Read by QxMD icon Read

Monte carlo dose calculation

K Bergaoui, N Reguigui, C Brown, B Yousfi, M A Nasri, K Gary
A deuterium-deuterium (D-D) neutron generator facility has been developed with a wide range of applications in mind. D-D neutron generators provide a safe, convenient, and low-cost solution for the production of thermal, epithermal, and fast neutrons for laboratory and industrial applications. The regulatory burden for operating one of these generators is small as it contains no radioactive material and produces no radiation when turned off. One such D-D neutron generator has been installed at the National Center of Nuclear Sciences and Technologies (CNSTN)...
February 2, 2019: Applied Radiation and Isotopes
J E Johnson, C Beltran, H Wan Chan Tseung, D W Mundy, J J Kruse, T J Whitaker, M G Herman, K M Furutani
The purpose of this work was to develop an end-to-end patient-specific quality assurance (QA) technique for spot-scanned proton therapy that is more sensitive and efficient than traditional approaches. The patient-specific methodology relies on independently verifying the accuracy of the delivered proton fluence and the dose calculation in the heterogeneous patient volume. A Monte Carlo dose calculation engine, which was developed in-house, recalculates a planned dose distribution on the patient CT data set to verify the dose distribution represented by the treatment planning system...
2019: PloS One
Kento Hoshida, Fujio Araki, Takeshi Ohno, Hirofumi Tominaga, Kazuki Komatsu, Kentaro Tamura
The purpose of this study was to verify the accuracy of dose calculation algorithms of a treatment planning system for a single-isocenter volumetric modulated arc therapy (VMAT) plan in multiple brain metastases, by comparing the dose distributions of treatment planning system with those of Monte Carlo (MC) simulations. We used a multitarget phantom containing 9 acrylic balls with a diameter of 15.9 mm inside a Lucy phantom measuring 17 × 17 × 17 cm3 . Seven VMAT plans were created using the multitarget phantom: 1 multitarget plan (MTP) and 6 single target plans (STP)...
February 6, 2019: Medical Dosimetry: Official Journal of the American Association of Medical Dosimetrists
Husein Alhamada, Stephane Simon, Catherine Philippson, Christophe Vandekerkhove, Younes Jourani, Nicolas Pauly, Dirk VanGestel, Nick Reynaert
PURPOSE: This paper studies the feasibility of using Monte Carlo (MC) for treatment planning of intraoperative electron radiation therapy (IOERT) procedure to get 3D dose by using patient's CT images. METHODS: The IOERT treatment planning was performed using the following successive steps: I) The Mobetron 1000® machine was modelled with the EGSnrc MC codes. II) The MC model was validated with measurements of percentage depth doses and profiles for three energies (12, 9, 6) MeV...
January 2019: Physica Medica: PM
Angeliki Karambatsakidou, Artur Omar, Annette Fransson, Gavin Poludniowski
PURPOSE: To estimate effective dose (E), equivalent organ doses (HT ) and associated conversion coefficients (CCE:KAP  = E/KAP, CCHT:KAP  = HT /KAP; KAP = Kerma-area product) in paediatric cardiac interventions, using detailed exposure data from radiation dose structured reports (RDSR). These "RDSR dose estimations" have been compared with estimations performed using the approach currently implemented in the clinic that is based on a simplified assumptions method (SAM)...
January 2019: Physica Medica: PM
I Veltchev, R Price, X Chen, K Howell, J Meyer, C-M Ma
PURPOSE: The directional planar palladium-103 LDR device (CivaSheet™ ) may be used for intra-operative implantation at the interface between the tumor site and healthy tissue. Its dosimetric properties have been studied in the ideal case of application on a at surface. The dosimetric impact of implanting this highly directional device on a curved surface that may be encountered in clinical treatments is analyzed. METHODS: CivaSheet is designed as an array of directional palladium-103 sources (CivaDots)...
February 8, 2019: Medical Physics
John Baines, S Zawlodzka, T Markwell, M Chan
An Advanced Markus chamber on the surface of solid water phantom was used to determine surface dose reduction, with either a lead or air interface, as a function of surface-interface separation (t). The beam quality dependence of dose reduction was investigated using the 50 kV, 100 kV and 150 kV beams of an Xstrahl 150 superficial X-ray unit. For each beam the dose correction factor, DCF(t), namely the ratio of surface dose (t) to surface dose (t = 100 mm), was determined. Monte Carlo simulations of DCF(t) with a lead interface were compared with corresponding measured values...
