abstract：PURPOSE:This paper describes the clinical implementation and medical commissioning of the MedAustron Particle Therapy Accelerator (MAPTA) for non-isocentric scanned proton beam treatments. METHODS:Medical physics involvement during technical commissioning work is presented. Acceptance testing procedures, including adv...

journal_title：Medical physics

authors： Grevillot L,Osorio Moreno J,Letellier V,Dreindl R,Elia A,Fuchs H,Carlino A,Kragl G,Palmans H,Vatnitsky S,Stock M

更新日期：2020-02-01 00:00:00

abstract：PURPOSE:A modular phantom for dosimetry and imaging performance evaluation in cone-beam computed tomography (CBCT) is reported, providing a tool for quantitative technical assessment that can be adapted to a broad variety of CBCT imaging configurations and clinical applications. METHODS:The phantom presents a set of m...

journal_title：Medical physics

authors： Siewerdsen JH,Uneri A,Hernandez AM,Burkett GW,Boone JM

更新日期：2020-02-01 00:00:00

abstract：PURPOSE:Two ultra-high-resolution (UHR) computed tomography (CT) scanners are clinically available. One is achieved by a CT system with a 0.25 mm × 160 row detector (Detector-UHR), whereas the other is with a 0.6 mm × 32 row detector with in-plane comb filtering in a dual source CT (Comb-UHR). We compared radiation dos...

journal_title：Medical physics

authors： Kawashima H,Ichikawa K,Takata T,Nagata H,Hoshika M,Akagi N

更新日期：2020-02-01 00:00:00

abstract：PURPOSE:To develop a novel system for patient-specific combined optimization of couch, collimator, and gantry angles for use in volumetric modulated arc therapy (VMAT) treatment planning. The system was designed to produce highly compact dose distributions by extensively sampling the 4π space. Automated fixed couch tra...

journal_title：Medical physics

authors： MacDonald RL,Syme A,Little B,Ward L,Thomas CG

更新日期：2020-02-01 00:00:00

abstract：PURPOSE:New preclinical image-guided irradiators and treatment planning systems represent a huge progress in radiobiology. Nevertheless, quality control of preclinical treatments is not as advanced as in clinical radiotherapy and in vivo dosimetry is less developed. In this study, we evaluate the use of a scintillating...

journal_title：Medical physics

authors： Le Deroff C,Pérès EA,Ledoux X,Toutain J,Frelin-Labalme AM

更新日期：2020-01-01 00:00:00

abstract：PURPOSE:To develop a new scintillating fiber-based electronic portal imaging device (EPID) with a high quantum efficiency (QE) while preserving an adequate spatial resolution. METHODS:Two prototypes were built: one with a single pixel readout and the other with an active matrix flat-panel imager (AMFPI) for readout. T...

journal_title：Medical physics

authors： Liu J,Xu Y,Teymurazyan A,Papandreou Z,Pang G

更新日期：2020-01-01 00:00:00

abstract：PURPOSE:The thermoluminescence dosimeter (TLD) has desirable features including low cost, reusability, small size, and relatively low energy dependence. However, the commonly available poly-crystal TLDs (e.g., TLD-100) exhibit high interdetector variability that requires individual calibration for high detection accura...

journal_title：Medical physics

authors： Shang D,Gu W,Landers A,Woods K,Yu V,Neph R,Tenn S,Sheng K

更新日期：2020-01-01 00:00:00

abstract：PURPOSE:The aim of this work was to provide a novel description of how the radiotherapy community configures treatment planning system (TPS) radiation beam models for clinically used treatment machines. Here we describe the results of a survey of self-reported TPS beam modeling parameter values across different C-arm l...

journal_title：Medical physics

authors： Glenn MC,Peterson CB,Followill DS,Howell RM,Pollard-Larkin JM,Kry SF

更新日期：2020-01-01 00:00:00

abstract：PURPOSE:Manual delineation of head and neck (H&N) organ-at-risk (OAR) structures for radiation therapy planning is time consuming and highly variable. Therefore, we developed a dynamic multiatlas selection-based approach for fast and reproducible segmentation. METHODS:Our approach dynamically selects and weights the a...

journal_title：Medical physics

authors： Haq R,Berry SL,Deasy JO,Hunt M,Veeraraghavan H

更新日期：2019-12-01 00:00:00

abstract：PURPOSE:To provide an overview of the types of adverse events reported to the US Food and Drug Administration (US FDA) for magnetic resonance (MR) systems over a 10-yr period. METHODS:Two reviewers independently reviewed adverse events reported to FDA for MR systems from 1 January 2008 to 31 December 2017 and manually...

