary function of nasopharyngeal cancer patients. Forty-six patients were treated by SMART with 2.5Gy/fraction at gross tumor volume to a total does of 70 Gy, and 2.0 Gy/fraction at the clinical treatment volume to a total does of 56 Gy. The SMART was practiced in step-and-shoot mode, one time a day, and five times each week. Fourteen patients were treated by conventional radiation therapy. All the patients received salivary gland function imaging for their uptake index, excretive index and excretive speed, so as to evaluate their degree of salivary function injury. Meanwhile, the dry discomfort in mouth of the patients was recorded and classified. The results showed that the functional indexes of the SMART group were significantly higher than those of the conventional radiation therapy group (P 2 =23.52, P<0.005). Therefore, SMART can play a key role in protecting salivary gland function of naso- pharyngeal cancer patients. (authors)

  7. Decay J/π → 3γ and a search for the eta/sub c/

    International Nuclear Information System (INIS)

    Partridge, R.; Peck, C.; Porter, F.; Kollman, W.; Richardson, M.; Strauch, K.; Wacker, K.; Aschman, D.; Burnett, T.; Cavalli-Sforza, M.; Coyne, D.; Sadrozinski, H.; Bloom, E.; Bulos, F.; Chestnut, R.; Gaiser, J.; Godfrey, G.; Kiesling, C.; Oreglia, M.; Hofstadter, R.; Kirkbride, I.; Kolanoski, H.; Liberman, A.; O'Reilly, J.; Tompkins, J.

    1980-01-01

    The decay J/psi into 3γ final states has been studied. No evidence is found for the existence of the X(2.83) or any heavy narrow state (e.g., the eta/sub c/) decaying into two photons. Upper limits are given on the branching ratio J/psi → eta/sub c/,eta/sub c/ → 2γ for eta/sub c/ masses in the 2.7--3.0-GeV region. In addition, the branching ratios J/psi → γeta,γeta' are measured. It is found that the eta' branching ratio is higher than previously reported

  8. Accommodating practical constraints for intensity modulated radiation therapy by means of compensators

    International Nuclear Information System (INIS)

    Meyer, Juergen

    2002-01-01

    The thesis deals with the practical implementation of intensity modulated radiation therapy (IMRT) generated by means of patient specific metal compensators. An elaborate comparison between several compensator-machining techniques, with respect to their suitability for production within a hospital workshop, is presented. The limitations associated with the selected compensator manufacturing technique are identified and implemented as constraints in an existing inverse treatment-planning algorithm. In order to obtain the profile of a compensator, which produces a desired intensity distribution, inverse modeling of the radiation attenuation within the compensator is required. Two novel and independent approaches, based on deconvolution and system identification, are proposed to accomplish this. To compare the approach with the 'rival' state of the art beam modulation technique, a theoretical and experimental examination of the modulated fields generated by manufactured compensators and multileaf collimators is presented. This comparison focused on the achievable resolution of the intensity modulated beams in lateral and longitudinal directions. To take into account the characteristics of a clinical environment the suitability of the most common commercially available treatment couch systems for IMRT treatments is studied. An original rule based advisory system is developed to alert the operator of any potential collision of the beam with the movable supporting structures of the treatment couch. The system is capable of finding alternative positions for the supporting frames and, if necessary, can suggest alternative beam directions. Finally, a head and neck phantom is designed for gel dosimetry to assess IMRT treatment delivery techniques. The phantom is based on a simplistic but realistic design and contains the main anatomical features

  9. SU-F-T-539: Dosimetric Comparison of Volumetric Modulated Arc Therapy and Intensity Modulated Radiation Therapy for Whole Brain Hippocampal Sparing Radiation Therapy Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Kendall, E; Higby, C; Algan, O; Ahmad, S; Hossain, S [University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2016-06-15

    Purpose: To compare the treatment plan quality and dose gradient near the hippocampus between VMAT (RapidArc) and IMRT delivery techniques for whole brain radiation therapy. Methods: Fifteen patients were evaluated in this retrospective study. All treatments were planned on Varian Eclipse TPS, using 3-Arc VMAT and 9-Field IMRT, following NRG Oncology protocol NRG-CC001 guidelines evaluated by a single radiation oncologist. Prescribed doses in all plans were 30 Gy delivered over 10 fractions normalized to a minimum of 100% of the dose covering 95% of the target volume. Identical contour sets and dose-volume constraints following protocol guidelines were also applied in all plans. A paired t-test analysis was used to compare VMAT and IMRT plans. Results: NRG-CC001 protocol dose-volume constraints were met for all VMAT and IMRT plans. For the planning target volume (PTV), the average values for D2% and D98% were 6% lower and 4% higher in VMAT than in IMRT, respectively. The average mean and maximum hippocampus doses in Gy for VMAT vs IMRT plans were (11.85±0.81 vs. 12.24±0.56, p=0.10) and (16.27±0.78 vs. 16.59±0.71, p=0.24), respectively. In VMAT, the average mean and maximum chiasm doses were 3% and 1% higher than in IMRT plans, respectively. For the left optic nerve, the average mean and maximum doses were 10% and 5% higher in VMAT than in IMRT plans, respectively. These values were 12% and 3% for the right optic nerve. The average percentage of dose gradient around the hippocampus in the 0–5mm and 5–10mm abutted regions for VMAT vs. IMRT were (4.42%±2.22% /mm vs. 3.95%±2.61% /mm, p=0.43) and (4.54%±1.50% /mm vs. 4.39%±1.28% /mm, p=0.73), respectively. Conclusion: VMAT plans can achieve higher hippocampus sparing with a faster dose fall-off than IMRT plans. Though statistically insignificant, VMAT offers better PTV coverage with slightly higher doses to OARs.

  10. SU-F-T-539: Dosimetric Comparison of Volumetric Modulated Arc Therapy and Intensity Modulated Radiation Therapy for Whole Brain Hippocampal Sparing Radiation Therapy Treatments

    International Nuclear Information System (INIS)

    Kendall, E; Higby, C; Algan, O; Ahmad, S; Hossain, S

    2016-01-01

    Purpose: To compare the treatment plan quality and dose gradient near the hippocampus between VMAT (RapidArc) and IMRT delivery techniques for whole brain radiation therapy. Methods: Fifteen patients were evaluated in this retrospective study. All treatments were planned on Varian Eclipse TPS, using 3-Arc VMAT and 9-Field IMRT, following NRG Oncology protocol NRG-CC001 guidelines evaluated by a single radiation oncologist. Prescribed doses in all plans were 30 Gy delivered over 10 fractions normalized to a minimum of 100% of the dose covering 95% of the target volume. Identical contour sets and dose-volume constraints following protocol guidelines were also applied in all plans. A paired t-test analysis was used to compare VMAT and IMRT plans. Results: NRG-CC001 protocol dose-volume constraints were met for all VMAT and IMRT plans. For the planning target volume (PTV), the average values for D2% and D98% were 6% lower and 4% higher in VMAT than in IMRT, respectively. The average mean and maximum hippocampus doses in Gy for VMAT vs IMRT plans were (11.85±0.81 vs. 12.24±0.56, p=0.10) and (16.27±0.78 vs. 16.59±0.71, p=0.24), respectively. In VMAT, the average mean and maximum chiasm doses were 3% and 1% higher than in IMRT plans, respectively. For the left optic nerve, the average mean and maximum doses were 10% and 5% higher in VMAT than in IMRT plans, respectively. These values were 12% and 3% for the right optic nerve. The average percentage of dose gradient around the hippocampus in the 0–5mm and 5–10mm abutted regions for VMAT vs. IMRT were (4.42%±2.22% /mm vs. 3.95%±2.61% /mm, p=0.43) and (4.54%±1.50% /mm vs. 4.39%±1.28% /mm, p=0.73), respectively. Conclusion: VMAT plans can achieve higher hippocampus sparing with a faster dose fall-off than IMRT plans. Though statistically insignificant, VMAT offers better PTV coverage with slightly higher doses to OARs.

  11. Quality of Intensity Modulated Radiation Therapy Treatment Plans Using a 60Co Magnetic Resonance Image Guidance Radiation Therapy System

    International Nuclear Information System (INIS)

    Wooten, H. Omar; Green, Olga; Yang, Min; DeWees, Todd; Kashani, Rojano; Olsen, Jeff; Michalski, Jeff; Yang, Deshan; Tanderup, Kari; Hu, Yanle; Li, H. Harold; Mutic, Sasa

    2015-01-01

    Purpose: This work describes a commercial treatment planning system, its technical features, and its capabilities for creating 60 Co intensity modulated radiation therapy (IMRT) treatment plans for a magnetic resonance image guidance radiation therapy (MR-IGRT) system. Methods and Materials: The ViewRay treatment planning system (Oakwood Village, OH) was used to create 60 Co IMRT treatment plans for 33 cancer patients with disease in the abdominal, pelvic, thorax, and head and neck regions using physician-specified patient-specific target coverage and organ at risk (OAR) objectives. Backup plans using a third-party linear accelerator (linac)-based planning system were also created. Plans were evaluated by attending physicians and approved for treatment. The 60 Co and linac plans were compared by evaluating conformity numbers (CN) with 100% and 95% of prescription reference doses and heterogeneity indices (HI) for planning target volumes (PTVs) and maximum, mean, and dose-volume histogram (DVH) values for OARs. Results: All 60 Co IMRT plans achieved PTV coverage and OAR sparing that were similar to linac plans. PTV conformity for 60 Co was within <1% and 3% of linac plans for 100% and 95% prescription reference isodoses, respectively, and heterogeneity was on average 4% greater. Comparisons of OAR mean dose showed generally better sparing with linac plans in the low-dose range <20 Gy, but comparable sparing for organs with mean doses >20 Gy. The mean doses for all 60 Co plan OARs were within clinical tolerances. Conclusions: A commercial 60 Co MR-IGRT device can produce highly conformal IMRT treatment plans similar in quality to linac IMRT for a variety of disease sites. Additional work is in progress to evaluate the clinical benefit of other novel features of this MR-IGRT system

  12. Cost-Effectiveness Analysis of Intensity Modulated Radiation Therapy Versus 3-Dimensional Conformal Radiation Therapy for Anal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hodges, Joseph C., E-mail: joseph.hodges@utsouthwestern.edu [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Beg, Muhammad S. [Division of Hematology and Oncology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Das, Prajnan [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Meyer, Jeffrey [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas (United States)

    2014-07-15

    Purpose: To compare the cost-effectiveness of intensity modulated radiation therapy (IMRT) and 3-dimensional conformal radiation therapy (3D-CRT) for anal cancer and determine disease, patient, and treatment parameters that influence the result. Methods and Materials: A Markov decision model was designed with the various disease states for the base case of a 65-year-old patient with anal cancer treated with either IMRT or 3D-CRT and concurrent chemotherapy. Health states accounting for rates of local failure, colostomy failure, treatment breaks, patient prognosis, acute and late toxicities, and the utility of toxicities were informed by existing literature and analyzed with deterministic and probabilistic sensitivity analysis. Results: In the base case, mean costs and quality-adjusted life expectancy in years (QALY) for IMRT and 3D-CRT were $32,291 (4.81) and $28,444 (4.78), respectively, resulting in an incremental cost-effectiveness ratio of $128,233/QALY for IMRT compared with 3D-CRT. Probabilistic sensitivity analysis found that IMRT was cost-effective in 22%, 47%, and 65% of iterations at willingness-to-pay thresholds of $50,000, $100,000, and $150,000 per QALY, respectively. Conclusions: In our base model, IMRT was a cost-ineffective strategy despite the reduced acute treatment toxicities and their associated costs of management. The model outcome was sensitive to variations in local and colostomy failure rates, as well as patient-reported utilities relating to acute toxicities.

  13. Cost-Effectiveness Analysis of Intensity Modulated Radiation Therapy Versus 3-Dimensional Conformal Radiation Therapy for Anal Cancer

    International Nuclear Information System (INIS)

    Hodges, Joseph C.; Beg, Muhammad S.; Das, Prajnan; Meyer, Jeffrey

    2014-01-01

    Purpose: To compare the cost-effectiveness of intensity modulated radiation therapy (IMRT) and 3-dimensional conformal radiation therapy (3D-CRT) for anal cancer and determine disease, patient, and treatment parameters that influence the result. Methods and Materials: A Markov decision model was designed with the various disease states for the base case of a 65-year-old patient with anal cancer treated with either IMRT or 3D-CRT and concurrent chemotherapy. Health states accounting for rates of local failure, colostomy failure, treatment breaks, patient prognosis, acute and late toxicities, and the utility of toxicities were informed by existing literature and analyzed with deterministic and probabilistic sensitivity analysis. Results: In the base case, mean costs and quality-adjusted life expectancy in years (QALY) for IMRT and 3D-CRT were $32,291 (4.81) and $28,444 (4.78), respectively, resulting in an incremental cost-effectiveness ratio of $128,233/QALY for IMRT compared with 3D-CRT. Probabilistic sensitivity analysis found that IMRT was cost-effective in 22%, 47%, and 65% of iterations at willingness-to-pay thresholds of $50,000, $100,000, and $150,000 per QALY, respectively. Conclusions: In our base model, IMRT was a cost-ineffective strategy despite the reduced acute treatment toxicities and their associated costs of management. The model outcome was sensitive to variations in local and colostomy failure rates, as well as patient-reported utilities relating to acute toxicities

  14. Minute Temperature Fluctuations Detected in Eta Bootis

    Science.gov (United States)

    1994-11-01

    A group of astronomers from the Aarhus University (Denmark) and the European Southern Observatory (2) have for the first time succeeded in detecting solar-type oscillations in another star. They observed the temperature of the bright northern star Eta Bootis during six nights with the 2.5-metre Nordic Optical Telescope at the Roque de los Muchachos observatory on the island of La Palma (Canary Islands) and were able to show that it varies periodically by a few hundredths of a degree. These changes are caused by pressure waves in the star and are directly dependent on its inner structure. A detailed analysis by the astronomers has shown that the observed effects are in good agreement with current stellar models. This is a most important, independent test of stellar theory. The Sun is an Oscillating Star About twenty years ago, it was discovered that the nearest star, our Sun, oscillates like the ringing of a bell with a period of about 5 minutes. The same phenomenon is known in the Earth, which begins to vibrate after earthquakes; in this way seismologists have been able to discern a layered structure in the Earth's interior. The recent impacts of a comet on Jupiter most likely had a similar effect on that planet. The observed solar oscillations concern the entire gaseous body of the Sun, but we can of course only observe them on its surface. It has been found that each mode moves the surface up and down by less than 25 metres; the combined motion is very complicated, because there are many different, simultaneous modes, each of which has a slightly different period. The exact values of these periods are sensitive to the speed of sound in the Sun's interior, which in turn depends on the density of the material there. Thus, by measuring the periods of solar oscillations, we may probe the internal structure of the Sun, that is otherwise inaccessible to observations. Why does the Sun oscillate and what is the cause of these oscillations ? We do not know yet, but it is

  15. Observation of eta-c and other structures in the radiative decay psi to eta pi-plus pi-minus

    International Nuclear Information System (INIS)

    Becker, J.J.

    1984-01-01

    The Mark III detector at SPEAR was used to observe the exclusive radiative decay psi → γetaπ + π - . The eta/sub c/ was seen as an intermediate state in this decay, psi → γeta/sub c/, eta/sub c/ → etaπ + π - . The product branching ratio B(psi → γeta/sub c/) B(eta/sub c/ → etaπ + π - ) was measured to be 4.2 +/- 0.5 (stat) +/- 0.5 (sys) x 10 -4 . Other resonant structure was observed in the etaπ + π - spectrum in the range 1 + π - / 2 , which appears to decay via X → delta -+ π +- , delta -+ → etaπ +- . A spin-parity analysis was performed to determine the quantum numbers of the resonances responsible for this structure. However, the result was seen to be model dependent, so that it was not possible to conclusively resolve the underlying structure in the spectrum. No evidence was seen for the decay iota → etaπ + π - . An upper limit was set for the ratio of branching ratios for iota → etaππ relative to iota → KKπ, R = (B(psi → γiota) B(iota → etaππ))/(B(psi → γiota) B(iota → KKπ)) < 0.2 (90% C.L.)

  16. Observation of eta-c and other structures in the radiative decay psi to gamma eta pi-plus pi-minus

    International Nuclear Information System (INIS)

    Becker, J.J.

    1984-01-01

    The Mark III detector at SPEAR was used to observe the exclusive radiative decay psi → γ eta π + π - . The eta c was seen as an intermediate state in this decay, psi → γ eta c, eta c → eta π + π - . The product branching ratio B(psi → γ eta c) B(eta c → eta π + π - ) was measured to be 4.2 +- 0.5 (stat) +- 0.5 (sys) x 10 -4 . Other resonant structure was observed in the eta π + π - spectrum in the range 1 + π-/ 2 , which appears to decay via X → delta +- π -+ , delta +- → eta π +- . A spin-parity analysis was performed to determine the quantum numbers of the resonances responsible for this structure. However, the result was seen to be model dependent, so that it was not possible to conclusively resolve the underlying structure in the spectrum. No evidence was seen for the decay iota → eta π + π - . An upper limit was set for the ratio of branching ratios for iota → eta ππ relative to iota → KKπ, R = B(psi → γiota)B(iota → eta ππ)/B(psi → γiota)B(iota → KKπ) < 0.2 (90% C.L.). 54 references, 59 figures

  17. Comparison of the initial ETA gas propagation experiments with theoretical models

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, F.W.; Clark, J.C.; Fessenden, T.J.

    1982-04-20

    This report contains a description of the initial ETA propagation experiments in air at a beam current of 4.5 kA. The beam was observed to propagate at the pressures anticipated on the basis of previous theory and experiment. A comparison of measured net current waveforms with predictions of the PHOENIX code showed good agreement over the pressure range 0.1 to 200 torr. However, the beam was observed to expand with Z at a faster rate than theory predicts. Excessive transverse beam modulation at injection complicated the experiments and limited their comparison with theory.

  18. Comparison of the initial ETA gas propagation experiments with theoretical models

    International Nuclear Information System (INIS)

    Chambers, F.W.; Clark, J.C.; Fessenden, T.J.

    1982-01-01

    This report contains a description of the initial ETA propagation experiments in air at a beam current of 4.5 kA. The beam was observed to propagate at the pressures anticipated on the basis of previous theory and experiment. A comparison of measured net current waveforms with predictions of the PHOENIX code showed good agreement over the pressure range 0.1 to 200 torr. However, the beam was observed to expand with Z at a faster rate than theory predicts. Excessive transverse beam modulation at injection complicated the experiments and limited their comparison with theory

  19. Expected Increase of Activity of Eta Aquariids Meteor Shower

    Science.gov (United States)

    Kulikova, N. V.; Chepurova, V. M.

    2018-04-01

    Analysis of the results of modeling disintegration of Comet 1P/Halley after its flare in 1991 has allowed us to predict an increase of the activity of the associated Eta Aquariids meteor shower in April-May 2018.

  20. Magnetic diagnostics for the proto-eta Tokamak

    International Nuclear Information System (INIS)

    Ferreira, J.L.; Aso, Y.; Ueda, M.; Ferreira, J.G.

    1991-04-01

    This work gives a general view of the magnetic diagnostics rat will be used in the Proto-Eta Tokamak. These diagnostics will be useful tools to measure currents, electric and magnetic fields involved in the plasma magnetic confinement. (author)

  1. A study of tau decays involving eta and omega mesons

    CERN Document Server

    Buskulic, Damir; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Nief, J Y; Odier, P; Pietrzyk, B; Casado, M P; Chmeissani, M; Crespo, J M; Delfino, M C; Efthymiopoulos, I; Fernández, E; Fernández-Bosman, M; Carrido, L; Juste, A; Martínez, M; Orteu, S; Padilla, C; Park, I C; Pascual, A; Perlas, J A; Riu, I; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Gelao, G; Girone, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Alemany, R; Bazarko, A O; Bonvicini, G; Bright-Thomas, P G; Cattaneo, M; Comas, P; Coyle, P; Drevermann, H; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Lutters, G; Martin, E B; Mato, P; Minten, Adolf G; Miquel, R; Mir, L M; Moneta, L; Oest, T; Pacheco, A; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rizzo, G; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schmitt, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wagner, A; Ajaltouni, Ziad J; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rosnet, P; Rossignol, J M; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Rougé, A; Rumpf, M; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Casper, David William; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Dorris, S J; Halley, A W; Knowles, I G; Lynch, J G; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Teixeira-Dias, P; Thompson, A S; Thomson, F; Thorn, S; Turnbull, R M; Becker, U; Geweniger, C; Graefe, G; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Schmidt, M; Sommer, J; Tittel, K; Werner, S; Wunsch, M; Abbaneo, D; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Moutoussi, A; Nash, J; Sedgbeer, J K; Stacey, A M; Williams, M D; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Betteridge, A P; Bowdery, C K; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Williams, M I; Galla, A; Giehl, I; Greene, A M; Hoffmann, C; Jakobs, K; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Bencheikh, A M; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Diaconu, C A; Etienne, F; Konstantinidis, N P; Payre, P; Rousseau, D; Talby, M; Sadouki, A; Thulasidas, M; Trabelsi, K; Aleppo, M; Ragusa, F; Bauer, C; Berlich, R; Blum, Walter; Büscher, V; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Stenzel, H; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Choi, Y; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Höcker, A; Jacholkowska, A; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Nikolic, I A; Park, H J; Schune, M H; Simion, S; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Vannini, C; Verdini, P G; Walsh, J; Blair, G A; Bryant, L M; Cerutti, F; Chambers, J T; Gao, Y; Green, M G; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Maley, P; Norton, P R; Thompson, J C; Wright, A E; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Marx, B; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Black, S N; Dann, J H; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Boswell, R; Brew, C A J; Cartwright, S L; Combley, F; Köksal, A; Lehto, M H; Newton, W M; Reeve, J; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Grupen, Claus; Minguet-Rodríguez, J A; Rivera, F; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Greening, T C; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, A M; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G

    1997-01-01

    The 132 pb$^{-1}$ of data collected by ALEPH from 1991 to 1994 have been used to analyze $\\eta$ and $\\omega$ production in $\\tau$ decays. The following branching fractions have been measured: \\begin{eqnarray*} B(\\tau^-\\to\

  2. Measurement of the /eta/ parameter in /mu//sup +/ decay

    Energy Technology Data Exchange (ETDEWEB)

    Bossingham, R.R.

    1989-04-01

    This paper discusses the following topics on the muon plus decay; muon decay spectrum; previous determinations of /eta/; experimental apparatus; distortions of the spectrum; and data analysis and results. 31 figs. (LSP)

  3. Clinical Outcomes and Patterns of Disease Recurrence After Intensity Modulated Proton Therapy for Oropharyngeal Squamous Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Gunn, G. Brandon [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Blanchard, Pierre [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Oncology, Institut Gustave Roussy, Villejuif (France); Garden, Adam S. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhu, X. Ronald [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Fuller, C. David [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Medical Physics Program, The University of Texas Graduate School of Biomedical Sciences, Houston, Texas (United States); Mohamed, Abdallah S. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Clinical Oncology and Nuclear Medicine, University of Alexandria (Egypt); Morrison, William H.; Phan, Jack; Beadle, Beth M.; Skinner, Heath D. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Sturgis, Erich M. [Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kies, Merrill S. [Department of Thoracic/Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Hutcheson, Kate A. [Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Rosenthal, David I. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Mohan, Radhe; Gillin, Michael T. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); and others

    2016-05-01

    Purpose: A single-institution prospective study was conducted to assess disease control and toxicity of proton therapy for patients with head and neck cancer. Methods and Materials: Disease control, toxicity, functional outcomes, and patterns of failure for the initial cohort of patients with oropharyngeal squamous carcinoma (OPC) treated with intensity modulated proton therapy (IMPT) were prospectively collected in 2 registry studies at a single institution. Locoregional failures were analyzed by using deformable image registration. Results: Fifty patients with OPC treated from March 3, 2011, to July 2014 formed the cohort. Eighty-four percent were male, 50% had never smoked, 98% had stage III/IV disease, 64% received concurrent therapy, and 35% received induction chemotherapy. Forty-four of 45 tumors (98%) tested for p16 were positive. All patients received IMPT (multifield optimization to n=46; single-field optimization to n=4). No Common Terminology Criteria for Adverse Events grade 4 or 5 toxicities were observed. The most common grade 3 toxicities were acute mucositis in 58% of patients and late dysphagia in 12%. Eleven patients had a gastrostomy (feeding) tube placed during therapy, but none had a feeding tube at last follow-up. At a median follow-up time of 29 months, 5 patients had disease recurrence: local in 1, local and regional in 1, regional in 2, and distant in 1. The 2-year actuarial overall and progression-free survival rates were 94.5% and 88.6%. Conclusions: The oncologic, toxicity, and functional outcomes after IMPT for OPC are encouraging and provide the basis for ongoing and future clinical studies.

  4. Acute Toxicity After Image-Guided Intensity Modulated Radiation Therapy Compared to 3D Conformal Radiation Therapy in Prostate Cancer Patients

    NARCIS (Netherlands)

    Wortel, Ruud C.; Incrocci, Luca; Pos, Floris J.; Lebesque, Joos V.; Witte, Marnix G.; van der Heide, Uulke A.; van Herk, Marcel; Heemsbergen, Wilma D.

    2015-01-01

    Purpose: Image-guided intensity modulated radiation therapy (IG-IMRT) allows significant dose reductions to organs at risk in prostate cancer patients. However, clinical data identifying the benefits of IG-IMRT in daily practice are scarce. The purpose of this study was to compare dose distributions

  5. Euskarazko denbora-egiturak. Azterketa eta etiketatze-esperimentua

    Directory of Open Access Journals (Sweden)

    Begoña Altuna

    2014-12-01

    Full Text Available Denbora-informazioa erauztea oso erabilgarria da hizkuntzaren prozesamenduan (HP, besteak beste, testuen sinplifikazioan, informazio-erauzketako eta itzulpen automatikoko sistemetan balia baitaiteke. Lan honetan, euskaraz informazio hori baliagarri bihurtzeko egin diren lehen urratsak azaltzen dira: batetik, euskaraz denbora adierazteko erabiltzen diren egiturak zein eratakoak diren aztertu da gramatiketan oinarrituta, eta bestetik, egitura horiek testuetan etiketatzeko lehen erabakiak hartu dira. Halaber, ekonomiari buruzko corpus bat osatuta egin den etiketatze-lanaren esperimentua azaltzen da.

  6. Theories of the eta-meson-nucleus interaction

    International Nuclear Information System (INIS)

    Liu, L.C.

    1994-01-01

    It is sown that the pion-nucleon elastic scattering, eta-nucleon scattering length and the cross sections for pion-induced eta production on a nucleon satisfy a set of consistency relations. These relations are used to examine the ηN scattering lengths given by the various models. The nature of the threshold ηN interaction is discussed and recent advancements in ηN interaction is discussed and recent advancements in η-nucleus reaction theory are reviewed

  7. Comparison of acute and subacute genitourinary and gastrointestinal adverse events of radiotherapy for prostate cancer using intensity-modulated radiation therapy, three-dimensional conformal radiation therapy, permanent implant brachytherapy and high-dose-rate brachytherapy

    NARCIS (Netherlands)

    Morimoto, Masahiro; Yoshioka, Yasuo; Konishi, Koji; Isohashi, Fumiaki; Takahashi, Yutaka; Ogata, Toshiyuki; Koizumi, Masahiko; Teshima, Teruki; Bijl, Henk P; van der Schaaf, Arjen; Langendijk, Johannes A; Ogawa, Kazuhiko

    2014-01-01

    AIMS AND BACKGROUND: To examine acute and subacute urinary and rectal toxicity in patients with localized prostate cancer monotherapeutically treated with the following four radiotherapeutic techniques: intensity-modulated radiation therapy, three-dimensional conformal radiation therapy,

  8. American Society of Radiation Oncology Recommendations for Documenting Intensity-Modulated Radiation Therapy Treatments

    International Nuclear Information System (INIS)

    Holmes, Timothy; Das, Rupak; Low, Daniel; Yin Fangfang; Balter, James; Palta, Jatinder; Eifel, Patricia

    2009-01-01

    Despite the widespread use of intensity-modulated radiation therapy (IMRT) for approximately a decade, a lack of adequate guidelines for documenting these treatments persists. Proper IMRT treatment documentation is necessary for accurate reconstruction of prior treatments when a patient presents with a marginal recurrence. This is especially crucial when the follow-up care is managed at a second treatment facility not involved in the initial IMRT treatment. To address this issue, an American Society for Radiation Oncology (ASTRO) workgroup within the American ASTRO Radiation Physics Committee was formed at the request of the ASTRO Research Council to develop a set of recommendations for documenting IMRT treatments. This document provides a set of comprehensive recommendations for documenting IMRT treatments, as well as image-guidance procedures, with example forms provided.

  9. Matching Intensity-Modulated Radiation Therapy to an Anterior Low Neck Field

    International Nuclear Information System (INIS)

    Amdur, Robert J.; Liu, Chihray; Li, Jonathan; Mendenhall, William; Hinerman, Russell

    2007-01-01

    When using intensity-modulated radiation therapy (IMRT) to treat head and neck cancer with the primary site above the level of the larynx, there are two basic options for the low neck lymphatics: to treat the entire neck with IMRT, or to match the IMRT plan to a conventional anterior 'low neck' field. In view of the potential advantages of using a conventional low neck field, it is important to look for ways to minimize or manage the problems of matching IMRT to a conventional radiotherapy field. Treating the low neck with a single anterior field and the standard larynx block decreases the dose to the larynx and often results in a superior IMRT plan at the primary site. The purpose of this article is to review the most applicable studies and to discuss our experience with implementing a technique that involves moving the position of the superior border of the low neck field several times during a single treatment fraction

  10. A method of segment weight optimization for intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Pei Xi; Cao Ruifen; Jing Jia; Cheng Mengyun; Zheng Huaqing; Li Jia; Huang Shanqing; Li Gui; Song Gang; Wang Weihua; Wu Yican; FDS Team

    2011-01-01

    The error caused by leaf sequencing often leads to planning of Intensity-Modulated Radiation Therapy (IMRT) arrange system couldn't meet clinical demand. The optimization approach in this paper can reduce this error and improve efficiency of plan-making effectively. Conjugate Gradient algorithm was used to optimize segment weight and readjust segment shape, which could minimize the error anterior-posterior leaf sequencing eventually. Frequent clinical cases were tasted by precise radiotherapy system, and then compared Dose-Volume histogram between target area and organ at risk as well as isodose line in computed tomography (CT) film, we found that the effect was improved significantly after optimizing segment weight. Segment weight optimizing approach based on Conjugate Gradient method can make treatment planning meet clinical request more efficiently, so that has extensive application perspective. (authors)

  11. Dosimetric comparison of helical tomotherapy, intensity-modulated radiation therapy, volumetric-modulated arc therapy, and 3-dimensional conformal therapy for the treatment of T1N0 glottic cancer

    International Nuclear Information System (INIS)

    Ekici, Kemal; Pepele, Eda K.; Yaprak, Bahaddin; Temelli, Oztun; Eraslan, Aysun F.; Kucuk, Nadir; Altınok, Ayse Y.; Sut, Pelin A.; Alpak, Ozlem D.; Colak, Cemil; Mayadagli, Alpaslan

    2016-01-01

    Various radiotherapy planning methods for T1N0 laryngeal cancer have been proposed to decrease normal tissue toxicity. We compare helical tomotherapy (HT), linac-based intensity-modulated radiation therapy (IMRT), volumetric-modulated arc therapy (VMAT), and 3-D conformal radiotherapy (3D-CRT) techniques for T1N0 laryngeal cancer. Overall, 10 patients with T1N0 laryngeal cancer were selected and evaluated. Furthermore, 10 radiotherapy treatment plans have been created for all 10 patients, including HT, IMRT, VMAT, and 3D-CRT. IMRT, VMAT, and HT plans vs 3D-CRT plans consistently provided superior planning target volume (PTV) coverage. Similar target coverage was observed between the 3 IMRT modalities. Compared with 3D-CRT, IMRT, HT, and VMAT significantly reduced the mean dose to the carotid arteries. VMAT resulted in the lowest mean dose to the submandibular and thyroid glands. Compared with 3D-CRT, IMRT, HT, and VMAT significantly increased the maximum dose to the spinal cord It was observed that the 3 IMRT modalities studied showed superior target coverage with less variation between each plan in comparison with 3D-CRT. The 3D-CRT plans performed better at the D max of the spinal cord. Clinical investigation is warranted to determine if these treatment approaches would translate into a reduction in radiation therapy–induced toxicities.

  12. {eta} meson photoproduction on deuterium; Photoproduction du meson {eta} sur le deuterium

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann-Rothe, P.

    1996-05-30

    Measurements of the total and differential cross sections for {eta}-meson photoproduction on a D{sub 2} liquid target from threshold to 1.2 GeV, have been taken using the tagged Bremsstrahlung photon beam produced by the electrons extracted from the ELSA storage ring at Bonn. The reaction was identified by detecting the eta decay products in the neutral meson spectrometer SPES0-2{pi}, while the recoil baryons (proton, neutron or deuteron) were detected by a variety of large angle scintillator detectors. We succeeded to identify completely the final states corresponding to the production of an {eta} meson on a Quasi-Free (QF) proton, a QF neutron and the coherent deuteron. The differential cross sections corresponding to the production of a coherent deuteron n the final state have been measured, from threshold to 800 MeV; they are 6 times smaller the only previous measurement reported by Anderson and Prepost in 1969. This is consistent with an Isoscalar part of the Amplitude much smaller than the Isovector one. The differential cross sections are in good agreement with the theoretical prediction on the impulse approximation mechanism; indicating in particular, fairly small contributions from rescattering terms. A direct measurement of the neutron to proton cross section ratios has been obtained by integrating the counting rates on the corresponding QF peaks and is 0.70 {+-} 0.03, from 700 MeV to 900 MeV, with a small angular dependence. These two results by comparison to the measured free proton data should allow to reconstruct the free neutron cross sections in a rather model-independent way. (authors). 56 refs., 90 figs., 13 tabs.

  13. Introducing an on-line adaptive procedure for prostate image guided intensity modulate proton therapy.

    Science.gov (United States)

    Zhang, M; Westerly, D C; Mackie, T R

    2011-08-07

    With on-line image guidance (IG), prostate shifts relative to the bony anatomy can be corrected by realigning the patient with respect to the treatment fields. In image guided intensity modulated proton therapy (IG-IMPT), because the proton range is more sensitive to the material it travels through, the realignment may introduce large dose variations. This effect is studied in this work and an on-line adaptive procedure is proposed to restore the planned dose to the target. A 2D anthropomorphic phantom was constructed from a real prostate patient's CT image. Two-field laterally opposing spot 3D-modulation and 24-field full arc distal edge tracking (DET) plans were generated with a prescription of 70 Gy to the planning target volume. For the simulated delivery, we considered two types of procedures: the non-adaptive procedure and the on-line adaptive procedure. In the non-adaptive procedure, only patient realignment to match the prostate location in the planning CT was performed. In the on-line adaptive procedure, on top of the patient realignment, the kinetic energy for each individual proton pencil beam was re-determined from the on-line CT image acquired after the realignment and subsequently used for delivery. Dose distributions were re-calculated for individual fractions for different plans and different delivery procedures. The results show, without adaptive, that both the 3D-modulation and the DET plans experienced delivered dose degradation by having large cold or hot spots in the prostate. The DET plan had worse dose degradation than the 3D-modulation plan. The adaptive procedure effectively restored the planned dose distribution in the DET plan, with delivered prostate D(98%), D(50%) and D(2%) values less than 1% from the prescription. In the 3D-modulation plan, in certain cases the adaptive procedure was not effective to reduce the delivered dose degradation and yield similar results as the non-adaptive procedure. In conclusion, based on this 2D phantom

  14. Monte Carlo based treatment planning for modulated electron beam radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Michael C. [Radiation Physics Division, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States)]. E-mail: mclee@reyes.stanford.edu; Deng Jun; Li Jinsheng; Jiang, Steve B.; Ma, C.-M. [Radiation Physics Division, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States)

    2001-08-01

    A Monte Carlo based treatment planning system for modulated electron radiation therapy (MERT) is presented. This new variation of intensity modulated radiation therapy (IMRT) utilizes an electron multileaf collimator (eMLC) to deliver non-uniform intensity maps at several electron energies. In this way, conformal dose distributions are delivered to irregular targets located a few centimetres below the surface while sparing deeper-lying normal anatomy. Planning for MERT begins with Monte Carlo generation of electron beamlets. Electrons are transported with proper in-air scattering and the dose is tallied in the phantom for each beamlet. An optimized beamlet plan may be calculated using inverse-planning methods. Step-and-shoot leaf sequences are generated for the intensity maps and dose distributions recalculated using Monte Carlo simulations. Here, scatter and leakage from the leaves are properly accounted for by transporting electrons through the eMLC geometry. The weights for the segments of the plan are re-optimized with the leaf positions fixed and bremsstrahlung leakage and electron scatter doses included. This optimization gives the final optimized plan. It is shown that a significant portion of the calculation time is spent transporting particles in the leaves. However, this is necessary since optimizing segment weights based on a model in which leaf transport is ignored results in an improperly optimized plan with overdosing of target and critical structures. A method of rapidly calculating the bremsstrahlung contribution is presented and shown to be an efficient solution to this problem. A homogeneous model target and a 2D breast plan are presented. The potential use of this tool in clinical planning is discussed. (author)

  15. Modulation of intrinsic brain activity by electroconvulsive therapy in major depression

    Science.gov (United States)

    Leaver, Amber M.; Espinoza, Randall; Pirnia, Tara; Joshi, Shantanu H.; Woods, Roger P.; Narr, Katherine L.

    2015-01-01

    Introduction One of the most effective interventions for intractable major depressive episodes is electroconvulsive therapy (ECT). Because ECT is also relatively fast-acting, longitudinal study of its neurobiological effects offers critical insight into the mechanisms underlying depression and antidepressant response. Here we assessed modulation of intrinsic brain activity in corticolimbic networks associated with ECT and clinical response. Methods We measured resting-state functional connectivity (RSFC) in patients with treatment-resistant depression (n=30), using functional magnetic resonance imaging (fMRI) acquired before and after completing a treatment series with right-unilateral ECT. Using independent component analysis, we assessed changes in RSFC with 1) symptom improvement and 2) ECT regardless of treatment outcome in patients, with reference to healthy controls (n=33, also scanned twice). Results After ECT, consistent changes in RSFC within targeted depression-relevant functional networks were observed in the dorsal anterior cingulate (ACC), mediodorsal thalamus (mdTh), hippocampus, and right anterior temporal, medial parietal, and posterior cingulate cortex in all patients. In a separate analysis, changes in depressive symptoms were associated with RSFC changes in the dorsal ACC, mdTh, putamen, medial prefrontal, and lateral parietal cortex. RSFC of these regions did not change in healthy controls. Conclusions Neuroplasticity underlying clinical change was in part separable from changes associated with the effects of ECT observed in all patients. However, both ECT and clinical change were associated with RSFC modulation in dorsal ACC, mdTh and hippocampus, which may indicate that these regions underlie the mechanisms of clinical outcome in ECT and may be effective targets for future neurostimulation therapies. PMID:26878070

  16. [Intensity modulated radiation therapy for patients with gynecological malignancies after hysterectomy and chemotherapy/radiotherapy].

    Science.gov (United States)

    Chen, Zhen-yun; Ma, Yue-bing; Sheng, Xiu-gui; Zhang, Xiao-ling; Xue, Li; Song, Qu-qing; Liu, Nai-fu; Miao, Hua-qin

    2007-04-01

    To investigate the value of intensity modulated radiation therapy (IMRT) for patient with gynecological malignancies after treatment of hysterectomy and chemotherapy/radiotherapy. All 32 patients with cervical or endometrial cancer after hysterectomy received full course IMRT after 1 to 3 cycles of chemotherapy (Karnofsky performance status(KPS) > or =70). Seventeen of these patients underwent postoperative preventive irradiation and the other 15 patients were pelvic wall recurrence and/or retroperitoneal lymph node metastasis, though postoperative radiotherapy and/or chemotherapy had been given after operation. The median dose delivered to the PTV was 56.8 Gy for preventive irradiation, and 60.6 Gy for pelvic wall recurrence or retroperioneal lymph node metastasis irradiation. It was required that 90% of iso-dose curve could covere more than 99% of GTV. However, The mean dose irradiated to small intestine, bladder, rectum, kidney and spinal cord was 21.3 Gy, 37.8 Gy, 35.3 Gy, 8.5 Gy, 22.1 Gy, respectively. Fourteen patients presented grade I (11 patients) or II (3 patients) digestive tract side-effects, Five patients developed grade I or II bone marrow depression. Twelve patients had grade I skin reaction. The overall 1-year survival rate was 100%. The 2- and 3- year survival rate for preventive irradiation were both 100%, but which was 5/7 and 3/6 for the patients with pelvic wall recurrence or retroperioneal lymph node metastasis. Intensity modulated radiation therapy can provide a better dose distribution than traditional radiotherapy for both prevention and pelvic wall recurrence or retroperioneal lymph node metastasis. The toxicity is tolerable. The adjacent organs at risk can well be protected.

  17. Determination of the {eta} mass from the production threshold for the {gamma}p {yields} p{eta} reaction

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaev, Alexander

    2012-09-06

    This thesis is dedicated to a new precise determination of the {eta} meson mass based on a measurement of the threshold for the {gamma}p {yields} p{eta} reaction. This experiment was performed in the years 2004/2005 using the Crystal Ball/TAPS detector setup and the recently developed tagger focal-plane microscope detector at the MAMI-B facility in the Institut fuer Kernphysik of the Johannes Gutenberg-Universitaet Mainz. The real photon beam was produced by Bremsstrahlung of the 883 MeV electrons from MAMI-B on a thin diamond radiator. The {eta} mesons were identified via their two main decay modes, {eta} {yields} 2{gamma} and {eta} {yields} 3{pi}{sup 0}, with the Crystal Ball/TAPS setup, which measured energies and emission angles of particles. The identification of the {eta} {yields} 2{gamma} decay was performed using events with two clusters detected as photons, ignoring all other particles, and the standard invariant mass analysis. Cuts were applied on the invariant and missing mass distributions. The identification of the {eta} {yields} 3{pi}{sup 0} {yields} 6{gamma} decay concentrated on events with six clusters detected as photons. Among fifteen possible combinations of six photons to be arranged in three pairs, the combination with the smallest {chi}{sup 2}-value for the three pion masses was assumed to be correct. Cuts were applied on the {chi}{sup 2}-distribution and on the invariant and missing mass distributions. The normalization of the total cross section was obtained from the target thickness, the intensity of the photon flux, the simulated acceptance of the Crystal Ball, and the branching ratios of the {eta} decays. The determination of the {eta} mass required a very precise measurement of the production threshold. This was obtained by fitting the measured cross section as a function of photon energy and gave the result for the {eta} mass, m{sub {eta}}=(547.851{+-}0.031{sub stat.}{+-}0.062{sub syst.}) MeV.

