Education review articles - a call for advanced courses in Medical Imaging and Radiation Oncology Physics.
PMID: 31322826 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - July 19, 2019 Category: Physics Authors: Mills M Tags: J Appl Clin Med Phys Source Type: research

Can automated treatment plans gain traction in the clinic?
Abstract Recently, there has been an increased interest in the feasibility and impact of automation within the field of medical dosimetry. While there have been many commercialized solutions for automatic treatment planning, the use of an application programming interface to achieve complete plan generation for specific treatment sites is a process only recently available for certain commercial vendors. Automatic plan generation for 20 prostate patients was achieved via a stand-alone automated planning script that accessed a knowledge-based planning solution. Differences between the auto plans and clinically treat...
Source: Journal of Applied Clinical Medical Physics - July 16, 2019 Category: Physics Authors: Amaloo C, Hayes L, Manning M, Liu H, Wiant D Tags: J Appl Clin Med Phys Source Type: research

Dosimetric impact and detectability of multi-leaf collimator positioning errors on Varian Halcyon.
Abstract The purpose of this study is to investigate the dosimetric impact of multi-leaf collimator (MLC) positioning errors on a Varian Halcyon for both random and systematic errors, and to evaluate the effectiveness of portal dosimetry quality assurance in catching clinically significant changes caused by these errors. Both random and systematic errors were purposely added to 11 physician-approved head and neck volumetric modulated arc therapy (VMAT) treatment plans, yielding a total of 99 unique plans. Plans were then delivered on a preclinical Varian Halcyon linear accelerator and the fluence was captured by a...
Source: Journal of Applied Clinical Medical Physics - July 11, 2019 Category: Physics Authors: Gay SS, Netherton TJ, Cardenas CE, Ger RB, Balter PA, Dong L, Mihailidis D, Court LE Tags: J Appl Clin Med Phys Source Type: research

Development and clinical implementation of eclipse scripting-based automated patient-specific collision avoidance software.
CONCLUSIONS: A collision detection application utilizing patient CT contours was developed and successfully clinically implemented. This application allows collisions to be detected early during the planning process, avoiding patient delays and unnecessary resource utilization if detected during delivery. PMID: 31282083 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - July 7, 2019 Category: Physics Authors: Mann TD, Ploquin NP, Gill WR, Thind KS Tags: J Appl Clin Med Phys Source Type: research

Evaluation of auto-planning in IMRT and VMAT for head and neck cancer.
Abstract PURPOSE: The purposes of this work are to (a) investigate whether the use of auto-planning and multiple iterations improves quality of head and neck (HN) radiotherapy plans; (b) determine whether delivery methods such as step-and-shoot (SS) and volumetric modulated arc therapy (VMAT) impact plan quality; (c) report on the observations of plan quality predictions of a commercial feasibility tool. MATERIALS AND METHODS: Twenty HN cases were retrospectively selected from our clinical database for this study. The first ten plans were used to test setting up planning goals and other optimization parameter...
Source: Journal of Applied Clinical Medical Physics - July 4, 2019 Category: Physics Authors: Ouyang Z, Liu Shen Z, Murray E, Kolar M, LaHurd D, Yu N, Joshi N, Koyfman S, Bzdusek K, Xia P Tags: J Appl Clin Med Phys Source Type: research

Tissue segmentation-based electron density mapping for MR-only radiotherapy treatment planning of brain using conventional T1-weighted MR images.
CONCLUSIONS: A MR-sCT generation technique was developed based on tissue segmentation and voxel-based tissue ED mapping. The generated sCT is comparable to real CT in terms of anatomical position of tissues and similarity to the ED assignment. This method provides a feasible method to generate sCT for MR-only radiotherapy treatment planning. PMID: 31257709 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - July 1, 2019 Category: Physics Authors: Yu H, Oliver M, Leszczynski K, Lee Y, Karam I, Sahgal A Tags: J Appl Clin Med Phys Source Type: research

Measurement validation of treatment planning for a MR-Linac.
Abstract PURPOSE: The magnetic field can cause a nonnegligible dosimetric effect in an MR-Linac system. This effect should be accurately accounted for by the beam models in treatment planning systems (TPS). The purpose of the study was to verify the beam model and the entire treatment planning and delivery process for a 1.5 T MR-Linac based on comprehensive dosimetric measurements and end-to-end tests. MATERIAL AND METHODS: Dosimetry measurements and end-to-end tests were performed on a preclinical MR-Linac (Elekta AB) using a multitude of detectors and were compared to the corresponding beam model calcu...
Source: Journal of Applied Clinical Medical Physics - June 29, 2019 Category: Physics Authors: Chen X, Paulson ES, Ahunbay E, Sanli A, Klawikowski S, Li XA Tags: J Appl Clin Med Phys Source Type: research