journal_title：Medical physics

authors： Delfino JG,Krainak DM,Flesher SA,Miller DL

更新日期：2019-12-01 00:00:00

abstract：PURPOSE:To automatically and efficiently segment the lesion area of the colonoscopy polyp image, a polyp segmentation method has been presented. METHODS:An ensemble model of pretrained convolutional neural networks was proposed, using Unet-VGG, SegNet-VGG, and PSPNet. Firstly, the Unet-VGG is obtained by the first 10 ...

journal_title：Medical physics

authors： Guo X,Zhang N,Guo J,Zhang H,Hao Y,Hang J

更新日期：2019-12-01 00:00:00

abstract：PURPOSE:The Nakagami statistical model and Nakagami shape parameter m have been widely used in linear tissue characterization and preliminarily characterized the envelope distributions of nonlinear encapsulated microbubbles (EMBs). However, the Nakagami distribution of nonlinear scattering EMBs lacked a systematical in...

journal_title：Medical physics

authors： Wang D,Sang Y,Zhang X,Hu H,Lu S,Zhang Y,Fu C,Cloutier G,Wan M

更新日期：2019-12-01 00:00:00

abstract：PURPOSE:To apply the recent code of practice from the IAEA/AAPM, TRS 483, to helical tomotherapy (HT) for reference and relative dosimetry obtaining correction factors for the Exradin A1SL ionization chamber. METHODS:The beam quality correction factor for the A1SL chamber was obtained through three different approache...

journal_title：Medical physics

authors： Lopes MDC,Santos T,Ventura T,Capela M

更新日期：2019-12-01 00:00:00

abstract：PURPOSE:By means of Monte Carlo (MC) simulations and indirect measurements, we have evaluated the maximum dose rates achievable with conventional x-ray tubes and related them to FLASH therapy dose rates of >40 Gy/s. METHODS:Monte Carlo models of two 160 kV x-ray tubes, the 3-kW MXR-160/22 and the 6-kW MXR-165, were bu...

journal_title：Medical physics

authors： Bazalova-Carter M,Esplen N

更新日期：2019-12-01 00:00:00

abstract：PURPOSE:The pulse line ion accelerator (PLIA) is a low-cost accelerator concept originally designed to accelerate heavy ions. Our group has been investigating the use of PLIA to accelerate light ions and believe a multi-stage PLIA could be useful for short half-life PET isotope production. The goal of this work was to ...

journal_title：Medical physics

authors： Behbahani RA,Diot Q,Kavanagh B,Serkova NJ,Miften M,Westerly DC

更新日期：2019-12-01 00:00:00

abstract：PURPOSE:To achieve more translatable preclinical research results, small animal irradiation needs to more closely simulate human radiotherapy. Although the clinical gold standard is intensity-modulated radiation therapy (IMRT), the direct translation of this method for small animals is impractical. In this study we des...

journal_title：Medical physics

authors： Woods K,Nguyen D,Neph R,Ruan D,O'Connor D,Sheng K

更新日期：2019-12-01 00:00:00

abstract：PURPOSE:To develop a method of using two-dimensional (2D) magnetic resonance thermometry, and three-dimensional (3D) Gaussian modeling to predict the volume, shape, and location of 1 day postoperative T1w high-intensity focused ultrasound lesions in medication refractory tremor patients; thereby facilitating a better c...

journal_title：Medical physics

authors： Seasons GM,Mazerolle EL,Sankar T,Martino D,Kiss ZHT,Pichardo S,Pike GB

更新日期：2019-12-01 00:00:00

abstract：PURPOSE:Accurate, patient-specific radiation dosimetry for CT scanning is critical to optimize radiation doses and balance dose against image quality. While Monte Carlo (MC) simulation is often used to estimate doses from CT, comparison of estimates to experimentally measured values is lacking for advanced CT scanners ...

journal_title：Medical physics

authors： Prinsen P,Trattner S,Wiegert J,Gerland EL,Shefer E,Morton T,Thompson CM,Cheng B,Halliburton SS,Einstein AJ

更新日期：2019-11-01 00:00:00

abstract：BACKGROUND:The rapid development and complexity of new x-ray computed tomography (CT) technologies and the need for evidence-based optimization of image quality with respect to radiation and contrast media dose call for an updated approach towards CT performance evaluation. AIMS:This report offers updated testing guid...

journal_title：Medical physics

authors： Samei E,Bakalyar D,Boedeker KL,Brady S,Fan J,Leng S,Myers KJ,Popescu LM,Ramirez Giraldo JC,Ranallo F,Solomon J,Vaishnav J,Wang J