  18. Intensity-modulated radiation therapy: not a dry eye in the house

    International Nuclear Information System (INIS)

    Arnold, Anthony; Arnold, Belinda; Capp, Anne; Fox, Chris; Metcalfe, Peter; Chapman, Alison; Tangboonduangjit, Puangpeng

    2004-01-01

    Inverse planned intensity-modulated radiation therapy (IMRT) has been applied to patients in a conformal fashion in order to avoid the lacrimal gland. In the present study, we report a patient in which a potential planned dose of 63 Gy to the lacrimal gland for a conventional plan was reduced to 12 Gy to the lacrimal gland for the IMRT plan. Dose objective inverse planning was provided using a Pinnacle treatment planning computer and treatment was delivered using a Varian dynamic multileaf collimator (MLC) on a Varian linear accelerator. Because multiple MLC segments are used to deliver the modulated treatment, conventional dose checks by manual calculation are not practical. To aid in an alternative dosimetric verification process, the Pinnacle planning computer has two unique dose tools, which provide axial and beams eye view doses on user-specified check phantoms. The combined field axial dose tool matched our ion chamber dose checks within ± 2.4% at the isocentre. The individual beams eye view dose tool matched film dose maps within ± 3% in the umbra Copyright (2004) Blackwell Publishing Asia Pty Ltd

  19. A comparison of the quality assurance of four dosimetric tools for intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Son, Jaeman; Baek, Taesung; Lee, Boram; Shin, Dongho; Park, Sung Yong; Park, Jeonghoon; Lim, Young Kyung; Lee, Se Byeong; Kim, Jooyoung; Yoon, Myonggeun

    2015-01-01

    This study was designed to compare the quality assurance (QA) results of four dosimetric tools used for intensity modulated radiation therapy (IMRT) and to suggest universal criteria for the passing rate in QA, irrespective of the dosimetric tool used. Thirty fields of IMRT plans from five patients were selected, followed by irradiation onto radiochromic film, a diode array (Mapcheck), an ion chamber array (MatriXX) and an electronic portal imaging device (EPID) for patient-specific QA. The measured doses from the four dosimetric tools were compared with the dose calculated by the treatment planning system. The passing rates of the four dosimetric tools were calculated using the gamma index method, using as criteria a dose difference of 3% and a distance-to-agreement of 3 mm. The QA results based on Mapcheck, MatriXX and EPID showed good agreement, with average passing rates of 99.61%, 99.04% and 99.29%, respectively. However, the average passing rate based on film measurement was significantly lower, 95.88%. The average uncertainty (1 standard deviation) of passing rates for 6 intensity modulated fields was around 0.31 for film measurement, larger than those of the other three dosimetric tools. QA results and consistencies depend on the choice of dosimetric tool. Universal passing rates should depend on the normalization or inter-comparisons of dosimetric tools if more than one dosimetric tool is used for patient specific QA

  20. A comparison of the quality assurance of four dosimetric tools for intensity modulated radiation therapy.

    Science.gov (United States)

    Son, Jaeman; Baek, Taesung; Lee, Boram; Shin, Dongho; Park, Sung Yong; Park, Jeonghoon; Lim, Young Kyung; Lee, Se Byeong; Kim, Jooyoung; Yoon, Myonggeun

    2015-09-01

    This study was designed to compare the quality assurance (QA) results of four dosimetric tools used for intensity modulated radiation therapy (IMRT) and to suggest universal criteria for the passing rate in QA, irrespective of the dosimetric tool used. Thirty fields of IMRT plans from five patients were selected, followed by irradiation onto radiochromic film, a diode array (Mapcheck), an ion chamber array (MatriXX) and an electronic portal imaging device (EPID) for patient-specific QA. The measured doses from the four dosimetric tools were compared with the dose calculated by the treatment planning system. The passing rates of the four dosimetric tools were calculated using the gamma index method, using as criteria a dose difference of 3% and a distance-to-agreement of 3 mm. The QA results based on Mapcheck, MatriXX and EPID showed good agreement, with average passing rates of 99.61%, 99.04% and 99.29%, respectively. However, the average passing rate based on film measurement was significantly lower, 95.88%. The average uncertainty (1 standard deviation) of passing rates for 6 intensity modulated fields was around 0.31 for film measurement, larger than those of the other three dosimetric tools. QA results and consistencies depend on the choice of dosimetric tool. Universal passing rates should depend on the normalization or inter-comparisons of dosimetric tools if more than one dosimetric tool is used for patient specific QA.

  1. Eta Carinae: Viewed from Multiple Vantage Points

    Science.gov (United States)

    Gull, Theodore

    2007-01-01

    The central source of Eta Carinae and its ejecta is a massive binary system buried within a massive interacting wind structure which envelops the two stars. However the hot, less massive companion blows a small cavity in the very massive primary wind, plus ionizes a portion of the massive wind just beyond the wind-wind boundary. We gain insight on this complex structure by examining the spatially-resolved Space Telescope Imaging Spectrograph (STIS) spectra of the central source (0.1") with the wind structure which extends out to nearly an arcsecond (2300AU) and the wind-blown boundaries, plus the ejecta of the Little Homunculus. Moreover, the spatially resolved Very Large Telescope/UltraViolet Echelle Spectrograph (VLT/UVES) stellar spectrum (one arcsecond) and spatially sampled spectra across the foreground lobe of the Homunculus provide us vantage points from different angles relative to line of sight. Examples of wind line profiles of Fe II, and the.highly excited [Fe III], [Ne III], [Ar III] and [S III)], plus other lines will be presented.

  2. Search for the weak decay eta ' -> K-+/-pi(-/+) and precise measurement of the branching fraction B(J/psi -> phi eta ')

    NARCIS (Netherlands)

    Haddadi, Z.; Kalantar-Nayestanaki, N.; Kavatsyuk, M.; Löhner, H.; Messchendorp, J. G.; Tiemens, M.

    2016-01-01

    We present the first search for the rare decay of eta' into K-+/- pi(-/+) in J/psi -> phi eta', using a sample of 1.3 x 10(9) J/psi events collected with the BESIII detector. No significant signal is observed, and the upper limit at the 90% confidence level for the ratio B(eta' -> K-+/-

  3. Improved Beam Angle Arrangement in Intensity Modulated Proton Therapy Treatment Planning for Localized Prostate Cancer

    International Nuclear Information System (INIS)

    Cao, Wenhua; Lim, Gino J.; Li, Yupeng; Zhu, X. Ronald; Zhang, Xiaodong

    2015-01-01

    Purpose: This study investigates potential gains of an improved beam angle arrangement compared to a conventional fixed gantry setup in intensity modulated proton therapy (IMPT) treatment for localized prostate cancer patients based on a proof of principle study. Materials and Methods: Three patients with localized prostate cancer retrospectively selected from our institution were studied. For each patient, IMPT plans were designed using two, three and four beam angles, respectively, obtained from a beam angle optimization algorithm. Those plans were then compared with ones using two lateral parallel-opposed beams according to the conventional planning protocol for localized prostate cancer adopted at our institution. Results: IMPT plans with two optimized angles achieved significant improvements in rectum sparing and moderate improvements in bladder sparing against those with two lateral angles. Plans with three optimized angles further improved rectum sparing significantly over those two-angle plans, whereas four-angle plans found no advantage over three-angle plans. A possible three-beam class solution for localized prostate patients was suggested and demonstrated with preserved dosimetric benefits because individually optimized three-angle solutions were found sharing a very similar pattern. Conclusions: This study has demonstrated the potential of using an improved beam angle arrangement to better exploit the theoretical dosimetric benefits of proton therapy and provided insights of selecting quality beam angles for localized prostate cancer treatment

  4. Australia-wide comparison of intensity modulated radiation therapy prostate plans

    International Nuclear Information System (INIS)

    Skala, M.; Holloway, L.; Bailey, M.; Kneebone, A.

    2005-01-01

    The aim of this study was to investigate the ability of Australian centres to produce high-dose intensity modulated radiation therapy (IMRT) prostate plans, and to compare the planning parameters and resultant dose distributions. Five Australian radiation therapy departments were invited to participate. Each centre received an identical 5 mm-slice CT data set complete with contours of the prostate, seminal vesicles, rectum, bladder, femoral heads and body outline. The planning team was asked to produce the best plan possible, using published Memorial Sloan-Kettering Cancer Centre prescription and dose constraints. Three centres submitted plans for evaluation. All plans covered the planning target volume adequately; however, only one plan met all the critical organ dose constraints. Although the planning parameters, beam arrangements and planning systems were different for each centre, the resulting plans were similar. In Australia, IMRT for prostate cancer is in the early stages of implementation, with routine use limited to a few centres. Copyright (2005) Blackwell Science Pty Ltd

  5. Statistical process control analysis for patient quality assurance of intensity modulated radiation therapy

    Science.gov (United States)

    Lee, Rena; Kim, Kyubo; Cho, Samju; Lim, Sangwook; Lee, Suk; Shim, Jang Bo; Huh, Hyun Do; Lee, Sang Hoon; Ahn, Sohyun

    2017-11-01

    This study applied statistical process control to set and verify the quality assurances (QA) tolerance standard for our hospital's characteristics with the criteria standards that are applied to all the treatment sites with this analysis. Gamma test factor of delivery quality assurances (DQA) was based on 3%/3 mm. Head and neck, breast, prostate cases of intensity modulated radiation therapy (IMRT) or volumetric arc radiation therapy (VMAT) were selected for the analysis of the QA treatment sites. The numbers of data used in the analysis were 73 and 68 for head and neck patients. Prostate and breast were 49 and 152 by MapCHECK and ArcCHECK respectively. C p value of head and neck and prostate QA were above 1.0, C pml is 1.53 and 1.71 respectively, which is close to the target value of 100%. C pml value of breast (IMRT) was 1.67, data values are close to the target value of 95%. But value of was 0.90, which means that the data values are widely distributed. C p and C pml of breast VMAT QA were respectively 1.07 and 2.10. This suggests that the VMAT QA has better process capability than the IMRT QA. Consequently, we should pay more attention to planning and QA before treatment for breast Radiotherapy.

  6. Volumetric Modulated Arc (Radio Therapy in Pets Treatment: The “La Cittadina Fondazione” Experience

    Directory of Open Access Journals (Sweden)

    Mario Dolera

    2018-01-01

    Full Text Available Volumetric Modulated Arc Therapy (VMAT is a modern technique, widely used in human radiotherapy, which allows a high dose to be delivered to tumor volumes and low doses to the surrounding organs at risk (OAR. Veterinary clinics takes advantage of this feature due to the small target volumes and distances between the target and the OAR. Sparing the OAR permits dose escalation, and hypofractionation regimens reduce the number of treatment sessions with a simpler manageability in the veterinary field. Multimodal volumes definition is mandatory for the small volumes involved and a positioning device precisely reproducible with a setup confirmation is needed before each session for avoiding missing the target. Additionally, the elaborate treatment plan must pursue hard constraints and objectives, and its feasibility must be evaluated with a per patient quality control. The aim of this work is to report results with regard to brain meningiomas and gliomas, trigeminal nerve tumors, brachial plexus tumors, adrenal tumors with vascular invasion and rabbit thymomas, in comparison with literature to determine if VMAT is a safe and viable alternative to surgery or chemotherapy alone, or as an adjuvant therapy in pets.

  7. Transcranial cavitation-mediated ultrasound therapy at sub-MHz frequency via temporal interference modulation

    Science.gov (United States)

    Sun, Tao; Sutton, Jonathan T.; Power, Chanikarn; Zhang, Yongzhi; Miller, Eric L.; McDannold, Nathan J.

    2017-10-01

    Sub-megahertz transmission is not usually adopted in pre-clinical small animal experiments for focused ultrasound (FUS) brain therapy due to the large focal size. However, low frequency FUS is vital for preclinical evaluations due to the frequency-dependence of cavitation behavior. To maximize clinical relevance, a dual-aperture FUS system was designed for low-frequency (274.3 kHz) cavitation-mediated FUS therapy. Combining two spherically curved transducers provides significantly improved focusing in the axial direction while yielding an interference pattern with strong side lobes, leading to inhomogeneously distributed cavitation activities. By operating the two transducers at slightly offset frequencies to modulate this interference pattern over the period of sonication, the acoustic energy was redistributed and resulted in a spatially homogenous treatment profile. Simulation and pressure field measurements in water were performed to assess the beam profiles. In addition, the system performance was demonstrated in vivo in rats via drug delivery through microbubble-mediated blood-brain barrier disruption. This design resulted in a homogenous treatment profile that was fully contained within the rat brain at a clinically relevant acoustic frequency.

  8. Multicentre quality assurance of intensity-modulated radiation therapy plans: a precursor to clinical trials

    International Nuclear Information System (INIS)

    Williams, M. J.; Bailey, M. J.; Forstner, D.; Metcalfe, P. E

    2007-01-01

    Full text: A multicentre planning study comparing intensity-modulated radiation therapy (IMRT) plans for the treatment of a head and neck cancer has been carried out. Three Australian radiotherapy centres, each with a different planning system, were supplied a fully contoured CT dataset and requested to generate an IMRT plan in accordance with the requirements of an IMRT-based radiation therapy oncology group clinical trial. Plan analysis was carried out using software developed specifically for reviewing multicentre clinical trial data. Two out of the three plans failed to meet the prescription requirements with one misinterpreting the prescription and the third failed to meet one of the constraints. Only one plan achieved all of the dose objectives for the critical structures and normal tissues. Although each centre used very similar planning parameters and beam arrangements the resulting plans were quite different. The subjective interpretation and application of the prescription and planning objectives emphasize one of the many difficulties in carrying out multicentre IMRT planning studies. The treatment prescription protocol in a clinical trial must be both lucid and unequivocally stated to avoid misinterpretation. Australian radiotherapy centres must show that they can produce a quality IMRT plan and that they can adhere to protocols for IMRT planning before using it in a clinical trial

  9. Multifield Optimization Intensity Modulated Proton Therapy for Head and Neck Tumors: A Translation to Practice

    Energy Technology Data Exchange (ETDEWEB)

    Frank, Steven J., E-mail: sjfrank@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Cox, James D. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Gillin, Michael; Mohan, Radhe [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Garden, Adam S.; Rosenthal, David I.; Gunn, G. Brandon [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Weber, Randal S. [Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kies, Merrill S. [Department of Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Lewin, Jan S. [Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Munsell, Mark F. [Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Palmer, Matthew B. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Sahoo, Narayan; Zhang, Xiaodong; Liu, Wei; Zhu, X. Ronald [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2014-07-15

    Background: We report the first clinical experience and toxicity of multifield optimization (MFO) intensity modulated proton therapy (IMPT) for patients with head and neck tumors. Methods and Materials: Fifteen consecutive patients with head and neck cancer underwent MFO-IMPT with active scanning beam proton therapy. Patients with squamous cell carcinoma (SCC) had comprehensive treatment extending from the base of the skull to the clavicle. The doses for chemoradiation therapy and radiation therapy alone were 70 Gy and 66 Gy, respectively. The robustness of each treatment plan was also analyzed to evaluate sensitivity to uncertainties associated with variations in patient setup and the effect of uncertainties with proton beam range in patients. Proton beam energies during treatment ranged from 72.5 to 221.8 MeV. Spot sizes varied depending on the beam energy and depth of the target, and the scanning nozzle delivered the spot scanning treatment “spot by spot” and “layer by layer.” Results: Ten patients presented with SCC and 5 with adenoid cystic carcinoma. All 15 patients were able to complete treatment with MFO-IMPT, with no need for treatment breaks and no hospitalizations. There were no treatment-related deaths, and with a median follow-up time of 28 months (range, 20-35 months), the overall clinical complete response rate was 93.3% (95% confidence interval, 68.1%-99.8%). Xerostomia occurred in all 15 patients as follows: grade 1 in 10 patients, grade 2 in 4 patients, and grade 3 in 1 patient. Mucositis within the planning target volumes was seen during the treatment of all patients: grade 1 in 1 patient, grade 2 in 8 patients, and grade 3 in 6 patients. No patient experienced grade 2 or higher anterior oral mucositis. Conclusions: To our knowledge, this is the first clinical report of MFO-IMPT for head and neck tumors. Early clinical outcomes are encouraging and warrant further investigation of proton therapy in prospective clinical trials.

  10. A Prospective Comparison of the Effects of Interfractional Variations on Proton Therapy and Intensity Modulated Radiation Therapy for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Moteabbed, Maryam, E-mail: mmoteabbed@partners.org; Trofimov, Alexei; Sharp, Gregory C.; Wang, Yi; Zietman, Anthony L.; Efstathiou, Jason A.; Lu, Hsiao-Ming

    2016-05-01

    Purpose: To quantify and compare the impact of interfractional setup and anatomic variations on proton therapy (PT) and intensity modulated radiation therapy (IMRT) for prostate cancer. Methods and Materials: Twenty patients with low-risk or intermediate-risk prostate cancer randomized to receive passive-scattering PT (n=10) and IMRT (n=10) were selected. For both modalities, clinical treatment plans included 50.4 Gy(RBE) to prostate and proximal seminal vesicles, and prostate-only boost to 79.2 Gy(RBE) in 1.8 Gy(RBE) per fraction. Implanted fiducials were used for prostate localization and endorectal balloons were used for immobilization. Patients in PT and IMRT arms received weekly computed tomography (CT) and cone beam CT (CBCT) scans, respectively. The planned dose was recalculated on each weekly image, scaled, and mapped onto the planning CT using deformable registration. The resulting accumulated dose distribution over the entire treatment course was compared with the planned dose using dose-volume histogram (DVH) and γ analysis. Results: The target conformity index remained acceptable after accumulation. The largest decrease in the average prostate D{sub 98} was 2.2 and 0.7 Gy for PT and IMRT, respectively. On average, the mean dose to bladder increased by 3.26 ± 7.51 Gy and 1.97 ± 6.84 Gy for PT and IMRT, respectively. These values were 0.74 ± 2.37 and 0.56 ± 1.90 for rectum. Differences between changes in DVH indices were not statistically significant between modalities. All volume indices remained within the protocol tolerances after accumulation. The average pass rate for the γ analysis, assuming tolerances of 3 mm and 3%, for clinical target volume, bladder, rectum, and whole patient for PT/IMRT were 100/100, 92.6/99, 99.2/100, and 97.2/99.4, respectively. Conclusion: The differences in target coverage and organs at risk dose deviations for PT and IMRT were not statistically significant under the guidelines of this protocol.

  11. Predictors of Hypothyroidism in Hodgkin Lymphoma Survivors After Intensity Modulated Versus 3-Dimensional Radiation Therapy.

    Science.gov (United States)

    Pinnix, Chelsea C; Cella, Laura; Andraos, Therese Y; Ayoub, Zeina; Milgrom, Sarah A; Gunther, Jillian; Thosani, Sonali; Wogan, Christine; Conson, Manuel; D'Avino, Vittoria; Oki, Yasuhiro; Fanale, Michelle; Lee, Hun J; Neelapu, Sattva; Fayad, Luis; Hagemeister, Frederick; Rodriguez, M Alma; Nastoupil, Loretta J; Nieto, Yago; Qiao, Wei; Pacelli, Roberto; Dabaja, Bouthaina

    2018-03-14

    To identify predictors of hypothyroidism after chemoradiation therapy for Hodgkin lymphoma (HL) and to compare outcomes after intensity modulated radiation therapy (IMRT) with those after 3-dimensional (3D) conformal radiation therapy (CRT). Ninety patients who underwent involved-site IMRT in 2009 through 2014 were evaluated for treatment-induced hypothyroidism, defined as elevated thyroid-stimulating hormone or decreased free thyroxine levels (or both). Receiver operating characteristic curve analysis identified individuals at low versus high risk based on dosimetric variables. Dosimetric cutoff points were verified with an external data set of 50 patients who underwent 3D-CRT. In the IMRT group, most patients (75 [83%]) had stage II HL, and the median prescribed dose was 30.6 Gy; in the 3D-CRT group, 32 patients (64%) had stage II HL, and the median prescribed dose was 32.0 Gy. No differences were found in the proportions of patients with bilateral (P = .982) or unilateral (P = .074) neck involvement between the 2 groups. Hypothyroidism rates were marginally higher in the IMRT group, with estimated 3-year rates of freedom from hypothyroidism of 56.1% in the 3D-CRT group and 40% in the IMRT group (P = .057). Univariate analysis showed that smaller thyroid volume and higher thyroid dose were associated with hypothyroidism in both groups (P hypothyroidism (P = .001 and P hypothyroidism (P hypothyroidism after either IMRT or 3D-CRT for HL. IMRT may confer a higher risk than 3D-CRT unless a treatment avoidance structure is used during planning. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Intensity-Modulated Radiation Therapy With Concurrent Chemotherapy as Preoperative Treatment for Localized Gastric Adenocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Chakravarty, Twisha; Crane, Christopher H. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Ajani, Jaffer A. [Department of Gastrointestinal Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Mansfield, Paul F. [Department of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Briere, Tina M.; Beddar, A. Sam [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Mok, Henry; Reed, Valerie K.; Krishnan, Sunil; Delclos, Marc E. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Das, Prajnan, E-mail: PrajDas@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2012-06-01

    Purpose: The goal of this study was to evaluate dosimetric parameters, acute toxicity, pathologic response, and local control in patients treated with preoperative intensity-modulated radiation therapy (IMRT) and concurrent chemotherapy for localized gastric adenocarcinoma. Methods: Between November 2007 and April 2010, 25 patients with localized gastric adenocarcinoma were treated with induction chemotherapy, followed by preoperative IMRT and concurrent chemotherapy and, finally, surgical resection. The median radiation therapy dose was 45 Gy. Concurrent chemotherapy was 5-fluorouracil and oxaliplatin in 18 patients, capecitabine in 3, and other regimens in 4. Subsequently, resection was performed with total gastrectomy in 13 patients, subtotal gastrectomy in 7, and other surgeries in 5. Results: Target coverage, expressed as the ratio of the minimum dose received by 99% of the planning target volume to the prescribed dose, was a median of 0.97 (range, 0.92-1.01). The median V{sub 30} (percentage of volume receiving at least 30 Gy) for the liver was 26%; the median V{sub 20} (percentage of volume receiving at least 20 Gy) for the right and left kidneys was 14% and 24%, respectively; and the median V{sub 40} (percentage of volume receiving at least 40 Gy) for the heart was 18%. Grade 3 acute toxicity developed in 14 patients (56%), including dehydration in 10, nausea in 8, and anorexia in 5. Grade 4 acute toxicity did not develop in any patient. There were no significant differences in the rates of acute toxicity, hospitalization, or feeding tube use in comparison to those in a group of 50 patients treated with preoperative three-dimensional conformal radiation therapy with concurrent chemotherapy. R0 resection was obtained in 20 patients (80%), and pathologic complete response occurred in 5 (20%). Conclusions: Preoperative IMRT for gastric adenocarcinoma was well tolerated, accomplished excellent target coverage and normal structure sparing, and led to appropriate

  13. Intensity-Modulated Radiation Therapy With Concurrent Chemotherapy as Preoperative Treatment for Localized Gastric Adenocarcinoma

    International Nuclear Information System (INIS)

    Chakravarty, Twisha; Crane, Christopher H.; Ajani, Jaffer A.; Mansfield, Paul F.; Briere, Tina M.; Beddar, A. Sam; Mok, Henry; Reed, Valerie K.; Krishnan, Sunil; Delclos, Marc E.; Das, Prajnan

    2012-01-01

    Purpose: The goal of this study was to evaluate dosimetric parameters, acute toxicity, pathologic response, and local control in patients treated with preoperative intensity-modulated radiation therapy (IMRT) and concurrent chemotherapy for localized gastric adenocarcinoma. Methods: Between November 2007 and April 2010, 25 patients with localized gastric adenocarcinoma were treated with induction chemotherapy, followed by preoperative IMRT and concurrent chemotherapy and, finally, surgical resection. The median radiation therapy dose was 45 Gy. Concurrent chemotherapy was 5-fluorouracil and oxaliplatin in 18 patients, capecitabine in 3, and other regimens in 4. Subsequently, resection was performed with total gastrectomy in 13 patients, subtotal gastrectomy in 7, and other surgeries in 5. Results: Target coverage, expressed as the ratio of the minimum dose received by 99% of the planning target volume to the prescribed dose, was a median of 0.97 (range, 0.92–1.01). The median V 30 (percentage of volume receiving at least 30 Gy) for the liver was 26%; the median V 20 (percentage of volume receiving at least 20 Gy) for the right and left kidneys was 14% and 24%, respectively; and the median V 40 (percentage of volume receiving at least 40 Gy) for the heart was 18%. Grade 3 acute toxicity developed in 14 patients (56%), including dehydration in 10, nausea in 8, and anorexia in 5. Grade 4 acute toxicity did not develop in any patient. There were no significant differences in the rates of acute toxicity, hospitalization, or feeding tube use in comparison to those in a group of 50 patients treated with preoperative three-dimensional conformal radiation therapy with concurrent chemotherapy. R0 resection was obtained in 20 patients (80%), and pathologic complete response occurred in 5 (20%). Conclusions: Preoperative IMRT for gastric adenocarcinoma was well tolerated, accomplished excellent target coverage and normal structure sparing, and led to appropriate pathologic

  14. Acute Esophagus Toxicity in Lung Cancer Patients After Intensity Modulated Radiation Therapy and Concurrent Chemotherapy

    International Nuclear Information System (INIS)

    Kwint, Margriet; Uyterlinde, Wilma; Nijkamp, Jasper; Chen, Chun; Bois, Josien de; Sonke, Jan-Jakob; Heuvel, Michel van den; Knegjens, Joost; Herk, Marcel van; Belderbos, José

    2012-01-01

    Purpose: The purpose of this study was to investigate the dose-effect relation between acute esophageal toxicity (AET) and the dose-volume parameters of the esophagus after intensity modulated radiation therapy (IMRT) and concurrent chemotherapy for patients with non-small cell lung cancer (NSCLC). Patients and Methods: One hundred thirty-nine patients with inoperable NSCLC treated with IMRT and concurrent chemotherapy were prospectively analyzed. The fractionation scheme was 66 Gy in 24 fractions. All patients received concurrently a daily dose of cisplatin (6 mg/m²). Maximum AET was scored according to Common Toxicity Criteria 3.0. Dose-volume parameters V5 to V70, D mean and D max of the esophagus were calculated. A logistic regression analysis was performed to analyze the dose-effect relation between these parameters and grade ≥2 and grade ≥3 AET. The outcome was compared with the clinically used esophagus V35 prediction model for grade ≥2 after radical 3-dimensional conformal radiation therapy (3DCRT) treatment. Results: In our patient group, 9% did not experience AET, and 31% experienced grade 1 AET, 38% grade 2 AET, and 22% grade 3 AET. The incidence of grade 2 and grade 3 AET was not different from that in patients treated with CCRT using 3DCRT. The V50 turned out to be the most significant dosimetric predictor for grade ≥3 AET (P=.012). The derived V50 model was shown to predict grade ≥2 AET significantly better than the clinical V35 model (P<.001). Conclusions: For NSCLC patients treated with IMRT and concurrent chemotherapy, the V50 was identified as most accurate predictor of grade ≥3 AET. There was no difference in the incidence of grade ≥2 AET between 3DCRT and IMRT in patients treated with concurrent chemoradiation therapy.

  15. Intensity-modulated radiation therapy for pediatric medulloblastoma: early report on the reduction of ototoxicity

    International Nuclear Information System (INIS)

    Huang, Eugene; Teh, Bin S.; Strother, Douglas R.; Davis, Quillin G.; Chiu, J. Kam; Lu, Hsin H.; Carpenter, L. Steven; Mai Weiyuan; Chintagumpala, Murali M.; South, Michael; Grant, Walter H. III; Butler, E. Brian; Woo, Shiao Y.

    2002-01-01

    Purpose: The combination of cisplatin chemotherapy and radiation therapy for the treatment of medulloblastoma has been shown to cause significant ototoxicity, impairing a child's cognitive function and quality of life. Our purpose is to determine whether the new conformal technique of intensity-modulated radiation therapy (IMRT) can achieve lower rates of hearing loss by decreasing the radiation dose delivered to the cochlea and eighth cranial nerve (auditory apparatus). Patients and Methods: Twenty-six pediatric patients treated for medulloblastoma were retrospectively divided into two groups that received either conventional radiotherapy (Conventional-RT Group) or IMRT (IMRT Group). One hundred thirteen pure-tone audiograms were evaluated retrospectively, and hearing function was graded on a scale of 0 to 4 according to the Pediatric Oncology Group's toxicity criteria. Statistical analysis comparing the rates of ototoxicity was performed using Fisher's exact test with two-tailed analysis. Results: When compared to conventional radiotherapy, IMRT delivered 68% of the radiation dose to the auditory apparatus (mean dose: 36.7 vs. 54.2 Gy). Audiometric evaluation showed that mean decibel hearing thresholds of the IMRT Group were lower at every frequency compared to those of the Conventional-RT Group, despite having higher cumulative doses of cisplatin. The overall incidence of ototoxicity was lower in the IMRT Group. Thirteen percent of the IMRT Group had Grade 3 or 4 hearing loss, compared to 64% of the Conventional-RT Group (p<0.014). Conclusion: The conformal technique of IMRT delivered much lower doses of radiation to the auditory apparatus, while still delivering full doses to the desired target volume. Our findings suggest that, despite higher doses of cisplatin, and despite radiotherapy before cisplatin therapy, treatment with IMRT can achieve a lower rate of hearing loss

  16. Dosimetric analysis of testicular doses in prostate intensity-modulated and volumetric-modulated arc radiation therapy at different energy levels

    Energy Technology Data Exchange (ETDEWEB)

    Onal, Cem, E-mail: hcemonal@hotmail.com; Arslan, Gungor; Dolek, Yemliha; Efe, Esma

    2016-01-01

    The aim of this study is to evaluate the incidental testicular doses during prostate radiation therapy with intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc radiotherapy (VMAT) at different energies. Dosimetric data of 15 patients with intermediate-risk prostate cancer who were treated with radiotherapy were analyzed. The prescribed dose was 78 Gy in 39 fractions. Dosimetric analysis compared testicular doses generated by 7-field intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy with a single arc at 6, 10, and 15 MV energy levels. Testicular doses calculated from the treatment planning system and doses measured from the detectors were analyzed. Mean testicular doses from the intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy per fraction calculated in the treatment planning system were 16.3 ± 10.3 cGy vs 21.5 ± 11.2 cGy (p = 0.03) at 6 MV, 13.4 ± 10.4 cGy vs 17.8 ± 10.7 cGy (p = 0.04) at 10 MV, and 10.6 ± 8.5 cGy vs 14.5 ± 8.6 cGy (p = 0.03) at 15 MV, respectively. Mean scattered testicular doses in the phantom measurements were 99.5 ± 17.2 cGy, 118.7 ± 16.4 cGy, and 193.9 ± 14.5 cGy at 6, 10, and 15 MV, respectively, in the intensity-modulated radiotherapy plans. In the volumetric-modulated arc radiotherapy plans, corresponding testicular doses per course were 90.4 ± 16.3 cGy, 103.6 ± 16.4 cGy, and 139.3 ± 14.6 cGy at 6, 10, and 15 MV, respectively. In conclusions, this study was the first to measure the incidental testicular doses by intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy plans at different energy levels during prostate-only irradiation. Higher photon energy and volumetric-modulated arc radiotherapy plans resulted in higher incidental testicular doses compared with lower photon energy and intensity-modulated radiotherapy plans.

  17. Three-Dimensional Dosimetric Validation of a Magnetic Resonance Guided Intensity Modulated Radiation Therapy System

    Energy Technology Data Exchange (ETDEWEB)

    Rankine, Leith J., E-mail: Leith_Rankine@med.unc.edu [Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri (United States); Department of Radiation Oncology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina (United States); Mein, Stewart [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Cai, Bin; Curcuru, Austen [Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri (United States); Juang, Titania; Miles, Devin [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Mutic, Sasa; Wang, Yuhe [Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri (United States); Oldham, Mark [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Li, H. Harold, E-mail: hli@radonc.wustl.edu [Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri (United States)

    2017-04-01

    Purpose: To validate the dosimetric accuracy of a commercially available magnetic resonance guided intensity modulated radiation therapy (MRgIMRT) system using a hybrid approach: 3-dimensional (3D) measurements and Monte Carlo calculations. Methods and Materials: We used PRESAGE radiochromic plastic dosimeters with remote optical computed tomography readout to perform 3D high-resolution measurements, following a novel remote dosimetry protocol. We followed the intensity modulated radiation therapy commissioning recommendations of American Association of Physicists in Medicine Task Group 119, adapted to incorporate 3D data. Preliminary tests (“AP” and “3D-Bands”) were delivered to 9.5-cm usable diameter cylindrical PRESAGE dosimeters to validate the treatment planning system (TPS) for nonmodulated deliveries; assess the sensitivity, uniformity, and rotational symmetry of the PRESAGE dosimeters; and test the robustness of the remote dosimetry protocol. Following this, 4 clinical MRgIMRT plans (“MultiTarget,” “Prostate,” “Head/Neck,” and “C-Shape”) were measured using 13-cm usable diameter PRESAGE dosimeters. For all plans, 3D-γ (3% or 3 mm global, 10% threshold) passing rates were calculated and 3D-γ maps were examined. Point doses were measured with an IBA-CC01 ionization chamber for validation of absolute dose. Finally, by use of an in-house-developed, GPU-accelerated Monte Carlo algorithm (gPENELOPE), we independently calculated dose for all 6 Task Group 119 plans and compared against the TPS. Results: For PRESAGE measurements, 3D-γ analysis yielded passing rates of 98.7%, 99.2%, 98.5%, 98.0%, 99.2%, and 90.7% for AP, 3D-Bands, MultiTarget, Prostate, Head/Neck, and C-Shape, respectively. Ion chamber measurements were within an average of 0.5% (±1.1%) from the TPS dose. Monte Carlo calculations demonstrated good agreement with the TPS, with a mean 3D-γ passing rate of 98.5% ± 1.9% using a stricter 2%/2-mm criterion. Conclusions: We

  18. Three-Dimensional Dosimetric Validation of a Magnetic Resonance Guided Intensity Modulated Radiation Therapy System

    International Nuclear Information System (INIS)

    Rankine, Leith J.; Mein, Stewart; Cai, Bin; Curcuru, Austen; Juang, Titania; Miles, Devin; Mutic, Sasa; Wang, Yuhe; Oldham, Mark; Li, H. Harold

    2017-01-01

    Purpose: To validate the dosimetric accuracy of a commercially available magnetic resonance guided intensity modulated radiation therapy (MRgIMRT) system using a hybrid approach: 3-dimensional (3D) measurements and Monte Carlo calculations. Methods and Materials: We used PRESAGE radiochromic plastic dosimeters with remote optical computed tomography readout to perform 3D high-resolution measurements, following a novel remote dosimetry protocol. We followed the intensity modulated radiation therapy commissioning recommendations of American Association of Physicists in Medicine Task Group 119, adapted to incorporate 3D data. Preliminary tests (“AP” and “3D-Bands”) were delivered to 9.5-cm usable diameter cylindrical PRESAGE dosimeters to validate the treatment planning system (TPS) for nonmodulated deliveries; assess the sensitivity, uniformity, and rotational symmetry of the PRESAGE dosimeters; and test the robustness of the remote dosimetry protocol. Following this, 4 clinical MRgIMRT plans (“MultiTarget,” “Prostate,” “Head/Neck,” and “C-Shape”) were measured using 13-cm usable diameter PRESAGE dosimeters. For all plans, 3D-γ (3% or 3 mm global, 10% threshold) passing rates were calculated and 3D-γ maps were examined. Point doses were measured with an IBA-CC01 ionization chamber for validation of absolute dose. Finally, by use of an in-house-developed, GPU-accelerated Monte Carlo algorithm (gPENELOPE), we independently calculated dose for all 6 Task Group 119 plans and compared against the TPS. Results: For PRESAGE measurements, 3D-γ analysis yielded passing rates of 98.7%, 99.2%, 98.5%, 98.0%, 99.2%, and 90.7% for AP, 3D-Bands, MultiTarget, Prostate, Head/Neck, and C-Shape, respectively. Ion chamber measurements were within an average of 0.5% (±1.1%) from the TPS dose. Monte Carlo calculations demonstrated good agreement with the TPS, with a mean 3D-γ passing rate of 98.5% ± 1.9% using a stricter 2%/2-mm criterion. Conclusions: We

  19. Nearly isentropic flow at sizeable $\\eta/s$ arXiv

    CERN Document Server

    Kurkela, Aleksi; Wu, Bin

    Non-linearities in the harmonic spectra of hadron-nucleus and nucleus-nucleus collisions provide evidence for the dynamical response to azimuthal spatial eccentricities. Here, we demonstrate within the framework of transport theory that even the mildest interaction correction to a picture of free-streaming particle distributions, namely the inclusion of one perturbatively weak interaction ("one-hit dynamics"), will generically give rise to all observed linear and non-linear structures. We further argue that transport theory naturally accounts within the range of its validity for realistic signal sizes of the linear and non-linear response coefficients observed in azimuthal momentum anisotropies with a large mean free path of the order of the system size in peripheral ($\\sim 50 \\%$ centrality) PbPb or central pPb collisions. The shear viscosity to entropy density ratio $\\eta/s$ of such a transport theory is approximately an order of magnitude larger than that of an almost perfect fluid. The phenomenological su...

  20. Measurement of $\\mid\\eta_{00}\\mid^{2}$/$\\mid\\eta_{+-}\\mid^{2}$

    CERN Multimedia

    2002-01-01

    The aim of this experiment is an accurate determination of the ratio of neutral to charged two pion decays of $K_{L}$ and $K_{S}$ mesons: \\\\ R=$|\\eta_{00}|^{2}/|\\eta_{+-}|^{2} = \\Gamma(K _{L} \\rightarrow 2\\pi^{0})/\\Gamma(K _{S} \\rightarrow 2\\pi^{0}) : \\Gamma(K_{L} \\rightarrow \\pi^{+}\\pi^{-})/\\Gamma(K_{S} \\rightarrow \\pi^{+}\\pi^{-})$ \\\\ In the superweak model of CP violation this ratio is equal to one exactly. Sizeable deviations from unity are predicted in popular models of the weak and electromagnetic interaction among six quarks. \\\\ The two decay modes $K^{0} \\rightarrow 2\\pi^{0}$ and $K^{0} \\rightarrow \\pi^{+}\\pi^{-}$ are measured simultaneously, and alternately in $K_{L}$ and $K_{S}$ beams. The detector consists of\\\\ 1) an evacuated decay region; \\\\ 2) proportional wire chambers to measure the charged pion directions; \\\\ 3) a liquid argon calorimeter with good energy and position resolution to measure the photons from $\\pi^{0}$ decays; \\\\ 4) a hadron calorimeter to measure the energy of the charged pio...

  1. Multi-dimensional modulations of alpha and gamma cortical dynamics following mindfulness-based cognitive therapy in Major Depressive Disorder

    NARCIS (Netherlands)

    Schoenberg, P.L.; Speckens, A.E.M.

    2015-01-01

    To illuminate candidate neural working mechanisms of Mindfulness-Based Cognitive Therapy (MBCT) in the treatment of recurrent depressive disorder, parallel to the potential interplays between modulations in electro-cortical dynamics and depressive symptom severity and self-compassionate experience.

  2. SU-F-T-209: Multicriteria Optimization Algorithm for Intensity Modulated Radiation Therapy Using Pencil Proton Beam Scanning

    Energy Technology Data Exchange (ETDEWEB)

    Beltran, C; Kamal, H [Mayo Clinic, Rochester, MN (United States)

    2016-06-15

    Purpose: To provide a multicriteria optimization algorithm for intensity modulated radiation therapy using pencil proton beam scanning. Methods: Intensity modulated radiation therapy using pencil proton beam scanning requires efficient optimization algorithms to overcome the uncertainties in the Bragg peaks locations. This work is focused on optimization algorithms that are based on Monte Carlo simulation of the treatment planning and use the weights and the dose volume histogram (DVH) control points to steer toward desired plans. The proton beam treatment planning process based on single objective optimization (representing a weighted sum of multiple objectives) usually leads to time-consuming iterations involving treatment planning team members. We proved a time efficient multicriteria optimization algorithm that is developed to run on NVIDIA GPU (Graphical Processing Units) cluster. The multicriteria optimization algorithm running time benefits from up-sampling of the CT voxel size of the calculations without loss of fidelity. Results: We will present preliminary results of Multicriteria optimization for intensity modulated proton therapy based on DVH control points. The results will show optimization results of a phantom case and a brain tumor case. Conclusion: The multicriteria optimization of the intensity modulated radiation therapy using pencil proton beam scanning provides a novel tool for treatment planning. Work support by a grant from Varian Inc.

  3. SU-F-T-209: Multicriteria Optimization Algorithm for Intensity Modulated Radiation Therapy Using Pencil Proton Beam Scanning

    International Nuclear Information System (INIS)

    Beltran, C; Kamal, H

    2016-01-01

    Purpose: To provide a multicriteria optimization algorithm for intensity modulated radiation therapy using pencil proton beam scanning. Methods: Intensity modulated radiation therapy using pencil proton beam scanning requires efficient optimization algorithms to overcome the uncertainties in the Bragg peaks locations. This work is focused on optimization algorithms that are based on Monte Carlo simulation of the treatment planning and use the weights and the dose volume histogram (DVH) control points to steer toward desired plans. The proton beam treatment planning process based on single objective optimization (representing a weighted sum of multiple objectives) usually leads to time-consuming iterations involving treatment planning team members. We proved a time efficient multicriteria optimization algorithm that is developed to run on NVIDIA GPU (Graphical Processing Units) cluster. The multicriteria optimization algorithm running time benefits from up-sampling of the CT voxel size of the calculations without loss of fidelity. Results: We will present preliminary results of Multicriteria optimization for intensity modulated proton therapy based on DVH control points. The results will show optimization results of a phantom case and a brain tumor case. Conclusion: The multicriteria optimization of the intensity modulated radiation therapy using pencil proton beam scanning provides a novel tool for treatment planning. Work support by a grant from Varian Inc.

  4. Application of fluence field modulation to proton computed tomography for proton therapy imaging.

    Science.gov (United States)

    Dedes, G; De Angelis, L; Rit, S; Hansen, D; Belka, C; Bashkirov, V; Johnson, R P; Coutrakon, G; Schubert, K E; Schulte, R W; Parodi, K; Landry, G

    2017-07-12

    This simulation study presents the application of fluence field modulated computed tomography, initially developed for x-ray CT, to proton computed tomography (pCT). By using pencil beam (PB) scanning, fluence modulated pCT (FMpCT) may achieve variable image quality in a pCT image and imaging dose reduction. Three virtual phantoms, a uniform cylinder and two patients, were studied using Monte Carlo simulations of an ideal list-mode pCT scanner. Regions of interest (ROI) were selected for high image quality and only PBs intercepting them preserved full fluence (FF). Image quality was investigated in terms of accuracy (mean) and noise (standard deviation) of the reconstructed proton relative stopping power compared to reference values. Dose calculation accuracy on FMpCT images was evaluated in terms of dose volume histograms (DVH), range difference (RD) for beam-eye-view (BEV) dose profiles and gamma evaluation. Pseudo FMpCT scans were created from broad beam experimental data acquired with a list-mode pCT prototype. FMpCT noise in ROIs was equivalent to FF images and accuracy better than  -1.3%(-0.7%) by using 1% of FF for the cylinder (patients). Integral imaging dose reduction of 37% and 56% was achieved for the two patients for that level of modulation. Corresponding DVHs from proton dose calculation on FMpCT images agreed to those from reference images and 96% of BEV profiles had RD below 2 mm, compared to only 1% for uniform 1% of FF. Gamma pass rates (2%, 2 mm) were 98% for FMpCT while for uniform 1% of FF they were as low as 59%. Applying FMpCT to preliminary experimental data showed that low noise levels and accuracy could be preserved in a ROI, down to 30% modulation. We have shown, using both virtual and experimental pCT scans, that FMpCT is potentially feasible and may allow a means of imaging dose reduction for a pCT scanner operating in PB scanning mode. This may be of particular importance to proton therapy given the low integral dose found

  5. Analysis of autonomic modulation of heart rate in patients with Parkinson's disease and elderly individuals submitted to game therapy training.