Assessment of longitudinal beam property and contrast uniformity for 256- and 320-row area detector computed tomography scanners in the 160-mm nonhelical volume-acquisition mode.
CONCLUSION: This study reveals that the radiation dose on the anode side of the x-ray tube shows approximately 40%-45% reduction compared with that on the isocenter position, and the heel effect properties for 256- and 320-row ADCT scanners longitudinally differ throughout the x-ray beam. The x-ray tube for individual ADCT scanners is mounted in an opposite direction along the long axis of the patient. PMID: 31254457 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - June 29, 2019 Category: Physics Authors: Hara T, Niwa S, Urikura A, Matsubara K, Hoshino T, Nishimaru E, Taniguchi T Tags: J Appl Clin Med Phys Source Type: research

Bleeding detection in wireless capsule endoscopy videos - Color versus texture features.
Abstract Wireless capsule endoscopy (WCE) is an effective technology that can be used to make a gastrointestinal (GI) tract diagnosis of various lesions and abnormalities. Due to a long time required to pass through the GI tract, the resulting WCE data stream contains a large number of frames which leads to a tedious job for clinical experts to perform a visual check of each and every frame of a complete patient's video footage. In this paper, an automated technique for bleeding detection based on color and texture features is proposed. The approach combines the color information which is an essential feature for ...
Source: Journal of Applied Clinical Medical Physics - June 28, 2019 Category: Physics Authors: Pogorelov K, Suman S, Azmadi Hussin F, Saeed Malik A, Ostroukhova O, Riegler M, Halvorsen P, Hooi Ho S, Goh KL Tags: J Appl Clin Med Phys Source Type: research

Physical and biological impacts of collimator-scattered protons in spot-scanning proton therapy.
Abstract To improve the penumbra of low-energy beams used in spot-scanning proton therapy, various collimation systems have been proposed and used in clinics. In this paper, focused on patient-specific brass collimators, the collimator-scattered protons' physical and biological effects were investigated. The Geant4 Monte Carlo code was used to model the collimators mounted on the scanning nozzle of the Hokkaido University Hospital. A systematic survey was performed in water phantom with various-sized rectangular targets; range (5-20 cm), spread-out Bragg peak (SOBP) (5-10 cm), and field size (2 &tim...
Source: Journal of Applied Clinical Medical Physics - June 24, 2019 Category: Physics Authors: Ueno K, Matsuura T, Hirayama S, Takao S, Ueda H, Matsuo Y, Yoshimura T, Umegaki K Tags: J Appl Clin Med Phys Source Type: research

The Medical Physicist in the balance.
PMID: 31231922 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - June 23, 2019 Category: Physics Authors: Herman MG Tags: J Appl Clin Med Phys Source Type: research

On the need for tuning the dosimetric leaf gap for stereotactic treatment plans in the Eclipse treatment planning system.
In this study, we investigated the dosimetric impact of limitations associated with the T&G modeling in stereotactic plans and its relationship with the need for tuning the DLG in the Eclipse TPS. Measurements were carried out using Varian TrueBeam STx systems from two different institutions. Test fields presenting MLC patterns with several MLC gap sizes (meanGap) and different amounts of T&G effect (TGi) were first evaluated. Secondly, dynamic conformal arc (DCA) and volumetric modulated arc therapy (VMAT) deliveries of stereotactic cases were analyzed in terms of meanGap and TGi. Two DLG values were used in the T...
Source: Journal of Applied Clinical Medical Physics - June 21, 2019 Category: Physics Authors: Vieillevigne L, Khamphan C, Saez J, Hernandez V Tags: J Appl Clin Med Phys Source Type: research

Development of twist-correction system for radiotherapy of head and neck cancer patients.
Abstract To propose a concept for correcting the twist between the head and neck and the body frequently occurring in radiotherapy patients and to develop a prototype device for achieving this. Furthermore, the operational accuracy of this device under no load was evaluated. We devised a concept for correcting the twist of patients by adjustment of the three rotation (pitch, roll, and yaw) angles in two independent plates connected by a joint (fulcrum). The two plates (head and neck plate and body plate) rotate around the fulcrum by adjusting screws under each of them. A prototype device was created to materialize...
Source: Journal of Applied Clinical Medical Physics - June 20, 2019 Category: Physics Authors: Shimizu H, Sasaki K, Aoyama T, Matsushima S, Isomura T, Fukuma H, Tachibana H, Kodaira T Tags: J Appl Clin Med Phys Source Type: research

Reliability of CT-based texture features: Phantom study.
CONCLUSION: Following large-scale validation, identification of reliable CTTA metrics can aid in conducting large-scale multicenter CTTA analysis using sample sets acquired using different imaging protocols, scanners etc. PMID: 31222919 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - June 20, 2019 Category: Physics Authors: Varghese BA, Hwang D, Cen SY, Levy J, Liu D, Lau C, Rivas M, Desai B, Goodenough DJ, Duddalwar VA Tags: J Appl Clin Med Phys Source Type: research