更新日期：2019-11-01 00:00:00

abstract：PURPOSE:The automated segmentation of each lung and trachea in CT scans is commonly taken as a solved problem. Indeed, existing approaches may easily fail in the presence of some abnormalities caused by a disease, trauma, or previous surgery. For robustness, we present ALTIS (implementation is available at http://lids....

journal_title：Medical physics

authors： Sousa AM,Martins SB,Falcão AX,Reis F,Bagatin E,Irion K

更新日期：2019-11-01 00:00:00

abstract：PURPOSE:The purpose of the paper was to use a virtual phantom to identify a set of radiomic features from T1-weighted and T2-weighted magnetic resonance imaging (MRI) of the brain which is stable to variations in image acquisition parameters and to evaluate the effect of image preprocessing on radiomic features stabili...

journal_title：Medical physics

authors： Bologna M,Corino V,Mainardi L

更新日期：2019-11-01 00:00:00

abstract：PURPOSE:Respiratory motion in the chest region during single photon emission computed tomography (SPECT) is a major degrading factor that reduces the accuracy of image quantification. This effect is more notable when the tumor is very small, or the spatial resolution of the imaging system is less than the respiratory m...

journal_title：Medical physics

authors： Naseri M,Rajabi H,Wang J,Abbasi M,Kalantari F

更新日期：2019-11-01 00:00:00

abstract：PURPOSE:Positron emission tomography (PET) is an important tool for nuclear medical imaging. It has been widely used in clinical diagnosis, scientific research, and drug testing. PET is a kind of emission computed tomography. Its basic imaging principle is to use the positron annihilation radiation generated by radionu...

journal_title：Medical physics

authors： Zhang W,Gao J,Yang Y,Liang D,Liu X,Zheng H,Hu Z

更新日期：2019-11-01 00:00:00

abstract：PURPOSE:To study the relationships between dose (D), kerma (K), and collision kerma ( K col ) in photon beams and to investigate total radiative yields for electrons and positrons as a functio...

journal_title：Medical physics

authors： Rogers DWO,Townson RW

更新日期：2019-11-01 00:00:00

abstract：PURPOSE:Automated segmentation of brain structures (objects) in MR three-dimensional (3D) images for quantitative analysis has been a challenge and probabilistic atlases (PAs) are among the most well-succeeded approaches. However, the existing models do not adapt to possible object anomalies due to the presence of a di...

journal_title：Medical physics

authors： Martins SB,Bragantini J,Falcão AX,Yasuda CL

更新日期：2019-11-01 00:00:00

abstract：PURPOSE:Computed tomography (CT) and, in particular, cone beam CT (CBCT) have been increasingly used as a diagnostic tool in recent years. Patient motion during acquisition is common in CBCT due to long scan times. This results in degraded image quality and may potentially increase the number of retakes. Our aim was to...

journal_title：Medical physics

authors： Niebler S,Schömer E,Tjaden H,Schwanecke U,Schulze R

更新日期：2019-10-01 00:00:00

abstract：PURPOSE:As the predominant driver of respiratory motion, the diaphragm represents a key surrogate for motion management during the irradiation of thoracic cancers. Existing approaches to diaphragm tracking often produce phase-based estimates, suffer from lateral side failures or are not executable in real-time. In this...

journal_title：Medical physics

authors： Hindley N,Keall P,Booth J,Shieh CC

更新日期：2019-10-01 00:00:00

abstract：PURPOSE:Computational models of microwave tissue ablation are widely used to guide the development of ablation devices, and are increasingly being used for the development of treatment planning and monitoring platforms. Knowledge of temperature-dependent dielectric properties of lung tissue is essential for accurate mo...

journal_title：Medical physics

authors： Sebek J,Bortel R,Prakash P

更新日期：2019-10-01 00:00:00

abstract：PURPOSE:In the practice code of dosimetry, humidity effect is assumed to be constant as far as the measurements are performed in the relative humidity (RH) range of (20-80)%; thus, the humidity effect can be ignored with a dose uncertainty of 0.15%. This assumption is based on the previous experimental results by Niate...

journal_title：Medical physics

authors： Sato Y,Shimizu M,Morishita Y,Sato M,Hoshina M

更新日期：2019-09-01 00:00:00

abstract：PURPOSE:The advent of three-dimensional breast imaging systems such as digital breast tomosynthesis (DBT) has great promise for improving the detection and diagnosis of breast cancer. With these new technologies comes an essential need for testing methods to assess the resultant image quality. Although randomized clini...