    Science.gov (United States)

    Rocha, Rodrigo Santiago Barbosa; De Oliveira Rocha, Larissa Salgado; Pena, Elza Sara Maués; Caldas, Laiz Cristinna Ponce; Moreno, Marlene Aparecida

    2018-01-01

    Elderly patients and individuals with Parkinson's disease have a reduction in autonomic heart rate modulation, which may influence the survival of these patients, and rehabilitation can minimize this event. We tested the hypothesis that rehabilitation protocol with game console would influence the cardiac autonomic modulation of patients with Parkinson's Disease. Eight-seven volunteers were divided into two groups, control (n = 45) and Parkinson's (n = 42), they completed the study 40 volunteers in the control group (CG) and 31 patients in the Parkinson group (PG), and subjected to 24 sessions of game therapy physiotherapy, thrice a week. Analysis of autonomic HR modulation was conducted before and after the rehabilitation program using a Polar RS800CX HR sensor. For the analysis of heart rate variability the data were transferred to the Kubios HRV 2.2 program. Statistical analysis was performed in the Biostat 5.2 program, the comparison of the data by ANOVA followed by Tukey test, and the general characteristics by the chi-square test. The critical value for rejecting the null hypothesis was set at P modulation of HR values. Subjects with PD exhibit less autonomic modulation of HR and the rehabilitation protocol with game therapy improved autonomic modulation of HR. Geriatr Gerontol Int 2018; 18: 20-25. © 2017 Japan Geriatrics Society.

  6. Odd and even partial waves of eta pi(-) and eta 'pi(-) in pi(-) p -> eta(('))pi(-)p at 191 GeV/c

    Czech Academy of Sciences Publication Activity Database

    Adolph, C.; Akhunzyanov, R.; Alexeev, M. G.; Alexeev, G. D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Badelek, B.; Balestra, F.; Barth, J.; Baum, G.; Beck, R.; Bedfer, Y.; Berlin, A.; Bernhard, J.; Bicker, K.; Bielert, E. R.; Bieling, J.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Büchele, M.; Burtin, E.; Capozza, L.; Chiosso, M.; Chung, S. U.; Cicuttin, A.; Crespo, M.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S. S.; Dasgupta, S.; Denisov, O. Yu.; Donskov, S. V.; Doshita, N.; Duic, V.; Dünnweber, W.; Dziewiecki, M.; Efremov, A.; Elia, C.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger jr., M.; Fischer, A.; Franco, C.; Fresne von Hohenesche, N.; Friedrich, J. M.; Frolov, V.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Geyer, R.; Gnesi, I.; Gobbo, B.; Goertz, S.; Gorzellik, M.; Grabmüller, S.; Grasso, A.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; von Harrach, D.; Hahne, D.; Hashimoto, R.; Heinsius, F. H.; Herrmann, F.; Hinterberger, F.; Höppner, Ch.; Horikawa, N.; d´Hose, N.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jasinski, P.; Jörg, P.; Joosten, R.; Kabuss, E.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Kisselev, Y.; Klein, F.; Klimaszewski, A. D.; Koivuniemi, J. H.; Kolosov, V. N.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Kotzinian, A. M.; Kouznetsov, O.; Krämer, M.; Kroumchtein, Z. V.; Kuchinski, N.; Kunne, F.; Kurek, K.; Kurjata, R. P.; Lednev, A. A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Maggiora, A.; Magnon, A.; Makke, N.; Mallot, G. K.; Marchand, C.; Martin, A.; Marzec, J.; Matoušek, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nový, J.; Nowak, W. D.; Nunes, A.S.; Olshevsky, A. G.; Orlov, I.; Ostrick, M.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peshekhonov, D. V.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Rocco, E.; Rossiyskaya, N. S.; Ryabchikov, D.; Rychter, A.; Samoylenko, V. D.; Sandacz, A.; Sarkar, S.; Savin, I. A.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schlüter, T.; Schmidt, K.; Schmieden, H.; Schönning, K.; Schopferer, S.; Schott, M.; Shevchenko, O. Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sosio, S.; Sozzi, F.; Srnka, Aleš; Steiger, L.; Stolarski, M.; Sulc, M.; Sulej, R.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Ter Wolbeek, J.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Uhl, S.; Uman, I.; Virius, M.; Wang, L.; Weisrock, T.; Wilfert, M.; Windmolders, R.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2015-01-01

    Roč. 740, 5 JAN (2015), s. 303-311 ISSN 0370-2693 R&D Projects: GA MŠk(CZ) LO1212 Institutional support: RVO:68081731 Keywords : eta-pi * annihilation * resonance * systems * state * rest Subject RIV: BH - Optics, Masers, Lasers Impact factor: 4.787, year: 2015

  7. Disease Control After Reduced Volume Conformal and Intensity Modulated Radiation Therapy for Childhood Craniopharyngioma

    Energy Technology Data Exchange (ETDEWEB)

    Merchant, Thomas E., E-mail: thomas.merchant@stjude.org [St Jude Children' s Research Hospital, Radiological Sciences, Memphis, Tennessee (United States); Kun, Larry E.; Hua, Chia-Ho [St Jude Children' s Research Hospital, Radiological Sciences, Memphis, Tennessee (United States); Wu, Shengjie; Xiong, Xiaoping [St Jude Children' s Research Hospital, Biostatistics, Memphis, Tennessee (United States); Sanford, Robert A.; Boop, Frederick A. [Semmes Murphey Neurologic and Spine Institute, Neurosurgery, Memphis, Tennessee (United States)

    2013-03-15

    Purpose: To estimate the rate of disease control after conformal radiation therapy using reduced clinical target volume (CTV) margins and to determine factors that predict for tumor progression. Methods and Materials: Eighty-eight children (median age, 8.5 years; range, 3.2-17.6 years) received conformal or intensity modulated radiation therapy between 1998 and 2009. The study group included those prospectively treated from 1998 to 2003, using a 10-mm CTV, defined as the margin surrounding the solid and cystic tumor targeted to receive the prescription dose of 54 Gy. The CTV margin was subsequently reduced after 2003, yielding 2 groups of patients: those treated with a CTV margin greater than 5 mm (n=26) and those treated with a CTV margin less than or equal to 5 mm (n=62). Disease progression was estimated on the basis of additional variables including sex, race, extent of resection, tumor interventions, target volume margins, and frequency of weekly surveillance magnetic resonance (MR) imaging during radiation therapy. Median follow-up was 5 years. Results: There was no difference between progression-free survival rates based on CTV margins (>5 mm vs ≤5 mm) at 5 years (88.1% ± 6.3% vs 96.2% ± 4.4% [P=.6386]). There were no differences based on planning target volume (PTV) margins (or combined CTV plus PTV margins). The PTV was systematically reduced from 5 to 3 mm during the time period of the study. Factors predictive of superior progression-free survival included Caucasian race (P=.0175), no requirement for cerebrospinal fluid shunting (P=.0066), and number of surveillance imaging studies during treatment (P=.0216). Patients whose treatment protocol included a higher number of weekly surveillance MR imaging evaluations had a lower rate of tumor progression. Conclusions: These results suggest that targeted volume reductions for radiation therapy using smaller margins are feasible and safe but require careful monitoring. We are currently investigating

  8. Image Guided Hypofractionated Postprostatectomy Intensity Modulated Radiation Therapy for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Stephen L.; Patel, Pretesh; Song, Haijun [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Freedland, Stephen J. [Surgery Section, Durham Veterans Administration, and Division of Urology, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California (United States); Bynum, Sigrun; Oh, Daniel; Palta, Manisha; Yoo, David; Oleson, James [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Salama, Joseph K., E-mail: joseph.salama@duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)

    2016-03-01

    Purpose: Hypofractionated radiation therapy (RT) has promising long-term biochemical relapse-free survival (bRFS) with comparable toxicity for definitive treatment of prostate cancer. However, data reporting outcomes after adjuvant and salvage postprostatectomy hypofractionated RT are sparse. Therefore, we report the toxicity and clinical outcomes after postprostatectomy hypofractionated RT. Methods and Materials: From a prospectively maintained database, men receiving image guided hypofractionated intensity modulated RT (HIMRT) with 2.5-Gy fractions constituted our study population. Androgen deprivation therapy was used at the discretion of the radiation oncologist. Acute toxicities were graded according to the Common Terminology Criteria for Adverse Events version 4.0. Late toxicities were scored using the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer scale. Biochemical recurrence was defined as an increase of 0.1 in prostate-specific antigen (PSA) from posttreatment nadir or an increase in PSA despite treatment. The Kaplan-Meier method was used for the time-to-event outcomes. Results: Between April 2008 and April 2012, 56 men received postoperative HIMRT. The median follow-up time was 48 months (range, 21-67 months). Thirty percent had pre-RT PSA <0.1; the median pre-RT detectable PSA was 0.32 ng/mL. The median RT dose was 65 Gy (range, 57.5-65 Gy). Ten patients received neoadjuvant and concurrent hormone therapy. Posttreatment acute urinary toxicity was limited. There was no acute grade 3 toxicity. Late genitourinary (GU) toxicity of any grade was noted in 52% of patients, 40% of whom had pre-RT urinary incontinence. The 4-year actuarial rate of late grade 3 GU toxicity (exclusively gross hematuria) was 28% (95% confidence interval [CI], 16%-41%). Most grade 3 GU toxicity resolved; only 7% had persistent grade ≥3 toxicity at the last follow-up visit. Fourteen patients experienced biochemical recurrence at a

  9. Search for the $\\Lambda_b^0 \\rightarrow \\Lambda \\eta^\\prime$ and $\\Lambda_b^0\\rightarrow \\Lambda \\eta$ decays with the LHCb detector

    CERN Document Server

    Aaij, Roel; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; d'Argent, Philippe; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Bel, Lennaert; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bertolin, Alessandro; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Birnkraut, Alex; Bizzeti, Andrea; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Braun, Svende; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casanova Mohr, Raimon; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cavallero, Giovanni; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Di Ruscio, Francesco; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dufour, Laurent; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferrari, Fabio; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fohl, Klaus; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gastaldi, Ugo; Gauld, Rhorry; Gavardi, Laura; Gazzoni, Giulio; Geraci, Angelo; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Girard, Olivier Göran; Giubega, Lavinia-Helena; Gligorov, V.V.; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Humair, Thibaud; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Kenzie, Matthew; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kuonen, Axel Kevin; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Liu, Xuesong; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lucchesi, Donatella; Lucio Martinez, Miriam; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Maciuc, Florin; Maev, Oleg; Maguire, Kevin; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Manning, Peter Michael; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathad, Abhijit; Mathe, Zoltan; Matteuzzi, Clara; Matthieu, Kecke; Mauri, Andrea; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Mitzel, Dominik Stefan; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Janine; Müller, Katharina; Müller, Vanessa; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Ninci, Daniele; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Osorio Rodrigues, Bruno; Otalora Goicochea, Juan Martin; Otto, Adam; Owen, Patrick; Oyanguren, Maria Aranzazu; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Pescatore, Luca; Petridis, Konstantinos; Petrolini, Alessandro; Petruzzo, Marco; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Piucci, Alessio; Playfer, Stephen; Plo Casasus, Maximo; Poikela, Tuomas; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Quagliani, Renato; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Lopez, Jairo Alexis; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santimaria, Marco; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmelzer, Timon; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schubiger, Maxime; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skillicorn, Ian; Skwarnicki, Tomasz; Smith, Edmund; Smith, Eluned; Smith, Iwan Thomas; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Sterpka, Christopher Francis; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Tekampe, Tobias; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Todd, Jacob; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Trabelsi, Karim; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Weiden, Andreas; Whitehead, Mark; Wiedner, Dirk; Wilkinson, Guy; Wilkinson, Michael; Williams, Mark Richard James; Williams, Matthew; Williams, Mike; Williams, Timothy; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xu, Zhirui; Yang, Zhenwei; Yu, Jiesheng; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang

    2015-09-01

    A search is performed for the as yet unobserved baryonic $\\Lambda_b^0 \\rightarrow \\Lambda \\eta^\\prime$ and $\\Lambda_b^0 \\rightarrow \\Lambda \\eta$ decays with 3$fb^{-1}$ of proton-proton collision data recorded by the LHCb experiment. The $B^0 \\rightarrow K_S^0 \\eta^\\prime$ decay is used as a normalisation channel. No significant signal is observed for the $\\Lambda_b^0 \\rightarrow \\Lambda \\eta^\\prime$ decay. An upper limit is found on the branching fraction of $\\mathcal{B}(\\Lambda_b^0 \\rightarrow \\Lambda \\eta^\\prime)<3.1\\times10^{-6}$ at 90% confidence level. Evidence is seen for the presence of the $\\Lambda_b^0 \\rightarrow \\Lambda \\eta$ decay at the level of $3\\sigma$ significance, with a branching fraction $\\mathcal{B}(\\Lambda_b^0 \\rightarrow \\Lambda \\eta)=(9.3^{+7.3}_{-5.3})\\times10^{-6}$.

  10. The reactions K-p→Λπ0, Λeta, Λeta' at 4.2 GeV/c

    International Nuclear Information System (INIS)

    Marzano, F.; Hemingway, R.J.; Loverre, P.F.; Marechal, B.; Schrempp, B.; Blokzijl, R.; Hoogland, W.; Kluyver, J.C.; Massaro, G.G.G.; Tiecke, H.G.; Walle, R.T. van de; Vergeest, J.S.M.

    1977-01-01

    In a high statistics CERN 2 m bubble chamber experiment the differential cross sections and polarizations of the Λ for the reactions K - p→Λπ 0 , Λeta, Λeta' at 4.2 GeV/c have been measured. The reaction K - p→Λeta exhibits a pronounced dip around -t approximately 0.5 (GeV/c) 2 and all three reactions show a significant backward peaking (-u 2 ). The Λ polarization in the reaction K - p→Λπ 0 is measured to be significantly different from zero throughout most of the available t-range. Forward cross sections enable a determination of Rsub(T), the ratio of singlet/octet coupling eta 1 KK**/eta 8 KK**. Backward cross sections are utilized to estimate the effective eta-nucleon coupling constant gsub(etaNN) 2 over the -u range 0-1.5 (GeV/c) 2 . (Auth.)

  11. Gravity Chromatic Imaging of the Eta Car's Core

    Science.gov (United States)

    Sanchez-Bermudez, Joel

    2018-04-01

    Eta Car is one of the most massive, and intriguing, Luminous Blue Variables known. In its core resides a binary with a 5.54 years orbital period. Visible, infrared, and X-raobservations suggest that the primary star exhibits a very dense wind with a terminal velocity of about 420 km/s, while the secondary shows a much faster and less dense wind with a terminal velocity of 3000 km/s. The wind-wind collision zone at the core of Eta Car is thus a complex region that deserves a detailed study to understand the effect of the binary interaction in the evolution of the system. Here, we will present a unique imaging campaign with GRAVITY/VLTI of the Eta Car's core. The superb quality of our interferometric data, together with state-of-the-art image reconstruction techniques, allowed us to obtain, with milliarcsecond resolution, continuum and chromatic images cross the BrG and HeI lines in the Eta Car K-band spectrum (R 4000). These new data together with models of the primary wind of Eta Car has letting us to characterize the spatial distribution of the dust and gas in the inner 40 AU wind-wind collision zone of the target.

  12. Intensity-modulated photon arc therapy for treatment of pleural mesothelioma

    International Nuclear Information System (INIS)

    Tobler, Matt; Watson, Gordon; Leavitt, Dennis

    2002-01-01

    Radiotherapy plays a key role in the definitive or adjuvant management of patients with mesothelioma of the pleural surface. Many patients are referred for radiation with intact lung following biopsy or subtotal pleurectomy. Delivery of efficacious doses of radiation to the pleural lining while avoiding lung parenchyma toxicity has been a difficult technical challenge. Using opposed photon fields produce doses in lung that result in moderate-to-severe pulmonary toxicity in 100% of patients treated. Combined photon-electron beam treatment, at total doses of 4250 cGy to the pleural surface, results in two-thirds of the lung volume receiving over 2100 cGy. We have developed a technique using intensity-modulated photon arc therapy (IMRT) that significantly improves the dose distribution to the pleural surface with concomitant decrease in dose to lung parenchyma compared to traditional techniques. IMRT treatment of the pleural lining consists of segments of photon arcs that can be intensity modulated with varying beam weights and multileaf positions to produce a more uniform distribution to the pleural surface, while at the same time reducing the overall dose to the lung itself. Computed tomography (CT) simulation is critical for precise identification of target volumes as well as critical normal structures (lung and heart). Rotational arc trajectories and individual leaf positions and weightings are then defined for each CT plane within the patient. This paper will describe the proposed rotational IMRT technique and, using simulated isodose distributions, show the improved potential for sparing of dose to the critical structures of the lung, heart, and spinal cord

  13. Role of beam orientation optimization in intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Pugachev, Andrei; Li, Jonathan G.; Boyer, Arthur L.; Hancock, Steven L.; Le, Quynh-Thu; Donaldson, Sarah S.; Lei Xing

    2001-01-01

    Purpose: To investigate the role of beam orientation optimization in intensity-modulated radiation therapy (IMRT) and to examine the potential benefits of noncoplanar intensity-modulated beams. Methods and Materials: A beam orientation optimization algorithm was implemented. For this purpose, system variables were divided into two groups: beam position (gantry and table angles) and beam profile (beamlet weights). Simulated annealing was used for beam orientation optimization and the simultaneous iterative inverse treatment planning algorithm (SIITP) for beam intensity profile optimization. Three clinical cases were studied: a localized prostate cancer, a nasopharyngeal cancer, and a paraspinal tumor. Nine fields were used for all treatments. For each case, 3 types of treatment plan optimization were performed: (1) beam intensity profiles were optimized for 9 equiangular spaced coplanar beams; (2) orientations and intensity profiles were optimized for 9 coplanar beams; (3) orientations and intensity profiles were optimized for 9 noncoplanar beams. Results: For the localized prostate case, all 3 types of optimization described above resulted in dose distributions of a similar quality. For the nasopharynx case, optimized noncoplanar beams provided a significant gain in the gross tumor volume coverage. For the paraspinal case, orientation optimization using noncoplanar beams resulted in better kidney sparing and improved gross tumor volume coverage. Conclusion: The sensitivity of an IMRT treatment plan with respect to the selection of beam orientations varies from site to site. For some cases, the choice of beam orientations is important even when the number of beams is as large as 9. Noncoplanar beams provide an additional degree of freedom for IMRT treatment optimization and may allow for notable improvement in the quality of some complicated plans

  14. A review of stereotactic body radiotherapy – is volumetric modulated arc therapy the answer?

    Energy Technology Data Exchange (ETDEWEB)

    Sapkaroski, Daniel, E-mail: daniel.sapkaroski@gmail.com; Osborne, Catherine; Knight, Kellie A [Department of Medical Imaging and Radiation Sciences, Faculty of Medicine, Nursing and Health Sciences, School of Biomedical Sciences, Monash University, Clayton, Vic. (Australia)

    2015-06-15

    Stereotactic body radiotherapy (SBRT) is a high precision radiotherapy technique used for the treatment of small to moderate extra-cranial tumours. Early studies utilising SBRT have shown favourable outcomes. However, major disadvantages of static field SBRT include long treatment times and toxicity complications. Volumetric modulated arc therapy (VMAT) and intensity modulated radiotherapy (IMRT) may potentially mitigate these disadvantages. This review aims to assess the feasibility of emerging VMAT and IMRT-based SBRT treatment techniques and qualify which offers the best outcome for patients, whilst identifying any emerging and advantageous SBRT planning trends. A review and synthesis of data from current literature up to September 2013 was conducted on EMBASE, Medline, PubMed, Science Direct, Proquest central, Google Scholar and the Cochrane Database of Systematic reviews. Only full text papers comparing VMAT and or IMRT and or Static SBRT were included. Ten papers were identified that evaluated the results of VMAT/IMRT SBRT. Five related to medically inoperable stage 1 and 2 non-small-cell lung cancer (NSCLC), three to spinal metastasis, one related to abdominal lymph node malignancies, with the final one looking at pancreatic adenocarcinoma. Overall treatment times with VMAT were reduced by 66–70% for lung, 46–58% for spine, 42% and 21% for lymph node and pancreatic metastasis respectively, planning constraints were met with several studies showing improved organs at risk sparing with IMRT/VMAT to static SBRT. Both IMRT and VMAT were able to meet all planning constraints in the studies reviewed, with VMAT offering the greatest treatment efficiency. Early clinical outcomes with VMAT and IMRT SBRT have demonstrated excellent local control and favourable survival outcomes.

  15. A review of stereotactic body radiotherapy – is volumetric modulated arc therapy the answer?

    International Nuclear Information System (INIS)

    Sapkaroski, Daniel; Osborne, Catherine; Knight, Kellie A

    2015-01-01

    Stereotactic body radiotherapy (SBRT) is a high precision radiotherapy technique used for the treatment of small to moderate extra-cranial tumours. Early studies utilising SBRT have shown favourable outcomes. However, major disadvantages of static field SBRT include long treatment times and toxicity complications. Volumetric modulated arc therapy (VMAT) and intensity modulated radiotherapy (IMRT) may potentially mitigate these disadvantages. This review aims to assess the feasibility of emerging VMAT and IMRT-based SBRT treatment techniques and qualify which offers the best outcome for patients, whilst identifying any emerging and advantageous SBRT planning trends. A review and synthesis of data from current literature up to September 2013 was conducted on EMBASE, Medline, PubMed, Science Direct, Proquest central, Google Scholar and the Cochrane Database of Systematic reviews. Only full text papers comparing VMAT and or IMRT and or Static SBRT were included. Ten papers were identified that evaluated the results of VMAT/IMRT SBRT. Five related to medically inoperable stage 1 and 2 non-small-cell lung cancer (NSCLC), three to spinal metastasis, one related to abdominal lymph node malignancies, with the final one looking at pancreatic adenocarcinoma. Overall treatment times with VMAT were reduced by 66–70% for lung, 46–58% for spine, 42% and 21% for lymph node and pancreatic metastasis respectively, planning constraints were met with several studies showing improved organs at risk sparing with IMRT/VMAT to static SBRT. Both IMRT and VMAT were able to meet all planning constraints in the studies reviewed, with VMAT offering the greatest treatment efficiency. Early clinical outcomes with VMAT and IMRT SBRT have demonstrated excellent local control and favourable survival outcomes

  16. Applicator-guided volumetric-modulated arc therapy for low-risk endometrial cancer

    Energy Technology Data Exchange (ETDEWEB)

    Cilla, Savino, E-mail: savinocilla@gmail.com [Medical Physics Unit, Fondazione di ricerca e cura “Giovanni Paolo II,” Università Cattolica del Sacro Cuore, Campobasso (Italy); Macchia, Gabriella [Radiation Oncology Unit, Fondazione di ricerca e cura “Giovanni Paolo II,” Università Cattolica del Sacro Cuore, Campobasso (Italy); Sabatino, Domenico [Medical Physics Unit, Fondazione di ricerca e cura “Giovanni Paolo II,” Università Cattolica del Sacro Cuore, Campobasso (Italy); Digesù, Cinzia; Deodato, Francesco [Radiation Oncology Unit, Fondazione di ricerca e cura “Giovanni Paolo II,” Università Cattolica del Sacro Cuore, Campobasso (Italy); Piermattei, Angelo [Physics Institute, Università Cattolica del Sacro Cuore, Rome (Italy); De Spirito, Marco [Medical Physics Unit, Fondazione di ricerca e cura “Giovanni Paolo II,” Università Cattolica del Sacro Cuore, Campobasso (Italy); Morganti, Alessio G. [Radiation Oncology Unit, Fondazione di ricerca e cura “Giovanni Paolo II,” Università Cattolica del Sacro Cuore, Campobasso (Italy); Radiation Oncology Unit, Università Cattolica del Sacro Cuore, Rome (Italy)

    2013-04-01

    The aim of this study was to report the feasibility of volumetric-modulated arc therapy (VMAT) in the postoperative irradiation of the vaginal vault. Moreover, the VMAT technique was compared with 3D conformal radiotherapy (3D-CRT) and fixed-field intensity-modulated radiotherapy (IMRT), in terms of target coverage and organs at risk sparing. The number of monitor units and the delivery time were analyzed to score the treatment efficiency. All plans were verified in a dedicated solid water phantom using a 2D array of ionization chambers. Twelve patients with endometrial carcinoma who underwent radical hystero-adenexectomy and fixed-field IMRT treatments were retrospectively included in this analysis; for each patient, plans were compared in terms of dose-volume histograms, homogeneity index, and conformity indexes. All techniques met the prescription goal for planning target volume coverage, with VMAT showing the highest level of conformity at all dose levels. VMAT resulted in significant reduction of rectal and bladder volumes irradiated at all dose levels compared with 3D-CRT. No significant differences were found with respect to IMRT. Moreover, a significant improvement of the dose conformity was reached by VMAT technique not only at the 95% dose level (0.74 vs. 0.67 and 0.62) but also at 50% and 75% levels of dose prescription. In addition, VMAT plans showed a significant reduction of monitor units by nearly 28% with respect to IMRT, and reduced treatment time from 11 to <3 minutes for a single 6-Gy fraction. In conclusion, VMAT plans can be planned and carried out with high quality and efficiency for the irradiation of vaginal vault alone, providing similar or better sparing of organs at risk to fixed-field IMRT and resulting in the most efficient treatment option. VMAT is currently our standard approach for radiotherapy of low-risk endometrial cancer.

  17. Volumetric-modulated arc therapy in postprostatectomy radiotherapy patients: A planning comparison study

    International Nuclear Information System (INIS)

    Forde, Elizabeth; Kneebone, Andrew; Bromley, Regina; Guo, Linxin; Hunt, Peter; Eade, Thomas

    2013-01-01

    The purpose of this study was to compare postprostatectomy planning for volumetric-modulated arc therapy (VMAT) with both single arc (SA) and double arcs (DA) against dynamic sliding window intensity-modulated radiotherapy (IMRT). Ten cases were planned with IMRT, SA VMAT, and DA VMAT. All cases were planned to achieve a minimum dose of 68 Gy to 95% of the planning target volume (PTV) and goals to limit rectal volume >40 Gy to 35% and >65 Gy to 17%, and bladder volumes >40 Gy to 50% and >65 Gy to 25%. Plans were averaged across the 10 patients and compared for mean dose, conformity, homogeneity, rectal and bladder doses, and monitor units. The mean dose to the clinical target volume and PTV was significantly higher (p<0.05) for SA compared with DA or IMRT. The homogeneity index was not significantly different: SA = 0.09; DA = 0.08; and IMRT = 0.07. The rectal V40 was lowest for the DA plan. The rectal V20 was significantly lower (p<0.05) for both the VMAT plans compared with IMRT. There were no significant differences for bladder V40 or rectal and bladder V65. The IMRT plans required 1400 MU compared with 745 for DA and 708 for SA. This study shows that for equivalent dose coverage, SA and DA VMAT plans result in higher mean doses to the clinical target volume and PTV. This greater dose heterogeneity is balanced by improved low-range rectal doses and halving of the monitor units

  18. Volumetric-modulated arc therapy in postprostatectomy radiotherapy patients: A planning comparison study

    Energy Technology Data Exchange (ETDEWEB)

    Forde, Elizabeth, E-mail: eforde@tcd.ie [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Kneebone, Andrew [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Northern Clinical School, University of Sydney, New South Wales (Australia); Bromley, Regina [Institute of Medical Physics, School of Physics, University of Sydney, New South Wales (Australia); Guo, Linxin; Hunt, Peter [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Eade, Thomas [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Northern Clinical School, University of Sydney, New South Wales (Australia)

    2013-10-01

    The purpose of this study was to compare postprostatectomy planning for volumetric-modulated arc therapy (VMAT) with both single arc (SA) and double arcs (DA) against dynamic sliding window intensity-modulated radiotherapy (IMRT). Ten cases were planned with IMRT, SA VMAT, and DA VMAT. All cases were planned to achieve a minimum dose of 68 Gy to 95% of the planning target volume (PTV) and goals to limit rectal volume >40 Gy to 35% and >65 Gy to 17%, and bladder volumes >40 Gy to 50% and >65 Gy to 25%. Plans were averaged across the 10 patients and compared for mean dose, conformity, homogeneity, rectal and bladder doses, and monitor units. The mean dose to the clinical target volume and PTV was significantly higher (p<0.05) for SA compared with DA or IMRT. The homogeneity index was not significantly different: SA = 0.09; DA = 0.08; and IMRT = 0.07. The rectal V40 was lowest for the DA plan. The rectal V20 was significantly lower (p<0.05) for both the VMAT plans compared with IMRT. There were no significant differences for bladder V40 or rectal and bladder V65. The IMRT plans required 1400 MU compared with 745 for DA and 708 for SA. This study shows that for equivalent dose coverage, SA and DA VMAT plans result in higher mean doses to the clinical target volume and PTV. This greater dose heterogeneity is balanced by improved low-range rectal doses and halving of the monitor units.

  19. The dosimetric effects of photon energy on the quality of prostate volumetric modulated arc therapy.

    Science.gov (United States)

    Mattes, Malcolm D; Tai, Cyril; Lee, Alvin; Ashamalla, Hani; Ikoro, N C

    2014-01-01

    Studies comparing the dosimetric effects of high- and low-energy photons to treat prostate cancer using 3-dimensional conformal and intensity modulated radiation therapy have yielded mixed results. With the advent of newer radiation delivery systems like volumetric modulated arc therapy (VMAT), the impact of changing photon energy is readdressed. Sixty-five patients treated for prostate cancer at our institution from 2011 to 2012 underwent CT simulation. A target volume encompassing the prostate and entire seminal vesicles was treated to 50.4 Gy, followed by a boost to the prostate and proximal seminal vesicles to a total dose of 81 Gy. The VMAT plans were generated for 6-MV and 10-MV photons under identical optimization conditions using the Eclipse system version 8.6 (Varian Medical Systems, Palo Alto, CA). The analytical anisotropic algorithm was used for all dose calculations. Plans were normalized such that 98% of the planning target volume (PTV) received 100% of the prescribed dose. Dose-volumetric data from the treatment planning system was recorded for both 6-MV and 10-MV plans, which were compared for both the entire cohort and subsets of patients stratified according to the anterior-posterior separation. Plans using 10-MV photons had statistically significantly lower relative integral dose (4.1%), gradient measure (4.1%), skin Dmax (16.9%), monitor units (13.0%), and bladder V(30) (3.1%) than plans using 6-MV photons (P photons was more pronounced for thicker patients (anterior-posterior separation >21 cm) for most parameters, with statistically significant differences in bladder V(30), bladder V(65), integral dose, conformity index, and monitor units. The main dosimetric benefits of 10-MV as compared with 6-MV photons are seen in thicker patients, though for the entire cohort 10-MV plans resulted in a lower integral dose, gradient measure, skin Dmax, monitor units, and bladder V(30), possibly at the expense of higher rectum V(81). Copyright © 2014

  20. Computer-assisted selection of coplanar beam orientations in intensity-modulated radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Pugachev, A.; Xing, L. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States)]. E-mail: lei@reyes.stanford.edu

    2001-09-01

    In intensity-modulated radiation therapy (IMRT), the incident beam orientations are often determined by a trial and error search. The conventional beam's-eye view (BEV) tool becomes less helpful in IMRT because it is frequently required that beams go through organs at risk (OARs) in order to achieve a compromise between the dosimetric objectives of the planning target volume (PTV) and the OARs. In this paper, we report a beam's-eye view dosimetrics (BEVD) technique to assist in the selection of beam orientations in IMRT. In our method, each beam portal is divided into a grid of beamlets. A score function is introduced to measure the 'goodness' of each beamlet at a given gantry angle. The score is determined by the maximum PTV dose deliverable by the beamlet without exceeding the tolerance doses of the OARs and normal tissue located in the path of the beamlet. The overall score of the gantry angle is given by a sum of the scores of all beamlets. For a given patient, the score function is evaluated for each possible beam orientation. The directions with the highest scores are then selected as the candidates for beam placement. This procedure is similar to the BEV approach used in conventional radiation therapy, except that the evaluation by a human is replaced by a score function to take into account the intensity modulation. This technique allows one to select beam orientations without the excessive computing overhead of computer optimization of beam orientation. It also provides useful insight into the problem of selection of beam orientation and is especially valuable for complicated cases where the PTV is surrounded by several sensitive structures and where it is difficult to select a set of 'good' beam orientations. Several two-dimensional (2D) model cases were used to test the proposed technique. The plans obtained using the BEVD-selected beam orientations were compared with the plans obtained using equiangular spaced beams. For

  1. Beam angle optimization for intensity-modulated radiation therapy using a guided pattern search method

    International Nuclear Information System (INIS)

    Rocha, Humberto; Dias, Joana M; Ferreira, Brígida C; Lopes, Maria C

    2013-01-01

    Generally, the inverse planning of radiation therapy consists mainly of the fluence optimization. The beam angle optimization (BAO) in intensity-modulated radiation therapy (IMRT) consists of selecting appropriate radiation incidence directions and may influence the quality of the IMRT plans, both to enhance better organ sparing and to improve tumor coverage. However, in clinical practice, most of the time, beam directions continue to be manually selected by the treatment planner without objective and rigorous criteria. The goal of this paper is to introduce a novel approach that uses beam’s-eye-view dose ray tracing metrics within a pattern search method framework in the optimization of the highly non-convex BAO problem. Pattern search methods are derivative-free optimization methods that require a few function evaluations to progress and converge and have the ability to better avoid local entrapment. The pattern search method framework is composed of a search step and a poll step at each iteration. The poll step performs a local search in a mesh neighborhood and ensures the convergence to a local minimizer or stationary point. The search step provides the flexibility for a global search since it allows searches away from the neighborhood of the current iterate. Beam’s-eye-view dose metrics assign a score to each radiation beam direction and can be used within the pattern search framework furnishing a priori knowledge of the problem so that directions with larger dosimetric scores are tested first. A set of clinical cases of head-and-neck tumors treated at the Portuguese Institute of Oncology of Coimbra is used to discuss the potential of this approach in the optimization of the BAO problem. (paper)

  2. Replanning During Intensity Modulated Radiation Therapy Improved Quality of Life in Patients With Nasopharyngeal Carcinoma

    International Nuclear Information System (INIS)

    Yang Haihua; Hu Wei; Wang Wei; Chen Peifang; Ding Weijun; Luo Wei

    2013-01-01

    Purpose: Anatomic and dosimetric changes have been reported during intensity modulated radiation therapy (IMRT) in patients with nasopharyngeal carcinoma (NPC). The purpose of this study was to evaluate the effects of replanning on quality of life (QoL) and clinical outcomes during the course of IMRT for NPC patients. Methods and Materials: Between June 2007 and August 2011, 129 patients with NPC were enrolled. Forty-three patients received IMRT without replanning, while 86 patients received IMRT replanning after computed tomography (CT) images were retaken part way through therapy. Chinese versions of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 and Head and Neck Quality of Life Questionnaire 35 were completed before treatment began and at the end of treatment and at 1, 3, 6, and 12 months after the completion of treatment. Overall survival (OS) data were compared using the Kaplan-Meier method. Results: IMRT replanning had a profound impact on the QoL of NPC patients, as determined by statistically significant changes in global QoL and other QoL scales. Additionally, the clinical outcome comparison indicates that replanning during IMRT for NPC significantly improved 2-year local regional control (97.2% vs 92.4%, respectively, P=.040) but did not improve 2-year OS (89.8% vs 82.2%, respectively, P=.475). Conclusions: IMRT replanning improves QoL as well as local regional control in patients with NPC. Future research is needed to determine the criteria for replanning for NPC patients undergoing IMRT.

  3. Kilovoltage Intrafraction Monitoring for Prostate Intensity Modulated Arc Therapy: First Clinical Results

    International Nuclear Information System (INIS)

    Ng, Jin Aun; Booth, Jeremy T.; Poulsen, Per R.; Fledelius, Walther; Worm, Esben Schjødt; Eade, Thomas; Hegi, Fiona; Kneebone, Andrew; Kuncic, Zdenka; Keall, Paul J.

    2012-01-01

    Purpose: Most linear accelerators purchased today are equipped with a gantry-mounted kilovoltage X-ray imager which is typically used for patient imaging prior to therapy. A novel application of the X-ray system is kilovoltage intrafraction monitoring (KIM), in which the 3-dimensional (3D) tumor position is determined during treatment. In this paper, we report on the first use of KIM in a prospective clinical study of prostate cancer patients undergoing intensity modulated arc therapy (IMAT). Methods and Materials: Ten prostate cancer patients with implanted fiducial markers undergoing conventionally fractionated IMAT (RapidArc) were enrolled in an ethics-approved study of KIM. KIM involves acquiring kV images as the gantry rotates around the patient during treatment. Post-treatment, markers in these images were segmented to obtain 2D positions. From the 2D positions, a maximum likelihood estimation of a probability density function was used to obtain 3D prostate trajectories. The trajectories were analyzed to determine the motion type and the percentage of time the prostate was displaced ≥3, 5, 7, and 10 mm. Independent verification of KIM positional accuracy was performed using kV/MV triangulation. Results: KIM was performed for 268 fractions. Various prostate trajectories were observed (ie, continuous target drift, transient excursion, stable target position, persistent excursion, high-frequency excursions, and erratic behavior). For all patients, 3D displacements of ≥3, 5, 7, and 10 mm were observed 5.6%, 2.2%, 0.7% and 0.4% of the time, respectively. The average systematic accuracy of KIM was measured at 0.46 mm. Conclusions: KIM for prostate IMAT was successfully implemented clinically for the first time. Key advantages of this method are (1) submillimeter accuracy, (2) widespread applicability, and (3) a low barrier to clinical implementation. A disadvantage is that KIM delivers additional imaging dose to the patient.

  4. Postmastectomy intensity modulated radiation therapy following immediate expander-implant reconstruction

    International Nuclear Information System (INIS)

    Koutcher, Lawrence; Ballangrud, Ase; Cordeiro, Peter G.; McCormick, Beryl; Hunt, Margie; Zee, Kimberly J. Van; Hudis, Clifford; Beal, Kathryn

    2010-01-01

    Background/purpose: To evaluate radiation plans of patients undergoing mastectomy with immediate expander-implant reconstruction followed by postmastectomy radiation therapy (PMRT). Materials/methods: We identified 41 patients from June 2004 to May 2007 who underwent mastectomy, immediate expander-implant reconstruction, and PMRT with intensity-modulated radiation therapy. We assessed chest wall (CW) coverage and volume of heart and lung irradiated. Results: In 73% of patients, all CW borders were adequately covered, and in 22%, all but 1 border were adequately covered. The total lung V 20 was 20 was 13% (range, 3-23%), and the mean heart D mean was 2.81 Gy (range, 0.53-9.60 Gy). In patients with left-sided lesions without internal mammary nodes (IMNs) treatment (n = 22), the mean lung V 20 was 12.6% and the mean heart D mean was 3.90 Gy, and in the patient with IMN treatment, the lung V 20 was 18% and heart D mean was 8.04 Gy. For right-sided lesions without IMN treatment (n = 12), the mean lung V 20 was 12.4% and the mean heart D mean was 0.90 Gy, and in patients with IMN treatment (n = 6), these numbers were 17.8% and 1.76 Gy. At a median follow-up of 29 months, the 30-month actuarial local control was 97%. Conclusions: In women undergoing immediate expander-implant reconstruction, PMRT can achieve excellent local control with acceptable heart and lung doses. These results can be achieved even when the IMN are being treated, although doses to the heart and lungs will be higher.

  5. Adoption of Intensity Modulated Radiation Therapy For Early-Stage Breast Cancer From 2004 Through 2011

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Elyn H. [Yale School of Medicine, New Haven, Connecticut (United States); Mougalian, Sarah S. [Yale School of Medicine, New Haven, Connecticut (United States); Yale Cancer Center, New Haven, Connecticut (United States); Cancer Outcomes, Public Policy, and Effectiveness Research Center at Yale, New Haven, Connecticut (United States); Soulos, Pamela R. [Yale School of Medicine, New Haven, Connecticut (United States); Cancer Outcomes, Public Policy, and Effectiveness Research Center at Yale, New Haven, Connecticut (United States); Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut (United States); Smith, Benjamin D. [Department of Radiation Oncology, MD Anderson Cancer Center, Houston, Texas (United States); Haffty, Bruce G. [Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey (United States); Gross, Cary P. [Yale School of Medicine, New Haven, Connecticut (United States); Cancer Outcomes, Public Policy, and Effectiveness Research Center at Yale, New Haven, Connecticut (United States); Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut (United States); Yu, James B., E-mail: james.b.yu@yale.edu [Yale School of Medicine, New Haven, Connecticut (United States); Cancer Outcomes, Public Policy, and Effectiveness Research Center at Yale, New Haven, Connecticut (United States); Department of Therapeutic Radiology, Yale School of Medicine, New Haven, Connecticut (United States)

    2015-02-01

    Purpose: Intensity modulated radiation therapy (IMRT) is a newer method of radiation therapy (RT) that has been increasingly adopted as an adjuvant treatment after breast-conserving surgery (BCS). IMRT may result in improved cosmesis compared to standard RT, although at greater expense. To investigate the adoption of IMRT, we examined trends and factors associated with IMRT in women under the age of 65 with early stage breast cancer. Methods and Materials: We performed a retrospective study of early stage breast cancer patients treated with BCS followed by whole-breast irradiation (WBI) who were ≤65 years old in the National Cancer Data Base from 2004 to 2011. We used logistic regression to identify factors associated with receipt of IMRT (vs standard RT). Results: We identified 11,089 women with early breast cancer (9.6%) who were treated with IMRT and 104,448 (90.4%) who were treated with standard RT, after BCS. The proportion of WBI patients receiving IMRT increased yearly from 2004 to 2009, with 5.3% of WBI patients receiving IMRT in 2004 and 11.6% receiving IMRT in 2009. Further use of IMRT declined afterward, with the proportion remaining steady at 11.0% and 10.7% in 2010 and 2011, respectively. Patients treated in nonacademic community centers were more likely to receive IMRT (odds ratio [OR], 1.36; 95% confidence interval [CI], 1.30-1.43 for nonacademic vs academic center). Compared to privately insured patients, the uninsured patients (OR, 0.81; 95% CI, 0.70-0.95) and those with Medicaid insurance (OR, 0.87; 95% CI, 0.79-0.95) were less likely to receive IMRT. Conclusions: The use of IMRT rose from 2004 to 2009 and then stabilized. Important nonclinical factors associated with IMRT use included facility type and insurance status.

  6. Adoption of Intensity Modulated Radiation Therapy For Early-Stage Breast Cancer From 2004 Through 2011

    International Nuclear Information System (INIS)

    Wang, Elyn H.; Mougalian, Sarah S.; Soulos, Pamela R.; Smith, Benjamin D.; Haffty, Bruce G.; Gross, Cary P.; Yu, James B.