The irregular breathing effect on target volume and coverage for lung stereotactic body radiotherapy.
Abstract The major challenge in treating a mobile target is obtaining the temporal and spatial information imaging and treatment details. This phantom study quantitatively evaluates the geometric and dosimetric effects of various treatment techniques under different respiratory patterns. The regular motion model was a sinusoidal waveform with a longitudinal range of ±1.5 cm and a period of 4 sec, while irregular motion models were generated by extracting signals from clinical cases. Helical CT for a static target and 4D CT with retrospective sorting were acquired. Phase bin, maximum, and average i...
Source: Journal of Applied Clinical Medical Physics - June 17, 2019 Category: Physics Authors: Pan CH, Shiau AC, Li KC, Hsu SH, Liang JA Tags: J Appl Clin Med Phys Source Type: research

Characterizing mechanical and medical imaging properties of polyvinyl chloride-based tissue-mimicking materials.
Abstract Polyvinyl chloride (PVC) is a commonly used tissue-mimicking material (TMM) for phantom construction using 3D printing technology. PVC-based TMMs consist of a mixture of PVC powder and dioctyl terephthalate as a softener. In order to allow the clinical use of a PVC-based phantom use across CT and magnetic resonance imaging (MRI) imaging platforms, we evaluated the mechanical and physical imaging characteristics of ten PVC samples. The samples were made with different PVC-softener ratios to optimize phantom bioequivalence with physiologic human tissue. Phantom imaging characteristics, including computed to...
Source: Journal of Applied Clinical Medical Physics - June 17, 2019 Category: Physics Authors: He Y, Qin S, Dyer BA, Zhang H, Zhao L, Chen T, Zheng F, Sun Y, Shi L, Rong Y, Qiu J Tags: J Appl Clin Med Phys Source Type: research

Impact of patient comfort on diagnostic image quality during PET/MR exam: A quantitative survey study for clinical workflow management.
CONCLUSION: Our results show that PET/MR scanning is generally safe and comfortable for most of the patients. Statistical analysis does not support the hypothesis that bad patient's perception leads to degraded image quality. PMID: 31207077 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - June 17, 2019 Category: Physics Authors: Chen S, Hu P, Gu Y, Pang L, Zhang Z, Zhang Y, Meng X, Cao T, Liu X, Fan Z, Shi H Tags: J Appl Clin Med Phys Source Type: research

Evaluation of Elekta Agility multi-leaf collimator performance using statistical process control tools.
CONCLUSIONS: The Elekta Agility MLC model was found to perform with high stability, as evidenced by the tight control limits. The in-specification durations support the current recommendation of monthly MLC QC tests with a ±1 mm tolerance. Future work is on-going to determine if performance can be optimized further using high-frequency QC test results to drive recalibration frequency. PMID: 31199568 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - June 14, 2019 Category: Physics Authors: Meyers SM, Balderson MJ, Létourneau D Tags: J Appl Clin Med Phys Source Type: research

Radiological tissue equivalence of deformable silicone-based chemical radiation dosimeters (FlexyDos3D).
In this study we investigated its tissue-equivalence in comparison with water and Solid Water (RMI457). We found that its effective and mean atomic numbers were 40% and 20% higher and the total interaction probabilities for kV x-ray photons were larger than those of water respectively. To assess the influence of its over-response to kV photons, its HU value was measured by kV computed tomography (CT) and was found higher than all the soft-tissue substitutes. When applied for dose calculation without correction, this effect led to an 8% overestimation in electron density via HU-value mapping and 0.65% underestimation in tar...
Source: Journal of Applied Clinical Medical Physics - June 11, 2019 Category: Physics Authors: Du Y, Wang R, Wang M, Yue H, Zhang Y, Wu H, Wang W Tags: J Appl Clin Med Phys Source Type: research

Treatment of cervical cancer with electronic brachytherapy.
CONCLUSIONS: The first results of treatment with the Axxent eBT device are promising, as no recurrences have been observed and toxicity is very low. eBT is a good alternative for treating cervical cancer in centers without access to conventional HDR. PMID: 31183970 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - June 11, 2019 Category: Physics Authors: Lozares-Cordero S, Font-Gómez JA, Gandía-Martínez A, Miranda-Burgos A, Méndez-Villamón A, Villa-Gazulla D, Alba-Escorihuela V, Jiménez-Puertas S, González-Pérez V Tags: J Appl Clin Med Phys Source Type: research