February 6, 2019: Australasian Physical & Engineering Sciences in Medicine
Daniel Zucca Aparicio, Ovidio Hernando Requejo, Miguel Ángel de la Casa de Julián, Carmen Rubio Rodríguez, Pedro Fernández Letón
Aim: To evaluate dose differences in lung metastases treated with stereotactic body radiotherapy (SBRT), and the correlation with local control, regarding the dose algorithm, target volume and tissue density. Background: Several studies showed excellent local control rates in SBRT for lung metastases, with different fractionation schemes depending on the tumour location or size. These results depend on the dose distributions received by the lesions in terms of the tissue heterogeneity corrections performed by the dose algorithms...
March 2019: Reports of Practical Oncology and Radiotherapy
Adela Carnicer, Gaëlle Angellier, Petter Hofverberg, Jean-Marc Bergerot, Anaïs Gerard, Cécile Peucelle, Marie Vidal, Joël Hérault
Ambient dose equivalent measurements with radiation protection instruments are associated to large uncertainties, mostly due to the energy dependence of the instrument response and to the dissimilarity between the spectra of the standard calibration source and the workplace field. The purpose of this work is to evaluate its impact on the performance of area and environmental detectors in the proton therapy environment, and to provide practical solutions whenever needed and possible. The study was carried out at the Centre Antoine Lacassagne (CAL) proton therapy site, and included a number of commercially available area detectors and a home-made environmental thermoluminescent dosimeter based on a polyethylene moderator loaded with TLD600H/TLD700H pairs...
February 5, 2019: Journal of Radiological Protection: Official Journal of the Society for Radiological Protection
Jesús Mendoza, Lilia Gutierrez, José Á Gutiérrez, Felipe A Bustos, Hector Sumano
The pharmacokinetics, PK/PD ratios, and Monte Carlo modeling of enrofloxacin HCl-2H2 O (Enro-C) and its reference preparation (Enro-R) were determined in cows. Fifty-four Jersey cows were randomly assigned to six groups receiving a single IM dose of 10, 15, or 20 mg/kg of Enro-C (Enro-C10 , Enro-C15 , Enro-C20 ) or Enro-R. Serial serum samples were collected and enrofloxacin concentrations quantified. A composite set of minimum inhibitory concentrations (MIC) of Leptospira spp. was utilized to calculate PK/PD ratios: maximum serum concentration/MIC (Cmax /MIC90 ) and area under the serum vs...
February 3, 2019: Journal of Veterinary Pharmacology and Therapeutics
Edward Greg Huang, Yimin Lin, Mark Ebert, Dae Woong Ham, Claire Yunzhi Zhang, Rainer K Sachs
Experimental studies reporting murine Harderian gland (HG) tumourigenesis have been a NASA concern for many years. Studies used particle accelerators to produce beams that, on beam entry, consist of a single isotope also present in the galactic cosmic ray (GCR) spectrum. In this paper synergy theory is described, potentially applicable to corresponding mixed-field experiments, in progress, planned, or hypothetical. The "obvious" simple effect additivity (SEA) approach of comparing an observed mixture dose-effect relationship (DER) to the sum of the components' DERs is known from other fields of biology to be unreliable when the components' DERs are highly curvilinear...
February 2, 2019: Radiation and Environmental Biophysics
Stefan J van Hoof, Joana B Verde, Frank Verhaegen
OBJECTIVE: Using synchronized three-dimensional stage translation and multiangle radiation delivery to improve conformality and homogeneity of radiation delivery to complexly shaped target volumes for precision preclinical radiotherapy. METHODS: A CT image of a mouse was used to design irradiation plans to target the spinal cord and an orthotopic lung tumour. A dose painting method is proposed that combines heterogeneous two-dimensional area irradiations from multiple beam directions...
February 1, 2019: British Journal of Radiology
Yana Zlateva, Bryan R Muir, Jan P Seuntjens, Issam El Naqa
PURPOSE: Cherenkov emission (CE) is ubiquitous in external radiotherapy. It is also unique in that it carries the promise of 3D micrometer-resolution perturbation-free in-water dosimetry with a beam quality-independent detector response calibration. Our aim is to bring CE-based dosimetry into the clinic and we motivate this here with electron beams. We Monte Carlo-calculate and characterize broad-beam CE-to-dose conversion factors in water for a clinically representative library of electron beam qualities, address beam quality specification and reference depth selection, and develop a preliminary uncertainty budget based on our Monte Carlo results and relative experimental work of a companion study (Paper I)...