    2015-01-01

    Purpose: Intensity modulated radiation therapy (IMRT) is a newer method of radiation therapy (RT) that has been increasingly adopted as an adjuvant treatment after breast-conserving surgery (BCS). IMRT may result in improved cosmesis compared to standard RT, although at greater expense. To investigate the adoption of IMRT, we examined trends and factors associated with IMRT in women under the age of 65 with early stage breast cancer. Methods and Materials: We performed a retrospective study of early stage breast cancer patients treated with BCS followed by whole-breast irradiation (WBI) who were ≤65 years old in the National Cancer Data Base from 2004 to 2011. We used logistic regression to identify factors associated with receipt of IMRT (vs standard RT). Results: We identified 11,089 women with early breast cancer (9.6%) who were treated with IMRT and 104,448 (90.4%) who were treated with standard RT, after BCS. The proportion of WBI patients receiving IMRT increased yearly from 2004 to 2009, with 5.3% of WBI patients receiving IMRT in 2004 and 11.6% receiving IMRT in 2009. Further use of IMRT declined afterward, with the proportion remaining steady at 11.0% and 10.7% in 2010 and 2011, respectively. Patients treated in nonacademic community centers were more likely to receive IMRT (odds ratio [OR], 1.36; 95% confidence interval [CI], 1.30-1.43 for nonacademic vs academic center). Compared to privately insured patients, the uninsured patients (OR, 0.81; 95% CI, 0.70-0.95) and those with Medicaid insurance (OR, 0.87; 95% CI, 0.79-0.95) were less likely to receive IMRT. Conclusions: The use of IMRT rose from 2004 to 2009 and then stabilized. Important nonclinical factors associated with IMRT use included facility type and insurance status

  7. SU-F-T-79: Monte Carlo Investigation of Optimizing Parameters for Modulated Electron Arc Therapy

    International Nuclear Information System (INIS)

    Al Ashkar, E; Eraba, K; Imam, M; Eldib, A; Ma, C

    2016-01-01

    Purpose: Electron arc therapy provides excellent dose distributions for treating superficial tumors along curved surfaces. However this modality has not received widespread application due to the lack of needed advancement in electron beam delivery, accurate electron dose calculation and treatment plan optimization. The aim of the current work is to investigate possible parameters that can be optimized for electron arc (eARC) therapy. Methods: The MCBEAM code was used to generate phase space files for 6 and 12MeV electron beam energies from a Varian trilogy machine. An Electron Multi-leaf collimator eMLC of 2cm thickness positioned at 82 cm source collimated distance was used in the study. Dose distributions for electron arcs were calculated inside a cylindrical phantom using the MCSIM code. The Cylindrical phantom was constructed with 0.2cm voxels and a 15cm diameter. Electron arcs were delivered with two different approaches. The first approach was to deliver the arc as segments of very small field widths. In this approach we also tested the impact of the segment size and the arc increment angle. The second approach is to deliver the arc as a sum of large fields each covering the whole target as seen from the beam eye view. Results: In considering 90 % as the prescription isodose line, the first approach showed a region of buildup proceeding before the prescription zone. This build up is minimizing with the second approach neglecting need for bolus. The second approach also showed less x-ray contamination. In both approaches the variation of the segment size changed the size and location of the prescription isodose line. The optimization process for eARC could involve interplay between small and large segments to achieve desired coverage. Conclusion: An advanced modulation of eARCs will allow for tailored dose distribution for superficial curved target as with challenging scalp cases

  8. Fast voxel and polygon ray-tracing algorithms in intensity modulated radiation therapy treatment planning

    International Nuclear Information System (INIS)

    Fox, Christopher; Romeijn, H. Edwin; Dempsey, James F.

    2006-01-01

    We present work on combining three algorithms to improve ray-tracing efficiency in radiation therapy dose computation. The three algorithms include: An improved point-in-polygon algorithm, incremental voxel ray tracing algorithm, and stereographic projection of beamlets for voxel truncation. The point-in-polygon and incremental voxel ray-tracing algorithms have been used in computer graphics and nuclear medicine applications while the stereographic projection algorithm was developed by our group. These algorithms demonstrate significant improvements over the current standard algorithms in peer reviewed literature, i.e., the polygon and voxel ray-tracing algorithms of Siddon for voxel classification (point-in-polygon testing) and dose computation, respectively, and radius testing for voxel truncation. The presented polygon ray-tracing technique was tested on 10 intensity modulated radiation therapy (IMRT) treatment planning cases that required the classification of between 0.58 and 2.0 million voxels on a 2.5 mm isotropic dose grid into 1-4 targets and 5-14 structures represented as extruded polygons (a.k.a. Siddon prisms). Incremental voxel ray tracing and voxel truncation employing virtual stereographic projection was tested on the same IMRT treatment planning cases where voxel dose was required for 230-2400 beamlets using a finite-size pencil-beam algorithm. Between a 100 and 360 fold cpu time improvement over Siddon's method was observed for the polygon ray-tracing algorithm to perform classification of voxels for target and structure membership. Between a 2.6 and 3.1 fold reduction in cpu time over current algorithms was found for the implementation of incremental ray tracing. Additionally, voxel truncation via stereographic projection was observed to be 11-25 times faster than the radial-testing beamlet extent approach and was further improved 1.7-2.0 fold through point-classification using the method of translation over the cross product technique

  9. Photon and electron collimator effects on electron output and abutting segments in energy modulated electron therapy

    International Nuclear Information System (INIS)

    Olofsson, Lennart; Karlsson, Magnus G.; Karlsson, Mikael

    2005-01-01

    In energy modulated electron therapy a large fraction of the segments will be arranged as abutting segments where inhomogeneities in segment matching regions must be kept as small as possible. Furthermore, the output variation between different segments should be minimized and must in all cases be well predicted. For electron therapy with add-on collimators, both the electron MLC (eMLC) and the photon MLC (xMLC) contribute to these effects when an xMLC tracking technique is utilized to reduce the x-ray induced leakage. Two add-on electron collimator geometries have been analyzed using Monte Carlo simulations: One isocentric eMLC geometry with an isocentric clearance of 35 cm and air or helium in the treatment head, and one conventional proximity geometry with a clearance of 5 cm and air in the treatment head. The electron fluence output for 22.5 MeV electrons is not significantly affected by the xMLC if the shielding margins are larger than 2-3 cm. For small field sizes and 9.6 MeV electrons, the isocentric design with helium in the treatment head or shielding margins larger than 3 cm is needed to avoid a reduced electron output. Dose inhomogeneity in the matching region of electron segments is, in general, small when collimator positions are adjusted to account for divergence in the field. The effect of xMLC tracking on the electron output can be made negligible while still obtaining a substantially reduced x-ray leakage contribution. Collimator scattering effects do not interfere significantly when abutting beam techniques are properly applied

  10. SU-E-T-124: Dosimetric Comparison of HDR Brachytherapy and Intensity Modulated Proton Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J [Purdue University, West Lafayette, IN (United States); Wu, H [IUPUI, Indianapolis, IN (United States); Das, I [Indiana University- School of Medicine, Indianapolis, IN (United States)

    2014-06-01

    Purpose: Brachytherapy is known to be able to deliver more radiation dose to tumor while minimizing radiation dose to surrounding normal tissues. Proton therapy also provides superior dose distribution due to Bragg peak. Since both HDR and Intensity Modulated Proton Therapy (IMPT) are beneficial for their quick dose drop off, our goal in this study is to compare the pace of dose gradient drop-off between HDR and IMPT plans based on the same CT image data-set. In addition, normal tissues sparing were also compared among HDR, IMPT and SBRT. Methods: Five cervical cancer cases treated with EBRT + HDR boost combination with Tandem and Ovoid applicator were used for comparison purpose. Original HDR plans with prescribed dose of 5.5 Gy x 5 fractions were generated and optimized. The 100% isodose line of HDR plans was converted to a dose volume, and treated as CTV for IMPT and SBRT planning. The same HDR CT scans were also used for IMPT plan and SBRT plan for direct comparison. The philosophy of the IMPT and SBRT planning was to create the same CTV coverage as HDR plans. All three modalities treatment plans were compared to each other with a set of predetermined criteria. Results: With similar target volume coverage in cervix cancer boost treatment, HDR provides a slightly sharper dose drop-off from 100% to 50% isodose line, averagely in all directions compared to IMPT. However, IMPT demonstrated more dose gradient drop-off at the junction of the target and normal tissues by providing more normal tissue sparing and superior capability to reduce integral dose. Conclusion: IMPT is capable of providing comparable dose drop-off as HDR. IMPT can be explored as replacement for HDR brachytherapy in various applications.

  11. Target tracking using DMLC for volumetric modulated arc therapy: A simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Sun Baozhou; Rangaraj, Dharanipathy; Papiez, Lech; Oddiraju, Swetha; Yang Deshan; Li, H. Harold [Department of Radiation Oncology, School of Medicine, Washington University, 4921 Parkview Place, St. Louis, Missouri 63110 (United States); Department of Radiation Oncology, Southwestern Medical Center, University of Texas, Dallas, Texas 75390 (United States); Department of Radiation Oncology, School of Medicine, Washington University, 4921 Parkview Place, St. Louis, Missouri 63110 (United States)

    2010-12-15

    Purpose: Target tracking using dynamic multileaf collimator (DMLC) is a promising approach for intrafraction motion management in radiation therapy. The purpose of this work is to develop a DMLC tracking algorithm capable of delivering volumetric-modulated arc therapy (VMAT) to the targets that experience two-dimensional (2D) rigid motion in the beam's eye view. Methods: The problem of VMAT delivery to moving targets is formulated as a control problem with constraints. The relationships between gantry speed, gantry acceleration, MLC leaf-velocity, dose rate, and target motion are derived. An iterative search algorithm is developed to find numerical solutions for efficient delivery of a specific VMAT plan to the moving target using 2D DMLC tracking. The delivery of five VMAT lung plans is simulated. The planned and delivered fluence maps in the target-reference frame are calculated and compared. Results: The simulation demonstrates that the 2D tracking algorithm is capable of delivering the VMAT plan to a moving target fast and accurately without violating the machine constraints and the integrity of the treatment plan. The average delivery time is only 29 s longer than that of no-tracking delivery, 101 versus 72 s, respectively. The fluence maps are normalized to 200 MU and the average root-mean-square error between the desired and the delivered fluence is 2.1 MU, compared to 14.8 MU for no-tracking and 3.6 MU for one-dimensional tracking. Conclusions: A locally optimal MLC tracking algorithm for VMAT delivery is proposed, aiming at shortest delivery time while maintaining treatment plan invariant. The inconsequential increase of treatment time due to DMLC tracking is clinically desirable, which makes VMAT with DMLC tracking attractive in treating moving tumors.

  12. A class solution for volumetric-modulated arc therapy planning in postprostatectomy radiotherapy

    International Nuclear Information System (INIS)

    Forde, Elizabeth; Bromley, Regina; Kneebone, Andrew; Eade, Thomas

    2014-01-01

    This study is aimed to test a postprostatectomy volumetric-modulated arc therapy (VMAT) planning class solution. The solution applies to both the progressive resolution optimizer algorithm version 2 (PRO 2) and the algorithm version 3 (PRO 3), addressing the effect of an upgraded algorithm. A total of 10 radical postprostatectomy patients received 68 Gy to 95% of the planning target volume (PTV), which was planned using VMAT. Each case followed a set of planning instructions; including contouring, field setup, and predetermined optimization parameters. Each case was run through both algorithms only once, with no user interaction. Results were averaged and compared against Radiation Therapy Oncology Group (RTOG) 0534 end points. In addition, the clinical target volume (CTV) D 100 , PTV D 99 , and PTV mean doses were recorded, along with conformity indices (CIs) (95% and 98%) and the homogeneity index. All cases satisfied PTV D 95 of 68 Gy and a maximum dose < 74.8 Gy. The average result for the PTV D 99 was 64.1 Gy for PRO 2 and 62.1 Gy for PRO 3. The average PTV mean dose for PRO 2 was 71.4 Gy and 71.5 Gy for PRO 3. The CTV D 100 average dose was 67.7 and 68.0 Gy for PRO 2 and PRO 3, respectively. The mean homogeneity index for both algorithms was 0.08. The average 95% CI was 1.17 for PRO 2 and 1.19 for PRO 3. For 98%, the average results were 1.08 and 1.12 for PRO 2 and PRO 3, respectively. All cases for each algorithm met the RTOG organs at risk dose constraints. A successful class solution has been established for prostate bed VMAT radiotherapy regardless of the algorithm used

  13. A class solution for volumetric-modulated arc therapy planning in postprostatectomy radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Forde, Elizabeth, E-mail: eforde@tcd.ie [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Bromley, Regina [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Institute of Medical Physics, School of Physics, University of Sydney, New South Wales (Australia); Kneebone, Andrew; Eade, Thomas [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Northern Clinical School, University of Sydney, New South Wales (Australia)

    2014-10-01

    This study is aimed to test a postprostatectomy volumetric-modulated arc therapy (VMAT) planning class solution. The solution applies to both the progressive resolution optimizer algorithm version 2 (PRO 2) and the algorithm version 3 (PRO 3), addressing the effect of an upgraded algorithm. A total of 10 radical postprostatectomy patients received 68 Gy to 95% of the planning target volume (PTV), which was planned using VMAT. Each case followed a set of planning instructions; including contouring, field setup, and predetermined optimization parameters. Each case was run through both algorithms only once, with no user interaction. Results were averaged and compared against Radiation Therapy Oncology Group (RTOG) 0534 end points. In addition, the clinical target volume (CTV) D{sub 100}, PTV D{sub 99}, and PTV mean doses were recorded, along with conformity indices (CIs) (95% and 98%) and the homogeneity index. All cases satisfied PTV D{sub 95} of 68 Gy and a maximum dose < 74.8 Gy. The average result for the PTV D{sub 99} was 64.1 Gy for PRO 2 and 62.1 Gy for PRO 3. The average PTV mean dose for PRO 2 was 71.4 Gy and 71.5 Gy for PRO 3. The CTV D{sub 100} average dose was 67.7 and 68.0 Gy for PRO 2 and PRO 3, respectively. The mean homogeneity index for both algorithms was 0.08. The average 95% CI was 1.17 for PRO 2 and 1.19 for PRO 3. For 98%, the average results were 1.08 and 1.12 for PRO 2 and PRO 3, respectively. All cases for each algorithm met the RTOG organs at risk dose constraints. A successful class solution has been established for prostate bed VMAT radiotherapy regardless of the algorithm used.

  14. Intensity-Modulated Radiation Therapy in the Salvage of Locally Recurrent Nasopharyngeal Carcinoma

    International Nuclear Information System (INIS)

    Qiu Sufang; Lin Shaojun; Tham, Ivan W.K.; Pan Jianji; Lu Jun; Lu, Jiade J.

    2012-01-01

    Purpose: Local recurrences of nasopharyngeal carcinoma (NPC) may be salvaged by reirradiation with conventional techniques, but with significant morbidity. Intensity-modulated radiation therapy (IMRT) may improve the therapeutic ratio by reducing doses to normal tissue. The aim of this study was to address the efficacy and toxicity profile of IMRT for a cohort of patients with locally recurrent NPC. Methods and Materials: Between August 2003 and June 2009, 70 patients with radiologic or pathologically proven locally recurrent NPC were treated with IMRT. The median time to recurrence was 30 months after the completion of conventional radiation to definitive dose. Fifty-seven percent of the tumors were classified asrT3–4. The minimum planned doses were 59.4 to 60 Gy in 1.8- to 2-Gy fractions per day to the gross disease with margins, with or without chemotherapy. Results: The median dose to the recurrent tumor was 70 Gy (range, 50–77.4 Gy). Sixty-five patients received the planned radiation therapy; 5 patients received between 50 and 60 Gy because of acute side effects. With a median follow-up time of 25 months, the rates of 2-year locoregional recurrence-free survival, disease-free survival, and overall survival were 65.8%, 65.8%, and 67.4%, respectively. Moderate to severe late toxicities were noted in 25 patients (35.7%). Eleven patients (15.7%) had posterior nasal space ulceration, 17 (24.3%) experienced cranial nerve palsies, 12 (17.1%) had trismus, and 12 (17.1%) experienced deafness. Extended disease-free interval (relative risk 2.049) and advanced T classification (relative risk 3.895) at presentation were adverse prognostic factors. Conclusion: Reirradiation with IMRT provides reasonable long-term control in patients with locally recurrent NPC.

  15. Expert Consensus Contouring Guidelines for Intensity Modulated Radiation Therapy in Esophageal and Gastroesophageal Junction Cancer

    International Nuclear Information System (INIS)

    Wu, Abraham J.; Bosch, Walter R.; Chang, Daniel T.; Hong, Theodore S.; Jabbour, Salma K.; Kleinberg, Lawrence R.; Mamon, Harvey J.; Thomas, Charles R.; Goodman, Karyn A.

    2015-01-01

    Purpose/Objective(s): Current guidelines for esophageal cancer contouring are derived from traditional 2-dimensional fields based on bony landmarks, and they do not provide sufficient anatomic detail to ensure consistent contouring for more conformal radiation therapy techniques such as intensity modulated radiation therapy (IMRT). Therefore, we convened an expert panel with the specific aim to derive contouring guidelines and generate an atlas for the clinical target volume (CTV) in esophageal or gastroesophageal junction (GEJ) cancer. Methods and Materials: Eight expert academically based gastrointestinal radiation oncologists participated. Three sample cases were chosen: a GEJ cancer, a distal esophageal cancer, and a mid-upper esophageal cancer. Uniform computed tomographic (CT) simulation datasets and accompanying diagnostic positron emission tomographic/CT images were distributed to each expert, and the expert was instructed to generate gross tumor volume (GTV) and CTV contours for each case. All contours were aggregated and subjected to quantitative analysis to assess the degree of concordance between experts and to generate draft consensus contours. The panel then refined these contours to generate the contouring atlas. Results: The κ statistics indicated substantial agreement between panelists for each of the 3 test cases. A consensus CTV atlas was generated for the 3 test cases, each representing common anatomic presentations of esophageal cancer. The panel agreed on guidelines and principles to facilitate the generalizability of the atlas to individual cases. Conclusions: This expert panel successfully reached agreement on contouring guidelines for esophageal and GEJ IMRT and generated a reference CTV atlas. This atlas will serve as a reference for IMRT contours for clinical practice and prospective trial design. Subsequent patterns of failure analyses of clinical datasets using these guidelines may require modification in the future

  16. SU-F-T-79: Monte Carlo Investigation of Optimizing Parameters for Modulated Electron Arc Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Al Ashkar, E; Eraba, K; Imam, M [Azhar university, Nasr City, Cairo (Egypt); Eldib, A; Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States)

    2016-06-15

    Purpose: Electron arc therapy provides excellent dose distributions for treating superficial tumors along curved surfaces. However this modality has not received widespread application due to the lack of needed advancement in electron beam delivery, accurate electron dose calculation and treatment plan optimization. The aim of the current work is to investigate possible parameters that can be optimized for electron arc (eARC) therapy. Methods: The MCBEAM code was used to generate phase space files for 6 and 12MeV electron beam energies from a Varian trilogy machine. An Electron Multi-leaf collimator eMLC of 2cm thickness positioned at 82 cm source collimated distance was used in the study. Dose distributions for electron arcs were calculated inside a cylindrical phantom using the MCSIM code. The Cylindrical phantom was constructed with 0.2cm voxels and a 15cm diameter. Electron arcs were delivered with two different approaches. The first approach was to deliver the arc as segments of very small field widths. In this approach we also tested the impact of the segment size and the arc increment angle. The second approach is to deliver the arc as a sum of large fields each covering the whole target as seen from the beam eye view. Results: In considering 90 % as the prescription isodose line, the first approach showed a region of buildup proceeding before the prescription zone. This build up is minimizing with the second approach neglecting need for bolus. The second approach also showed less x-ray contamination. In both approaches the variation of the segment size changed the size and location of the prescription isodose line. The optimization process for eARC could involve interplay between small and large segments to achieve desired coverage. Conclusion: An advanced modulation of eARCs will allow for tailored dose distribution for superficial curved target as with challenging scalp cases.

  17. Study of pp{yields}pp{eta} reaction at threshold; Etude de la reaction pp{yields}pp{eta} au seuil

    Energy Technology Data Exchange (ETDEWEB)

    Taleb, A

    1994-11-01

    The {eta} production has been studied through the pp {yields} pp{eta} reaction at threshold. Data were taken at the Synchrotron of the ``Laboratoire National Saturne``. The detection in coincidence of the two protons scattered near 0 deg and analysed with the magnetic spectrometer SPES3 allows the reconstruction of missing mass spectra for the {eta} signature. A simulation program which takes into account all the experimental set up characteristics has been realized and tested through the pp {yields} d{pi}{sup +} reaction detected simultaneously with pp {yields} pp{eta}. The generated proton momentum spectra for pp {yields} pp{eta} show a pronounced {eta} mass dependence. This characteristic, connected to the kinematical properties of pp {yields} pp{eta} at threshold, is used to extract the mass of the meson {eta}. The obtained value, m{sub {eta}} = 547.65 {+-} 0.18 MeV, is in good agreement with measurement done recently through the pd {yields} {sup H}e{eta} reaction. The total cross section {sigma}{sub t} of pp {yields} pp{eta} measured at 1260, 1265 and 1300 MeV presents a strong energy dependence. This cross section increases less with energy than the phase-space. The influence of p-p and {eta}-p final state interactions in our measurements is studied. Our results are compared with theoretical predictions and assess the dominant character of the baryonic resonance N{sup *}(1535) in the {eta} mechanism production at threshold. These experimental results give an energy dependence which is not well reproduced by the theoretical predictions. This discrepancy could be an incorrect description of the {eta}-p interaction in the models. (author). 48 refs., 60 figs., 15 tabs.

  18. Dosimetric and QA aspects of Konrad inverse planning system for commissioning intensity-modulated radiation therapy

    Directory of Open Access Journals (Sweden)

    Deshpande Shrikant

    2007-01-01

    Full Text Available The intensity-modulated radiation therapy (IMRT planning is performed using the Konrad inverse treatment planning system and the delivery of the treatment by using Siemens Oncor Impression Plus linear accelerator (step and shoot, which has been commissioned recently. The basic beam data required for commissioning the system were generate. The quality assurance of relative and absolute dose distribution was carried out before clinical implementation. The salient features of Konrad planning system, like dependence of grid size on dose volume histogram (DVH, number of intensity levels and step size in sequencer, are studied quantitatively and qualitatively. To verify whether the planned dose [from treatment planning system (TPS] and delivered dose are the same, the absolute dose at a point is determined using CC01 ion chamber and the axial plane dose distribution is carried out using Kodak EDR2 in conjunction with OmniPro IMRT Phantom and OmniPro IMRT software from Scanditronix Wellhofer. To obtain the optimum combination in leaf sequencer module, parameters like number of intensity levels, step size are analyzed. The difference between pixel values of optimum fluence profile and the fluence profile obtained for various combinations of number of intensity levels and step size is compared and plotted. The calculations of the volume of any RT structure in the dose volume histogram are compared using grid sizes 3 mm and 4 mm. The measured and planned dose at a point showed good agreement (< 3% except for a few cases wherein the chamber was placed in a relatively high dose gradient region. The axial plane dose distribution using film dosimetry shows excellent agreement (correlation coefficient> 0.97 in all the cases. In the leaf sequencer module, the combination of number of intensity level 7 with step size of 3 is the optimal solution for obtaining deliverable segments. The RT structure volume calculation is found to be more accurate with grid size of

  19. Potential Benefits of Scanned Intensity-Modulated Proton Therapy Versus Advanced Photon Therapy With Regard to Sparing of the Salivary Glands in Oropharyngeal Cancer

    International Nuclear Information System (INIS)

    Water, Tara A. van de; Lomax, Antony J.; Bijl, Hendrik P.; Jong, Marije E. de; Schilstra, Cornelis; Hug, Eugen B.; Langendijk, Johannes A.

    2011-01-01

    Purpose: To test the hypothesis that scanned intensity-modulated proton therapy (IMPT) results in a significant dose reduction to the parotid and submandibular glands as compared with intensity-modulated radiotherapy with photons (IMRT) and three-dimensional conformal radiotherapy (3D-CRT) for oropharyngeal cancer. In addition, we investigated whether the achieved dose reductions would theoretically translate into a reduction of salivary dysfunction and xerostomia. Methods and Materials: Ten patients with N0 oropharyngeal carcinoma were used. The intensity-modulated plans delivered simultaneously 70 Gy to the boost planning target volume (PTV2) and 54 Gy to the elective nodal areas (PTV1). The 3D-CRT technique delivered sequentially 70 Gy and 46 Gy to PTV2 and PTV1, respectively. Normal tissue complication probabilities were calculated for salivary dysfunction and xerostomia. Results: Planning target volume coverage results were similar for IMPT and IMRT. Intensity-modulated proton therapy clearly improved the conformity. The 3D-CRT results were inferior to these results. The mean dose to the parotid glands by 3D-CRT (50.8 Gy), IMRT (25.5 Gy), and IMPT (16.8 Gy) differed significantly. For the submandibular glands no significant differences between IMRT and IMPT were found. The dose reductions obtained with IMPT theoretically translated into a significant reduction in normal tissue complication probability. Conclusion: Compared with IMRT and 3D-CRT, IMPT improved sparing of the organs at risk, while keeping similar target coverage results. The dose reductions obtained with IMPT vs. IMRT and 3D-CRT varied widely per individual patient. Intensity-modulated proton therapy theoretically translated into a clinical benefit for most cases, but this requires clinical validation.

  20. Predictors of Dysgeusia in Patients With Oropharyngeal Cancer Treated With Chemotherapy and Intensity Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Sapir, Eli [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Tao, Yebin [Department of Biostatistics, University of Michigan, Ann Arbor, Michigan (United States); Feng, Felix; Samuels, Stuart; El Naqa, Issam [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Murdoch-Kinch, Carol A. [School of Dentistry, University of Michigan, Ann Arbor, Michigan (United States); Feng, Mary [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Schipper, Matthew [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Biostatistics, University of Michigan, Ann Arbor, Michigan (United States); Eisbruch, Avraham, E-mail: eisbruch@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)

    2016-10-01

    Objective(s): Dysgeusia is a significant factor reducing quality of life and worsening dysphagia in patients receiving chemoradiation therapy for head and neck cancer. The factors affecting dysgeusia severity are uncertain. We investigated the effects on patient-reported dysgeusia of doses to the oral cavity, salivary output (required to dissolve food particles), and patient-reported xerostomia. Methods and Materials: Seventy-three patients with stage III to IV oropharyngeal cancer (OPC) (N=73) receiving definitive intensity modulated radiation therapy concurrently with chemotherapy participated in a prospective, longitudinal study of quality of life (QOL), including assessment of patient-reported gustatory function by taste-related questions from the Head and Neck QOL instrument (HNQOL) and the University of Washington Head and Neck-related QOL instrument (UWQOL), before therapy and periodically after treatment. At these intervals, patients also completed a validated xerostomia-specific questionnaire (XQ) and underwent unstimulated and stimulated major salivary gland flow rate measurements. Results: At 1, 3, 6, and 12 months after treatment, dysgeusia improved over time: severe dysgeusia was reported by 50%, 40%, 22%, and 23% of patients, respectively. Significant associations were found between patient-reported severe dysgeusia and radiation dose to the oral cavity (P=.005) and tongue (P=.019); normal tissue complication probability for severe dysgeusia at 3 months showed mean oral cavity D{sub 50} doses 53 Gy and 57 Gy in the HNQOL and WUQOL questionnaires, respectively, with curve slope (m) of 0.41. Measured salivary output was not statistically significantly correlated with severe taste dysfunction, whereas patient-reported XQ summary scores and xerostomia while eating scores were correlated with severe dysgeusia in the UWQOL tool (P=.04). Conclusions: Taste impairment is significantly correlated with mean radiation dose to the oral cavity. Patient

  1. Predictors of Dysgeusia in Patients With Oropharyngeal Cancer Treated With Chemotherapy and Intensity Modulated Radiation Therapy

    International Nuclear Information System (INIS)

    Sapir, Eli; Tao, Yebin; Feng, Felix; Samuels, Stuart; El Naqa, Issam; Murdoch-Kinch, Carol A.; Feng, Mary; Schipper, Matthew; Eisbruch, Avraham

    2016-01-01

    Objective(s): Dysgeusia is a significant factor reducing quality of life and worsening dysphagia in patients receiving chemoradiation therapy for head and neck cancer. The factors affecting dysgeusia severity are uncertain. We investigated the effects on patient-reported dysgeusia of doses to the oral cavity, salivary output (required to dissolve food particles), and patient-reported xerostomia. Methods and Materials: Seventy-three patients with stage III to IV oropharyngeal cancer (OPC) (N=73) receiving definitive intensity modulated radiation therapy concurrently with chemotherapy participated in a prospective, longitudinal study of quality of life (QOL), including assessment of patient-reported gustatory function by taste-related questions from the Head and Neck QOL instrument (HNQOL) and the University of Washington Head and Neck-related QOL instrument (UWQOL), before therapy and periodically after treatment. At these intervals, patients also completed a validated xerostomia-specific questionnaire (XQ) and underwent unstimulated and stimulated major salivary gland flow rate measurements. Results: At 1, 3, 6, and 12 months after treatment, dysgeusia improved over time: severe dysgeusia was reported by 50%, 40%, 22%, and 23% of patients, respectively. Significant associations were found between patient-reported severe dysgeusia and radiation dose to the oral cavity (P=.005) and tongue (P=.019); normal tissue complication probability for severe dysgeusia at 3 months showed mean oral cavity D_5_0 doses 53 Gy and 57 Gy in the HNQOL and WUQOL questionnaires, respectively, with curve slope (m) of 0.41. Measured salivary output was not statistically significantly correlated with severe taste dysfunction, whereas patient-reported XQ summary scores and xerostomia while eating scores were correlated with severe dysgeusia in the UWQOL tool (P=.04). Conclusions: Taste impairment is significantly correlated with mean radiation dose to the oral cavity. Patient

  2. Bile Acid Malabsorption After Pelvic and Prostate Intensity Modulated Radiation Therapy: An Uncommon but Treatable Condition

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Victoria [Academic Urology Unit, Institute of Cancer Research and The Royal Marsden Hospital, London and Sutton (United Kingdom); Benton, Barbara [Gastroenterology Unit, Institute of Cancer Research and The Royal Marsden Hospital, London and Sutton (United Kingdom); Sohaib, Aslam [Department of Radiology, Institute of Cancer Research and The Royal Marsden Hospital, London and Sutton (United Kingdom); Dearnaley, David [Academic Urology Unit, Institute of Cancer Research and The Royal Marsden Hospital, London and Sutton (United Kingdom); Andreyev, H. Jervoise N., E-mail: j@andreyev.demon.co.uk [Gastroenterology Unit, Institute of Cancer Research and The Royal Marsden Hospital, London and Sutton (United Kingdom)

    2012-12-01

    Purpose: Intensity modulated radiation therapy (IMRT) is a significant therapeutic advance in prostate cancer, allowing increased tumor dose delivery and increased sparing of normal tissues. IMRT planning uses strict dose constraints to nearby organs to limit toxicity. Bile acid malabsorption (BAM) is a treatable disorder of the terminal ileum (TI) that presents with symptoms similar to radiation therapy toxicity. It has not been described in patients receiving RT for prostate cancer in the contemporary era. We describe new-onset BAM in men after IMRT for prostate cancer. Methods and Materials: Diagnosis of new-onset BAM was established after typical symptoms developed, selenium-75 homocholic acid taurine (SeHCAT) scanning showed 7-day retention of <15%, and patients' symptoms unequivocally responded to a bile acid sequestrant. The TI was identified on the original radiation therapy plan, and the radiation dose delivered was calculated and compared with accepted dose-volume constraints. Results: Five of 423 men treated in a prospective series of high-dose prostate and pelvic IMRT were identified with new onset BAM (median age, 65 years old). All reported having normal bowel habits before RT. The volume of TI ranged from 26-141 cc. The radiation dose received by the TI varied between 11.4 Gy and 62.1 Gy (uncorrected). Three of 5 patients had TI treated in excess of 45 Gy (equivalent dose calculated in 2-Gy fractions, using an {alpha}/{beta} ratio of 3) with volumes ranging from 1.6 cc-49.0 cc. One patient had mild BAM (SeHCAT retention, 10%-15%), 2 had moderate BAM (SeHCAT retention, 5%-10%), and 2 had severe BAM (SeHCAT retention, <5%). The 3 patients whose TI received {>=}45 Gy developed moderate to severe BAM, whereas those whose TI received <45 Gy had only mild to moderate BAM. Conclusions: Radiation delivered to the TI during IMRT may cause BAM. Identification of the TI from unenhanced RT planning computed tomography scans is difficult and may impede

  3. SU-E-T-338: Dosimetric Study of Volumetric Modulated Arc Therapy (VMAT) and Intensity Modulated Radiation Therapy (IMRT) for Stereotactic Body Radiation Therapy (SBRT) in Early Stage Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, I; Quinn, K; Seebach, A; Wang, H [OSF Saint Anthony Medical Center, Rockford, IL (United States); Yah, R [University of Illinois College of Medicine at Rockford, Rockford, IL (United States)

    2015-06-15

    Purpose: This study evaluates the dosimetric differences using volumetric modulated arc therapy (VMAT) in patients previously treated with intensity modulated radiation therapy IMRT for stereotactic body radiotherapy (SBRT) in early stage lung cancer. Methods: We evaluated 9 consecutive medically inoperable lung cancer patients at the start of the SBRT program who were treated with IMRT from November 2010 to October 2011. These patients were treated using 6 MV energy. The 9 cases were then re-planned with VMAT performed with arc therapy using 6 MV flattening filter free (FFF) energy with the same organs at risk (OARS) constraints. Data collected for the treatment plans included target coverage, beam on time, dose to OARS and gamma pass rate. Results: Five patients were T1N0 and four patients were T2N0 with all tumors less than 5 cm. The average GTV was 13.02 cm3 (0.83–40.87) and average PTV was 44.65 cm3 (14.06–118.08). The IMRT plans had a mean of 7.2 angles (6–9) and 5.4 minutes (3.6–11.1) per plan. The VMAT plans had a mean of 2.8 arcs (2–3) and 4.0 minutes (2.2–6.0) per plan. VMAT had slightly more target coverage than IMRT with average increase in D95 of 2.68% (1.24–5.73) and D99 of 3.65% (0.88–8.77). VMAT produced lower doses to all OARs. The largest reductions were in maximum doses to the spinal cord with an average reduction of 24.1%, esophagus with an average reduction of 22.1%, and lung with an average reduction in the V20 of 16.3% The mean gamma pass rate was 99.8% (99.2–100) at 3 mm and 3% for VMAT with comparable values for IMRT. Conclusion: These findings suggest that using VMAT for SBRT in early stage lung cancer is superior to IMRT in terms of dose coverage, OAR dose and a lower treatment delivery time with a similar gamma pass rate.

  4. An Ensemble Approach to Knowledge-Based Intensity-Modulated Radiation Therapy Planning

    Directory of Open Access Journals (Sweden)

    Jiahan Zhang

    2018-03-01

    Full Text Available Knowledge-based planning (KBP utilizes experienced planners’ knowledge embedded in prior plans to estimate optimal achievable dose volume histogram (DVH of new cases. In the regression-based KBP framework, previously planned patients’ anatomical features and DVHs are extracted, and prior knowledge is summarized as the regression coefficients that transform features to organ-at-risk DVH predictions. In our study, we find that in different settings, different regression methods work better. To improve the robustness of KBP models, we propose an ensemble method that combines the strengths of various linear regression models, including stepwise, lasso, elastic net, and ridge regression. In the ensemble approach, we first obtain individual model prediction metadata using in-training-set leave-one-out cross validation. A constrained optimization is subsequently performed to decide individual model weights. The metadata is also used to filter out impactful training set outliers. We evaluate our method on a fresh set of retrospectively retrieved anonymized prostate intensity-modulated radiation therapy (IMRT cases and head and neck IMRT cases. The proposed approach is more robust against small training set size, wrongly labeled cases, and dosimetric inferior plans, compared with other individual models. In summary, we believe the improved robustness makes the proposed method more suitable for clinical settings than individual models.

  5. Molecular switch of Cre/loxP for radiation modulated gene therapy on hepatoma

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Y.-J. [Institute of Radiological Sciences, National Yang-Ming University, Taiwan (China); Chen, Fu-Du [Institute of Radiological Sciences, National Yang-Ming University, Taiwan (China); Institute of Radiological Sciences, Central Taiwan University of Science and Technology, Taiwan (China); Wang, F.H. [National Yang-Ming University Medical School, Taiwan (China); Ke, C.C. [National PET/Cyclotron Center, Taipei Veterans General Hospital, Taiwan (China); Wang, H.-E. [Institute of Radiological Sciences, National Yang-Ming University, Taiwan (China); Liu, R.-S. [Institute of Radiological Sciences, National Yang-Ming University, Taiwan (China) and National Yang-Ming University Medical School, Taiwan (China) and National PET/Cyclotron Center, Taipei Veterans General Hospital, Taiwan (China)]. E-mail: maimai5010@yahoo.com.tw

    2007-02-01

    For the purpose of enhancement of AFP promoter for the use of radiation modulated gene therapy for hepatocellular carcinoma (HCC), we combined hepatitis B virus (HBV) enhancer II with AFP promoter which shows the selectivity to the target cells to control the Cre/loxP system. Different gene constructs, pE4luc, pE4Tk, EIIAPA-Cre, E4CMV-STOP-Tk and chimeric promoters combined with HBV enhancer were constructed and transfected into HepG2, HeLa and NIH-3T3 cell lines. Cell experiments revealed that E4 enhancer responses to radiation best after 60 h irradiation at a dose range of 5-7 Gy in HepG2 stable clone. The EIIAPA promoter provided high specificity to hepatoma and activated the Cre downstream and removed the stop cassette only in hepatoma cells. After removal of the stop cassette, the E4 response to radiation could encode more Tk protein and kill more tumor cells. In summary, the chimeric EIIAPA promoter can stringently control the expression of Cre recombinase only in HCC. The radiation effect of the EIIAPA-Cre and E4CMV-STOP-Tk system shows promising results in terms of cell survival of HCC.

  6. Three-dimensional cluster formation and structure in heterogeneous dose distribution of intensity modulated radiation therapy.

    Science.gov (United States)

    Chao, Ming; Wei, Jie; Narayanasamy, Ganesh; Yuan, Yading; Lo, Yeh-Chi; Peñagarícano, José A

    2018-05-01

    To investigate three-dimensional cluster structure and its correlation to clinical endpoint in heterogeneous dose distributions from intensity modulated radiation therapy. Twenty-five clinical plans from twenty-one head and neck (HN) patients were used for a phenomenological study of the cluster structure formed from the dose distributions of organs at risks (OARs) close to the planning target volumes (PTVs). Initially, OAR clusters were searched to examine the pattern consistence among ten HN patients and five clinically similar plans from another HN patient. Second, clusters of the esophagus from another ten HN patients were scrutinized to correlate their sizes to radiobiological parameters. Finally, an extensive Monte Carlo (MC) procedure was implemented to gain deeper insights into the behavioral properties of the cluster formation. Clinical studies showed that OAR clusters had drastic differences despite similar PTV coverage among different patients, and the radiobiological parameters failed to positively correlate with the cluster sizes. MC study demonstrated the inverse relationship between the cluster size and the cluster connectivity, and the nonlinear changes in cluster size with dose thresholds. In addition, the clusters were insensitive to the shape of OARs. The results demonstrated that the cluster size could serve as an insightful index of normal tissue damage. The clinical outcome of the same dose-volume might be potentially different. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Influence of intensity-modulated radiation therapy on parotid function in nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Cui Tiantian; Wu Shaoxiong; Han Fei; Lu Lixia; Huang Shaomin; Deng Xiaowu; Lu Taixiang; Zhao Chong

    2009-01-01

    Objective: To evaluate the effect of intensity-modulated radiation therapy (IMRT) on parotid function in nasopharyngeal carcinoma (NPC). Methods: Eighty-three NPC patients received prima- ry IMRT between 2001 and 2003. Xerostomia before radiotherapy, at the end of radiotherapy, at 6-month, 1-, 2-,3-,4- and 5-year after radiotherapy were investigated, respectively. The relation between xerostomia and parotid dose distribution was analyzed. Results: Of all the patients, 4, 31, 31 and 17 had stage I, II, III and IV A disease, respectively. Sixteen patients received chemo-radiotherapy. The median followed-up time was 65 months. The 5-year local control and regional control rate were 96% and 95%, respectively. The 5- year overall survival rate was 80%. The mild xerostomia rate at the seven time points was 42%, 51%, 71%, 77%, 58%, 38% and 26%. The corresponding moderate xerostomia rate was 52%, 53%, 21%, 8%, 3%, 2% and 2%, respectively. No serious xerostomia was observed. The mean dose of the bilateral parotid glands was 34.34 Gy. Xerostomia at 6-month after radiotherapy was positively correlated with the mean dose of the parotid glands, and D 50 was the independent factor in predicting the xerostomia. Parotid function was well protected when the mean dose and D 50 were no more than 33 Gy and 29 Gy, respectively. Conclusions: IMRT can improve the local-regional control of NPC and protect the parotid glands from radiation-induced injury. (authors)

  8. Molecular switch of Cre/loxP for radiation modulated gene therapy on hepatoma

    International Nuclear Information System (INIS)

    Hsieh, Y.-J.; Chen, Fu-Du; Wang, F.H.; Ke, C.C.; Wang, H.-E.; Liu, R.-S.

    2007-01-01

    For the purpose of enhancement of AFP promoter for the use of radiation modulated gene therapy for hepatocellular carcinoma (HCC), we combined hepatitis B virus (HBV) enhancer II with AFP promoter which shows the selectivity to the target cells to control the Cre/loxP system. Different gene constructs, pE4luc, pE4Tk, EIIAPA-Cre, E4CMV-STOP-Tk and chimeric promoters combined with HBV enhancer were constructed and transfected into HepG2, HeLa and NIH-3T3 cell lines. Cell experiments revealed that E4 enhancer responses to radiation best after 60 h irradiation at a dose range of 5-7 Gy in HepG2 stable clone. The EIIAPA promoter provided high specificity to hepatoma and activated the Cre downstream and removed the stop cassette only in hepatoma cells. After removal of the stop cassette, the E4 response to radiation could encode more Tk protein and kill more tumor cells. In summary, the chimeric EIIAPA promoter can stringently control the expression of Cre recombinase only in HCC. The radiation effect of the EIIAPA-Cre and E4CMV-STOP-Tk system shows promising results in terms of cell survival of HCC

  9. Meningioma Causing Visual Impairment: Outcomes and Toxicity After Intensity Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Maclean, Jillian, E-mail: jillian.maclean@uclh.nhs.uk [Radiotherapy Department, University College London Hospital, London (United Kingdom); Fersht, Naomi [Radiotherapy Department, University College London Hospital, London (United Kingdom); Bremner, Fion [Neuro-Ophthalmology Department, National Hospital for Neurology and Neurosurgery, London (United Kingdom); Stacey, Chris; Sivabalasingham, Suganya [Radiotherapy Department, University College London Hospital, London (United Kingdom); Short, Susan [Radiotherapy Department, University College London Hospital, London (United Kingdom); Leeds Institute of Molecular Medicine, St James University Hospital, Leeds (United Kingdom)

    2013-03-15

    Purpose: To evaluate ophthalmologic outcomes and toxicity of intensity modulated radiation therapy (IMRT) in patients with meningiomas causing visual deficits. Methods and Materials: A prospective observational study with formal ophthalmologic and clinical assessment of 30 consecutive cases of meningioma affecting vision treated with IMRT from 2007 to 2011. Prescriptions were 50.4 Gy to mean target dose in 28 daily fractions. The median follow-up time was 28 months. Twenty-six meningiomas affected the anterior visual pathway (including 3 optic nerve sheath meningiomas); 4 were posterior to the chiasm. Results: Vision improved objectively in 12 patients (40%). Improvements were in visual field (5/16 patients), color vision (4/9 patients), acuity (1/15 patients), extraocular movements (3/11 patients), ptosis (1/5 patients), and proptosis (2/6 patients). No predictors of clinical response were found. Two patients had minor reductions in tumor dimensions on magnetic resonance imaging, 1 patient had radiological progression, and the other patients were stable. One patient experienced grade 2 keratitis, 1 patient had a minor visual field loss, and 5 patients had grade 1 dry eye. Conclusion: IMRT is an effective method for treating meningiomas causing ophthalmologic deficits, and toxicity is minimal. Thorough ophthalmologic assessment is important because clinical responses often occur in the absence of radiological change.

