Report of the IPSM working party on low- and medium-energy x-ray dosimetry. Institute of Physical Sciences in Medicine.

abstract：:This paper reports an inverse arc-modulated radiation therapy planning technique based on linear models. It is implemented with a two-step procedure. First, fluence maps for 36 fixed-gantry beams are generated using a linear model-based intensity-modulated radiation therapy (IMRT) optimization algorithm. The 2D fluenc...

journal_title：Physics in medicine and biology

authors： Zhu X,Thongphiew D,McMahon R,Li T,Chankong V,Yin FF,Wu QJ

更新日期：2010-07-07 00:00:00

abstract：:To investigate the profile measurement capabilities of an IBA-Dosimetry scintillation detector and to assess its feasibility for determining the low-intensity tails of pencil-beam scanning spots, the responses of the scintillation detector and Gafchromic EBT2 film to a 115 MeV proton spot were measured in-air at the i...

journal_title：Physics in medicine and biology

authors： Lin L,Ainsley CG,Mertens T,De Wilde O,Talla PT,McDonough JE

更新日期：2013-06-21 00:00:00

abstract：:This paper explores fast reconstruction strategies for 3D time-of-flight (TOF) positron emission tomography (PET), based on 2D data rebinning. Starting from pre-corrected 3D TOF data, a rebinning algorithm estimates for each transaxial slice the 2D TOF sinogram that would have been acquired by a single-ring scanner. T...

journal_title：Physics in medicine and biology

authors： Defrise M,Casey ME,Michel C,Conti M

更新日期：2005-06-21 00:00:00

abstract：:Average cross-sections for inactivation of dry ribonuclease by H, He and N projectiles with energies between 100 eV and 10 keV are presented. The trend of the damage cross-sections with particle energy is consistent with the trend of the molecular quasi-elastic scattering and ionization cross-sections. A tentative rad...

journal_title：Physics in medicine and biology

authors： Watt DE,Sutcliffe JF

更新日期：1975-11-01 00:00:00

abstract：:While megavoltage cone-beam computed tomography (CBCT) using an electronic portal imaging device (EPID) provides many advantages over kilovoltage (kV) CBCT, clinical adoption is limited by its high doses. Multi-layer imager (MLI) EPIDs increase DQE(0) while maintaining high resolution. However, even well-designed, hig...

journal_title：Physics in medicine and biology

authors： Hu YH,Rottmann J,Fueglistaller R,Myronakis M,Wang A,Huber P,Shedlock D,Morf D,Baturin P,Star-Lack J,Berbeco R

更新日期：2018-01-30 00:00:00

abstract：:The measured attenuation correction technique is widely used in cardiac positron tomographic studies. However, the success of this technique is limited because of insufficient counting statistics achievable in practical transmission scan times, and of the scattered radiation in transmission measurement which leads to ...

journal_title：Physics in medicine and biology

authors： Yu SK,Nahmias C

更新日期：1996-10-01 00:00:00

abstract：:We find the dose distribution that maximizes the tumour control probability (TCP) for a fixed mean tumour dose per fraction. We consider a heterogeneous tumour volume having a radiation response characterized by the linear quadratic model with heterogeneous radiosensitivity and repopulation rate that may vary in time....

journal_title：Physics in medicine and biology

authors： Levin-Plotnik D,Hamilton RJ

更新日期：2004-02-07 00:00:00

abstract：:When dosimetric effects in time-dependent geometries are studied, usually either the results of individual three-dimensional (3D) calculations are combined or probability-based approaches are applied. These methods may become cumbersome and time-consuming if high time resolution is required or if the geometry is compl...

journal_title：Physics in medicine and biology

authors： Paganetti H,Jiang H,Trofimov A

更新日期：2005-03-07 00:00:00

abstract：:This study presents a theoretical approach to the dosimetry for small and non-equilibrium radiation fields. We applied the newly developed VMCBC algorithm to the dosimetry for megavoltage photon beams using Monte Carlo techniques. The approach assumes that a Monte Carlo simulated beam can be calibrated per incident pa...

journal_title：Physics in medicine and biology

authors： Ding GX,Duggan DM,Coffey CW

更新日期：2008-07-07 00:00:00

abstract：:We have investigated the tongue-and-groove effect on the IMRT dose distributions for a Varian MLC. We have compared the dose distributions calculated using the intensity maps with and without the tongue-and-groove effect. Our results showed that, for one intensity-modulated treatment field, the maximum tongue-and-groo...