journal_title：Medical physics

authors： Ikejimba LC,Salad J,Graff CG,Ghammraoui B,Cheng WC,Lo JY,Glick SJ

更新日期：2019-09-01 00:00:00

abstract：PURPOSE:There is an increasing interest in calculating linear energy transfer (LET) distributions for proton therapy treatments in order to assess the influence of this quantity in biological terms. Microdosimetric Monte Carlo (MC) simulations are useful tools to calculate dose-averaged LET, as this has been broadly pr...

journal_title：Medical physics

authors： Bertolet A,Baratto-Roldán A,Barbieri S,Baiocco G,Carabe A,Cortés-Giraldo MA

更新日期：2019-09-01 00:00:00

abstract：PURPOSE:Current treatment planning for 90 Y radioembolization estimates lung mean dose (LMD) by measuring the lung shunt fraction (LSF) from 99m Tc-macroaggregated albumin (MAA) planar imaging and assuming a 1-kg lung mass. This methodology, however, overestimates LSF and LMD and could therefore unnecessarily limit the...

journal_title：Medical physics

authors： Lopez B,Mahvash A,Lam MGEH,Kappadath SC

更新日期：2019-09-01 00:00:00

abstract：PURPOSE:Cardiac motion is typically not accounted for during pretreatment imaging for central lung and mediastinal tumors. However, cardiac induced tumor motion averages 5.8 mm for esophageal tumors and 3-5 mm for some lung tumors, which can result in positioning errors. Our aim is to reduce both cardiac- and respirato...

journal_title：Medical physics

authors： Reynolds T,Shieh CC,Keall PJ,O'Brien RT

更新日期：2019-09-01 00:00:00

abstract：PURPOSE:Scatter is a major factor degrading the image quality of cone beam computed tomography (CBCT). Conventional scatter correction strategies require handcrafted analytical models with ad hoc assumptions, which often leads to less accurate scatter removal. This study aims to develop an effective scatter correction ...

journal_title：Medical physics

authors： Nomura Y,Xu Q,Shirato H,Shimizu S,Xing L

更新日期：2019-07-01 00:00:00

abstract：PURPOSE:The need for four-dimensional (4D) treatment planning becomes indispensable when it comes to radiation therapy for moving tumors in the thoracic and abdominal regions. The primary purpose of this study is to combine the actual breathing trace during each individual treatment fraction with the Linac's log file i...

journal_title：Medical physics

authors： Freislederer P,von Münchow A,Kamp F,Heinz C,Gerum S,Corradini S,Söhn M,Reiner M,Roeder F,Floca R,Alber M,Belka C,Parodi K

更新日期：2019-07-01 00:00:00

abstract：PURPOSE:The complex beam delivery techniques for patient treatment using a clinical linear accelerator (linac) may result in variations in the photon spectra, which can lead to dosimetric differences in patients that cannot be accounted for by current treatment planning systems (TPSs). Therefore, precise knowledge of t...

journal_title：Medical physics

authors： Choi HJ,Park H,Yi CY,Kim BC,Shin WG,Min CH

更新日期：2019-07-01 00:00:00

abstract：PURPOSE:The limited-angle intrafractional verification (LIVE) system was developed to track tumor movement during stereotactic body radiation therapy (SBRT). However, the four-dimensional (4D) MV/kV imaging procedure results in additional radiation dose to patients. This study is to quantify imaging radiation dose from...

journal_title：Medical physics

authors： Ding GX,Zhang Y,Ren L

更新日期：2019-06-01 00:00:00

abstract：PURPOSE:Color images are visualized on medical monitors that are adjusted by a grayscale standard display function (GSDF) or γ2.2. Although the GSDF is visually displayed as a linear graded grayscale, it does not specify how color medical images should be presented. On the other hand, the usual gamma setting for color ...

journal_title：Medical physics

authors： Shibutani T,Onoguchi M,Yoneyama H,Nakajima K,Matsuo S,Bamba Y,Saito S

更新日期：2019-06-01 00:00:00

abstract：PURPOSE:Intensity-Modulated Radiation Therapy (IMRT), including its variations (including IMRT, Volumetric Arc Therapy (VMAT), and Tomotherapy), is a widely used and critically important technology for cancer treatment. It is a knowledge-intensive technology due not only to its own technical complexity, but also to the...

journal_title：Medical physics

authors： Ge Y,Wu QJ

更新日期：2019-06-01 00:00:00

abstract：PURPOSE:The fundamental nature of positron emission tomography (PET), as an event detection system, provides some flexibility for data handling, including retrospective data manipulation. The reorganization of acquisition data allows the emulation of new scans arising from identical radiotracer spatial distributions, b...

journal_title：Medical physics

authors： Schaefferkoetter J,Nai YH,Reilhac A,Townsend DW,Eriksson L,Conti M

更新日期：2019-06-01 00:00:00