  10. A novel linear programming approach to fluence map optimization for intensity modulated radiation therapy treatment planning

    International Nuclear Information System (INIS)

    Romeijn, H Edwin; Ahuja, Ravindra K; Dempsey, James F; Kumar, Arvind; Li, Jonathan G

    2003-01-01

    We present a novel linear programming (LP) based approach for efficiently solving the intensity modulated radiation therapy (IMRT) fluence-map optimization (FMO) problem to global optimality. Our model overcomes the apparent limitations of a linear-programming approach by approximating any convex objective function by a piecewise linear convex function. This approach allows us to retain the flexibility offered by general convex objective functions, while allowing us to formulate the FMO problem as a LP problem. In addition, a novel type of partial-volume constraint that bounds the tail averages of the differential dose-volume histograms of structures is imposed while retaining linearity as an alternative approach to improve dose homogeneity in the target volumes, and to attempt to spare as many critical structures as possible. The goal of this work is to develop a very rapid global optimization approach that finds high quality dose distributions. Implementation of this model has demonstrated excellent results. We found globally optimal solutions for eight 7-beam head-and-neck cases in less than 3 min of computational time on a single processor personal computer without the use of partial-volume constraints. Adding such constraints increased the running times by a factor of 2-3, but improved the sparing of critical structures. All cases demonstrated excellent target coverage (>95%), target homogeneity (<10% overdosing and <7% underdosing) and organ sparing using at least one of the two models

  11. Comparison of two heterogeneity correction algorithms in pituitary gland treatments with intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Albino, Lucas D.; Santos, Gabriela R.; Ribeiro, Victor A.B.; Rodrigues, Laura N.; Weltman, Eduardo; Braga, Henrique F.

    2013-01-01

    The dose accuracy calculated by a treatment planning system is directly related to the chosen algorithm. Nowadays, several calculation doses algorithms are commercially available and they differ in calculation time and accuracy, especially when individual tissue densities are taken into account. The aim of this study was to compare two different calculation algorithms from iPlan®, BrainLAB, in the treatment of pituitary gland tumor with intensity-modulated radiation therapy (IMRT). These tumors are located in a region with variable electronic density tissues. The deviations from the plan with no heterogeneity correction were evaluated. To initial validation of the data inserted into the planning system, an IMRT plan was simulated in a anthropomorphic phantom and the dose distribution was measured with a radiochromic film. The gamma analysis was performed in the film, comparing it with dose distributions calculated with X-ray Voxel Monte Carlo (XVMC) algorithm and pencil beam convolution (PBC). Next, 33 patients plans, initially calculated by PBC algorithm, were recalculated with XVMC algorithm. The treatment volumes and organs-at-risk dose-volume histograms were compared. No relevant differences were found in dose-volume histograms between XVMC and PBC. However, differences were obtained when comparing each plan with the plan without heterogeneity correction. (author)

  12. Intensity-modulated radiation therapy for nasopharyngeal carcinoma parotid sparing with euivalent uiform dose optimization

    International Nuclear Information System (INIS)

    Yue Weiyou; Dai Jianrong; Gao Li

    2006-01-01

    Objective: The aim of this study was to evaluate the role of an euivalent uiform dose (EUD) based optimization algorithm in sparing the parotids of patients with nasopharyngeal carcinoma (NPC) when they are treated with intensity-modulated radiation therapy (IMRT). Methods: 12 patients were randomly selected from the NPC patients who received IMRT treatments. For these patients, the treatment plans were designed with physical optimization constraints (dose/dose-volume constraints). Based on these plans, new plans were designed through replacing the physical constraints with maximum EUD for parotids, while keeping the physical objectives for targets and other organs at risk(OARs) unchanged. Comparison was then made between the new plan, which had EUD constraints to parotids, and the former for each individual patient. Results: While maintaining the dose to the targets and the other OARs un- changed, optimization with EUD constraints to parotids decreased the mean dose and V 30 of parotids significantly, simultaneously, the dose of target volume and other organs at risk keep stable, the values of probability were less than 0.05 by T-test. Conclusions: The doses to parotids can be reduced through optimization with EUD constraints. This finding is quite helpful to reduce the occurrence rate of parotid complications, and to provide spaces for escalating target dose. (authors)

  13. In vivo measurements with MOSFET detectors in oropharynx and nasopharynx intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Marcie, Serge; Charpiot, Elisabeth; Bensadoun, Rene-Jean; Ciais, Gaston; Herault, Joel; Costa, Andre; Gerard, Jean-Pierre

    2005-01-01

    Purpose: To evaluate the feasibility of in vivo measurements with metal oxide semiconductor field effect transistor (MOSFET) dosimeters for oropharynx and nasopharynx intensity-modulated radiation therapy (IMRT). Methods and Materials: During a 1-year period, in vivo measurements of the dose delivered to one or two points of the oral cavity by IMRT were obtained with MOSFET dosimeters. Measurements were obtained during each session of 48 treatment plans for 21 patients, all of whom were fitted with a custom-made mouth plate. Calculated and measured values were compared. Results: A total of 344 and 452 measurements were performed for the right and left sides, respectively, of the oral cavity. Seventy percent of the discrepancies between calculated and measured values were within ±5%. Uncertainties were due to interfraction patient positions, intrafraction patient movements, and interfraction MOSFET positions. Nevertheless, the discrepancies between the measured and calculated means were within ±5% for 92% and 95% of the right and left sides, respectively. Comparison of these discrepancies and the discrepancies between calculated values and measurements made on a phantom revealed that all differences were within ±5%. Conclusion: Our experience demonstrates the feasibility of in vivo measurements with MOSFET dosimeters for oropharynx and nasopharynx IMRT

  14. Rational use of intensity-modulated radiation therapy: the importance of clinical outcome.

    Science.gov (United States)

    De Neve, Wilfried; De Gersem, Werner; Madani, Indira

    2012-01-01

    During the last 2 decades, intensity-modulated radiation therapy (IMRT) became a standard technique despite its drawbacks of volume delineation, planning, robustness of delivery, challenging quality assurance, and cost as compared with non-IMRT. The theoretic advantages of IMRT dose distributions are generally accepted, but the clinical advantages remain debatable because of the lack of clinical assessment of the effort that is required to overshadow the disadvantages. Rational IMRT use requires a positive advantage/drawback balance. Only 5 randomized clinical trials (RCTs), 3 in the breast and 2 in the head and neck, which compare IMRT with non-IMRT (2-dimensional technique in four fifths of the trials), have been published (as of March 2011), and all had toxicity as the primary endpoint. More than 50 clinical trials compared results of IMRT-treated patients with a non-IMRT group, mostly historical controls. RCTs systematically showed a lower toxicity in IMRT-treated patients, and the non-RCTs confirmed these findings. Toxicity reduction, counterbalancing the drawbacks of IMRT, was convincing for breast and head and neck IMRT. For other tumor sites, the arguments favoring IMRT are weaker because of the inability to control bias outside the randomized setting. For anticancer efficacy endpoints, like survival, disease-specific survival, or locoregional control, the balance between advantages and drawbacks is fraught with uncertainties because of the absence of robust clinical data. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. A modified method of planning and delivery for dynamic multileaf collimator intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Dogan, Nesrin; Leybovich, Leonid B.; Sethi, Anil; Krasin, Matthew; Emami, Bahman

    2000-01-01

    Purpose: To develop a modified planning and delivery technique that reduces dose nonuniformity for tomographic delivery of intensity-modulated radiation therapy (IMRT). Methods and Materials: The NOMOS-CORVUS system delivers IMRT in a tomographic paradigm. This type of delivery is prone to create multiple dose nonuniformity regions at the arc abutment regions. The modified technique was based on the cyclical behavior of arc positions as a function of a target length. With the modified technique, two plans are developed for the same patient, one with the original target and the second with a slightly increased target length and the abutment regions shifted by ∼5 mm compared to the first plan. Each plan is designed to deliver half of the target prescription dose delivered on alternate days, resulting in periodic shifts of abutment regions. This method was experimentally tested in phantoms with and without intentionally introduced errors in couch indexing. Results: With the modified technique, the degree of dose nonuniformity was reduced. For example, with 1 mm error in couch indexing, the degree of dose nonuniformity changed from ∼25% to ∼12%. Conclusion: Use of the modified technique reduces dose nonuniformity due to periodic shifts of abutment regions during treatment delivery

  16. Fully Automated Volumetric Modulated Arc Therapy Plan Generation for Prostate Cancer Patients

    International Nuclear Information System (INIS)

    Voet, Peter W.J.; Dirkx, Maarten L.P.; Breedveld, Sebastiaan; Al-Mamgani, Abrahim; Incrocci, Luca; Heijmen, Ben J.M.

    2014-01-01

    Purpose: To develop and evaluate fully automated volumetric modulated arc therapy (VMAT) treatment planning for prostate cancer patients, avoiding manual trial-and-error tweaking of plan parameters by dosimetrists. Methods and Materials: A system was developed for fully automated generation of VMAT plans with our commercial clinical treatment planning system (TPS), linked to the in-house developed Erasmus-iCycle multicriterial optimizer for preoptimization. For 30 randomly selected patients, automatically generated VMAT plans (VMAT auto ) were compared with VMAT plans generated manually by 1 expert dosimetrist in the absence of time pressure (VMAT man ). For all treatment plans, planning target volume (PTV) coverage and sparing of organs-at-risk were quantified. Results: All generated plans were clinically acceptable and had similar PTV coverage (V 95%  > 99%). For VMAT auto and VMAT man plans, the organ-at-risk sparing was similar as well, although only the former plans were generated without any planning workload. Conclusions: Fully automated generation of high-quality VMAT plans for prostate cancer patients is feasible and has recently been implemented in our clinic

  17. Linac-based total body irradiation (TBI) with volumetric modulated arc therapy (VMAT)

    Science.gov (United States)

    Tas, B.; Durmus, I. F.; Okumus, A.; Uzel, O. E.

    2017-02-01

    To evaluate dose distribution of Volumetric modulated arc therapy (VMAT) planning tecnique using Versa HD® lineer accelerator to deliver Total Body Irradiation (TBI) on the coach. Eight TBI patient's Treatment Planning System (TPS) were performed with dual arc VMAT for each patient. The VMAT-TBI consisted of three isocentres and three dual overlapping arcs. The prescribed dose was 12 Gy. Mean dose to lung and kidney were restricted less than 10 Gy and max. dose to lens were restricted less than 6 Gy. The plans were verified using 2D array and ion chamber. The comparison between calculation and measurement were made by γ-index analysis and absolute dose. An average total delivery time was determined 923±34 seconds and an average MU was determined 2614±228 MUs for dual arc VMAT. Mean dose to lungs was 9.7±0.2 Gy, mean dose to kidneys was 8.8±0.3 Gy, max. dose to lens was 5.5±0.3 Gy and max. dose was 14.6±0.3 Gy, HI of PTV was 1.13±0.2, mean dose to PTV was 12.6±1.5 Gy and mean γ-index pass rate was %97.1±1.9. The results show that the tecnique for TBI using VMAT on the treatment coach is feasible.

  18. Direct-aperture optimization applied to selection of beam orientations in intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Bedford, J L; Webb, S

    2007-01-01

    Direct-aperture optimization (DAO) was applied to iterative beam-orientation selection in intensity-modulated radiation therapy (IMRT), so as to ensure a realistic segmental treatment plan at each iteration. Nested optimization engines dealt separately with gantry angles, couch angles, collimator angles, segment shapes, segment weights and wedge angles. Each optimization engine performed a random search with successively narrowing step sizes. For optimization of segment shapes, the filtered backprojection (FBP) method was first used to determine desired fluence, the fluence map was segmented, and then constrained direct-aperture optimization was used thereafter. Segment shapes were fully optimized when a beam angle was perturbed, and minimally re-optimized otherwise. The algorithm was compared with a previously reported method using FBP alone at each orientation iteration. An example case consisting of a cylindrical phantom with a hemi-annular planning target volume (PTV) showed that for three-field plans, the method performed better than when using FBP alone, but for five or more fields, neither method provided much benefit over equally spaced beams. For a prostate case, improved bladder sparing was achieved through the use of the new algorithm. A plan for partial scalp treatment showed slightly improved PTV coverage and lower irradiated volume of brain with the new method compared to FBP alone. It is concluded that, although the method is computationally intensive and not suitable for searching large unconstrained regions of beam space, it can be used effectively in conjunction with prior class solutions to provide individually optimized IMRT treatment plans

  19. A fast optimization algorithm for multicriteria intensity modulated proton therapy planning

    International Nuclear Information System (INIS)

    Chen Wei; Craft, David; Madden, Thomas M.; Zhang, Kewu; Kooy, Hanne M.; Herman, Gabor T.

    2010-01-01

    Purpose: To describe a fast projection algorithm for optimizing intensity modulated proton therapy (IMPT) plans and to describe and demonstrate the use of this algorithm in multicriteria IMPT planning. Methods: The authors develop a projection-based solver for a class of convex optimization problems and apply it to IMPT treatment planning. The speed of the solver permits its use in multicriteria optimization, where several optimizations are performed which span the space of possible treatment plans. The authors describe a plan database generation procedure which is customized to the requirements of the solver. The optimality precision of the solver can be specified by the user. Results: The authors apply the algorithm to three clinical cases: A pancreas case, an esophagus case, and a tumor along the rib cage case. Detailed analysis of the pancreas case shows that the algorithm is orders of magnitude faster than industry-standard general purpose algorithms (MOSEK's interior point optimizer, primal simplex optimizer, and dual simplex optimizer). Additionally, the projection solver has almost no memory overhead. Conclusions: The speed and guaranteed accuracy of the algorithm make it suitable for use in multicriteria treatment planning, which requires the computation of several diverse treatment plans. Additionally, given the low memory overhead of the algorithm, the method can be extended to include multiple geometric instances and proton range possibilities, for robust optimization.

  20. Comparison of optimization algorithms in intensity-modulated radiation therapy planning

    Science.gov (United States)

    Kendrick, Rachel

    Intensity-modulated radiation therapy is used to better conform the radiation dose to the target, which includes avoiding healthy tissue. Planning programs employ optimization methods to search for the best fluence of each photon beam, and therefore to create the best treatment plan. The Computational Environment for Radiotherapy Research (CERR), a program written in MATLAB, was used to examine some commonly-used algorithms for one 5-beam plan. Algorithms include the genetic algorithm, quadratic programming, pattern search, constrained nonlinear optimization, simulated annealing, the optimization method used in Varian EclipseTM, and some hybrids of these. Quadratic programing, simulated annealing, and a quadratic/simulated annealing hybrid were also separately compared using different prescription doses. The results of each dose-volume histogram as well as the visual dose color wash were used to compare the plans. CERR's built-in quadratic programming provided the best overall plan, but avoidance of the organ-at-risk was rivaled by other programs. Hybrids of quadratic programming with some of these algorithms seems to suggest the possibility of better planning programs, as shown by the improved quadratic/simulated annealing plan when compared to the simulated annealing algorithm alone. Further experimentation will be done to improve cost functions and computational time.

  1. Automation of the solution type of intensity modulated radiation therapy with direct planning neoplastic breast lesions

    International Nuclear Information System (INIS)

    Fuente Rosales, Liset De La; Larrinaga Cortina, Eduardo Francisco

    2009-01-01

    Breast cancer ranks first among the lesions malignancies involving the Cuban women and the second in mortality only surpassed by lung injury. The breast-conserving surgery is becoming less appeal, with an increase in the choice of radiotherapy to the breast operated, and the surgical bed. Intensity Modulated Radiation Therapy, IMRT has demonstrated better results in the dose distribution for irradiation dimensional treatment breast shaping, 3DCRT. We developed a MATLAB application to obtain the solution type to direct planning IMRT for breast neoplasm. The technique was implemented in the Planning System Treatment Plus Theraplan v3.8 and Precise1 ELEKTA linear accelerator. Static segments are constructed for each portal of incidence and Excel files are exported as the positions of the blades. The technique was validated with a patient, which he performed a radiographic study of computerized axial tomography planning purposes. The standard solution built is consistent with those reported internationally and consists of a segment type and at least two segments of type B. The assignment of the relative weights of the segments is done manually by trial and error procedure, with the general rule of 90% by weight assigned to segment A and the remaining 10% divided equally between B-type segments IMRT breast obtained in a dose 17% homogeneity better than 3DCRT and reduced the average dose in the lung ipsilateral 15%. (author)

  2. The elementary discussion of volumetric modulated arc therapy using the orthogonal plane dose verification

    International Nuclear Information System (INIS)

    Shi Jinping; Chen Lixin; Xie Qiuying; Zhang Liwen; Teng Jianjian

    2012-01-01

    Objective: This study was to explore the feasibility of using the orthogonal plane dose formed by the coronal and sagittal plane to verify the volumetric modulated arc therapy (VMAT) plan. Methods: The VMAT plans of 12 patients were included in this study. The orthogonal plane dose formed by the coronal and sagittal plane were measured based on the combination of 2D ionization chamber array and multicube phantom, and the point dose were measured based on a multiple hole cylindrical phantom attached with two 0.125 cm 3 ionization chamber probes. Results: In the measurement of the point dose, the average error was 1.5% in high dose area (more than 80% of maximum), and 1.7% in low dose area (less than 80% of maximum), respectively. The discrepancy of point dose measurement was 1.3% between the 2D ionization chamber array and the VMAT planning system. In the measurement of the orthogonal plane dose, the pass rate of γ were 93.7% for 2%/2 mm and 97.2% for 3%/3 mm. Conclusion: It is reliable for using the orthogonal plane dose formed by the coronal and sagittal plane to verify the VMAT plan. (authors)

  3. A fast optimization algorithm for multicriteria intensity modulated proton therapy planning.

    Science.gov (United States)

    Chen, Wei; Craft, David; Madden, Thomas M; Zhang, Kewu; Kooy, Hanne M; Herman, Gabor T

    2010-09-01

    To describe a fast projection algorithm for optimizing intensity modulated proton therapy (IMPT) plans and to describe and demonstrate the use of this algorithm in multicriteria IMPT planning. The authors develop a projection-based solver for a class of convex optimization problems and apply it to IMPT treatment planning. The speed of the solver permits its use in multicriteria optimization, where several optimizations are performed which span the space of possible treatment plans. The authors describe a plan database generation procedure which is customized to the requirements of the solver. The optimality precision of the solver can be specified by the user. The authors apply the algorithm to three clinical cases: A pancreas case, an esophagus case, and a tumor along the rib cage case. Detailed analysis of the pancreas case shows that the algorithm is orders of magnitude faster than industry-standard general purpose algorithms (MOSEK'S interior point optimizer, primal simplex optimizer, and dual simplex optimizer). Additionally, the projection solver has almost no memory overhead. The speed and guaranteed accuracy of the algorithm make it suitable for use in multicriteria treatment planning, which requires the computation of several diverse treatment plans. Additionally, given the low memory overhead of the algorithm, the method can be extended to include multiple geometric instances and proton range possibilities, for robust optimization.

  4. Imaging Shock Fronts in the Outer Ejecta of Eta Carinae

    Science.gov (United States)

    Smith, Nathan

    2017-08-01

    Although Eta Car has been imaged many times with HST to monitor the central star and the bright Homunculus Nebula, we propose the first WFC3 imaging of Eta Car to study the more extended Outer Ejecta from previous eruptions. WFC3 has two key filters that have not been used before to image Eta Car, which will provide critical physical information about its eruptive history: (1) F280N with WFC3/UVIS will produce the first Mg II 2800 image of Eta Car, the sharpest image of its complex Outer Ejecta, and will unambiguously trace shock fronts, and (2) F126N with WFC3/IR will sample [Fe II] 12567 arising in the densest post-shock gas. Eta Car is surrounded by a bright, soft X-ray shell seen in Chandra images, which arises from the fastest 1840s ejecta overtaking slower older material. Our recent proper motion measurements show that the outer knots were ejected in two outbursts several hundred years before the 1840s eruption, and spectroscopy of light echoes has recently revealed extremely fast ejecta during the 1840s that indicate an explosive event. Were those previous eruptions explosive as well? If so, were they as energetic, did they also have such fast ejecta, and did they have the same geometry? The structure and excitation of the Outer Ejecta hold unique clues for reconstructing Eta Car's violent mass loss history. The locations of shock fronts in circumstellar material provide critical information, because they identify past discontinuities in the mass loss. This is one of the only ways to investigate the long term (i.e. centuries) evolution and duty cycle of eruptive mass loss in the most massive stars.

  5. Dosimetric effect of beam arrangement for intensity-modulated radiation therapy in the treatment of upper thoracic esophageal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Yuchuan [Division of Radiation Physics, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu (China); Deng, Min; Zhou, Xiaojuan [Department of Thoracic Oncology, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu (China); Lin, Qiang; Du, Bin [Division of Radiation Physics, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu (China); Tian, Xue; Xu, Yong; Wang, Jin; Lu, You [Department of Thoracic Oncology, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu (China); Gong, Youling, E-mail: gongyouling@hotmail.com [Department of Thoracic Oncology, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu (China)

    2017-04-01

    To evaluate the lung sparing in intensity-modulated radiation therapy (IMRT) for patients with upper thoracic esophageal tumors extending inferiorly to the thorax by different beam arrangement. Overall, 15 patient cases with cancer of upper thoracic esophagus were selected for a retrospective treatment-planning study. Intensity-modulated radiation therapy plans using 4, 5, and 7 beams (4B, 5B, and 7B) were developed for each patient by direct machine parameter optimization (DMPO). All plans were evaluated with respect to dose volumes to irradiated targets and normal structures, with statistical comparisons made between 4B with 5B and 7B intensity-modulated radiation therapy plans. Differences among plans were evaluated using a two-tailed Friedman test at a statistical significance of p < 0.05. The maximum dose, average dose, and the conformity index (CI) of planning target volume 1 (PTV1) were similar for 3 plans for each case. No significant difference of coverage for planning target volume 1 and maximum dose for spinal cords were observed among 3 plans in present study (p > 0.05). The average V{sub 5}, V{sub 13}, V{sub 20}, mean lung dose, and generalized equivalent uniform dose (gEUD) for the total lung were significantly lower in 4B-plans than those data in 5B-plans and 7B-plans (p < 0.01). Although the average V{sub 30} for the total lung were significantly higher in 4B-plans than those in 5B-plans and 7B-plans (p < 0.05). In addition, when comparing with the 4B-plans, the conformity/heterogeneity index of the 5B- and 7B-plans were significantly superior (p < 0.05). The 4B-intensity-modulated radiation therapy plan has advantage to address the specialized problem of lung sparing to low- and intermediate-dose exposure in the thorax when dealing with relative long tumors extended inferiorly to the thoracic esophagus for upper esophageal carcinoma with the cost for less conformity. Studies are needed to compare the superiority of volumetric modulated arc therapy

  6. Dosimetric effect of beam arrangement for intensity-modulated radiation therapy in the treatment of upper thoracic esophageal carcinoma

    International Nuclear Information System (INIS)

    Fu, Yuchuan; Deng, Min; Zhou, Xiaojuan; Lin, Qiang; Du, Bin; Tian, Xue; Xu, Yong; Wang, Jin; Lu, You; Gong, Youling

    2017-01-01

    To evaluate the lung sparing in intensity-modulated radiation therapy (IMRT) for patients with upper thoracic esophageal tumors extending inferiorly to the thorax by different beam arrangement. Overall, 15 patient cases with cancer of upper thoracic esophagus were selected for a retrospective treatment-planning study. Intensity-modulated radiation therapy plans using 4, 5, and 7 beams (4B, 5B, and 7B) were developed for each patient by direct machine parameter optimization (DMPO). All plans were evaluated with respect to dose volumes to irradiated targets and normal structures, with statistical comparisons made between 4B with 5B and 7B intensity-modulated radiation therapy plans. Differences among plans were evaluated using a two-tailed Friedman test at a statistical significance of p < 0.05. The maximum dose, average dose, and the conformity index (CI) of planning target volume 1 (PTV1) were similar for 3 plans for each case. No significant difference of coverage for planning target volume 1 and maximum dose for spinal cords were observed among 3 plans in present study (p > 0.05). The average V 5 , V 13 , V 20 , mean lung dose, and generalized equivalent uniform dose (gEUD) for the total lung were significantly lower in 4B-plans than those data in 5B-plans and 7B-plans (p < 0.01). Although the average V 30 for the total lung were significantly higher in 4B-plans than those in 5B-plans and 7B-plans (p < 0.05). In addition, when comparing with the 4B-plans, the conformity/heterogeneity index of the 5B- and 7B-plans were significantly superior (p < 0.05). The 4B-intensity-modulated radiation therapy plan has advantage to address the specialized problem of lung sparing to low- and intermediate-dose exposure in the thorax when dealing with relative long tumors extended inferiorly to the thoracic esophagus for upper esophageal carcinoma with the cost for less conformity. Studies are needed to compare the superiority of volumetric modulated arc therapy with intensity-modulated

  7. Multibeam tomotherapy: A new treatment unit devised for multileaf collimation, intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Achterberg, Nils; Mueller, Reinhold G.

    2007-01-01

    A fully integrated system for treatment planning, application, and verification for automated multileaf collimator (MLC) based, intensity-modulated, image-guided, and adaptive radiation therapy (IMRT, IGRT and ART, respectively) is proposed. Patient comfort, which was the major development goal, will be achieved through a new unit design and short treatment times. Our device for photon beam therapy will consist of a new dual energy linac with five fixed treatment heads positioned evenly along one plane but one electron beam generator only. A minimum of moving parts increases technical reliability and reduces motion times to a minimum. Motion is allowed solely for the MLCs, the robotic patient table, and the small angle gantry rotation of ±36 deg. . Besides sophisticated electron beam guidance, this compact setup can be built using existing modules. The flattening-filter-free treatment heads are characterized by reduced beam-on time and contain apertures restricted in one dimension to the area of maximum primary fluence output. In the case of longer targets, this leads to a topographic intensity modulation, thanks to the combination of ''step and shoot'' MLC delivery and discrete patient couch motion. Owing to the limited number of beam directions, this multislice cone beam serial tomotherapy is referred to as ''multibeam tomotherapy.'' Every patient slice is irradiated by one treatment head at any given moment but for one subfield only. The electron beam is then guided to the next head ready for delivery, while the other heads are preparing their leaves for the next segment. The ''Multifocal MLC-positioning'' algorithm was programmed to enable treatment planning and optimize treatment time. We developed an overlap strategy for the longitudinally adjacent fields of every beam direction, in doing so minimizing the field match problem and the effects of possible table step errors. Clinical case studies show for the same or better planning target volume coverage

  8. etaγ decays of rho0, ω, and phi mesons

    International Nuclear Information System (INIS)

    Andrews, D.E.; Fukushima, Y.; Harvey, J.; Lobkowicz, F.; May, E.N.; Nelson, C.A. Jr.; Thorndike, E.H.

    1977-01-01

    etaγ decays of rho 0 , ω, and phi are studied. We find GAMMA (phi→etaγ) =55 +- 12 keV. Our data admit two solutions for (rho 0 , ω) →etaγ: Either GAMMA (rho 0 →etaγ) =50 +- 13 keV, GAMMA (ω→etaγ) =3.0 +2 /sup ./ 5 /sub -/ 1 /sub ./ 8 keV, and the (ω,rho) →etaγ relative decay phase is near zero; or GAMMA (rho 0 →etaγ) =76 +- 15 keV, GAMMA (ω→etaγ) =29 +- 7 keV, and the decay phase is near 180degree

  9. Start of Eta Car's X-ray Minimum

    Science.gov (United States)

    Corcoran, Michael F.; Liburd, Jamar; Hamaguchi, Kenji; Gull, Theodore; Madura, Thomas; Teodoro, Mairan; Moffat, Anthony; Richardson, Noel; Russell, Chris; Pollock, Andrew; hide

    2014-01-01

    Analysis of Eta Car's X-ray spectrum in the 2-10 keV band using quicklook data from the XRay Telescope on Swift shows that the flux on July 30, 2014 was 4.9 plus or minus 2.0×10(exp-12) ergs s(exp-1)cm(exp-2). This flux is nearly equal to the X-ray minimum flux seen by RXTE in 2009, 2003.5, and 1998, and indicates that Eta Car has reached its X-ray minimum, as expected based on the 2024-day period derived from previous 2-10 keV observations with RXTE.

  10. Early Chandra X-ray Observations of Eta Carinae

    OpenAIRE

    Seward, F. D.; Butt, Y. M.; Karovska, M.; Schlegel, A. Prestwich. E. M.; Corcoran, M.

    2001-01-01

    Sub-arcsecond resolution Chandra observations of Eta Carinae reveal a 40 arcsec X 70 arcsec ring or partial shell of X-ray emission surrounding an unresolved, bright, central source. The spectrum of the central source is strongly absorbed and can be fit with a high-temperature thermal continuum and emission lines. The surrounding shell is well outside the optical/IR bipolar nebula and is coincident with the Outer Shell of Eta Carinae. The X-ray spectrum of the Shell is much softer than that o...

  11. Acute toxicity in comprehensive head and neck radiation for nasopharynx and paranasal sinus cancers: cohort comparison of 3D conformal proton therapy and intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    McDonald, Mark W.; Liu, Yuan; Moore, Michael G.; Johnstone, Peter A. S.

    2016-01-01

    To evaluate acute toxicity endpoints in a cohort of patients receiving head and neck radiation with proton therapy or intensity modulated radiation therapy (IMRT). Forty patients received comprehensive head and neck radiation including bilateral cervical nodal radiation, given with or without chemotherapy, for tumors of the nasopharynx, nasal cavity or paranasal sinuses, any T stage, N0-2. Fourteen received comprehensive treatment with proton therapy, and 26 were treated with IMRT, either comprehensively or matched to proton therapy delivered to the primary tumor site. Toxicity endpoints assessed included g-tube dependence at the completion of radiation and at 3 months after radiation, opioid pain medication requirement compared to pretreatment normalized as equivalent morphine dose (EMD) at completion of treatment, and at 1 and 3 months after radiation. In a multivariable model including confounding variables of concurrent chemotherapy and involved nodal disease, comprehensive head and neck radiation therapy using proton therapy was associated with a lower opioid pain requirement at the completion of radiation and a lower rate of gastrostomy tube dependence by the completion of radiation therapy and at 3 months after radiation compared to IMRT. Proton therapy was associated with statistically significant lower mean doses to the oral cavity, esophagus, larynx, and parotid glands. In subgroup analysis of 32 patients receiving concurrent chemotherapy, there was a statistically significant correlation with a greater opioid pain medication requirement at the completion of radiation and both increasing mean dose to the oral cavity and to the esophagus. Proton therapy was associated with significantly reduced radiation dose to assessed non-target normal tissues and a reduced rate of gastrostomy tube dependence and opioid pain medication requirements. This warrants further evaluation in larger studies, ideally with patient-reported toxicity outcomes and quality of life

  12. Study of high momentum eta' production in B {yields} {eta}{prime} X{sub s}

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B

    2004-01-05

    The authors measure the branching fraction for the charmless semi-inclusive process B {yields} {eta}{prime} X{sub s}, where the {eta}{prime} meson has a momentum in the range 2.0 to 2.7 GeV/c in the {Upsilon}(4S) center-of-mass frame and X{sub s} represents a system comprising a kaon and zero to four pions. They find {Beta}(B {yields} {eta}{prime} X{sub s}) = (3.9 {+-} 0.8(stat) {+-} 0.5(syst) {+-} 0.8(model)) x 10{sup -4}. They also obtain the X{sub s} mass distribution and find that it tends to favor models predicting high masses.

  13. State of the art on dose prescription, reporting and recording in Intensity-Modulated Radiation Therapy (ICRU report No. 83)

    International Nuclear Information System (INIS)

    Gregoire, V.; Mackie, T.R.

    2011-01-01

    The International Commission on Radiation Units and Measurements (ICRU) report No. 83 provides the information necessary to standardize techniques and procedures and to harmonize the prescribing, recording, and reporting of intensity modulated radiation therapy. Applicable concepts and recommendations in previous ICRU reports concerning radiation therapy were adopted, and new concepts were elaborated. In particular, additional recommendations were given on the selection and delineation of the targets volumes and the organs at risk; concepts of dose prescription and dose-volume reporting have also been refined. (authors)

  14. Comparison of a new noncoplanar intensity-modulated radiation therapy technique for craniospinal irradiation with 3 coplanar techniques

    DEFF Research Database (Denmark)

    Hansen, Anders T; Lukacova, Slavka; Lassen-Ramshad, Yasmin A.

    2015-01-01

    When standard conformal x-ray technique for craniospinal irradiation is used, it is a challenge to achieve satisfactory dose coverage of the target including the area of the cribriform plate, while sparing organs at risk. We present a new intensity-modulated radiation therapy (IMRT), noncoplanar...... patient using the noncoplanar IMRT-based technique, a coplanar IMRT-based technique, and a coplanar volumetric-modulated arch therapy (VMAT) technique. Dosimetry data for all patients were compared with the corresponding data from the conventional treatment plans. The new noncoplanar IMRT technique...... substantially reduced the mean dose to organs at risk compared with the standard radiation technique. The 2 other coplanar techniques also reduced the mean dose to some of the critical organs. However, this reduction was not as substantial as the reduction obtained by the noncoplanar technique. Furthermore...

  15. Dosimetric advantages of intensity-modulated proton therapy for oropharyngeal cancer compared with intensity-modulated radiation: A case-matched control analysis

    Energy Technology Data Exchange (ETDEWEB)

    Holliday, Emma B. [Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Kocak-Uzel, Esengul [Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Department of Radiation Therapy, Beykent University, Istanbul (Turkey); Feng, Lei [Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Thaker, Nikhil G.; Blanchard, Pierre; Rosenthal, David I.; Gunn, G. Brandon; Garden, Adam S. [Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Frank, Steven J., E-mail: sjfrank@mdanderson.org [Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2016-10-01

    A potential advantage of intensity-modulated proton therapy (IMPT) over intensity-modulated (photon) radiation therapy (IMRT) in the treatment of oropharyngeal carcinoma (OPC) is lower radiation dose to several critical structures involved in the development of nausea and vomiting, mucositis, and dysphagia. The purpose of this study was to quantify doses to critical structures for patients with OPC treated with IMPT and compare those with doses on IMRT plans generated for the same patients and with a matched cohort of patients actually treated with IMRT. In this study, 25 patients newly diagnosed with OPC were treated with IMPT between 2011 and 2012. Comparison IMRT plans were generated for these patients and for additional IMRT-treated controls extracted from a database of patients with OPC treated between 2000 and 2009. Cases were matched based on the following criteria, in order: unilateral vs bilateral therapy, tonsil vs base of tongue primary, T-category, N-category, concurrent chemotherapy, induction chemotherapy, smoking status, sex, and age. Results showed that the mean doses to the anterior and posterior oral cavity, hard palate, larynx, mandible, and esophagus were significantly lower with IMPT than with IMRT comparison plans generated for the same cohort, as were doses to several central nervous system structures involved in the nausea and vomiting response. Similar differences were found when comparing dose to organs at risks (OARs) between the IMPT cohort and the case-matched IMRT cohort. In conclusion, these findings suggest that patients with OPC treated with IMPT may experience fewer and less severe side effects during therapy. This may be the result of decreased beam path toxicities with IMPT due to lower doses to several dysphagia, odynophagia, and nausea and vomiting–associated OARs. Further study is needed to evaluate differences in long-term disease control and chronic toxicity between patients with OPC treated with IMPT in comparison to

  16. 29 CFR 500.132 - Applicable Federal standards: ETA and OSHA housing standards.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Applicable Federal standards: ETA and OSHA housing... Migrant Workers Housing Safety and Health § 500.132 Applicable Federal standards: ETA and OSHA housing... § 500.131, all migrant housing is subject to either the ETA standards or the OSHA standards, as follows...

  17. MO-AB-BRA-01: A Global Level Set Based Formulation for Volumetric Modulated Arc Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, D; Lyu, Q; Ruan, D; O’Connor, D; Low, D; Sheng, K [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA (United States)

    2016-06-15

    Purpose: The current clinical Volumetric Modulated Arc Therapy (VMAT) optimization is formulated as a non-convex problem and various greedy heuristics have been employed for an empirical solution, jeopardizing plan consistency and quality. We introduce a novel global direct aperture optimization method for VMAT to overcome these limitations. Methods: The global VMAT (gVMAT) planning was formulated as an optimization problem with an L2-norm fidelity term and an anisotropic total variation term. A level set function was used to describe the aperture shapes and adjacent aperture shapes were penalized to control MLC motion range. An alternating optimization strategy was implemented to solve the fluence intensity and aperture shapes simultaneously. Single arc gVMAT plans, utilizing 180 beams with 2° angular resolution, were generated for a glioblastoma multiforme (GBM), lung (LNG), and 2 head and neck cases—one with 3 PTVs (H&N3PTV) and one with 4 PTVs (H&N4PTV). The plans were compared against the clinical VMAT (cVMAT) plans utilizing two overlapping coplanar arcs. Results: The optimization of the gVMAT plans had converged within 600 iterations. gVMAT reduced the average max and mean OAR dose by 6.59% and 7.45% of the prescription dose. Reductions in max dose and mean dose were as high as 14.5 Gy in the LNG case and 15.3 Gy in the H&N3PTV case. PTV coverages (D95, D98, D99) were within 0.25% of the prescription dose. By globally considering all beams, the gVMAT optimizer allowed some beams to deliver higher intensities, yielding a dose distribution that resembles a static beam IMRT plan with beam orientation optimization. Conclusions: The novel VMAT approach allows for the search of an optimal plan in the global solution space and generates deliverable apertures directly. The single arc VMAT approach fully utilizes the digital linacs’ capability in dose rate and gantry rotation speed modulation. Varian Medical Systems, NIH grant R01CA188300, NIH grant R43CA183390.

  18. Characterization of a commercial multileaf collimator used for intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Low, Daniel A.; Sohn, Jason W.; Klein, Eric E.; Markman, Jerry; Mutic, Sasa; Dempsey, James F.

    2001-01-01

    The characteristics of a commercial multileaf collimator (MLC) to deliver static and dynamic multileaf collimation (SMLC and DMLC, respectively) were investigated to determine their influence on intensity modulated radiation therapy (IMRT) treatment planning and quality assurance. The influence of MLC leaf positioning accuracy on sequentially abutted SMLC fields was measured by creating abutting fields with selected gaps and overlaps. These data were also used to measure static leaf positioning precision. The characteristics of high leaf-velocity DMLC delivery were measured with constant velocity leaf sequences starting with an open field and closing a single leaf bank. A range of 1-72 monitor units (MU) was used providing a range of leaf velocities. The field abutment measurements yielded dose errors (as a percentage of the open field max dose) of 16.7±0.7% mm-1 and 12.8±0.7% mm-1 for 6 MV and 18 MV photon beams, respectively. The MLC leaf positioning precision was 0.080±0.018 mm (single standard deviation) highlighting the excellent delivery hardware tolerances for the tested beam delivery geometry. The high leaf-velocity DMLC measurements showed delivery artifacts when the leaf sequence and selected monitor units caused the linear accelerator to move the leaves at their maximum velocity while modulating the accelerator dose rate to deliver the desired leaf and MU sequence (termed leaf-velocity limited delivery). According to the vendor, a unique feature to their linear accelerator and MLC is that the dose rate is reduced to provide the correct cm MU-1 leaf velocity when the delivery is leaf-velocity limited. However, it was found that the system delivered roughly 1 MU per pulse when the delivery was leaf-velocity limited causing dose profiles to exhibit discrete steps rather than a smooth dose gradient. The root mean square difference between the steps and desired linear gradient was less than 3% when more than 4 MU were used. The average dose per MU was

  19. Measurement of the Color-Suppressed B0->D(*)0 pi0 /omega/eta/eta Prime Branching Fractions

    Energy Technology Data Exchange (ETDEWEB)

    Prudent, X

    2008-11-05

    The authors report results on the branching fraction (BF) measurement of the color-suppressed decays {bar B}{sup 0} {yields} D{sup 0}{pi}{sup 0}, D*{sup 0}{pi}{sup 0}, D{sup 0}{eta}, D*{sup 0}{eta}, D{sup 0}{omega}, D*{sup 0}{omega}, D{sup 0}{eta}{prime}, and D*{sup 0}{eta}{prime}. They measure the branching fractions BF(D{sup 0}{pi}{sup 0}) = (2.78 {+-} 0.08 {+-} 0.20) x 10{sup -4}, BF(D*{sup 0}{pi}{sup 0}) = (1.78 {+-} 0.13 {+-} 0.23) x 10{sup -4}, BF(D{sup 0}{eta}) = (2.41 {+-} 0.09 {+-} 0.17) x 10{sup -4}, BF(D*{sup 0}{eta}) = (2.32 {+-} 0.13 {+-} 0.22) x 10{sup -4}, BF(D{sup 0}{omega}) = (2.77 {+-} 0.13 {+-} 0.22) x 10{sup -4}, BF(D*{sup 0}{omega}) = (4.44 {+-} 0.23 {+-} 0.61) x 10{sup -4}, BF(D{sup 0}{eta}{prime}) = (1.38 {+-} 0.12 {+-} 0.22) x 10{sup -4} and BF(D*{sup 0}{eta}{prime}) = (1.29 {+-} 0.23 {+-} 0.23) x 10{sup -4}, where the first uncertainty is statistical and the second is systematic. The result is based on a sample of (454 {+-} 5) x 10{sup 6} B{bar B} pairs collected at the {Upsilon}(4S) resonance from 1999 to 2007, with the BABAR detector at the PEP-II storage rings at the Stanford Linear Accelerator Center. The measurements are compared to theoretical predictions by factorization, SCET and pQCD. The presence of final state interactions predictions by factorization, SCET and pQCD. The presence of final state interactions is confirmed and the measurements seem to be more in favor of SCET compared to pQCD.