journal_title：Physics in medicine and biology

authors： Deng J,Pawlicki T,Chen Y,Li J,Jiang SB,Ma CM

更新日期：2001-04-01 00:00:00

abstract：:The aim of this study was to investigate the utility of consistency metrics, such as inverse consistency, in contour-based deformable registration error analysis. Four images were acquired of the same phantom that has experienced varying levels of deformation. The deformations were simulated with deformable image regi...

journal_title：Physics in medicine and biology

authors： Bender ET,Tomé WA

更新日期：2009-09-21 00:00:00

abstract：:Simulation of small-angle x-ray scattering from collagen in healthy and cancerous breast tissue may reveal detailed information on the structural changes in collagen. Collagen fibril is modelled as a cylinder with axially periodic step-function electron density, and packing is approximated by placing the cylinders in ...

journal_title：Physics in medicine and biology

authors： Suhonen H,Fernández M,Serimaa R,Suortti P

更新日期：2005-11-21 00:00:00

abstract：:The automatic calibration in Fourier-domain optical coherence tomography (FD-OCT) systems allows for high resolution imaging with precise depth ranging functionality in many complex imaging scenarios, such as microsurgery. However, the accuracy and speed of the existing automatic schemes are limited due to the functio...

journal_title：Physics in medicine and biology

authors： Ratheesh KM,Seah LK,Murukeshan VM

更新日期：2016-11-07 00:00:00

abstract：:The dosimetric measurement and modeling of small radiation treatment fields (<2 × 2 cm2) are difficult to perform and prone to error. Measurements of small fields are often adversely influenced by the properties of the detectors used to make them. The dosimetric properties of small fields have been difficult to accura...

journal_title：Physics in medicine and biology

authors： Hundertmark B,Sterpin E,Mackie T

更新日期：2011-06-21 00:00:00

abstract：:Estimation of a set of parameters that describe the geometry of the cone-beam computed tomography system plays an important role in the geometrical calibration. In the calibration process, the helical phantom consisting of spherical markers arranged on a helical trajectory has been widely applied. To directly determin...

journal_title：Physics in medicine and biology

authors： Xu M,Zhang C,Liu X,Li D

更新日期：2014-10-07 00:00:00

abstract：:Gold nanoparticle (GNP) radio-enhancement is a promising technique to increase the dose deposition in a tumor while sparing neighboring healthy tissue. Previous experimental studies showed effects on cell survival and tumor control for keV x-rays but surprisingly also for MV-photons, proton and carbon-ion beams. In a ...

journal_title：Physics in medicine and biology

authors： Rudek B,McNamara A,Ramos-Méndez J,Byrne H,Kuncic Z,Schuemann J

更新日期：2019-08-28 00:00:00

abstract：:Quality control (QC) data of radiotherapy linear accelerators, collected by Helsinki University Central Hospital between the years 2000 and 2004, were analysed. The goal was to provide information for the evaluation and elaboration of QC of accelerator outputs and to propose a method for QC data analysis. Short- and l...

journal_title：Physics in medicine and biology

authors： Kapanen M,Tenhunen M,Hämäläinen T,Sipilä P,Parkkinen R,Järvinen H

更新日期：2006-07-21 00:00:00

abstract：:The in vivo electric conductivity (σ) values of tissue are essential for accurate electromagnetic simulations and specific absorption rate (SAR) assessment for applications such as thermal dose computations in hyperthermia. Currently used σ-values are mostly based on ex vivo measurements. In this study the conductivit...

journal_title：Physics in medicine and biology

authors： Balidemaj E,de Boer P,van Lier AL,Remis RF,Stalpers LJ,Westerveld GH,Nederveen AJ,van den Berg CA,Crezee J

更新日期：2016-02-21 00:00:00

abstract：:The dynamic magnetization of immobilized spherical single-domain magnetic nanoparticles (MNPs) with uniaxial or cubic magnetocrystalline anisotropy was studied computationally by executing simulations based on the Landau-Lifshitz-Gilbert (LLG) equation. For situations when a static magnetic field was suddenly applied ...

journal_title：Physics in medicine and biology

authors： Zhao Z,Garraud N,Arnold DP,Rinaldi C

更新日期：2020-01-17 00:00:00

abstract：:The external radiation exposure from an overhead plume containing gamma emitting radionuclides can contribute substantial dose to the ground receptor during normal operations as well as accidental release conditions of nuclear facilities. In order to estimate the effective dose conversion coefficients (DCCs) directly,...