January 31, 2019: Medical Physics
Pablo Yepes, Antony Adair, Steven J Frank, David R Grosshans, Zhongxing Liao, Amy Liu, Dragan Mirkovic, Falk Poenisch, Uwe Titt, Qianxia Wang, Radhe Mohan
Purpose: To evaluate how using models of proton therapy that incorporate variable relative biological effectiveness (RBE) versus the current practice of using a fixed RBE of 1.1 affects dosimetric indices on treatment plans for large cohorts of patients treated with intensity modulated proton therapy (IMPT). Methods and Materials: Treatment plans for 4 groups of patients who received IMPT for brain, head-and-neck, thoracic, or prostate cancer were selected. Dose distributions were recalculated in 4 ways: 1 with a fast-dose Monte Carlo calculator with fixed RBE and 3 with RBE calculated to 3 different models-McNamara, Wedenberg, and repair-misrepair-fixation...
January 2019: Advances in Radiation Oncology
Marjan Hashempour, Mahdi Ghorbani, Ernesto Amato, Courtney Knaup
Objectives: The purpose of this research is to study the effect of beta spectrum on absorbed fraction ( ϕ ) and to find suitable analytical functions for beta spectrum absorbed fractions in spherical and ellipsoidal volumes with a uniform distribution for several radionuclides that are commonly used in nuclear medicine. Methods: In order to obtain the beta particle absorbed fraction, Monte Carlo simulations were performed by using the MCNPX code. The validation of the simulations was performed by calculating the absorbed fractions in spheres and comparing the results with the data published by other investigators...
2019: Asia Oceania Journal of Nuclear Medicine & Biology
Lucas Provenzano, Silva Bortolussi, Sara J González, Ian Postuma, Nicoletta Protti, Agustina Portu, Maria Silvina Olivera, Luis Miguel Rodriguez, Daniel Fregenal, Saverio Altieri
Osteosarcoma is the most common primary malignant tumour of bone in young patients. The survival of these patients has largely been improved due to adjuvant and neo-adjuvant chemotherapy in addition to surgery. Boron neutron capture therapy (BNCT) is proposed as a complementary therapy, due to its ability to inactivate tumour cells that may survive the standard treatment and that may be responsible for recurrences and/or metastases. BNCT is based on neutron irradiation of a tumour enriched in 10 B with a boron-loaded drug...
January 28, 2019: Radiation and Environmental Biophysics
Ethan P M LaRochelle, Kayla Marra, Robert E LeBlanc, M Shane Chapman, Edward V Maytin, Brian W Pogue
BACKGROUND: Daylight-activated PDT has seen increased support in recent years as a treatment method for actinic keratosis and other non-melanoma skin cancers. The inherent variability observed in broad-spectrum light used in this methodology makes it difficult to plan and monitor light dose, or compare to lamp light doses. METHODS: The present study expands on the commonly used PpIX-weighted effective surface irradiance metric by introducing a Monte Carlo method for estimating effective fluence rates into depths of the skin...
January 24, 2019: Photodiagnosis and Photodynamic Therapy
Sarah E Anderson, Michael P Grams, Hok Wan Chan Tseung, Keith M Furutani, Chris J Beltran
Radiochromic film is a valuable dosimetric tool, primarily due to its sub-millimeter spatial resolution. For accurate proton dosimetry, the dependence of film response on linear energy transfer must be characterized and calibrated. In this work, we characterized film under-response, or "quenching," as a function of dose-weighted linear energy transfer (LETd) in several proton fields and established a simple, linear relationship with LETd. 
 We performed measurements as a function of depth in a PMMA phantom irradiated by a spot-scanning proton beam...
January 23, 2019: Physics in Medicine and Biology
Atiyeh Ebrahimi-Khankook, Parisa Akhlaghi, Alireza Vejdani-Noghreiyan
In recent years, there has been a growing interest in constructing a series of deformable phantoms, which follow statistical distributions of some anatomical variations, called "statistical phantoms". The main purpose of this study was to develop statistical phantoms by considering the variations of lung volume and shape, to evaluate the lung dose uncertainty for individuals undergoing chest computed tomography. Calculations were performed for 100 statistical lung volume phantoms and 70 statistical lung shape phantoms at tube voltage of 80 and 120 kVp with the use of Monte Carlo MCNP code...
January 23, 2019: Journal of Radiological Protection: Official Journal of the Society for Radiological Protection
Quan Chen, Janelle Molloy, Tadahide Izumi, Edmond Sterpin
The orthovoltage x-Ray energy frequently used in radiation research is prone to dosimetry errors due to insufficient backscatter conditions. In many radiobiology studies, especially for cell irradiations, precise dose calculation algorithms such as Convolution-Superposition or Monte Carlo are impractical and as such, less accurate hand calculation methods are used for dose estimation. These dose estimation methods typically assume full backscatter conditions. The purpose of this study is to demonstrate the magnitude of the dose error that results from insufficient backscatter, and to provide lookup tables to account this issue...
January 23, 2019: Physics in Medicine and Biology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"