  20. SU-F-T-184: 3D Range-Modulator for Scanned Particle Therapy: Development, Monte Carlo Simulations and Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Simeonov, Y; Penchev, P; Ringbaek, T Printz [University of Applied Sciences, Institute of Medical Physics and Radiation Protection, Giessen (Germany); Brons, S [Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg (Germany); Weber, U [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Zink, K [University of Applied Sciences, Institute of Medical Physics and Radiation Protection, Giessen (Germany); University Hospital Giessen-Marburg, Marburg (Germany)

    2016-06-15

    Purpose: Active raster scanning in particle therapy results in highly conformal dose distributions. Treatment time, however, is relatively high due to the large number of different iso-energy layers used. By using only one energy and the so called 3D range-modulator irradiation times of a few seconds only can be achieved, thus making delivery of homogeneous dose to moving targets (e.g. lung cancer) more reliable. Methods: A 3D range-modulator consisting of many pins with base area of 2.25 mm2 and different lengths was developed and manufactured with rapid prototyping technique. The form of the 3D range-modulator was optimised for a spherical target volume with 5 cm diameter placed at 25 cm in a water phantom. Monte Carlo simulations using the FLUKA package were carried out to evaluate the modulating effect of the 3D range-modulator and simulate the resulting dose distribution. The fine and complicated contour form of the 3D range-modulator was taken into account by a specially programmed user routine. Additionally FLUKA was extended with the capability of intensity modulated scanning. To verify the simulation results dose measurements were carried out at the Heidelberg Ion Therapy Center (HIT) with a 400.41 MeV 12C beam. Results: The high resolution measurements show that the 3D range-modulator is capable of producing homogeneous 3D conformal dose distributions, simultaneously reducing significantly irradiation time. Measured dose is in very good agreement with the previously conducted FLUKA simulations, where slight differences were traced back to minor manufacturing deviations from the perfect optimised form. Conclusion: Combined with the advantages of very short treatment time the 3D range-modulator could be an alternative to treat small to medium sized tumours (e.g. lung metastasis) with the same conformity as full raster-scanning treatment. Further simulations and measurements of more complex cases will be conducted to investigate the full potential of the 3D

  1. Multimodal hypoxia imaging and intensity modulated radiation therapy for unresectable non-small-cell lung cancer: the HIL trial

    Directory of Open Access Journals (Sweden)

    Askoxylakis Vasileios

    2012-09-01

    Full Text Available Abstract Background Radiotherapy, preferably combined with chemotherapy, is the treatment standard for locally advanced, unresectable non-small cell lung cancer (NSCLC. The tumor response to different therapy protocols is variable, with hypoxia known to be a major factor that negatively influences treatment effectiveness. Visualisation of tumor hypoxia prior to the use of modern radiation therapy strategies, such as intensity modulated radiation therapy (IMRT, might allow optimized dose applications to the target volume, leading to improvement of therapy outcome. 18 F-fluoromisonidazole dynamic positron emission tomography and computed tomography (18 F-FMISO dPET-CT and functional magnetic resonance imaging (functional MRI are attractive options for imaging tumor hypoxia. Methods/design The HIL trial is a single centre study combining multimodal hypoxia imaging with 18 F-FMISO dPET-CT and functional MRI, with intensity modulated radiation therapy (IMRT in patients with inoperable stage III NSCLC. 15 patients will be recruited in the study. All patients undergo initial FDG PET-CT and serial 18 F-FMISO dPET-CT and functional MRI before treatment, at week 5 of radiotherapy and 6 weeks post treatment. Radiation therapy is performed as inversely planned IMRT based on 4D-CT. Discussion Primary objectives of the trial are to characterize the correlation of 18 F-FMISO dPET-CT and functional MRI for tumor hypoxia imaging in NSCLC and evaluate possible effects of radiation therapy on tumor re-oxygenation. Further objectives include the generation of data regarding the prognostic value of 18 F-FMISO dPET-CT and functional MRI for locoregional control, progression free survival and overall survival of NSCLC treated with IMRT, which will form the basis for larger clinical trials focusing on possible interactions between tumor oxygenation and radiotherapy outcome. Trial registration The ClinicalTrials.gov protocol ID is NCT01617980

  2. Direct aperture optimization as a means of reducing the complexity of intensity modulated radiation therapy plans

    International Nuclear Information System (INIS)

    Broderick, Maria; Leech, Michelle; Coffey, Mary

    2009-01-01

    Intensity Modulated Radiation Therapy (IMRT) is a means of delivering radiation therapy where the intensity of the beam is varied within the treatment field. This is done by dividing a large beam into many small beamlets. Dose constraints are assigned to both the target and sensitive structures and computerised inverse optimization is performed to find the individual weights of this large number of beamlets. The computer adjusts the intensities of these beamlets according to the required planning dose objectives. The optimized intensity patterns are then decomposed into a series of deliverable multi leaf collimator (MLC) shapes in the sequencing step. One of the main problems of IMRT, which becomes even more apparent as the complexity of the IMRT plan increases, is the dramatic increase in the number of Monitor Units (MU) required to deliver a fractionated treatment. The difficulty with this increase in MU is its association with increased treatment times and a greater leakage of radiation from the MLCs increasing the total body dose and the risk of secondary cancers in patients. Therefore one attempts to find ways of reducing these MU without compromising plan quality. The design of inverse planning systems where the beam is divided into small beamlets to produce the required intensity map automatically introduces complexity into IMRT treatment planning. Plan complexity is associated with many negative factors such as dosimetric uncertainty and delivery issues A large search space is required necessitating much computing power. However, the limitations of the delivery technology are not taken into consideration when designing the ideal intensity map therefore a further step termed the sequencing step is required to convert the ideal intensity map into a deliverable one. Many approaches have been taken to reduce the complexity. These include setting intensity limits, putting penalties on the cost function and using smoothing filters Direct Aperture optimization

  3. Direct aperture optimization as a means of reducing the complexity of intensity modulated radiation therapy plans

    Directory of Open Access Journals (Sweden)

    Coffey Mary

    2009-02-01

    Full Text Available Abstract Intensity Modulated Radiation Therapy (IMRT is a means of delivering radiation therapy where the intensity of the beam is varied within the treatment field. This is done by dividing a large beam into many small beamlets. Dose constraints are assigned to both the target and sensitive structures and computerised inverse optimization is performed to find the individual weights of this large number of beamlets. The computer adjusts the intensities of these beamlets according to the required planning dose objectives. The optimized intensity patterns are then decomposed into a series of deliverable multi leaf collimator (MLC shapes in the sequencing step. One of the main problems of IMRT, which becomes even more apparent as the complexity of the IMRT plan increases, is the dramatic increase in the number of Monitor Units (MU required to deliver a fractionated treatment. The difficulty with this increase in MU is its association with increased treatment times and a greater leakage of radiation from the MLCs increasing the total body dose and the risk of secondary cancers in patients. Therefore one attempts to find ways of reducing these MU without compromising plan quality. The design of inverse planning systems where the beam is divided into small beamlets to produce the required intensity map automatically introduces complexity into IMRT treatment planning. Plan complexity is associated with many negative factors such as dosimetric uncertainty and delivery issues A large search space is required necessitating much computing power. However, the limitations of the delivery technology are not taken into consideration when designing the ideal intensity map therefore a further step termed the sequencing step is required to convert the ideal intensity map into a deliverable one. Many approaches have been taken to reduce the complexity. These include setting intensity limits, putting penalties on the cost function and using smoothing filters Direct

  4. Direct aperture optimization as a means of reducing the complexity of intensity modulated radiation therapy plans

    Energy Technology Data Exchange (ETDEWEB)

    Broderick, Maria; Leech, Michelle; Coffey, Mary [Division of Radiation Therapy, School of Medicine, Trinity College Dublin, Dublin, Ireland (United Kingdom)

    2009-02-16

    Intensity Modulated Radiation Therapy (IMRT) is a means of delivering radiation therapy where the intensity of the beam is varied within the treatment field. This is done by dividing a large beam into many small beamlets. Dose constraints are assigned to both the target and sensitive structures and computerised inverse optimization is performed to find the individual weights of this large number of beamlets. The computer adjusts the intensities of these beamlets according to the required planning dose objectives. The optimized intensity patterns are then decomposed into a series of deliverable multi leaf collimator (MLC) shapes in the sequencing step. One of the main problems of IMRT, which becomes even more apparent as the complexity of the IMRT plan increases, is the dramatic increase in the number of Monitor Units (MU) required to deliver a fractionated treatment. The difficulty with this increase in MU is its association with increased treatment times and a greater leakage of radiation from the MLCs increasing the total body dose and the risk of secondary cancers in patients. Therefore one attempts to find ways of reducing these MU without compromising plan quality. The design of inverse planning systems where the beam is divided into small beamlets to produce the required intensity map automatically introduces complexity into IMRT treatment planning. Plan complexity is associated with many negative factors such as dosimetric uncertainty and delivery issues A large search space is required necessitating much computing power. However, the limitations of the delivery technology are not taken into consideration when designing the ideal intensity map therefore a further step termed the sequencing step is required to convert the ideal intensity map into a deliverable one. Many approaches have been taken to reduce the complexity. These include setting intensity limits, putting penalties on the cost function and using smoothing filters Direct Aperture optimization

  5. Tumor trailing strategy for intensity-modulated radiation therapy of moving targets

    International Nuclear Information System (INIS)

    Trofimov, Alexei; Vrancic, Christian; Chan, Timothy C. Y.; Sharp, Gregory C.; Bortfeld, Thomas

    2008-01-01

    Internal organ motion during the course of radiation therapy of cancer affects the distribution of the delivered dose and, generally, reduces its conformality to the targeted volume. Previously proposed approaches aimed at mitigating the effect of internal motion in intensity-modulated radiation therapy (IMRT) included expansion of the target margins, motion-correlated delivery (e.g., respiratory gating, tumor tracking), and adaptive treatment plan optimization employing a probabilistic description of motion. We describe and test the tumor trailing strategy, which utilizes the synergy of motion-adaptive treatment planning and delivery methods. We regard the (rigid) target motion as a superposition of a relatively fast cyclic component (e.g., respiratory) and slow aperiodic trends (e.g., the drift of exhalation baseline). In the trailing approach, these two components of motion are decoupled and dealt with separately. Real-time motion monitoring is employed to identify the 'slow' shifts, which are then corrected by applying setup adjustments. The delivery does not track the target position exactly, but trails the systematic trend due to the delay between the time a shift occurs, is reliably detected, and, subsequently, corrected. The ''fast'' cyclic motion is accounted for with a robust motion-adaptive treatment planning, which allows for variability in motion parameters (e.g., mean and extrema of the tidal volume, variable period of respiration, and expiratory duration). Motion-surrogate data from gated IMRT treatments were used to provide probability distribution data for motion-adaptive planning and to test algorithms that identified systematic trends in the character of motion. Sample IMRT fields were delivered on a clinical linear accelerator to a programmable moving phantom. Dose measurements were performed with a commercial two-dimensional ion-chamber array. The results indicate that by reducing intrafractional motion variability, the trailing strategy

  6. Improving intensity-modulated radiation therapy using the anatomic beam orientation optimization algorithm

    International Nuclear Information System (INIS)

    Potrebko, Peter S.; McCurdy, Boyd M. C.; Butler, James B.; El-Gubtan, Adel S.

    2008-01-01

    A novel, anatomic beam orientation optimization (A-BOO) algorithm is proposed to significantly improve conventional intensity-modulated radiation therapy (IMRT). The A-BOO algorithm vectorially analyses polygonal surface mesh data of contoured patient anatomy. Five optimal (5-opt) deliverable beam orientations are selected based on (1) tangential orientation bisecting the target and adjacent organ's-at-risk (OARs) to produce precipitous dose gradients between them and (2) parallel incidence with polygon features of the target volume to facilitate conformal coverage. The 5-opt plans were compared to standard five, seven, and nine equiangular-spaced beam plans (5-equi, 7-equi, 9-equi) for: (1) gastric, (2) Radiation Therapy Oncology Group (RTOG) P-0126 prostate, and (3) RTOG H-0022 oropharyngeal (stage-III, IV) cancer patients. In the gastric case, the noncoplanar 5-opt plan reduced the right kidney V 20 Gy by 32.2%, 23.2%, and 20.6% compared to plans with five, seven, and nine equiangular-spaced beams. In the prostate case, the coplanar 5-opt plan produced similar rectal sparing as the 7-equi and 9-equi plans with a reduction of the V 75, V 70, V 65, and V 60 Gy of 2.4%, 5.3%, 7.0%, and 9.5% compared to the 5-equi plan. In the stage-III and IV oropharyngeal cases, the noncoplanar 5-opt plan substantially reduced the V 30 Gy and mean dose to the contralateral parotid compared to plans with five, seven, and nine equiangular-spaced beams: (stage-III) 7.1%, 5.2%, 6.8%, and 5.1, 3.5, 3.7 Gy and (stage-IV) 10.2%, 10.2%, 9.8% and 7.0, 7.1, 7.2 Gy. The geometry-based A-BOO algorithm has been demonstrated to be robust for application to a variety of IMRT treatment sites. Beam orientations producing significant improvements in OAR sparing over conventional IMRT can be automatically produced in minutes compared to hours with existing dose-based beam orientation optimization methods

  7. A convenient synthetic route to benz[cd]azulenes: versatile ligands with the potential to bind metals in an eta5, eta6, or eta7 fashion.

    Science.gov (United States)

    Balduzzi, Sonya; Müller-Bunz, Helge; McGlinchey, Michael J

    2004-10-25

    A facile method for preparing the 2H-benz[cd]azulene system, based upon an elaboration of the guaiazulene framework, is presented. Aerial oxidation to the corresponding 8-(2-propylidene)-benz[cd]azulene, and also cycloaddition reactions with tetracyanoethylene (TCNE), are described. The first X-ray crystal structure of a 2H-benz[cd]azulene, as an eta6-coordinated Cr(CO)3 complex, is reported.

  8. eta pi(+)pi(-) Resonant Structure around 1.8 GeV/c(2) and eta in J/psi -> omega eta pi(+)pi(-)

    NARCIS (Netherlands)

    Ablikim, M.; Achasov, M. N.; Alberto, D.; An, Q.; An, Z. H.; Bai, J. Z.; Baldini, R.; Ban, Y.; Becker, J.; Berger, N.; Bertani, M.; Bian, J. M.; Bondarenko, O.; Boyko, I.; Briere, R. A.; Bytev, V.; Cai, X.; Calcaterra, A. C.; Cao, G. F.; Cao, X. X.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, Y.; Chen, Y. B.; Cheng, H. P.; Chu, Y. P.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dedovich, D.; Deng, Z. Y.; Denysenko, I.; Destefanis, M.; Ding, Y.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Fan, R. R.; Fang, J.; Fang, S. S.; Feng, C. Q.; Fu, C. D.; Fu, J. L.; Gao, Y.; Geng, C.; Goetzen, K.; Gong, W. X.; Greco, M.; Grishin, S.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, Y. P.; Hao, X. Q.; Harris, F. A.; He, K. L.; He, M.; He, Z. Y.; Heng, Y. K.; Hou, Z. L.; Hu, H. M.; Hu, J. F.; Hu, T.; Huang, B.; Huang, G. M.; Huang, J. S.; Huang, X. T.; Huang, Y. P.; Hussain, T.; Ji, C. S.; Ji, Q.; Ji, X. B.; Ji, X. L.; Jia, L. K.; Jiang, L. L.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Jing, F. F.; Kalantar-Nayestanaki, N.; Kavatsyuk, M.; Komamiya, S.; Kuehn, W.; Lange, J. S.; Leung, J. K. C.; Li, Cheng; Li, Cui; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, K.; Li, Lei; Li, N. B.; Li, Q. J.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, X. R.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, X. T.; Liu, B. J.; Liu, B. J.; Liu, C. L.; Liu, C. X.; Liu, C. Y.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, G. C.; Liu, H.; Liu, H. B.; Liu, H. H.; Liu, H. M.; Liu, H. W.; Liu, J. P.; Liu, K.; Liu, K.; Liu, K. Y.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, X. H.; Liu, Y. B.; Liu, Y. W.; Liu, Yong; Liu, Z. A.; Liu, Z. Q.; Loehner, H.; Lu, G. R.; Lu, H. J.; Lu, J. G.; Lu, Q. W.; Lu, X. R.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Ma, C. L.; Ma, F. C.; Ma, H. L.; Ma, Q. M.; Ma, T.; Ma, X.; Ma, X. Y.; Maggiora, M.; Malik, Q. A.; Mao, H.; Mao, Y. J.; Mao, Z. P.; Messchendorp, J. G.; Min, J.; Mitchell, R. E.; Mo, X. H.; Muchnoi, N. Yu; Nefedov, Y.; Nikolaev, I. B.; Ning, Z.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pelizaeus, M.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Pun, C. S. J.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, X. S.; Qiu, J. F.; Rashid, K. H.; Rong, G.; Ruan, X. D.; Sarantsev, A.; Schulze, J.; Shao, M.; Shen, C. P.; Shen, X. Y.; Sheng, H. Y.; Shepherd, M. R.; Song, X. Y.; Sonoda, S.; Spataro, S.; Spruck, B.; Sun, D. H.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, X. D.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tian, H. L.; Toth, D.; Varner, G. S.; Wan, X.; Wang, B. Q.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q.; Wang, S. G.; Wang, X. L.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. Y.; Wei, D. H.; Wen, Q. G.; Wen, S. P.; Wiedner, U.; Wu, L. H.; Wu, N.; Wu, W.; Wu, Z.; Xiao, Z. J.; Xie, Y. G.; Xu, G. F.; Xu, G. M.; Xu, H.; Xu, Q. J.; Xu, X. P.; Xu, Y.; Xu, Z. R.; Xu, Z. Z.; Xue, Z.; Yan, L.; Yan, W. B.; Yan, Y. H.; Yang, H. X.; Yang, M.; Yang, T.; Yang, Y.; Yang, Y. X.; Ye, M.; Ye, M. H.; Yu, B. X.; Yu, C. X.; Yu, L.; Yu, S. P. Yu; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, L.; Zhang, S. H.; Zhang, T. R.; Zhang, X. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, H. S.; Zhao, Jiawei; Zhao, Jingwei; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, S. J.; Zhao, T. C.; Zhao, X. H.; Zhao, Y. B.; Zhao, Z. G.; Zhao, Z. L.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, Y. H.; Zheng, Z. P.; Zhong, B.; Zhong, J.; Zhong, L.; Zhou, L.; Zhou, X. K.; Zhou, X. R.; Zhu, C.; Zhu, K.; Zhu, K. J.; Zhu, S. H.; Zhu, X. L.; Zhu, X. W.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.; Zuo, J. X.

    2011-01-01

    We present results of a study of the decay J/psi -> omega eta pi(+)pi(-) using a sample of (225.2 +/- 2.8) x 10(6) J/psi events collected by the BESIII detector, and report the observation of a new process J/psi -> omega X(1870) with a statistical significance of 7.2 sigma, in which X(1870) decays

  9. Intensity modulated radiation-therapy for preoperative posterior abdominal wall irradiation of retroperitoneal liposarcomas

    International Nuclear Information System (INIS)

    Bossi, Alberto; De Wever, Ivo; Van Limbergen, Erik; Vanstraelen, Bianca

    2007-01-01

    Purpose: Preoperative external-beam radiation therapy (preop RT) in the management of Retroperitoneal Liposarcomas (RPLS) typically involves the delivery of radiation to the entire tumor mass: yet this may not be necessary. The purpose of this study is to evaluate a new strategy of preop RT for RPLS in which the target volume is limited to the contact area between the tumoral mass and the posterior abdominal wall. Methods and Materials: Between June 2000 and Jan 2005, 18 patients with the diagnosis of RPLS have been treated following a pilot protocol of pre-op RT, 50 Gy in 25 fractions of 2 Gy/day. The Clinical Target Volume (CTV) has been limited to the posterior abdominal wall, region at higher risk for local relapse. A Three-Dimensional conformal (3D-CRT) and an Intensity Modulated (IMRT) plan were generated and compared; toxicity was reported following the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events v3.0. Results: All patients completed the planned treatment and the acute toxicity was tolerable: 2 patients experienced Grade 3 and 1 Grade 2 anorexia while 2 patients developed Grade 2 nausea. IMRT allows a better sparing of the ipsilateral and the contralateral kidney. All tumors were successfully resected without major complications. At a median follow-up of 27 months 2 patients developed a local relapse and 1 lung metastasis. Conclusions: Our strategy of preop RT is feasible and well tolerated: the rate of resectability is not compromised by limiting the preop CTV to the posterior abdominal wall and a better critical-structures sparing is obtained with IMRT

  10. Gamma-index method sensitivity for gauging plan delivery accuracy of volumetric modulated arc therapy.

    Science.gov (United States)

    Park, Jong In; Park, Jong Min; Kim, Jung-In; Park, So-Yeon; Ye, Sung-Joon

    2015-12-01

    The aim of this study was to investigate the sensitivity of the gamma-index method according to various gamma criteria for volumetric modulated arc therapy (VMAT). Twenty head and neck (HN) and twenty prostate VMAT plans were retrospectively selected for this study. Both global and local 2D gamma evaluations were performed with criteria of 3%/3 mm, 2%/2 mm, 1%/2 mm and 2%/1 mm. In this study, the global and local gamma-index calculated the differences in doses relative to the maximum dose and the dose at the current measurement point, respectively. Using log files acquired during delivery, the differences in parameters at every control point between the VMAT plans and the log files were acquired. The differences in dose-volumetric parameters between reconstructed VMAT plans using the log files and the original VMAT plans were calculated. The Spearman's rank correlation coefficients (rs) were calculated between the passing rates and those differences. Considerable correlations with statistical significances were observed between global 1%/2 mm, local 1%/2 mm and local 2%/1 mm and the MLC position differences (rs = -0.712, -0.628 and -0.581). The numbers of rs values with statistical significance between the passing rates and the changes in dose-volumetric parameters were largest in global 2%/2 mm (n = 16), global 2%/1 mm (n = 15) and local 2%/1 mm (n = 13) criteria. Local gamma-index method with 2%/1 mm generally showed higher sensitivity to detect deviations between a VMAT plan and the delivery of the VMAT plan. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  11. A retrospective analysis for patient-specific quality assurance of volumetric-modulated arc therapy plans

    International Nuclear Information System (INIS)

    Li, Guangjun; Wu, Kui; Peng, Guang; Zhang, Yingjie; Bai, Sen

    2014-01-01

    Volumetric-modulated arc therapy (VMAT) is now widely used clinically, as it is capable of delivering a highly conformal dose distribution in a short time interval. We retrospectively analyzed patient-specific quality assurance (QA) of VMAT and examined the relationships between the planning parameters and the QA results. A total of 118 clinical VMAT cases underwent pretreatment QA. All plans had 3-dimensional diode array measurements, and 69 also had ion chamber measurements. Dose distribution and isocenter point dose were evaluated by comparing the measurements and the treatment planning system (TPS) calculations. In addition, the relationship between QA results and several planning parameters, such as dose level, control points (CPs), monitor units (MUs), average field width, and average leaf travel, were also analyzed. For delivered dose distribution, a gamma analysis passing rate greater than 90% was obtained for all plans and greater than 95% for 100 of 118 plans with the 3%/3-mm criteria. The difference (mean ± standard deviation) between the point doses measured by the ion chamber and those calculated by TPS was 0.9% ± 2.0% for all plans. For all cancer sites, nasopharyngeal carcinoma and gastric cancer have the lowest and highest average passing rates, respectively. From multivariate linear regression analysis, the dose level (p = 0.001) and the average leaf travel (p < 0.001) showed negative correlations with the passing rate, and the average field width (p = 0.003) showed a positive correlation with the passing rate, all indicating a correlation between the passing rate and the plan complexity. No statistically significant correlation was found between MU or CP and the passing rate. Analysis of the results of dosimetric pretreatment measurements as a function of VMAT plan parameters can provide important information to guide the plan parameter setting and optimization in TPS

  12. A retrospective analysis for patient-specific quality assurance of volumetric-modulated arc therapy plans

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guangjun [Radiation Physics Center, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan (China); Wu, Kui [Department of Radiotherapy, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province (China); Peng, Guang; Zhang, Yingjie [Radiation Physics Center, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan (China); Bai, Sen, E-mail: baisen@scu.edu.cn [Radiation Physics Center, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan (China)

    2014-01-01

    Volumetric-modulated arc therapy (VMAT) is now widely used clinically, as it is capable of delivering a highly conformal dose distribution in a short time interval. We retrospectively analyzed patient-specific quality assurance (QA) of VMAT and examined the relationships between the planning parameters and the QA results. A total of 118 clinical VMAT cases underwent pretreatment QA. All plans had 3-dimensional diode array measurements, and 69 also had ion chamber measurements. Dose distribution and isocenter point dose were evaluated by comparing the measurements and the treatment planning system (TPS) calculations. In addition, the relationship between QA results and several planning parameters, such as dose level, control points (CPs), monitor units (MUs), average field width, and average leaf travel, were also analyzed. For delivered dose distribution, a gamma analysis passing rate greater than 90% was obtained for all plans and greater than 95% for 100 of 118 plans with the 3%/3-mm criteria. The difference (mean ± standard deviation) between the point doses measured by the ion chamber and those calculated by TPS was 0.9% ± 2.0% for all plans. For all cancer sites, nasopharyngeal carcinoma and gastric cancer have the lowest and highest average passing rates, respectively. From multivariate linear regression analysis, the dose level (p = 0.001) and the average leaf travel (p < 0.001) showed negative correlations with the passing rate, and the average field width (p = 0.003) showed a positive correlation with the passing rate, all indicating a correlation between the passing rate and the plan complexity. No statistically significant correlation was found between MU or CP and the passing rate. Analysis of the results of dosimetric pretreatment measurements as a function of VMAT plan parameters can provide important information to guide the plan parameter setting and optimization in TPS.

  13. Intensity-modulated radiation therapy for T4 nasopharyngeal carcinoma. Treatment results and locoregional

    Energy Technology Data Exchange (ETDEWEB)

    Chen, J.L.Y.; Tsai, C.L.; Chen, W.Y.; Wang, C.W. [National Taiwan Univ. Hospital, Taipei (China). Div. of Radiation Oncology; Huang, Y.S.; Chen, Y.F. [National Taiwan Univ. Hospital, Taipei (China). Dept. of Medical Imaging; Kuo, S.H. [National Taiwan Univ. Hospital, Taipei (China). Div. of Radiation Oncology; National Taiwan Univ. College of Medicine, Taipei (China). Graduate Inst. of Clinical Medicine; Hong, R.L. [National Taiwan Univ. Hospital, Taipei (China). Div. of Medical Oncology; Ko, J.Y.; Lou, P.J. [National Taiwan Univ. Hospital, Taipei (China). Dept. of Otolaryngology

    2013-12-15

    Purpose: The purpose of this work was to examine outcomes in patients with T4 nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT). Methods and materials: Between 2007 and 2010, 154 patients with nonmetastatic T4 NPC were treated with IMRT to a total dose of 70 Gy in 33-35 fractions. In addition, 97 % of patients received concurrent platinum-based chemotherapy. The median follow-up time was 52.8 months. Results: The rates of 5-year actuarial locoregional control, distant metastasis-free survival, progression free-survival, and overall survival (OS) were 81.2, 72.2, 61.9, and 78.1 %, respectively. A total of 27 patients had locoregional recurrence: 85.2 % in-field failures, 11.1 % marginal failures, and 3.7 % out-of-field failures. Fourteen patients with locoregional recurrence received aggressive treatments, including nasopharyngectomy, neck dissection, or re-irradiation, and the 5-year OS rate tended to be better (61.9 %) compared to those receiving conservative treatment (32.0 %, p = 0.051). In patients treated with 1 course of radiotherapy, grade {>=} 3 toxicities of ototoxicity, neck fibrosis, xerostomia, epistaxis, and radiographic temporal lobe necrosis occurred in 18.2, 9.8, 6.3, 2.1, and 5.6 % of patients, respectively. Increased ototoxicity, osteonecrosis, severe nasal bleeding, and temporal necrosis were observed in patients treated by re-irradiation. Conclusion: IMRT offers good locoregional control in patients with T4 NPC. For patients with locoregional recurrence after definitive radiotherapy, aggressive local treatment may be considered for a better outcome. (orig.)

  14. A retrospective analysis for patient-specific quality assurance of volumetric-modulated arc therapy plans.

    Science.gov (United States)

    Li, Guangjun; Wu, Kui; Peng, Guang; Zhang, Yingjie; Bai, Sen

    2014-01-01

    Volumetric-modulated arc therapy (VMAT) is now widely used clinically, as it is capable of delivering a highly conformal dose distribution in a short time interval. We retrospectively analyzed patient-specific quality assurance (QA) of VMAT and examined the relationships between the planning parameters and the QA results. A total of 118 clinical VMAT cases underwent pretreatment QA. All plans had 3-dimensional diode array measurements, and 69 also had ion chamber measurements. Dose distribution and isocenter point dose were evaluated by comparing the measurements and the treatment planning system (TPS) calculations. In addition, the relationship between QA results and several planning parameters, such as dose level, control points (CPs), monitor units (MUs), average field width, and average leaf travel, were also analyzed. For delivered dose distribution, a gamma analysis passing rate greater than 90% was obtained for all plans and greater than 95% for 100 of 118 plans with the 3%/3-mm criteria. The difference (mean ± standard deviation) between the point doses measured by the ion chamber and those calculated by TPS was 0.9% ± 2.0% for all plans. For all cancer sites, nasopharyngeal carcinoma and gastric cancer have the lowest and highest average passing rates, respectively. From multivariate linear regression analysis, the dose level (p = 0.001) and the average leaf travel (p < 0.001) showed negative correlations with the passing rate, and the average field width (p = 0.003) showed a positive correlation with the passing rate, all indicating a correlation between the passing rate and the plan complexity. No statistically significant correlation was found between MU or CP and the passing rate. Analysis of the results of dosimetric pretreatment measurements as a function of VMAT plan parameters can provide important information to guide the plan parameter setting and optimization in TPS. Copyright © 2014 American Association of Medical Dosimetrists. Published by

  15. Dosimetric predictors of hypothyroidism in oropharyngeal cancer patients treated with intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Chyan, Arthur; Chen, Josephine; Shugard, Erin; Lambert, Louise; Quivey, Jeanne M; Yom, Sue S

    2014-01-01

    Radiation to the neck has long been associated with an elevated risk of hypothyroidism development. The goal of the present work is to define dosimetric predictors of hypothyroidism in oropharyngeal cancer (OPC) patients treated with intensity-modulated radiation therapy. Data for 123 patients, with a median follow up of 4.6 years, were retrospectively analyzed. Patients with elevated thyroid-stimulating hormone levels or with a clinical diagnosis were categorized as hypothyroid. Patient demographic parameters, thyroid volume, mean thyroid dose, the percent of thyroid volume receiving minimum specified dose levels (VxxGy), and the absolute thyroid volume spared from specified dose levels (VSxxGy) were analyzed. Normal-tissue complication probability (NTCP) was also calculated using several recently published models. Thyroid volume and many radiation dosimetric parameters were statistically different in the hypothyroid group. For the patients with initial thyroid volumes of 8 cc or greater, several dosimetric parameters were found to define subgroups at statistically significant lower risk of developing hypothyroidism. Patients with VS45 Gy of at least 3 cc, VS50 Gy at least 5 cc, VS50 Gy at least 6 cc, V50 Gy below 45%, V50 Gy below 55%, or mean thyroid dose below 49 Gy had a 28-38% estimated risk of hypothyroidism at 3 years compared to a 55% risk for the entire study group. Patients with a NTCP of less than 0.75 or 0.8, calculated using recently published models, were also observed to have a lower risk of developing hypothyroidism. Based on long-term follow up data for OPC patients treated with IMRT, we recommend plan optimization objectives to reduce the volume of thyroid receiving over 45 Gy to significantly decrease the risk of developing hypothyroidism. The online version of this article (doi:10.1186/s13014-014-0269-4) contains supplementary material, which is available to authorized users

  16. Automation and Intensity Modulated Radiation Therapy for Individualized High-Quality Tangent Breast Treatment Plans

    International Nuclear Information System (INIS)

    Purdie, Thomas G.; Dinniwell, Robert E.; Fyles, Anthony; Sharpe, Michael B.

    2014-01-01

    Purpose: To demonstrate the large-scale clinical implementation and performance of an automated treatment planning methodology for tangential breast intensity modulated radiation therapy (IMRT). Methods and Materials: Automated planning was used to prospectively plan tangential breast IMRT treatment for 1661 patients between June 2009 and November 2012. The automated planning method emulates the manual steps performed by the user during treatment planning, including anatomical segmentation, beam placement, optimization, dose calculation, and plan documentation. The user specifies clinical requirements of the plan to be generated through a user interface embedded in the planning system. The automated method uses heuristic algorithms to define and simplify the technical aspects of the treatment planning process. Results: Automated planning was used in 1661 of 1708 patients receiving tangential breast IMRT during the time interval studied. Therefore, automated planning was applicable in greater than 97% of cases. The time for treatment planning using the automated process is routinely 5 to 6 minutes on standard commercially available planning hardware. We have shown a consistent reduction in plan rejections from plan reviews through the standard quality control process or weekly quality review multidisciplinary breast rounds as we have automated the planning process for tangential breast IMRT. Clinical plan acceptance increased from 97.3% using our previous semiautomated inverse method to 98.9% using the fully automated method. Conclusions: Automation has become the routine standard method for treatment planning of tangential breast IMRT at our institution and is clinically feasible on a large scale. The method has wide clinical applicability and can add tremendous efficiency, standardization, and quality to the current treatment planning process. The use of automated methods can allow centers to more rapidly adopt IMRT and enhance access to the documented

  17. Pertinence analysis of intensity-modulated radiation therapy dosimetry error and parameters of beams

    International Nuclear Information System (INIS)

    Chi Zifeng; Liu Dan; Cao Yankun; Li Runxiao; Han Chun

    2012-01-01

    Objective: To study the relationship between parameter settings in the intensity-modulated radiation therapy (IMRT) planning in order to explore the effect of parameters on absolute dose verification. Methods: Forty-three esophageal carcinoma cases were optimized with Pinnacle 7.6c by experienced physicist using appropriate optimization parameters and dose constraints with a number of iterations to meet the clinical acceptance criteria. The plans were copied to water-phantom, 0.13 cc ion Farmer chamber and DOSE1 dosimeter was used to measure the absolute dose. The statistical data of the parameters of beams for the 43 cases were collected, and the relationships among them were analyzed. The statistical data of the dosimetry error were collected, and comparative analysis was made for the relation between the parameters of beams and ion chamber absolute dose verification results. Results: The parameters of beams were correlated among each other. Obvious affiliation existed between the dose accuracy and parameter settings. When the beam segment number of IMRT plan was more than 80, the dose deviation would be greater than 3%; however, if the beam segment number was less than 80, the dose deviation was smaller than 3%. When the beam segment number was more than 100, part of the dose deviation of this plan was greater than 4%. On the contrary, if the beam segment number was less than 100, the dose deviation was smaller than 4% definitely. Conclusions: In order to decrease the absolute dose verification error, less beam angles and less beam segments are needed and the beam segment number should be controlled within the range of 80. (authors)

  18. Beam's-Eye-View Dosimetrics-Guided Inverse Planning for Aperture-Modulated Arc Therapy

    International Nuclear Information System (INIS)

    Ma Yunzhi; Popple, Richard; Suh, Tae-Suk; Xing Lei

    2009-01-01

    Purpose: To use angular beam's-eye-view dosimetrics (BEVD) information to improve the computational efficiency and plan quality of inverse planning of aperture-modulated arc therapy (AMAT). Methods and Materials: In BEVD-guided inverse planning, the angular space spanned by a rotational arc is represented by a large number of fixed-gantry beams with angular spacing of ∼2.5 degrees. Each beam is assigned with an initial aperture shape determined by the beam's-eye-view (BEV) projection of the planning target volume (PTV) and an initial weight. Instead of setting the beam weights arbitrarily, which slows down the subsequent optimization process and may result in a suboptimal solution, a priori knowledge about the quality of the beam directions derived from a BEVD is adopted to initialize the weights. In the BEVD calculation, a higher score is assigned to directions that allow more dose to be delivered to the PTV without exceeding the dose tolerances of the organs at risk (OARs) and vice versa. Simulated annealing is then used to optimize the segment shapes and weights. The BEVD-guided inverse planning is demonstrated by using two clinical cases, and the results are compared with those of a conventional approach without BEVD guidance. Results: An a priori knowledge-guided inverse planning scheme for AMAT is established. The inclusion of BEVD guidance significantly improves the convergence behavior of AMAT inverse planning and results in much better OAR sparing as compared with the conventional approach. Conclusions: BEVD-guidance facilitates AMAT treatment planning and provides a comprehensive tool to maximally use the technical capacity of the new arc therapeutic modality.

  19. Design and dosimetry of a few leaf electron collimator for energy modulated electron therapy

    International Nuclear Information System (INIS)

    Al-Yahya, Khalid; Verhaegen, Frank; Seuntjens, Jan

    2007-01-01

    Despite the capability of energy modulated electron therapy (EMET) to achieve highly conformal dose distributions in superficial targets it has not been widely implemented due to problems inherent in electron beam radiotherapy such as planning dosimetry accuracy, and verification as well as a lack of systems for automated delivery. In previous work we proposed a novel technique to deliver EMET using an automated 'few leaf electron collimator' (FLEC) that consists of four motor-driven leaves fit in a standard clinical electron beam applicator. Integrated with a Monte Carlo based optimization algorithm that utilizes patient-specific dose kernels, a treatment delivery was incorporated within the linear accelerator operation. The FLEC was envisioned to work as an accessory tool added to the clinical accelerator. In this article the design and construction of the FLEC prototype that match our compact design goals are presented. It is controlled using an in-house developed EMET controller. The structure of the software and the hardware characteristics of the EMET controller are demonstrated. Using a parallel plate ionization chamber, output measurements were obtained to validate the Monte Carlo calculations for a range of fields with different energies and sizes. Further verifications were also performed for comparing 1-D and 2-D dose distributions using energy independent radiochromic films. Comparisons between Monte Carlo calculations and measurements of complex intensity map deliveries show an overall agreement to within ±3%. This work confirms our design objectives of the FLEC that allow for automated delivery of EMET. Furthermore, the Monte Carlo dose calculation engine required for EMET planning was validated. The result supports the potential of the prototype FLEC for the planning and delivery of EMET

  20. An Anatomically Validated Brachial Plexus Contouring Method for Intensity Modulated Radiation Therapy Planning

    International Nuclear Information System (INIS)

    Van de Velde, Joris; Audenaert, Emmanuel; Speleers, Bruno; Vercauteren, Tom; Mulliez, Thomas; Vandemaele, Pieter; Achten, Eric; Kerckaert, Ingrid; D'Herde, Katharina; De Neve, Wilfried; Van Hoof, Tom

    2013-01-01

    Purpose: To develop contouring guidelines for the brachial plexus (BP) using anatomically validated cadaver datasets. Magnetic resonance imaging (MRI) and computed tomography (CT) were used to obtain detailed visualizations of the BP region, with the goal of achieving maximal inclusion of the actual BP in a small contoured volume while also accommodating for anatomic variations. Methods and Materials: CT and MRI were obtained for 8 cadavers positioned for intensity modulated radiation therapy. 3-dimensional reconstructions of soft tissue (from MRI) and bone (from CT) were combined to create 8 separate enhanced CT project files. Dissection of the corresponding cadavers anatomically validated the reconstructions created. Seven enhanced CT project files were then automatically fitted, separately in different regions, to obtain a single dataset of superimposed BP regions that incorporated anatomic variations. From this dataset, improved BP contouring guidelines were developed. These guidelines were then applied to the 7 original CT project files and also to 1 additional file, left out from the superimposing procedure. The percentage of BP inclusion was compared with the published guidelines. Results: The anatomic validation procedure showed a high level of conformity for the BP regions examined between the 3-dimensional reconstructions generated and the dissected counterparts. Accurate and detailed BP contouring guidelines were developed, which provided corresponding guidance for each level in a clinical dataset. An average margin of 4.7 mm around the anatomically validated BP contour is sufficient to accommodate for anatomic variations. Using the new guidelines, 100% inclusion of the BP was achieved, compared with a mean inclusion of 37.75% when published guidelines were applied. Conclusion: Improved guidelines for BP delineation were developed using combined MRI and CT imaging with validation by anatomic dissection

  1. Application of influence diagrams to prostate intensity-modulated radiation therapy plan selection

    International Nuclear Information System (INIS)

    Meyer, Juergen; Phillips, Mark H; Cho, Paul S; Kalet, Ira; Doctor, Jason N

    2004-01-01

    The purpose is to incorporate clinically relevant factors such as patient-specific and dosimetric information as well as data from clinical trials in the decision-making process for the selection of prostate intensity-modulated radiation therapy (IMRT) plans. The approach is to incorporate the decision theoretic concept of an influence diagram into the solution of the multiobjective optimization inverse planning problem. A set of candidate IMRT plans was obtained by varying the importance factors for the planning target volume (PTV) and the organ-at-risk (OAR) in combination with simulated annealing to explore a large part of the solution space. The Pareto set for the PTV and OAR was analysed to demonstrate how the selection of the weighting factors influenced which part of the solution space was explored. An influence diagram based on a Bayesian network with 18 nodes was designed to model the decision process for plan selection. The model possessed nodes for clinical laboratory results, tumour grading, staging information, patient-specific information, dosimetric information, complications and survival statistics from clinical studies. A utility node was utilized for the decision-making process. The influence diagram successfully ranked the plans based on the available information. Sensitivity analyses were used to judge the reasonableness of the diagram and the results. In conclusion, influence diagrams lend themselves well to modelling the decision processes for IMRT plan selection. They provide an excellent means to incorporate the probabilistic nature of data and beliefs into one model. They also provide a means for introducing evidence-based medicine, in the form of results of clinical trials, into the decision-making process

  2. Assessment of volumetric-modulated arc therapy for constant and variable dose rates

    Directory of Open Access Journals (Sweden)

    Mariluz De Ornelas-Couto

    2017-01-01

    Full Text Available Purpose: The aim of this study is to compare the effects of dose rate on volumetric-modulated arc therapy plans to determine optimal dose rates for prostate and head and neck (HN cases. Materials and Methods: Ten prostate and ten HN cases were retrospectively studied. For each case, seven plans were generated: one variable dose rate (VDR and six constant dose rate (CDR (100–600 monitor units [MUs]/min plans. Prescription doses were: 80 Gy to planning target volume (PTV for the prostate cases, and 70, 60, and 54 Gy to PTV1, PTV2, and PTV3, respectively, for HN cases. Plans were normalized to 95% of the PTV and PTV1, respectively, with the prescription dose. Plans were assessed using Dose-Volume-Histogram metrics, homogeneity index, conformity index, MUs, and delivery time. Results: For the prostate cases, significant differences were found for rectum D35 between VDR and all CDR plans, except CDR500. Furthermore, VDR was significantly different than CDR100 and 200 for bladder D50. Delivery time for all CDR plans and MUs for CDR400–600 were significantly higher when compared to VDR. HN cases showed significant differences between VDR and CDR100, 500 and 600 for D2 to the cord and brainstem. Significant differences were found for delivery time and MUs for all CDR plans, except CDR100 for number of MUs. Conclusion: The most significant differences were observed in delivery time and number of MUs. All-in-all, the best CDR for prostate cases was found to be 300 MUs/min and 200 or 300 MUs/min for HN cases. However, VDR plans are still the choice in terms of MU efficiency and plan quality.