journal_title：Physics in medicine and biology

authors： Dey R,Patni HK,Deo Singh K,Kulkarni MS,Anand S

更新日期：2019-08-01 00:00:00

abstract：:The transverse magnetic field of an MRI-linac sweeps contaminant electrons away from the radiation beam. Films oriented perpendicular to the magnetic field and 5 cm from the radiation beam edge show a projection of the divergent beam, indicating that contaminant electrons spiral along magnetic field lines and deposit ...

journal_title：Physics in medicine and biology

authors： Hackett SL,van Asselen B,Wolthaus JWH,Bluemink JJ,Ishakoglu K,Kok J,Lagendijk JJW,Raaymakers BW

更新日期：2018-05-01 00:00:00

abstract：:We are developing a dedicated, combined breast positron emission tomography (PET)-tomosynthesis scanner. Both the PET and digital breast tomosynthesis (DBT) scanners are integrated in a single gantry to provide spatially co-registered 3D PET-tomosynthesis images. The DBT image will be used to identify the breast bound...

journal_title：Physics in medicine and biology

authors： Krishnamoorthy S,Vent T,Barufaldi B,Maidment ADA,Karp JS,Surti S

更新日期：2020-10-28 00:00:00

abstract：:The quality of radiation therapy delivered for treating cancer patients is related to set-up errors and organ motion. Due to the margins needed to ensure adequate target coverage, many breast cancer patients have been shown to develop late side effects such as pneumonitis and cardiac damage. Breathing-adapted radiatio...

journal_title：Physics in medicine and biology

authors： Kakar M,Nyström H,Aarup LR,Nøttrup TJ,Olsen DR

更新日期：2005-10-07 00:00:00

abstract：:Monte Carlo calculations of the energy response of LiF dosemeters have been carried out to help resolve the discrepancy between the measurements of Holt, Edelstein and Clark (1975) and those of Paliwal and Almond (1975) and others. It is concluded that the assumptions used by Holt et al. are largely responsible. They ...

journal_title：Physics in medicine and biology

authors： O'Brien K

更新日期：1977-09-01 00:00:00

abstract：:A micro beam synchrotron x-ray fluorescence (muSRXRF) technique has been used to determine the localization of metals in primary invasive ductal carcinoma of breast. Nine samples were examined, all of which were formalin fixed tissues arranged as micro arrays of 1.0 mm diameter and 10 microm thickness. Cu was the part...

journal_title：Physics in medicine and biology

authors： Farquharson MJ,Al-Ebraheem A,Falkenberg G,Leek R,Harris AL,Bradley DA

更新日期：2008-06-07 00:00:00

abstract：:Earlier work on the dielectric properties of cryoprotectant agents is extended using a modified measuring cell and method of data reduction yielding results more efficiently over a temperature range from -75 to +25 degrees C at frequencies from 27 MHz to 3 GHz. Dimethyl sulphoxide and butanediol are investigated at lo...

journal_title：Physics in medicine and biology

authors： Evans S,bin Azeman A

更新日期：1998-10-01 00:00:00

abstract：:We introduce a novel x-ray imaging approach that yields information about the local texture of structures smaller than the image pixel resolution inside an object. The approach is based on a recently developed x-ray dark-field imaging technique, using scattering from sub-micron structures in the sample. We show that t...

journal_title：Physics in medicine and biology

authors： Jensen TH,Bech M,Bunk O,Donath T,David C,Feidenhans'l R,Pfeiffer F

更新日期：2010-06-21 00:00:00

abstract：:The process of organ motion correction in scintigraphy is analysed in the frequency domain. The sequence of the chi- and gamma- coordinates registered during scintigraphic recording is converted to a frequency spectrum by a discrete Fourier transform. In the frequency domain motion correction is performed by linear fi...

journal_title：Physics in medicine and biology

authors： Schmidlin P

更新日期：1975-05-01 00:00:00

abstract：:Compton scatter poses a significant threat to volumetric x-ray computed tomography, bringing cupping and streak artefacts thus impacting qualitative and quantitative imaging procedures. To perform appropriate scatter compensation, it is necessary to estimate the magnitude and spatial distribution of x-ray scatter. The...

journal_title：Physics in medicine and biology

authors： Akbarzadeh A,Ay MR,Ghadiri H,Sarkar S,Zaidi H

更新日期：2010-04-21 00:00:00

abstract：:The purpose of this investigation is to propose new compensator design strategies for protons and heavier particles which are based on pencil-beam (PB) dose calculations and which significantly reduce the dose to tissues downstream from the target, yet provide acceptable target coverage under conditions of patient mot...

journal_title：Physics in medicine and biology

authors： Petti PL

更新日期：1997-07-01 00:00:00