  3. Intensity Modulated Radiation Therapy with Simultaneously Integrated Boost at University Hospital Centre Zagreb (KBC Zagreb)

    International Nuclear Information System (INIS)

    Barisic, L.; Bibic, J.; Grego, T.; Hrsak, H.; Kovacevic, N.

    2013-01-01

    Intensity Modulated Radiation Therapy technique (IMRT) is state of art in modern radiotherapy for bilateral Head and Neck (H and N) malignancies. IMRT of real patients is implemented at KBC Zagreb since June 2012. Our method is inspired partly by Hull IMRT technique. It differs from standard IMRT beam layout (7 beams, gantry angles in 51° steps) and it avoids direct irradiation of OARs. We also use simultaneous integrated boost (SIB IMRT) fractionation. The aim of this paper is to present in some details the whole process of our SIB IMRT including plan quality assurance. Results for several patients together with comparison with ConPas and standard IMRT are presented. In our department, in last several years, routine method for H and N cancer RT was ConPas. During this period we (together with ConPas plans) produced standard IMRT plans with seven equidistant fields for actual patients. Our comparative analysis showed clear superiority of IMRT over ConPas for H and N radiotherapy. Since spring 2012 we have produced also non-standard IMRT plans that are based on Hull (U.K.) experience, with beam gantry angles at 0, 50, 80, 150, 210, 280 and 310 degrees. Also, in this method, direct irradiation of OARs (particularly spinal cord) is avoided by shielding as initial constraint. This approach proved to be better than standard IMRT in all analyzed cases. Having all this in mind, we decided to implement 'our' IMRT technique on real patients. Second essential point of our method is SIB fractionation. It has dosimetric, logistic and radiobiological advantages over standard fractionation. IMRT plan QA is routinely performed using Seven29 and Gamma index method. We take 3 mm/3 % Gamma index and 85 % of passed points as passing rate.(author)

  4. Improvement of dose distributions in abutment regions of intensity modulated radiation therapy and electron fields

    International Nuclear Information System (INIS)

    Dogan, Nesrin; Leybovich, Leonid B.; Sethi, Anil; Emami, Bahman

    2002-01-01

    In recent years, intensity modulated radiation therapy (IMRT) is used to radiate tumors that are in close proximity to vital organs. Targets consisting of a deep-seated region followed by a superficial one may be treated with abutting photon and electron fields. However, no systematic study regarding matching of IMRT and electron beams was reported. In this work, a study of dose distributions in the abutment region between tomographic and step-and-shoot IMRT and electron fields was carried out. A method that significantly improves dose homogeneity between abutting tomographic IMRT and electron fields was developed and tested. In this method, a target region that is covered by IMRT was extended into the superficial target area by ∼2.0 cm. The length and shape of IMRT target extension was chosen such that high isodose lines bent away from the region treated by the electrons. This reduced the magnitude of hot spots caused by the 'bulging effect' of electron field penumbra. To account for the uncertainties in positioning of the IMRT and electron fields, electron field penumbra was modified using conventional (photon) multileaf collimator (MLC). The electron beam was delivered in two steps: half of the dose delivered with MLCs in retracted position and another half with MLCs extended to the edge of electron field that abuts tomographic IMRT field. The experimental testing of this method using film dosimetry has demonstrated that the magnitude of the hot spots was reduced from ∼45% to ∼5% of the prescription dose. When an error of ±1.5 mm in field positioning was introduced, the dose inhomogeneity in the abutment region did not exceed ±15% of the prescription dose. With step-and-shoot IMRT, the most homogeneous dose distribution was achieved when there was a 3 mm gap between the IMRT and electron fields

  5. Multi-GPU configuration of 4D intensity modulated radiation therapy inverse planning using global optimization

    Science.gov (United States)

    Hagan, Aaron; Sawant, Amit; Folkerts, Michael; Modiri, Arezoo

    2018-01-01

    We report on the design, implementation and characterization of a multi-graphic processing unit (GPU) computational platform for higher-order optimization in radiotherapy treatment planning. In collaboration with a commercial vendor (Varian Medical Systems, Palo Alto, CA), a research prototype GPU-enabled Eclipse (V13.6) workstation was configured. The hardware consisted of dual 8-core Xeon processors, 256 GB RAM and four NVIDIA Tesla K80 general purpose GPUs. We demonstrate the utility of this platform for large radiotherapy optimization problems through the development and characterization of a parallelized particle swarm optimization (PSO) four dimensional (4D) intensity modulated radiation therapy (IMRT) technique. The PSO engine was coupled to the Eclipse treatment planning system via a vendor-provided scripting interface. Specific challenges addressed in this implementation were (i) data management and (ii) non-uniform memory access (NUMA). For the former, we alternated between parameters over which the computation process was parallelized. For the latter, we reduced the amount of data required to be transferred over the NUMA bridge. The datasets examined in this study were approximately 300 GB in size, including 4D computed tomography images, anatomical structure contours and dose deposition matrices. For evaluation, we created a 4D-IMRT treatment plan for one lung cancer patient and analyzed computation speed while varying several parameters (number of respiratory phases, GPUs, PSO particles, and data matrix sizes). The optimized 4D-IMRT plan enhanced sparing of organs at risk by an average reduction of 26% in maximum dose, compared to the clinical optimized IMRT plan, where the internal target volume was used. We validated our computation time analyses in two additional cases. The computation speed in our implementation did not monotonically increase with the number of GPUs. The optimal number of GPUs (five, in our study) is directly related to the

  6. Reirradiation of Head and Neck Cancers With Intensity Modulated Radiation Therapy: Outcomes and Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Takiar, Vinita [Department of Radiation Oncology, University of Cincinnati, Cincinnati, Ohio (United States); Garden, Adam S.; Ma, Dominic; Morrison, William H.; Edson, Mark [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zafereo, Mark E. [Department of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Gunn, Gary B.; Fuller, Clifton D.; Beadle, Beth; Frank, Steven J. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); William, William N.; Kies, Merrill [Department of Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); El-Naggar, Adel K. [Department of Pathology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Weber, Randal [Department of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Rosenthal, David I. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Phan, Jack, E-mail: jphan@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2016-07-15

    Purpose: To review our 15-year institutional experience using intensity modulated radiation therapy (IMRT) to reirradiate patients with head and neck squamous cell carcinomas (HNSCC) and identify predictors of outcomes and toxicity. Methods and Materials: We retrospectively reviewed the records of 227 patients who received head and neck reirradiation using IMRT from 1999 to 2014. Patients treated with noncurative intent were excluded. Radiation-related acute and late toxicities were recorded. Prognostic variables included performance status, disease site, disease-free interval, chemotherapy, and RT dose and volume. Correlative analyses were performed separately for surgery and nonsurgery patients. Results: Two hundred six patients (91%) were retreated with curative intent, and 173 had HNSCC histology; 104 (50%) underwent salvage resection, and 135 (66%) received chemotherapy. Median follow-up after reirradiation was 24.7 months. Clinical outcomes were worse for HNSCC patients, with 5-year locoregional control, progression-free survival, and overall survival rates of 53%, 22%, and 32%, respectively, compared with 74%, 59%, and 79%, respectively, for non-HNSCC patients. On multivariate analysis, concurrent chemotherapy and retreatment site were associated with tumor control, whereas performance status was associated with survival. Favorable prognostic factors specific to surgery patients were neck retreatment and lack of extracapsular extension, whereas for nonsurgery patients, these were a nasopharynx subsite and complete response to induction chemotherapy. Actuarial rates of grade ≥3 toxicity were 32% at 2 years and 48% at 5 years, with dysphagia or odynophagia being most common. Increased grade ≥3 toxicity was associated with retreatment volume >50 cm{sup 3} and concurrent chemotherapy. Conclusions: Reirradiation with IMRT either definitively or after salvage surgery can produce promising local control and survival in selected patients with head and neck

  7. A critical evaluation of worst case optimization methods for robust intensity-modulated proton therapy planning

    International Nuclear Information System (INIS)

    Fredriksson, Albin; Bokrantz, Rasmus

    2014-01-01

    Purpose: To critically evaluate and compare three worst case optimization methods that have been previously employed to generate intensity-modulated proton therapy treatment plans that are robust against systematic errors. The goal of the evaluation is to identify circumstances when the methods behave differently and to describe the mechanism behind the differences when they occur. Methods: The worst case methods optimize plans to perform as well as possible under the worst case scenario that can physically occur (composite worst case), the combination of the worst case scenarios for each objective constituent considered independently (objectivewise worst case), and the combination of the worst case scenarios for each voxel considered independently (voxelwise worst case). These three methods were assessed with respect to treatment planning for prostate under systematic setup uncertainty. An equivalence with probabilistic optimization was used to identify the scenarios that determine the outcome of the optimization. Results: If the conflict between target coverage and normal tissue sparing is small and no dose-volume histogram (DVH) constraints are present, then all three methods yield robust plans. Otherwise, they all have their shortcomings: Composite worst case led to unnecessarily low plan quality in boundary scenarios that were less difficult than the worst case ones. Objectivewise worst case generally led to nonrobust plans. Voxelwise worst case led to overly conservative plans with respect to DVH constraints, which resulted in excessive dose to normal tissue, and less sharp dose fall-off than the other two methods. Conclusions: The three worst case methods have clearly different behaviors. These behaviors can be understood from which scenarios that are active in the optimization. No particular method is superior to the others under all circumstances: composite worst case is suitable if the conflicts are not very severe or there are DVH constraints whereas

  8. Beam orientation optimization for intensity modulated radiation therapy using adaptive l2,1-minimization

    International Nuclear Information System (INIS)

    Jia Xun; Men Chunhua; Jiang, Steve B; Lou Yifei

    2011-01-01

    Beam orientation optimization (BOO) is a key component in the process of intensity modulated radiation therapy treatment planning. It determines to what degree one can achieve a good treatment plan in the subsequent plan optimization process. In this paper, we have developed a BOO algorithm via adaptive l 2,1 -minimization. Specifically, we introduce a sparsity objective function term into our model which contains weighting factors for each beam angle adaptively adjusted during the optimization process. Such an objective function favors a small number of beam angles. By optimizing a total objective function consisting of a dosimetric term and the sparsity term, we are able to identify unimportant beam angles and gradually remove them without largely sacrificing the dosimetric objective. In one typical prostate case, the convergence property of our algorithm, as well as how beam angles are selected during the optimization process, is demonstrated. Fluence map optimization (FMO) is then performed based on the optimized beam angles. The resulting plan quality is presented and is found to be better than that of equiangular beam orientations. We have further systematically validated our algorithm in the contexts of 5-9 coplanar beams for five prostate cases and one head and neck case. For each case, the final FMO objective function value is used to compare the optimized beam orientations with the equiangular ones. It is found that, in the majority of cases tested, our BOO algorithm leads to beam configurations which attain lower FMO objective function values than those of corresponding equiangular cases, indicating the effectiveness of our BOO algorithm. Superior plan qualities are also demonstrated by comparing DVH curves between BOO plans and equiangular plans.

  9. Automatically-generated rectal dose constraints in intensity-modulated radiation therapy for prostate cancer

    Science.gov (United States)

    Hwang, Taejin; Kim, Yong Nam; Kim, Soo Kon; Kang, Sei-Kwon; Cheong, Kwang-Ho; Park, Soah; Yoon, Jai-Woong; Han, Taejin; Kim, Haeyoung; Lee, Meyeon; Kim, Kyoung-Joo; Bae, Hoonsik; Suh, Tae-Suk

    2015-06-01

    The dose constraint during prostate intensity-modulated radiation therapy (IMRT) optimization should be patient-specific for better rectum sparing. The aims of this study are to suggest a novel method for automatically generating a patient-specific dose constraint by using an experience-based dose volume histogram (DVH) of the rectum and to evaluate the potential of such a dose constraint qualitatively. The normal tissue complication probabilities (NTCPs) of the rectum with respect to V %ratio in our study were divided into three groups, where V %ratio was defined as the percent ratio of the rectal volume overlapping the planning target volume (PTV) to the rectal volume: (1) the rectal NTCPs in the previous study (clinical data), (2) those statistically generated by using the standard normal distribution (calculated data), and (3) those generated by combining the calculated data and the clinical data (mixed data). In the calculated data, a random number whose mean value was on the fitted curve described in the clinical data and whose standard deviation was 1% was generated by using the `randn' function in the MATLAB program and was used. For each group, we validated whether the probability density function (PDF) of the rectal NTCP could be automatically generated with the density estimation method by using a Gaussian kernel. The results revealed that the rectal NTCP probability increased in proportion to V %ratio , that the predictive rectal NTCP was patient-specific, and that the starting point of IMRT optimization for the given patient might be different. The PDF of the rectal NTCP was obtained automatically for each group except that the smoothness of the probability distribution increased with increasing number of data and with increasing window width. We showed that during the prostate IMRT optimization, the patient-specific dose constraints could be automatically generated and that our method could reduce the IMRT optimization time as well as maintain the

  10. Planning Hybrid Intensity Modulated Radiation Therapy for Whole-breast Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Farace, Paolo [Medical Physics Department, Regional Oncological Hospital, Cagliari (Italy); Zucca, Sergio; Solla, Ignazio; Fadda, Giuseppina; Durzu, Silvia; Porru, Sergio; Meleddu, Gianfranco [Medical Physics Department, Regional Oncological Hospital, Cagliari (Italy); Deidda, Maria Assunta; Possanzini, Marco; Orru, Sivia; Lay, Giancarlo [Radiotherapy Department, Regional Oncological Hospital, Cagliari (Italy)

    2012-09-01

    Purpose: To test tangential and not-tangential hybrid intensity modulated radiation therapy (IMRT) for whole-breast irradiation. Methods and Materials: Seventy-eight (36 right-, 42 left-) breast patients were randomly selected. Hybrid IMRT was performed by direct aperture optimization. A semiautomated method for planning hybrid IMRT was implemented using Pinnacle scripts. A plan optimization volume (POV), defined as the portion of the planning target volume covered by the open beams, was used as the target objective during inverse planning. Treatment goals were to prescribe a minimum dose of 47.5 Gy to greater than 90% of the POV and to minimize the POV and/or normal tissue receiving a dose greater than 107%. When treatment goals were not achieved by using a 4-field technique (2 conventional open plus 2 IMRT tangents), a 6-field technique was applied, adding 2 non tangential (anterior-oblique) IMRT beams. Results: Using scripts, manual procedures were minimized (choice of optimal beam angle, setting monitor units for open tangentials, and POV definition). Treatment goals were achieved by using the 4-field technique in 61 of 78 (78%) patients. The 6-field technique was applied in the remaining 17 of 78 (22%) patients, allowing for significantly better achievement of goals, at the expense of an increase of low-dose ({approx}5 Gy) distribution in the contralateral tissue, heart, and lungs but with no significant increase of higher doses ({approx}20 Gy) in heart and lungs. The mean monitor unit contribution to IMRT beams was significantly greater (18.7% vs 9.9%) in the group of patients who required 6-field procedure. Conclusions: Because hybrid IMRT can be performed semiautomatically, it can be planned for a large number of patients with little impact on human or departmental resources, promoting it as the standard practice for whole-breast irradiation.

  11. Planning hybrid intensity modulated radiation therapy for whole-breast irradiation.

    Science.gov (United States)

    Farace, Paolo; Zucca, Sergio; Solla, Ignazio; Fadda, Giuseppina; Durzu, Silvia; Porru, Sergio; Meleddu, Gianfranco; Deidda, Maria Assunta; Possanzini, Marco; Orrù, Sivia; Lay, Giancarlo

    2012-09-01

    To test tangential and not-tangential hybrid intensity modulated radiation therapy (IMRT) for whole-breast irradiation. Seventy-eight (36 right-, 42 left-) breast patients were randomly selected. Hybrid IMRT was performed by direct aperture optimization. A semiautomated method for planning hybrid IMRT was implemented using Pinnacle scripts. A plan optimization volume (POV), defined as the portion of the planning target volume covered by the open beams, was used as the target objective during inverse planning. Treatment goals were to prescribe a minimum dose of 47.5 Gy to greater than 90% of the POV and to minimize the POV and/or normal tissue receiving a dose greater than 107%. When treatment goals were not achieved by using a 4-field technique (2 conventional open plus 2 IMRT tangents), a 6-field technique was applied, adding 2 non tangential (anterior-oblique) IMRT beams. Using scripts, manual procedures were minimized (choice of optimal beam angle, setting monitor units for open tangentials, and POV definition). Treatment goals were achieved by using the 4-field technique in 61 of 78 (78%) patients. The 6-field technique was applied in the remaining 17 of 78 (22%) patients, allowing for significantly better achievement of goals, at the expense of an increase of low-dose (∼5 Gy) distribution in the contralateral tissue, heart, and lungs but with no significant increase of higher doses (∼20 Gy) in heart and lungs. The mean monitor unit contribution to IMRT beams was significantly greater (18.7% vs 9.9%) in the group of patients who required 6-field procedure. Because hybrid IMRT can be performed semiautomatically, it can be planned for a large number of patients with little impact on human or departmental resources, promoting it as the standard practice for whole-breast irradiation. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Planning Hybrid Intensity Modulated Radiation Therapy for Whole-breast Irradiation

    International Nuclear Information System (INIS)

    Farace, Paolo; Zucca, Sergio; Solla, Ignazio; Fadda, Giuseppina; Durzu, Silvia; Porru, Sergio; Meleddu, Gianfranco; Deidda, Maria Assunta; Possanzini, Marco; Orrù, Sivia; Lay, Giancarlo

    2012-01-01

    Purpose: To test tangential and not-tangential hybrid intensity modulated radiation therapy (IMRT) for whole-breast irradiation. Methods and Materials: Seventy-eight (36 right-, 42 left-) breast patients were randomly selected. Hybrid IMRT was performed by direct aperture optimization. A semiautomated method for planning hybrid IMRT was implemented using Pinnacle scripts. A plan optimization volume (POV), defined as the portion of the planning target volume covered by the open beams, was used as the target objective during inverse planning. Treatment goals were to prescribe a minimum dose of 47.5 Gy to greater than 90% of the POV and to minimize the POV and/or normal tissue receiving a dose greater than 107%. When treatment goals were not achieved by using a 4-field technique (2 conventional open plus 2 IMRT tangents), a 6-field technique was applied, adding 2 non tangential (anterior-oblique) IMRT beams. Results: Using scripts, manual procedures were minimized (choice of optimal beam angle, setting monitor units for open tangentials, and POV definition). Treatment goals were achieved by using the 4-field technique in 61 of 78 (78%) patients. The 6-field technique was applied in the remaining 17 of 78 (22%) patients, allowing for significantly better achievement of goals, at the expense of an increase of low-dose (∼5 Gy) distribution in the contralateral tissue, heart, and lungs but with no significant increase of higher doses (∼20 Gy) in heart and lungs. The mean monitor unit contribution to IMRT beams was significantly greater (18.7% vs 9.9%) in the group of patients who required 6-field procedure. Conclusions: Because hybrid IMRT can be performed semiautomatically, it can be planned for a large number of patients with little impact on human or departmental resources, promoting it as the standard practice for whole-breast irradiation.

  13. Gafchromic EBT-XD film: Dosimetry characterization in high-dose, volumetric-modulated arc therapy.

    Science.gov (United States)

    Miura, Hideharu; Ozawa, Shuichi; Hosono, Fumika; Sumida, Naoki; Okazue, Toshiya; Yamada, Kiyoshi; Nagata, Yasushi

    2016-11-08

    Radiochromic films are important tools for assessing complex dose distributions. Gafchromic EBT-XD films have been designed for optimal performance in the 40-4,000 cGy dose range. We investigated the dosimetric characteristics of these films, including their dose-response, postexposure density growth, and dependence on scanner orientation, beam energy, and dose rate with applications to high-dose volumetric-modulated arc therapy (VMAT) verification. A 10 MV beam from a TrueBeam STx linear accelerator was used to irradiate the films with doses in the 0-4,000 cGy range. Postexposure coloration was analyzed at postirradiation times ranging from several minutes to 48 h. The films were also irradiated with 6 MV (dose rate (DR): 600 MU/min), 6 MV flattening filter-free (FFF) (DR: 1,400 MU/ min), and 10 MV FFF (DR: 2,400 MU/min) beams to determine the energy and dose-rate dependence. For clinical examinations, we compared the dose distribu-tion measured with EBT-XD films and calculated by the planning system for four VMAT cases. The red channel of the EBT-XD film exhibited a wider dynamic range than the green and blue channels. Scanner orientation yielded a variation of ~ 3% in the net optical density (OD). The difference between the film front and back scan orientations was negligible, with variation of ~ 1.3% in the net OD. The net OD increased sharply within the first 6 hrs after irradiation and gradually afterwards. No significant difference was observed for the beam energy and dose rate, with a variation of ~ 1.5% in the net OD. The gamma passing rates (at 3%, 3 mm) between the film- measured and treatment planning system (TPS)-calculated dose distributions under a high dose VMAT plan in the absolute dose mode were more than 98.9%. © 2016 The Authors.

  14. Ototoxicity After Intensity-Modulated Radiation Therapy and Cisplatin-Based Chemotherapy in Children With Medulloblastoma

    International Nuclear Information System (INIS)

    Paulino, Arnold C.; Lobo, Mark; Teh, Bin S.; Okcu, M. Fatih; South, Michael; Butler, E. Brian; Su, Jack; Chintagumpala, Murali

    2010-01-01

    Purpose: To report the incidence of Pediatric Oncology Group (POG) Grade 3 or 4 ototoxicity in a cohort of patients treated with craniospinal irradiation (CSI) followed by posterior fossa (PF) and/or tumor bed (TB) boost using intensity-modulated radiation therapy (IMRT). Methods and Materials: From 1998 to 2006, 44 patients with medulloblastoma were treated with CSI followed by IMRT to the PF and/or TB and cisplatin-based chemotherapy. Patients with standard-risk disease were treated with 18 to 23.4 Gy CSI followed by either a (1) PF boost to 36 Gy and TB boost to 54 to 55.8 Gy or (2) TB boost to 55.8 Gy. Patients with high-risk disease received 36 to 39.6 Gy CSI followed by a (1) PF boost to 54 to 55.8 Gy, (2) PF boost to 45 Gy and TB boost to 55.8 Gy, or (3) TB boost to 55.8 Gy. Median audiogram follow-up was 41 months (range, 11-92.4 months). Results: POG Grade Ototoxicity 0, 1, 2, 3. and 4 was found in 29, 32, 11, 13. and 3 ears. respectively, with POG Grade 3 or 4 accounting for 18.2% of cases. There was a statistically significant difference in mean radiation dose (D mean ) cochlea according to degree of ototoxicity, with D mean cochlea increasing with severity of hearing loss (p = 0.027). Conclusions: Severe ototoxicity was seen in 18.2% of ears in children treated with IMRT boost and cisplatin-based chemotherapy. Increasing dose to the cochlea was associated with increasing severity of hearing loss.

  15. Hippocampal sparing radiotherapy for glioblastoma patients: a planning study using volumetric modulated arc therapy

    International Nuclear Information System (INIS)

    Hofmaier, Jan; Kantz, Steffi; Söhn, Matthias; Dohm, Oliver S.; Bächle, Stefan; Alber, Markus; Parodi, Katia; Belka, Claus; Niyazi, Maximilian

    2016-01-01

    The purpose of this study is to investigate the potential to reduce exposure of the contralateral hippocampus in radiotherapy for glioblastoma using volumetric modulated arc therapy (VMAT). Datasets of 27 patients who had received 3D conformal radiotherapy (3D-CRT) for glioblastoma with a prescribed dose of 60Gy in fractions of 2Gy were included in this planning study. VMAT plans were optimized with the aim to reduce the dose to the contralateral hippocampus as much as possible without compromising other parameters. Hippocampal dose and treatment parameters were compared to the 3D-CRT plans using the Wilcoxon signed-rank test. The influence of tumour location and PTV size on the hippocampal dose was investigated with the Mann–Whitney-U-test and Spearman’s rank correlation coefficient. The median reduction of the contralateral hippocampus generalized equivalent uniform dose (gEUD) with VMAT was 36 % compared to the original 3D-CRT plans (p < 0.05). Other dose parameters were maintained or improved. The median V30Gy brain could be reduced by 17.9 % (p < 0.05). For VMAT, a parietal and a non-temporal tumour localisation as well as a larger PTV size were predictors for a higher hippocampal dose (p < 0.05). Using VMAT, a substantial reduction of the radiotherapy dose to the contralateral hippocampus for patients with glioblastoma is feasible without compromising other treatment parameters. For larger PTV sizes, less sparing can be achieved. Whether this approach is able to preserve the neurocognitive status without compromising the oncological outcome needs to be investigated in the setting of prospective clinical trials

  16. Patterns of Disease Recurrence Following Treatment of Oropharyngeal Cancer With Intensity Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Garden, Adam S., E-mail: agarden@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Dong, Lei [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Morrison, William H. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Stugis, Erich M. [Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Department of Epidemiology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Glisson, Bonnie S. [Department of Thoracic/Head and Neck Medicine, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Frank, Steven J.; Beadle, Beth M.; Gunn, Gary B. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Schwartz, David L. [Department of Radiation Medicine, Long Island Jewish Medical Center, New Hyde Park, NY (United States); Kies, Merill S. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Department of Thoracic/Head and Neck Medicine, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Weber, Randal S. [Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Ang, K. Kian; Rosenthal, David I. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2013-03-15

    Purpose: To report mature results of a large cohort of patients diagnosed with squamous cell carcinoma of the oropharynx who were treated with intensity modulated radiation therapy (IMRT). Methods and Materials: The database of patients irradiated at The University of Texas, M.D. Anderson Cancer Center was searched for patients diagnosed with oropharyngeal cancer and treated with IMRT between 2000 and 2007. A retrospective review of outcome data was performed. Results: The cohort consisted of 776 patients. One hundred fifty-nine patients (21%) were current smokers, 279 (36%) former smokers, and 337 (43%) never smokers. T and N categories and American Joint Committee on Cancer group stages were distributed as follows: T1/x, 288 (37%); T2, 288 (37%); T3, 113 (15%); T4, 87 (11%); N0, 88(12%); N1/x, 140 (18%); N2a, 101 (13%); N2b, 269 (35%); N2c, 122 (16%); and N3, 56 (7%); stage I, 18(2%); stage II, 40(5%); stage III, 150(19%); and stage IV, 568(74%). Seventy-one patients (10%) presented with nodes in level IV. Median follow-up was 54 months. The 5-year overall survival, locoregional control, and overall recurrence-free survival rates were 84%, 90%, and 82%, respectively. Primary site recurrence developed in 7% of patients, and neck recurrence with primary site control in 3%. We could only identify 12 patients (2%) who had locoregional recurrence outside the high-dose target volumes. Poorer survival rates were observed in current smokers, patients with larger primary (T) tumors and lower neck disease. Conclusions: Patients with oropharyngeal cancer treated with IMRT have excellent disease control. Locoregional recurrence was uncommon, and most often occurred in the high dose volumes. Parotid sparing was accomplished in nearly all patients without compromising tumor coverage.

  17. SU-G-BRC-04: Collimator Angle Optimization in Volumetric Modulated Arc Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, A; Johnson, C; Bartlett, G; Das, I [Indiana University- School of Medicine, Indianapolis, IN (United States)

    2016-06-15

    Purpose: Volumetric modulated arc therapy (VMAT) has revolutionized radiation treatment by decreasing treatment time and monitor units, thus reducing scattered and whole body radiation dose. As the collimator angle changes the apparent leaf gap becomes larger which can impact plan quality, organ at risk (OAR) sparing as well as IMRT QA passing rate which is investigated. Methods: Two sites (prostate and head and neck) that have maximum utilization of VMAT were investigated. Two previously treated VMAT patients were chosen. For each patient 10 plans were created by maintaining constant optimization constraints while varying collimator angles from 0-90 deg at an interval of 10 degrees for the first arc and the appropriate complimentary angle for the second arc. Plans were created with AAA algorithm using 6 MV beam on a Varian IX machine with Millennium 120 MLC. The dose-volume histogram (DVH) for each plan was exported and dosimetric parameters (D98, D95, D50, D2) as well homogeneity index (HI) and conformity index (CI) were computed. Each plan was validated for QA using ArcCheck with gamma index passing criteria of 2%/2 mm and 3%/3 mm. Additionally, normal tissue complication probability (NTCP) for each OAR was computed using Uzan-Nahum software. Results: The CI values for both sites had no impact as target volume coverage in every collimator angle were the same since it was optimized for adequate coverage. The HI which is representative of DVH gradient or dose uniformity in PTV showed a clear trend in both sites. The NTCP for OAR (brain and cochlea) in H&N plan and (bladder and rectum) in prostate plan showed a distinct superiority for collimator angles between 15-30 deg. The gamma passing rates were not correlated with angle. Conclusion: Based on CI, HI, NTCP and gamma passing index, it can be concluded that collimator angles should be maintained within 15–30 deg.

  18. Reoptimization of Intensity Modulated Proton Therapy Plans Based on Linear Energy Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Unkelbach, Jan, E-mail: junkelbach@mgh.harvard.edu [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Botas, Pablo [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Faculty of Physics, Ruprecht-Karls-Universität Heidelberg, Heidelberg (Germany); Giantsoudi, Drosoula; Gorissen, Bram L.; Paganetti, Harald [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2016-12-01

    Purpose: We describe a treatment plan optimization method for intensity modulated proton therapy (IMPT) that avoids high values of linear energy transfer (LET) in critical structures located within or near the target volume while limiting degradation of the best possible physical dose distribution. Methods and Materials: To allow fast optimization based on dose and LET, a GPU-based Monte Carlo code was extended to provide dose-averaged LET in addition to dose for all pencil beams. After optimizing an initial IMPT plan based on physical dose, a prioritized optimization scheme is used to modify the LET distribution while constraining the physical dose objectives to values close to the initial plan. The LET optimization step is performed based on objective functions evaluated for the product of LET and physical dose (LET×D). To first approximation, LET×D represents a measure of the additional biological dose that is caused by high LET. Results: The method is effective for treatments where serial critical structures with maximum dose constraints are located within or near the target. We report on 5 patients with intracranial tumors (high-grade meningiomas, base-of-skull chordomas, ependymomas) in whom the target volume overlaps with the brainstem and optic structures. In all cases, high LET×D in critical structures could be avoided while minimally compromising physical dose planning objectives. Conclusion: LET-based reoptimization of IMPT plans represents a pragmatic approach to bridge the gap between purely physical dose-based and relative biological effectiveness (RBE)-based planning. The method makes IMPT treatments safer by mitigating a potentially increased risk of side effects resulting from elevated RBE of proton beams near the end of range.

  19. Individualized Selection of Beam Angles and Treatment Isocenter in Tangential Breast Intensity Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Penninkhof, Joan, E-mail: j.penninkhof@erasmusmc.nl [Department of Radiation Oncology, Erasmus M.C. Cancer Institute, Rotterdam (Netherlands); Spadola, Sara [Department of Radiation Oncology, Erasmus M.C. Cancer Institute, Rotterdam (Netherlands); Department of Physics and Astronomy, Alma Mater Studiorum, University of Bologna, Bologna (Italy); Breedveld, Sebastiaan; Baaijens, Margreet [Department of Radiation Oncology, Erasmus M.C. Cancer Institute, Rotterdam (Netherlands); Lanconelli, Nico [Department of Physics and Astronomy, Alma Mater Studiorum, University of Bologna, Bologna (Italy); Heijmen, Ben [Department of Radiation Oncology, Erasmus M.C. Cancer Institute, Rotterdam (Netherlands)

    2017-06-01

    Purpose and Objective: Propose a novel method for individualized selection of beam angles and treatment isocenter in tangential breast intensity modulated radiation therapy (IMRT). Methods and Materials: For each patient, beam and isocenter selection starts with the fully automatic generation of a large database of IMRT plans (up to 847 in this study); each of these plans belongs to a unique combination of isocenter position, lateral beam angle, and medial beam angle. The imposed hard planning constraint on patient maximum dose may result in plans with unacceptable target dose delivery. Such plans are excluded from further analyses. Owing to differences in beam setup, database plans differ in mean doses to organs at risk (OARs). These mean doses are used to construct 2-dimensional graphs, showing relationships between: (1) contralateral breast dose and ipsilateral lung dose; and (2) contralateral breast dose and heart dose (analyzed only for left-sided). The graphs can be used for selection of the isocenter and beam angles with the optimal, patient-specific tradeoffs between the mean OAR doses. For 30 previously treated patients (15 left-sided and 15 right-sided tumors), graphs were generated considering only the clinically applied isocenter with 121 tangential beam angle pairs. For 20 of the 30 patients, 6 alternative isocenters were also investigated. Results: Computation time for automatic generation of 121 IMRT plans took on average 30 minutes. The generated graphs demonstrated large variations in tradeoffs between conflicting OAR objectives, depending on beam angles and patient anatomy. For patients with isocenter optimization, 847 IMRT plans were considered. Adding isocenter position optimization next to beam angle optimization had a small impact on the final plan quality. Conclusion: A method is proposed for individualized selection of beam angles in tangential breast IMRT. This may be especially important for patients with cardiac risk factors or an

  20. Three-Year Outcomes of Breast Intensity-Modulated Radiation Therapy With Simultaneous Integrated Boost

    International Nuclear Information System (INIS)

    McDonald, Mark W.; Godette, Karen D.; Whitaker, Daisy J.; Davis, Lawrence W.; Johnstone, Peter A.S.

    2010-01-01

    Purpose: To report our clinical experience using breast intensity-modulated radiation therapy with simultaneous integrated boost (SIB-IMRT). Methods and Materials: Retrospective review identified 354 Stage 0 to III breast cancer patients treated with SIB-IMRT after conservative surgery between 2003 and 2006. The most common fractionation (89%) simultaneously delivered 1.8 Gy to the ipsilateral breast tissue and 2.14 Gy to the resection cavity, yielding a breast dose of 45 Gy (25 fractions) and cavity dose 59.92 Gy (28 fractions), biologically equivalent for tumor control to 45 Gy to the breast with sequential 16-Gy boost (33 fractions). Results: A total of 356 breasts in 354 patients were treated: 282 with invasive breast cancer, and 74 with ductal carcinoma in situ (DCIS). For left breast radiation, median cardiac V 15 was 2.9% and left ventricular V 15 1.7%. Median follow-up was 33 months (range, 4-73 months). Acute toxicity was Grade 1 in 57% of cases, Grade 2 in 43%, and Grade 3 in <1%. For invasive breast cancer, the 3-year overall survival was 97.6% and risk of any locoregional recurrence was 2.8%. For ductal carcinoma in situ, 3-year overall survival was 98% and risk of locoregional recurrence 1.4%. In 142 cases at a minimum of 3 years follow-up, global breast cosmesis was judged by physicians as good or excellent in 96.5% and fair in 3.5%. Conclusions: Breast SIB-IMRT reduced treatment duration by five fractions with a favorable acute toxicity profile and low cardiac dose for left breast treatment. At 3 years, locoregional control was excellent, and initial assessment suggested good or excellent cosmesis in a high percentage of evaluable patients.

  1. Intensity-modulated radiation therapy for T4 nasopharyngeal carcinoma. Treatment results and locoregional

    International Nuclear Information System (INIS)

    Chen, J.L.Y.; Tsai, C.L.; Chen, W.Y.; Wang, C.W.; Huang, Y.S.; Chen, Y.F.; Kuo, S.H.; National Taiwan Univ. College of Medicine, Taipei; Hong, R.L.; Ko, J.Y.; Lou, P.J.

    2013-01-01

    Purpose: The purpose of this work was to examine outcomes in patients with T4 nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT). Methods and materials: Between 2007 and 2010, 154 patients with nonmetastatic T4 NPC were treated with IMRT to a total dose of 70 Gy in 33-35 fractions. In addition, 97 % of patients received concurrent platinum-based chemotherapy. The median follow-up time was 52.8 months. Results: The rates of 5-year actuarial locoregional control, distant metastasis-free survival, progression free-survival, and overall survival (OS) were 81.2, 72.2, 61.9, and 78.1 %, respectively. A total of 27 patients had locoregional recurrence: 85.2 % in-field failures, 11.1 % marginal failures, and 3.7 % out-of-field failures. Fourteen patients with locoregional recurrence received aggressive treatments, including nasopharyngectomy, neck dissection, or re-irradiation, and the 5-year OS rate tended to be better (61.9 %) compared to those receiving conservative treatment (32.0 %, p = 0.051). In patients treated with 1 course of radiotherapy, grade ≥ 3 toxicities of ototoxicity, neck fibrosis, xerostomia, epistaxis, and radiographic temporal lobe necrosis occurred in 18.2, 9.8, 6.3, 2.1, and 5.6 % of patients, respectively. Increased ototoxicity, osteonecrosis, severe nasal bleeding, and temporal necrosis were observed in patients treated by re-irradiation. Conclusion: IMRT offers good locoregional control in patients with T4 NPC. For patients with locoregional recurrence after definitive radiotherapy, aggressive local treatment may be considered for a better outcome. (orig.)

  2. SU-G-BRC-04: Collimator Angle Optimization in Volumetric Modulated Arc Therapy

    International Nuclear Information System (INIS)

    Andersen, A; Johnson, C; Bartlett, G; Das, I

    2016-01-01

    Purpose: Volumetric modulated arc therapy (VMAT) has revolutionized radiation treatment by decreasing treatment time and monitor units, thus reducing scattered and whole body radiation dose. As the collimator angle changes the apparent leaf gap becomes larger which can impact plan quality, organ at risk (OAR) sparing as well as IMRT QA passing rate which is investigated. Methods: Two sites (prostate and head and neck) that have maximum utilization of VMAT were investigated. Two previously treated VMAT patients were chosen. For each patient 10 plans were created by maintaining constant optimization constraints while varying collimator angles from 0-90 deg at an interval of 10 degrees for the first arc and the appropriate complimentary angle for the second arc. Plans were created with AAA algorithm using 6 MV beam on a Varian IX machine with Millennium 120 MLC. The dose-volume histogram (DVH) for each plan was exported and dosimetric parameters (D98, D95, D50, D2) as well homogeneity index (HI) and conformity index (CI) were computed. Each plan was validated for QA using ArcCheck with gamma index passing criteria of 2%/2 mm and 3%/3 mm. Additionally, normal tissue complication probability (NTCP) for each OAR was computed using Uzan-Nahum software. Results: The CI values for both sites had no impact as target volume coverage in every collimator angle were the same since it was optimized for adequate coverage. The HI which is representative of DVH gradient or dose uniformity in PTV showed a clear trend in both sites. The NTCP for OAR (brain and cochlea) in H&N plan and (bladder and rectum) in prostate plan showed a distinct superiority for collimator angles between 15-30 deg. The gamma passing rates were not correlated with angle. Conclusion: Based on CI, HI, NTCP and gamma passing index, it can be concluded that collimator angles should be maintained within 15–30 deg.

  3. Chirally motivated separable potential model for eta N amplitudes

    Czech Academy of Sciences Publication Activity Database

    Cieplý, Aleš; Smejkal, J.

    2013-01-01

    Roč. 919, DEC (2013), s. 46-66 ISSN 0375-9474 R&D Projects: GA ČR(CZ) GAP203/12/2126 Institutional support: RVO:61389005 Keywords : Chrial model * eta-nucleon amplitude * Baryon resonances Subject RIV: BE - Theoretical Physics Impact factor: 2.499, year: 2013

  4. Study of the reaction π-p→eta'n

    International Nuclear Information System (INIS)

    Saleem, Mohammad; Fazal-e-Aleem

    1981-01-01

    The differential cross sections for the process π - p→eta'n measured very recently have been fitted by using simple Regge pole model with phenomenological residue functions and two exchanged trajectories A 2 and delta. The polarisations at p(lab)=15 and 40 GeV/c have been predicted

  5. Maitasunean eta errespetuan hezten: 0-3 urte bitartekoen harmonia

    OpenAIRE

    Erice Olaizola, Ane

    2015-01-01

    LABURPENA: Aurrerapen zientifikoek aurrera egin ahala, lehen haurtzarorako begirada eraldatu egin da, bereziki garapen motorraren alorrean. Haurtxoa izaki pasibo bezala ikusten zuten ikuskerek, subjektuaren konpetentzia goiztiarren aurrean begiruneko jarrerak gartu dituzte. Lan honetan kalitatezko hezkuntza eredu instituzionalizatua garatu zuen Emmi Pikler-en ekarpenak aztertuko ditugu. Eredu honek printzipio pedagogiko zehatz batzuen arabera jaioberria eta haurtxo txikia ikusteko beste era b...

  6. 31 CFR 208.5 - Availability of the ETA SM.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Availability of the ETA SM. 208.5 Section 208.5 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE MANAGEMENT OF FEDERAL AGENCY...

  7. High Energy Phenomena in Eta Carinae Roberto F. Viotti , Lucio ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    High Energy Phenomena in Eta Carinae ... Colliding winds model—non-thermal emission—stars: η ... very massive wind. Its unseen compan- ion should be a less evolved early-type star. It was found that the two last spectroscopic minima of June 1992 and December 1997 coincided with two X-ray eclipses detected.

  8. Search for eta '(c) decays into vector meson pairs

    NARCIS (Netherlands)

    Ablikim, M.; Achasov, M. N.; Alberto, D.; An, F. F.; An, Q.; An, Z. H.; Bai, J. Z.; Baldini, R.; Ban, Y.; Becker, J.; Berger, N.; Bertani, M.; Bian, J. M.; Boger, E.; Bondarenko, O.; Boyko, I.; Briere, R. A.; Bytev, V.; Cai, X.; Calcaterra, A. C.; Cao, G. F.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, Y.; Chen, Y. B.; Cheng, H. P.; Chu, Y. P.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dedovich, D.; Deng, Z. Y.; Denysenko, I.; Destefanis, M.; Ding, Y.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Fang, J.; Fang, S. S.; Feng, C. Q.; Fu, C. D.; Fu, J. L.; Gao, Y.; Geng, C.; Goetzen, K.; Gong, W. X.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, Y. P.; Han, Y. L.; Hao, X. Q.; Harris, F. A.; He, K. L.; He, M.; He, Z. Y.; Heng, Y. K.; Hou, Z. L.; Hu, H. M.; Hu, J. F.; Hu, T.; Huang, B.; Huang, G. M.; Huang, J. S.; Huang, X. T.; Huang, Y. P.; Hussain, T.; Ji, C. S.; Ji, Q.; Ji, X. B.; Ji, X. L.; Jia, L. K.; Jiang, L. L.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Jing, F. F.; Kalantar-Nayestanaki, N.; Kavatsyuk, M.; Kuehn, W.; Lai, W.; Lange, J. S.; Leung, J. K. C.; Li, C. H.; Li, Cheng; Li, Cui; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, K.; Li, Lei; Li, N. B.; Li, Q. J.; Li, S. L.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, X. R.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, X. T.; Liu, B. J.; Liu, C. L.; Liu, C. X.; Liu, C. Y.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H.; Liu, H. B.; Liu, H. H.; Liu, H. M.; Liu, H. W.; Liu, J. P.; Liu, K.; Liu, K.; Liu, K. Y.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, X. H.; Liu, Y. B.; Liu, Y. W.; Liu, Yong; Liu, Z. A.; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H.; Lu, G. R.; Lu, H. J.; Lu, J. G.; Lu, Q. W.; Lu, X. R.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lv, M.; Ma, C. L.; Ma, F. C.; Ma, H. L.; Ma, Q. M.; Ma, S.; Ma, T.; Ma, X.; Ma, X. Y.; Maggiora, M.; Malik, Q. A.; Mao, H.; Mao, Y. J.; Mao, Z. P.; Messchendorp, J. G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Muchnoi, N. Yu.; Nefedov, Y.; Nikolaev, I. B.; Ning, Z.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Park, J. W.; Pelizaeus, M.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Pun, C. S. J.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, X. S.; Qiu, J. F.; Rashid, K. H.; Rong, G.; Ruan, X. D.; Sarantsev, A.; Schulze, J.; Shao, M.; Shen, C. P.; Shen, X. Y.; Sheng, H. Y.; Shepherd, M. R.; Song, X. Y.; Spataro, S.; Spruck, B.; Sun, D. H.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, X. D.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tian, H. L.; Toth, D.; Varner, G. S.; Wang, B.; Wang, B. Q.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q.; Wang, Q. J.; Wang, S. G.; Wang, X. L.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. Y.; Wei, D. H.; Wen, Q. G.; Wen, S. P.; Wiedner, U.; Wu, L. H.; Wu, N.; Wu, W.; Wu, Z.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, G. M.; Xu, H.; Xu, Q. J.; Xu, X. P.; Xu, Y.; Xu, Z. R.; Xu, Z. Z.; Xue, Z.; Yan, L.; Yan, W. B.; Yan, Y. H.; Yang, H. X.; Yang, T.; Yang, Y.; Yang, Y. X.; Ye, H.; Ye, M.; Ye, M. H.; Yu, B. X.; Yu, C. X.; Yu, S. P.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, L.; Zhang, S. H.; Zhang, T. R.; Zhang, X. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. S.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, H. S.; Zhao, Jiawei; Zhao, Jingwei; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, S. J.; Zhao, T. C.; Zhao, X. H.; Zhao, Y. B.; Zhao, Z. G.; Zhao, Z. L.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, Y. H.; Zheng, Z. P.; Zhong, B.; Zhong, J.; Zhong, L.; Zhou, L.; Zhou, X. K.; Zhou, X. R.; Zhu, C.; Zhu, K.; Zhu, K. J.; Zhu, S. H.; Zhu, X. L.; Zhu, X. W.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.; Zuo, J. X.

    2011-01-01

    The processes eta'(c) -> rho(0)rho(0), K*0K*0, and phi phi are searched for using a sample of 1.06 x 10(8) psi' events collected with the BESIII detector at the BEPCII collider. No signals are observed in any of the three final states. The upper limits on the decay branching fractions are determined

  9. Conservation of charge conjugation in {eta} meson decay; Etude de la conservation de la conjugaison de charge dans les desintegrations du meson {eta}

    Energy Technology Data Exchange (ETDEWEB)

    Muller, A [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires

    1968-03-01

    The charge asymmetry in the {eta} meson decay is investigated. With 10709 events {eta} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup 0} the asymmetry is (0.3 {+-} 1.1) per cent. 1620 decays {eta} {yields} {pi}{sup +}{pi}{sup -}{gamma} give (1.5 {+-} 2.5) per cent. There is no evidence for charge conjugation violation in electro-magnetic or semi-strong interactions. (author) [French] La symetrie de charge est etudiee dans la desintegration du meson {eta}. Avec 10709 desintegrations {eta} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup 0} l'asymetrie obtenue est de (0.3 {+-} 1.1) pour cent. Les 1620 desintegrations {eta} {yields} {pi}{sup +}{pi}{sup -}{gamma} donnent (1.5 {+-} 2.5) pour cent. Il n'y a aucune evidence de violation de la conjugaison de charge dans les interactions electromagnetiques ou semi-fortes. (auteur)

  10. Can We Advance Proton Therapy for Prostate? Considering Alternative Beam Angles and Relative Biological Effectiveness Variations When Comparing Against Intensity Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, Tracy, E-mail: tunderwood@mgh.harvard.edu [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States); Department of Medical Physics and Bioengineering, University College London, London (United Kingdom); Giantsoudi, Drosoula; Moteabbed, Maryam; Zietman, Anthony; Efstathiou, Jason; Paganetti, Harald; Lu, Hsiao-Ming [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States)

    2016-05-01

    Purpose: For prostate treatments, robust evidence regarding the superiority of either intensity modulated radiation therapy (IMRT) or proton therapy is currently lacking. In this study we investigated the circumstances under which proton therapy should be expected to outperform IMRT, particularly the proton beam orientations and relative biological effectiveness (RBE) assumptions. Methods and Materials: For 8 patients, 4 treatment planning strategies were considered: (A) IMRT; (B) passively scattered standard bilateral (SB) proton beams; (C) passively scattered anterior oblique (AO) proton beams, and (D) AO intensity modulated proton therapy (IMPT). For modalities (B)-(D) the dose and linear energy transfer (LET) distributions were simulated using the TOPAS Monte Carlo platform and RBE was calculated according to 3 different models. Results: Assuming a fixed RBE of 1.1, our implementation of IMRT outperformed SB proton therapy across most normal tissue metrics. For the scattered AO proton plans, application of the variable RBE models resulted in substantial hotspots in rectal RBE weighted dose. For AO IMPT, it was typically not possible to find a plan that simultaneously met the tumor and rectal constraints for both fixed and variable RBE models. Conclusion: If either a fixed RBE of 1.1 or a variable RBE model could be validated in vivo, then it would always be possible to use AO IMPT to dose-boost the prostate and improve normal tissue sparing relative to IMRT. For a cohort without rectum spacer gels, this study (1) underlines the importance of resolving the question of proton RBE within the framework of an IMRT versus proton debate for the prostate and (2) highlights that without further LET/RBE model validation, great care must be taken if AO proton fields are to be considered for prostate treatments.

  11. Study of the radiative decay J/psi → γetaπ+π-

    International Nuclear Information System (INIS)

    Becker, J.J.; Blaylock, G.T.; Bolton, T.

    1987-02-01

    The Mark III collaboration has performed a high statistics study of the reaction J/psi → γetaπ + π - , with two different final states of the eta, eta → γγ and eta → π 0 π + π - . Both modes have a broad structure from 1.2 to 1.9 GeV/c 2 and two structures, which decay via δ +- π -+ , δ +- → etaπ +- , are identified at 1.28 and 1.39 GeV/c 2 . No signal is observed in the iota(1440) signal region

  12. Measurements of the Mass and Width of the eta(c) Using the Decay psi -> gamma eta(c)

    NARCIS (Netherlands)

    Ablikim, M.; Achasov, M. N.; Alberto, D.; Ambrose, D. J.; An, F. F.; An, Q.; An, Z. H.; Bai, J. Z.; Ferroli, R. B.; Ban, Y.; Becker, J.; Berger, N.; Bertani, M. B.; Bian, J. M.; Boger, E.; Bondarenko, O.; Boyko, I.; Briere, R. A.; Bytev, V.; Cai, X.; Calcaterra, A. C.; Cao, G. F.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, H. X.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, Y.; Chen, Y. B.; Cheng, H. P.; Chu, Y. P.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dedovich, D.; Deng, Z. Y.; Denysenko, I.; Destefanis, M.; Ding, W. L.; Ding, Y.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Fang, J.; Fang, S. S.; Feng, C. Q.; Fu, C. D.; Fu, J. L.; Gao, Y.; Geng, C.; Goetzen, K.; Gong, W. X.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, Y. P.; Han, Y. L.; Hao, X. Q.; Harris, F. A.; He, K. L.; He, M.; He, Z. Y.; Heng, Y. K.; Hou, Z. L.; Hu, H. M.; Hu, J. F.; Hu, T.; Huang, B.; Huang, G. M.; Huang, J. S.; Huang, X. T.; Huang, Y. P.; Hussain, T.; Ji, C. S.; Ji, Q.; Ji, X. B.; Ji, X. L.; Jia, L. K.; Jiang, L. L.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Jing, F. F.; Kalantar-Nayestanaki, N.; Kavatsyuk, M.; Kuehn, W.; Lai, W.; Lange, J. S.; Leung, J. K. C.; Li, C. H.; Li, Cheng; Li, Cui; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, K.; Li, Lei; Li, N. B.; Li, Q. J.; Li, S. L.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, X. R.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Liao, X. T.; Liu, B. J.; Liu, C. L.; Liu, C. X.; Liu, C. Y.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H.; Liu, H. B.; Liu, H. H.; Liu, H. M.; Liu, H. W.; Liu, J. P.; Liu, K.; Liu, K.; Liu, K. Y.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, X. H.; Liu, Y. B.; Liu, Yong; Liu, Z. A.; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H.; Lu, G. R.; Lu, H. J.; Lu, J. G.; Lu, Q. W.; Lu, X. R.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lv, M.; Ma, C. L.; Ma, F. C.; Ma, H. L.; Ma, Q. M.; Ma, S.; Ma, T.; Ma, X. Y.; Maggiora, M.; Malik, Q. A.; Mao, H.; Mao, Y. J.; Mao, Z. P.; Messchendorp, J. G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Muchnoi, N. Yu; Nefedov, Y.; Nikolaev, I. B.; Ning, Z.; Olsen, S. L.; Ouyang, Q.; Pacetti, S. P.; Park, J. W.; Pelizaeus, M.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Pun, C. S. J.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, X. S.; Qiu, J. F.; Rashid, K. H.; Rong, G.; Ruan, X. D.; Sarantsev, A.; Schulze, J.; Shao, M.; Shen, C. P.; Shen, X. Y.; Sheng, H. Y.; Shepherd, M. R.; Song, X. Y.; Spataro, S.; Spruck, B.; Sun, D. H.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, X. D.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Thorndike, E. H.; Tian, H. L.; Toth, D.; Varner, G. S.; Wang, B.; Wang, B. Q.; Wang, K.; Wang, L. L.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q.; Wang, Q. J.; Wang, S. G.; Wang, X. F.; Wang, X. L.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. Y.; Wei, D. H.; Wen, Q. G.; Wen, S. P.; Wiedner, U.; Wu, L. H.; Wu, N.; Wu, W.; Wu, Z.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, G. M.; Xu, H.; Xu, Q. J.; Xu, X. P.; Xu, Y.; Xu, Z. R.; Xue, Z.; Yan, L.; Yan, W. B.; Yan, Y. H.; Yang, H. X.; Yang, T.; Yang, Y.; Yang, Y. X.; Ye, H.; Ye, M.; Ye, M. H.; Yu, B. X.; Yu, C. X.; Yu, S. P.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Zafar, A. A.; Zallo, A. Z.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, L.; Zhang, S. H.; Zhang, T. R.; Zhang, X. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. S.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, H. S.; Zhao, Jingwei; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, S. J.; Zhao, T. C.; Zhao, X. H.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, Y. H.; Zheng, Z. P.; Zhong, B.; Zhong, J.; Zhou, L.; Zhou, X. K.; Zhou, X. R.; Zhu, C.; Zhu, K.; Zhu, K. J.; Zhu, S. H.; Zhu, X. L.; Zhu, X. W.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.; Zuo, J. X.

    2012-01-01

    The mass and width of the lowest-lying S-wave spin singlet charmonium state, the eta(c), are measured using a data sample of 1: 06 x 10(8) psi (3686) decays collected with the BESIII detector at the BEPCII storage ring. We use a model that incorporates full interference between the signal reaction,

  13. Dosimetric comparison to the heart and cardiac substructure in a large cohort of esophageal cancer patients treated with proton beam therapy or Intensity-modulated radiation therapy.

    Science.gov (United States)

    Shiraishi, Yutaka; Xu, Cai; Yang, Jinzhong; Komaki, Ritsuko; Lin, Steven H

    2017-10-01

    To compare heart and cardiac substructure radiation exposure using intensity-modulated radiotherapy (IMRT) vs. proton beam therapy (PBT) for patients with mid- to distal esophageal cancer who received chemoradiation therapy. We identified 727 esophageal cancer patients who received IMRT (n=477) or PBT (n=250) from March 2004 to December 2015. All patients were treated to 50.4Gy with IMRT or to 50.4 cobalt Gray equivalents with PBT. IMRT and PBT dose-volume histograms (DVHs) of the whole heart, atria, ventricles, and four coronary arteries were compared. For PBT patients, passive scattering proton therapy (PSPT; n=237) and intensity-modulated proton therapy (IMPT; n=13) DVHs were compared. Compared with IMRT, PBT resulted in significantly lower mean heart dose (MHD) and heart V5, V10, V20, V30, and V40as well as lower radiation exposure to the four chambers and four coronary arteries. Compared with PSPT, IMPT resulted in significantly lower heart V20, V30, and V40 but not MHD or heart V5 or V10. IMPT also resulted in significantly lower radiation doses to the left atrium, right atrium, left main coronary artery, and left circumflex artery, but not the left ventricle, right ventricle, left anterior descending artery, or right coronary artery. Factors associated with lower MHD included PBT (Pheart and cardiac substructures than IMRT. Long-term studies are necessary to determine how this cardiac sparing effect impacts the development of coronary artery disease and other cardiac complications. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Functional image guided radiation therapy planning in volumetric modulated arc therapy for patients with malignant pleural mesothelioma

    Directory of Open Access Journals (Sweden)

    Yoshiko Doi, MD

    2017-04-01

    Conclusions: Significant reductions in fV5, fV10, fMLD, V5, and MLD were achieved with the functional image guided VMAT plan without negative effects on other factors. LAA-based functional image guided radiation therapy planning in VMAT is a feasible method to spare the functional lung in patients with MPM.

  15. Emergency Victim Care. A Training Manual for Emergency Medical Technicians. Module 5. CPR, Oxygen Therapy. Revised.

    Science.gov (United States)

    Ohio State Dept. of Education, Columbus. Div. of Vocational Education.

    This student manual, the fifth in a set of 14 modules, is designed to train emergency medical technicians (EMTs) in Ohio. The module contains two sections covering the following course content; cardiopulmonary resuscitation (CPR) (including artificial ventilation, foreign body obstructions, adjunctive equipment and special techniques, artificial…

  16. Examination of geometric and dosimetric accuracies of gated step-and-shoot intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Wiersma, R. D.; Xing, L.

    2007-01-01

    Due to the complicated technical nature of gated radiation therapy, electronic and mechanical limitations may affect the precision of delivery. The purpose of this study is to investigate the geometric and dosimetric accuracies of gated step-and-shoot intensity modulated radiation treatments (SS-IMRT). Unique segmental MLC plans are designed, which allow quantitative testing of the gating process. Both ungated and gated deliveries are investigated for different dose sizes, dose rates, and gating window times using a commercial treatment system (Varian Trilogy) together with a respiratory gating system [Varian Real-Time Position Management system]. Radiographic film measurements are used to study the geometric accuracy, where it is found that with both ungated and gated SS-IMRT deliveries the MLC leaf divergence away from planned is less than or equal to the MLC specified leaf tolerance value for all leafs (leaf tolerance being settable from 0.5-5 mm). Nevertheless, due to the MLC controller design, failure to define a specific leaf tolerance value suitable to the SS-IMRT plan can lead to undesired geometric effects, such as leaf motion of up to the maximum 5 mm leaf tolerance value occurring after the beam is turned on. In this case, gating may be advantageous over the ungated case, as it allows more time for the MLC to reach the intended leaf configuration. The dosimetric precision of gated SS-IMRT is investigated using ionization chamber methods. Compared with the ungated case, it is found that gating generally leads to increased dosimetric errors due to the interruption of the ''overshoot phenomena.'' With gating the average timing deviation for intermediate segments is found to be 27 ms, compared to 18 ms for the ungated case. For a plan delivered at 600 MU/min this would correspond to an average segment dose error of ∼0.27 MU and ∼0.18 MU for gated and ungated deliveries, respectively. The maximum dosimetric errors for individual intermediate segments are

  17. Analytical incorporation of fractionation effects in probabilistic treatment planning for intensity-modulated proton therapy.

    Science.gov (United States)

    Wahl, Niklas; Hennig, Philipp; Wieser, Hans-Peter; Bangert, Mark

    2018-04-01

    We show that it is possible to explicitly incorporate fractionation effects into closed-form probabilistic treatment plan analysis and optimization for intensity-modulated proton therapy with analytical probabilistic modeling (APM). We study the impact of different fractionation schemes on the dosimetric uncertainty induced by random and systematic sources of range and setup uncertainty for treatment plans that were optimized with and without consideration of the number of treatment fractions. The APM framework is capable of handling arbitrarily correlated uncertainty models including systematic and random errors in the context of fractionation. On this basis, we construct an analytical dose variance computation pipeline that explicitly considers the number of treatment fractions for uncertainty quantitation and minimization during treatment planning. We evaluate the variance computation model in comparison to random sampling of 100 treatments for conventional and probabilistic treatment plans under different fractionation schemes (1, 5, 30 fractions) for an intracranial, a paraspinal and a prostate case. The impact of neglecting the fractionation scheme during treatment planning is investigated by applying treatment plans that were generated with probabilistic optimization for 1 fraction in a higher number of fractions and comparing them to the probabilistic plans optimized under explicit consideration of the number of fractions. APM enables the construction of an analytical variance computation model for dose uncertainty considering fractionation at negligible computational overhead. It is computationally feasible (a) to simultaneously perform a robustness analysis for all possible fraction numbers and (b) to perform a probabilistic treatment plan optimization for a specific fraction number. The incorporation of fractionation assumptions for robustness analysis exposes a dose to uncertainty trade-off, i.e., the dose in the organs at risk is increased for a

  18. Treatment of Oral Cavity Squamous Cell Carcinoma With Adjuvant or Definitive Intensity-Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Sher, David J., E-mail: dsher@lroc.harvard.edu [Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women' s Hospital, Boston, Massachusetts (United States); Thotakura, Vijaya [Department of Medical Oncology, Dana-Farber Cancer Institute and Department of Medicine, Brigham and Women' s Hospital, Boston, Massachusetts (United States); Balboni, Tracy A. [Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women' s Hospital, Boston, Massachusetts (United States); Norris, Charles M.; Haddad, Robert I.; Posner, Marshall R.; Lorch, Jochen [Department of Medical Oncology, Dana-Farber Cancer Institute and Department of Medicine, Brigham and Women' s Hospital, Boston, Massachusetts (United States); Goguen, Laura A.; Annino, Donald J. [Department of Surgery, Division of Otolaryngology, Brigham and Women' s Hospital, Boston, Massachusetts (United States); Tishler, Roy B. [Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women' s Hospital, Boston, Massachusetts (United States)

    2011-11-15

    Purpose: The optimal management of oral cavity squamous cell carcinoma (OCSCC) typically involves surgical resection followed by adjuvant radiotherapy or chemoradiotherapy (CRT) in the setting of adverse pathologic features. Intensity-modulated radiation therapy (IMRT) is frequently used to treat oral cavity cancers, but published IMRT outcomes specific to this disease site are sparse. We report the Dana-Farber Cancer Institute experience with IMRT-based treatment for OCSCC. Methods and Materials: Retrospective study of all patients treated at Dana-Farber Cancer Institute for OCSCC with adjuvant or definitive IMRT between August 2004 and December 2009. The American Joint Committee on Cancer disease stage criteria distribution of this cohort included 5 patients (12%) with stage I; 10 patients (24%) with stage II (n = 10, 24%),; 14 patients (33%) with stage III (n = 14, 33%),; and 13 patients (31%) with stage IV. The primary endpoint was overall survival (OS); secondary endpoints were locoregional control (LRC) and acute and chronic toxicity. Results: Forty-two patients with OCSCC were included, 30 of whom were initially treated with surgical resection. Twenty-three (77%) of 30 surgical patients treated with adjuvant IMRT also received concurrent chemotherapy, and 9 of 12 (75%) patients treated definitively without surgery were treated with CRT or induction chemotherapy and CRT. With a median follow-up of 2.1 years (interquartile range, 1.1-3.1 years) for all patients, the 2-year actuarial rates of OS and LRC following adjuvant IMRT were 85% and 91%, respectively, and the comparable results for definitive IMRT were 63% and 64% for OS and LRC, respectively. Only 1 patient developed symptomatic osteoradionecrosis, and among patients without evidence of disease, 35% experienced grade 2 to 3 late dysphagia, with only 1 patient who was continuously gastrostomy-dependent. Conclusions: In this single-institution series, postoperative IMRT was associated with promising LRC

  19. Particle swarm optimizer for weighting factor selection in intensity-modulated radiation therapy optimization algorithms.

    Science.gov (United States)

    Yang, Jie; Zhang, Pengcheng; Zhang, Liyuan; Shu, Huazhong; Li, Baosheng; Gui, Zhiguo

    2017-01-01

    In inverse treatment planning of intensity-modulated radiation therapy (IMRT), the objective function is typically the sum of the weighted sub-scores, where the weights indicate the importance of the sub-scores. To obtain a high-quality treatment plan, the planner manually adjusts the objective weights using a trial-and-error procedure until an acceptable plan is reached. In this work, a new particle swarm optimization (PSO) method which can adjust the weighting factors automatically was investigated to overcome the requirement of manual adjustment, thereby reducing the workload of the human planner and contributing to the development of a fully automated planning process. The proposed optimization method consists of three steps. (i) First, a swarm of weighting factors (i.e., particles) is initialized randomly in the search space, where each particle corresponds to a global objective function. (ii) Then, a plan optimization solver is employed to obtain the optimal solution for each particle, and the values of the evaluation functions used to determine the particle's location and the population global location for the PSO are calculated based on these results. (iii) Next, the weighting factors are updated based on the particle's location and the population global location. Step (ii) is performed alternately with step (iii) until the termination condition is reached. In this method, the evaluation function is a combination of several key points on the dose volume histograms. Furthermore, a perturbation strategy - the crossover and mutation operator hybrid approach - is employed to enhance the population diversity, and two arguments are applied to the evaluation function to improve the flexibility of the algorithm. In this study, the proposed method was used to develop IMRT treatment plans involving five unequally spaced 6MV photon beams for 10 prostate cancer cases. The proposed optimization algorithm yielded high-quality plans for all of the cases, without human

  20. Rules of parotid gland dose variations and shift during intensity modulated radiation therapy for nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Wang, Wei; Yang, Haihua; Mi, Yucheng; Hu, Wei; Ding, Weijun; Xie, Youyou; Cai, Yujie; Chen, Xiaofeng

    2015-01-01

    To determine the position and dose delivery changes rules of parotid gland (PG) during the course of intensity modulated radiation therapy (IMRT) in nasopharyngeal carcinoma patients (NPC). One hundred and forty one competed tomography (CT) images from 47 NPC patients (three images for each patient were acquired before treatment, at the 15th and 25th fraction during the treatment) who underwent radical IMRT were selected for this study. A total of 70-76Gy at 2.12–2.3 Gy/fraction/d was given to the GTVnx in 33 fractions. The distances between the lateral/medial aspects of PG and midline (DLM and DMM) at the level of odontoid process were measured. The dose differences between plan and actual delivery were calculated. The volume reductions of PGs between fractions 15 and 25 were larger than those in the first 15 fractions (4.68 ± 3.23 cc vs. 2.46 ± 4.55 cc for the right PG and 5.96 ± 2.99 cc vs. 2.06 ± 2.99 cc for the left PG). However, the percentage of gland volume receiving ≥30 Gy (V30) of bilateral PGs decreased more significantly in the first 15 fractions than that between fractions 15 and 25 (5.61 ± 16.04% vs. 1.14 ± 21.54% for the right PG and 6.87 ± 15.58% vs. 0.81 ± 15.94% for the left PG). The gross tumor volume of the nasopharynx (GTVnx) decreased more significantly in the first 15 fractions than that between the 15th and 25th fraction (8.23 ± 13.61 cc vs. 3.30 ± 8.09 cc). The DMM of ipsilateral PGs reduced in the first 15 fractions (0.80 ± 2.96 mm) but increased between fraction 15 and 25 (−2.19 ± 3.96 mm). While ipsilateral PG shifted into target volume but shifted out target volume between fraction 15 and 25. Parotid glands V30 was correlated with GTVnx, GTVnx reduction and DMM reduction (p < 0.01). Our results indicate that the reduction of GTVnx leads to the positional change of the parotid gland, which results in more significant dose change of the parotid gland in the first 15 fractions than that between fraction 15 and 25

  1. Including robustness in multi-criteria optimization for intensity-modulated proton therapy

    Science.gov (United States)

    Chen, Wei; Unkelbach, Jan; Trofimov, Alexei; Madden, Thomas; Kooy, Hanne; Bortfeld, Thomas; Craft, David

    2012-02-01

    We present a method to include robustness in a multi-criteria optimization (MCO) framework for intensity-modulated proton therapy (IMPT). The approach allows one to simultaneously explore the trade-off between different objectives as well as the trade-off between robustness and nominal plan quality. In MCO, a database of plans each emphasizing different treatment planning objectives, is pre-computed to approximate the Pareto surface. An IMPT treatment plan that strikes the best balance between the different objectives can be selected by navigating on the Pareto surface. In our approach, robustness is integrated into MCO by adding robustified objectives and constraints to the MCO problem. Uncertainties (or errors) of the robust problem are modeled by pre-calculated dose-influence matrices for a nominal scenario and a number of pre-defined error scenarios (shifted patient positions, proton beam undershoot and overshoot). Objectives and constraints can be defined for the nominal scenario, thus characterizing nominal plan quality. A robustified objective represents the worst objective function value that can be realized for any of the error scenarios and thus provides a measure of plan robustness. The optimization method is based on a linear projection solver and is capable of handling large problem sizes resulting from a fine dose grid resolution, many scenarios, and a large number of proton pencil beams. A base-of-skull case is used to demonstrate the robust optimization method. It is demonstrated that the robust optimization method reduces the sensitivity of the treatment plan to setup and range errors to a degree that is not achieved by a safety margin approach. A chordoma case is analyzed in more detail to demonstrate the involved trade-offs between target underdose and brainstem sparing as well as robustness and nominal plan quality. The latter illustrates the advantage of MCO in the context of robust planning. For all cases examined, the robust optimization for

  2. Postoperative Intensity Modulated Radiation Therapy in High Risk Prostate Cancer: A Dosimetric Comparison

    International Nuclear Information System (INIS)

    Digesu, Cinzia; Cilla, Savino; De Gaetano, Andrea; Massaccesi, Mariangela; Macchia, Gabriella; Ippolito, Edy; Deodato, Francesco; Panunzi, Simona; Iapalucci, Chiara; Mattiucci, Gian Carlo; D'Angelo, Elisa; Padula, Gilbert D.A.; Valentini, Vincenzo; Cellini, Numa

    2011-01-01

    The aim of this study was to compare intensity-modulated radiation therapy (IMRT) with 3D conformal technique (3D-CRT), with respect to target coverage and irradiation of organs at risk for high dose postoperative radiotherapy (PORT) of the prostate fossa. 3D-CRT and IMRT treatment plans were compared with respect to dose to the rectum and bladder. The dosimetric comparison was carried out in 15 patients considering 2 different scenarios: (1) exclusive prostate fossa irradiation, and (2) pelvic node irradiation followed by a boost on the prostate fossa. In scenario (1), a 3D-CRT plan (box technique) and an IMRT plan were calculated and compared for each patient. In scenario (2), 3 treatment plans were calculated and compared for each patient: (a) 3D-CRT box technique for both pelvic (prophylactic nodal irradiation) and prostate fossa irradiation (3D-CRT only); (b) 3D-CRT box technique for pelvic irradiation followed by an IMRT boost to the prostatic fossa (hybrid 3D-CRT and IMRT); and (c) IMRT for both pelvic and prostate fossa irradiation (IMRT only). For exclusive prostate fossa irradiation, IMRT significantly reduced the dose to the rectum (lower Dmean, V50%, V75%, V90%, V100%, EUD, and NTCP) and the bladder (lower Dmean, V50%, V90%, EUD and NTCP). When prophylactic irradiation of the pelvis was also considered, plan C (IMRT only) performed better than plan B (hybrid 3D-CRT and IMRT) as respect to both rectum and bladder irradiation (reduction of Dmean, V50%, V75%, V90%, equivalent uniform dose [EUD], and normal tissue complication probability [NTCP]). Plan (b) (hybrid 3D-CRT and IMRT) performed better than plan (a) (3D-CRT only) with respect to dose to the rectum (lower Dmean, V75%, V90%, V100%, EUD, and NTCP) and the bladder (Dmean, EUD, and NTCP). Postoperative IMRT in prostate cancer significantly reduces rectum and bladder irradiation compared with 3D-CRT.

  3. The dosimetric impact of dental implants on head-and-neck volumetric modulated arc therapy

    International Nuclear Information System (INIS)

    Lin, Mu-Han; Li Jinsheng; Price, Robert A Jr; Wang Lu; Ma, C-M; Lee, Chung-Chi

    2013-01-01

    This work aims to investigate the dosimetric impact of dental implants on volumetric modulated arc therapy (VMAT) for head-and-neck patients and to evaluate the effectiveness of using the material's electron-density ratio for the correction. An in-house Monte Carlo (MC) code was utilized for the dose calculation to account for the scattering and attenuation caused by the high-Z implant material. Three different dental implant materials were studied in this work: titanium, Degubond®4 and gold. The dose perturbations caused by the dental implant materials were first investigated in a water phantom with a 1 cm 3 insert. The per cent depth dose distributions of a 3 × 3 cm 2 photon field were compared with the insert material as water and the three selected dental implant materials. To evaluate the impact of the dental implant on VMAT patient dose calculation, four head-and-neck cases were selected. For each case, the VMAT plan was designed based on the artifact-corrected patient geometry using a treatment planning system (TPS) that was typically utilized for routine patient treatment. The plans were re-calculated using the MC code for five situations: uncorrected geometry, artifact-corrected geometry and artifact-corrected geometry with one of the three different implant materials. The isodose distributions and the dose–volume histograms were cross-compared with each other. To evaluate the effectiveness of using the material's electron-density ratio for dental implant correction, the implant region was set as water with the material's electron-density ratio and the calculated dose was compared with the MC simulation with the real material. The main effect of the dental implant was the severe attenuation in the downstream. The 1 cm 3 dental implant can lower the downstream dose by 10% (Ti) to 51% (Au) for a 3 × 3 cm 2 field. The TPS failed to account for the dose perturbation if the dental implant material was not precisely defined. For the VMAT patient dose

  4. Robustness Recipes for Minimax Robust Optimization in Intensity Modulated Proton Therapy for Oropharyngeal Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Voort, Sebastian van der [Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam (Netherlands); Section of Nuclear Energy and Radiation Applications, Department of Radiation, Science and Technology, Delft University of Technology, Delft (Netherlands); Water, Steven van de [Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam (Netherlands); Perkó, Zoltán [Section of Nuclear Energy and Radiation Applications, Department of Radiation, Science and Technology, Delft University of Technology, Delft (Netherlands); Heijmen, Ben [Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam (Netherlands); Lathouwers, Danny [Section of Nuclear Energy and Radiation Applications, Department of Radiation, Science and Technology, Delft University of Technology, Delft (Netherlands); Hoogeman, Mischa, E-mail: m.hoogeman@erasmusmc.nl [Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam (Netherlands)

    2016-05-01

    Purpose: We aimed to derive a “robustness recipe” giving the range robustness (RR) and setup robustness (SR) settings (ie, the error values) that ensure adequate clinical target volume (CTV) coverage in oropharyngeal cancer patients for given gaussian distributions of systematic setup, random setup, and range errors (characterized by standard deviations of Σ, σ, and ρ, respectively) when used in minimax worst-case robust intensity modulated proton therapy (IMPT) optimization. Methods and Materials: For the analysis, contoured computed tomography (CT) scans of 9 unilateral and 9 bilateral patients were used. An IMPT plan was considered robust if, for at least 98% of the simulated fractionated treatments, 98% of the CTV received 95% or more of the prescribed dose. For fast assessment of the CTV coverage for given error distributions (ie, different values of Σ, σ, and ρ), polynomial chaos methods were used. Separate recipes were derived for the unilateral and bilateral cases using one patient from each group, and all 18 patients were included in the validation of the recipes. Results: Treatment plans for bilateral cases are intrinsically more robust than those for unilateral cases. The required RR only depends on the ρ, and SR can be fitted by second-order polynomials in Σ and σ. The formulas for the derived robustness recipes are as follows: Unilateral patients need SR = −0.15Σ{sup 2} + 0.27σ{sup 2} + 1.85Σ − 0.06σ + 1.22 and RR=3% for ρ = 1% and ρ = 2%; bilateral patients need SR = −0.07Σ{sup 2} + 0.19σ{sup 2} + 1.34Σ − 0.07σ + 1.17 and RR=3% and 4% for ρ = 1% and 2%, respectively. For the recipe validation, 2 plans were generated for each of the 18 patients corresponding to Σ = σ = 1.5 mm and ρ = 0% and 2%. Thirty-four plans had adequate CTV coverage in 98% or more of the simulated fractionated treatments; the remaining 2 had adequate coverage in 97.8% and 97.9%. Conclusions: Robustness recipes were derived that can

  5. Radiotherapy with volumetric modulated arc therapy for hepatocellular carcinoma patients ineligible for surgery or ablative treatments

    Energy Technology Data Exchange (ETDEWEB)

    Wang, P.M.; Chung, N.N.; Chang, F.L. [Cheng-Ching General Hospital, Taichung, Taiwan (China). Dept. of Radiation Oncology; Hsu, W.C. [Cheng-Ching General Hospital, Taichung, Taiwan (China). Dept. of Radiation Oncology; Asia Univ., Taichung, Taiwan (China). Dept. of Healthcare Administration; Fogliata, A.; Cozzi, L. [Oncology Institute of Southern Switzerland, Bellinzona (Switzerland)

    2013-04-15

    The aim of this article is to report the dosimetric and clinical findings in the treatment of primary hepatocellular carcinoma (HCC) with volumetric modulated arc therapy (VMAT, RapidArc). A total of 138 patients were investigated. Dose prescription ranged from 45-66 Gy. Most patients (88.4 %) presented AJCC stage III or IV and 83 % were N0-M0. All were classified as Barcelona Clinic Liver Cancer (BCLC) stage A-C. All patients were treated using 10 MV photons with single or multiple, coplanar or non-coplanar arcs, and cone-down technique in case of early response of tumors. The patients' median age was 66 years (range 27-87 years), 83 % were treated with 60 Gy (12 % at 45 Gy, 6 % at 66 Gy), 62 % with cone-down, 98 % with multiple arcs. The mean initial planning target volume (PTV) was 777 {+-} 632 cm{sup 3}; the mean final PTV (after the cone-down) was 583 {+-} 548 cm{sup 3}. High target coverage was achieved. The final PTV was V{sub 98%} > 98 %. Kidneys received on average 5 and 8 Gy (left and right), while the maximum dose to the spinal cord was 22 Gy; mean doses to esophagus and stomach were 23 Gy and 15 Gy, respectively. The average volume of healthy liver receiving more than 30 Gy was 294 {+-} 145 cm{sup 3}. Overall survival at 12 months was 45 %; median survival was 10.3 months (95 % confidence interval 7.2-13.3 months). Actuarial local control at 6 months was 95 % and 93.7 % at 12 months. The median follow-up was 9 months and a maximum of 28 months. This study showed from the dosimetric point of view the feasibility and technical appropriateness of RapidArc for the treatment of HCC. Clinical results were positive and might suggest, with appropriate care, to consider RapidArc as an additional therapeutic opportunity for these patients. (orig.)

  6. Density overwrites of internal tumor volumes in intensity modulated proton therapy plans for mobile lung tumors

    Science.gov (United States)

    Botas, Pablo; Grassberger, Clemens; Sharp, Gregory; Paganetti, Harald

    2018-02-01

    The purpose of this study was to investigate internal tumor volume density overwrite strategies to minimize intensity modulated proton therapy (IMPT) plan degradation of mobile lung tumors. Four planning paradigms were compared for nine lung cancer patients. Internal gross tumor volume (IGTV) and internal clinical target volume (ICTV) structures were defined encompassing their respective volumes in every 4DCT phase. The paradigms use different planning CT (pCT) created from the average intensity projection (AIP) of the 4DCT, overwriting the density within the IGTV to account for movement. The density overwrites were: (a) constant filling with 100 HU (C100) or (b) 50 HU (C50), (c) maximum intensity projection (MIP) across phases, and (d) water equivalent path length (WEPL) consideration from beam’s-eye-view. Plans were created optimizing dose-influence matrices calculated with fast GPU Monte Carlo (MC) simulations in each pCT. Plans were evaluated with MC on the 4DCTs using a model of the beam delivery time structure. Dose accumulation was performed using deformable image registration. Interplay effect was addressed applying 10 times rescanning. Significantly less DVH metrics degradation occurred when using MIP and WEPL approaches. Target coverage (D99≥slant 70 Gy(RBE)) was fulfilled in most cases with MIP and WEPL (D{{99}WEPL}=69.2+/- 4.0 Gy (RBE)), keeping dose heterogeneity low (D5-D{{95}WEPL}=3.9+/- 2.0 Gy(RBE)). The mean lung dose was kept lowest by the WEPL strategy, as well as the maximum dose to organs at risk (OARs). The impact on dose levels in the heart, spinal cord and esophagus were patient specific. Overall, the WEPL strategy gives the best performance and should be preferred when using a 3D static geometry for lung cancer IMPT treatment planning. Newly available fast MC methods make it possible to handle long simulations based on 4D data sets to perform studies with high accuracy and efficiency, even prior to individual treatment planning.

  7. Origin of Tumor Recurrence After Intensity Modulated Radiation Therapy for Oropharyngeal Squamous Cell Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Raktoe, Sawan A.S. [Department of Radiotherapy, University Medical Center Utrecht, Utrecht (Netherlands); Dehnad, Homan, E-mail: h.dehnad@umcutrecht.nl [Department of Radiotherapy, University Medical Center Utrecht, Utrecht (Netherlands); Raaijmakers, Cornelis P.J. [Department of Radiotherapy, University Medical Center Utrecht, Utrecht (Netherlands); Braunius, Weibel [Department of ENT Head and Neck Surgery, University Medical Center Utrecht, Utrecht (Netherlands); Terhaard, Chris H.J. [Department of Radiotherapy, University Medical Center Utrecht, Utrecht (Netherlands)

    2013-01-01

    Purpose: To model locoregional recurrences of oropharyngeal squamous cell carcinomas (OSCC) treated with primary intensity modulated radiation therapy (IMRT) in order to find the origins from which recurrences grow and relate their location to original target volume borders. Methods and Materials: This was a retrospective analysis of OSCC treated with primary IMRT between January 2002 and December 2009. Locoregional recurrence volumes were delineated on diagnostic scans and coregistered rigidly with treatment planning computed tomography scans. Each recurrence was analyzed with two methods. First, overlapping volumes of a recurrence and original target were measured ('volumetric approach') and assessed as 'in-field', 'marginal', or 'out-field'. Then, the center of mass (COM) of a recurrence volume was assumed as the origin from where a recurrence expanded, the COM location was compared with original target volume borders and assessed as 'in-field', 'marginal', or 'out-field'. Results: One hundred thirty-one OSCC were assessed. For all patients alive at the end of follow-up, the mean follow-up time was 40 months (range, 12-83 months); 2 patients were lost to follow-up. The locoregional recurrence rate was 27%. Of all recurrences, 51% were local, 23% were regional, and 26% had both local and regional recurrences. Of all recurrences, 74% had imaging available for assessment. Regarding volumetric analysis of local recurrences, 15% were in-field gross tumor volume (GTV), and 65% were in-field clinical tumor volume (CTV). Using the COM approach, we found that 70% of local recurrences were in-field GTV and 90% were in-field CTV. Of the regional recurrences, 25% were volumetrically in-field GTV, and using the COM approach, we found 54% were in-field GTV. The COM of local out-field CTV recurrences were maximally 16 mm outside CTV borders, whereas for regional recurrences, this was 17 mm. Conclusions: The

  8. A GPU-accelerated and Monte Carlo-based intensity modulated proton therapy optimization system.

    Science.gov (United States)

    Ma, Jiasen; Beltran, Chris; Seum Wan Chan Tseung, Hok; Herman, Michael G

    2014-12-01

    Conventional spot scanning intensity modulated proton therapy (IMPT) treatment planning systems (TPSs) optimize proton spot weights based on analytical dose calculations. These analytical dose calculations have been shown to have severe limitations in heterogeneous materials. Monte Carlo (MC) methods do not have these limitations; however, MC-based systems have been of limited clinical use due to the large number of beam spots in IMPT and the extremely long calculation time of traditional MC techniques. In this work, the authors present a clinically applicable IMPT TPS that utilizes a very fast MC calculation. An in-house graphics processing unit (GPU)-based MC dose calculation engine was employed to generate the dose influence map for each proton spot. With the MC generated influence map, a modified least-squares optimization method was used to achieve the desired dose volume histograms (DVHs). The intrinsic CT image resolution was adopted for voxelization in simulation and optimization to preserve spatial resolution. The optimizations were computed on a multi-GPU framework to mitigate the memory limitation issues for the large dose influence maps that resulted from maintaining the intrinsic CT resolution. The effects of tail cutoff and starting condition were studied and minimized in this work. For relatively large and complex three-field head and neck cases, i.e., >100,000 spots with a target volume of ∼ 1000 cm(3) and multiple surrounding critical structures, the optimization together with the initial MC dose influence map calculation was done in a clinically viable time frame (less than 30 min) on a GPU cluster consisting of 24 Nvidia GeForce GTX Titan cards. The in-house MC TPS plans were comparable to a commercial TPS plans based on DVH comparisons. A MC-based treatment planning system was developed. The treatment planning can be performed in a clinically viable time frame on a hardware system costing around 45,000 dollars. The fast calculation and

  9. A GPU-accelerated and Monte Carlo-based intensity modulated proton therapy optimization system

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Jiasen, E-mail: ma.jiasen@mayo.edu; Beltran, Chris; Seum Wan Chan Tseung, Hok; Herman, Michael G. [Department of Radiation Oncology, Division of Medical Physics, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905 (United States)

    2014-12-15

    Purpose: Conventional spot scanning intensity modulated proton therapy (IMPT) treatment planning systems (TPSs) optimize proton spot weights based on analytical dose calculations. These analytical dose calculations have been shown to have severe limitations in heterogeneous materials. Monte Carlo (MC) methods do not have these limitations; however, MC-based systems have been of limited clinical use due to the large number of beam spots in IMPT and the extremely long calculation time of traditional MC techniques. In this work, the authors present a clinically applicable IMPT TPS that utilizes a very fast MC calculation. Methods: An in-house graphics processing unit (GPU)-based MC dose calculation engine was employed to generate the dose influence map for each proton spot. With the MC generated influence map, a modified least-squares optimization method was used to achieve the desired dose volume histograms (DVHs). The intrinsic CT image resolution was adopted for voxelization in simulation and optimization to preserve spatial resolution. The optimizations were computed on a multi-GPU framework to mitigate the memory limitation issues for the large dose influence maps that resulted from maintaining the intrinsic CT resolution. The effects of tail cutoff and starting condition were studied and minimized in this work. Results: For relatively large and complex three-field head and neck cases, i.e., >100 000 spots with a target volume of ∼1000 cm{sup 3} and multiple surrounding critical structures, the optimization together with the initial MC dose influence map calculation was done in a clinically viable time frame (less than 30 min) on a GPU cluster consisting of 24 Nvidia GeForce GTX Titan cards. The in-house MC TPS plans were comparable to a commercial TPS plans based on DVH comparisons. Conclusions: A MC-based treatment planning system was developed. The treatment planning can be performed