Cerebrospinal fluid T1 value phantom reproduction at scan room temperature.
In this study, 1.5 and 3.0 T magnetic resonance imaging scanners were used. We examined the signal intensity change in relation to pure water temperature, the T1 values of acetone-diluted solutions (0-100 v/v%, in 10 steps), and the correlation coefficients obtained from volunteers and the prepared phantoms. The T1 value was close to the value reported in the literature for cerebrospinal fluid when the acetone-diluted solution was 70 v/v% or higher at scan room temperature. The value at that time was 3532.81-4704.57 ms at 1.5 T and it ranged from 4052.41 to 5701.61 ms at 3.0 T. The highest cor...
Source: Journal of Applied Clinical Medical Physics - June 9, 2019 Category: Physics Authors: Yamashiro A, Kobayashi M, Saito T Tags: J Appl Clin Med Phys Source Type: research

Three Discipline Collaborative Radiation Therapy (3DCRT) Special Debate: I would treat prostate cancer with proton therapy.
PMID: 31166085 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - June 5, 2019 Category: Physics Authors: Carrier F, Liao Y, Mendenhall N, Guerrieri P, Todor D, Ahmad A, Dominello M, Joiner MC, Burmeister J Tags: J Appl Clin Med Phys Source Type: research

Overranging and overbeaming measurement in area detector computed tomography: A method for simultaneous measurement in volume helical acquisition.
CONCLUSION: We devised a method to simultaneously measure overbeaming and overranging with only one helical acquisition. Although the dynamic z-collimator reduced the overranging by approximately 17%, wider collimation widths and higher pitch settings would increase the exposure dose outside the scan range. PMID: 31165567 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - June 4, 2019 Category: Physics Authors: Urikura A, Hara T, Yoshida T, Nishimaru E, Hoshino T, Nakaya Y, Endo M Tags: J Appl Clin Med Phys Source Type: research

Image quality and radiation dose in planar imaging - Image quality figure of merits from the CDRAD phantom.
CONCLUSIONS: Inverse image quality figure and h are about equally related to dose level. The FOM h, which describes the size of a hole that should be seen in the image, may be a more intuitive FOM than IQFinv . However, considering the probabilities for overlap and their confidence intervals, the FOMs deduced from the CDRAD phantom are not sensitive to dose. Hence, CDRAD may not be an optimal phantom to differentiate between images acquired at different dose levels. PMID: 31152576 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - June 1, 2019 Category: Physics Authors: Konst B, Weedon-Fekjaer H, Båth M Tags: J Appl Clin Med Phys Source Type: research

Re: Simulation analysis for tumor radiotherapy based on three-component mathematical models.
PMID: 31145529 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 30, 2019 Category: Physics Authors: Ferrall-Fairbanks MC, Glazar DJ, Brady RJ, Kimmel GJ, Zahid MU, Altrock PM, Enderling H Tags: J Appl Clin Med Phys Source Type: research

Three discipline collaborative radiation therapy (3DCRT) special debate: Equipment development is stifling innovation in radiation oncology.
PMID: 31127693 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 25, 2019 Category: Physics Authors: Kim L, Markovina S, Van Nest SJ, Eisaman S, Santanam L, Sullivan JM, Dominello M, Joiner MC, Burmeister J Tags: J Appl Clin Med Phys Source Type: research

Secondary monitor unit calculations for VMAT using parallelized Monte Carlo simulations.
Abstract We have developed a fast and accurate in-house Monte Carlo (MC) secondary monitor unit (MU) check method, based on the EGSnrc system, for independent verification of volumetric modulated arc therapy (VMAT) treatment planning system dose calculations, in accordance with TG-114 recommendations. For a VMAT treatment plan created for a Varian Trilogy linac, DICOM information was exported from Eclipse. An open-source platform was used to generate input files for dose calculations using the EGSnrc framework. The full VMAT plan simulation employed 107 histories, and was parallelized to run on a computer cluster....
Source: Journal of Applied Clinical Medical Physics - May 24, 2019 Category: Physics Authors: Bhagroo S, French SB, Mathews JA, Nazareth DP Tags: J Appl Clin Med Phys Source Type: research

Nonrigid registration of medical image based on adaptive local structure tensor and normalized mutual information.
Abstract Nonrigid registration of medical images is especially critical in clinical treatment. Mutual information is a popular similarity measure for medical image registration; however, only the intensity statistical characteristics of the global consistency of image are considered in MI, and the spatial information is ignored. In this paper, a novel intensity-based similarity measure combining normalized mutual information with spatial information for nonrigid medical image registration is proposed. The different parameters of Gaussian filtering are defined according to the regional variance, the adaptive Gaussi...
Source: Journal of Applied Clinical Medical Physics - May 23, 2019 Category: Physics Authors: Yang T, Tang Q, Li L, Song J, Zhu C, Tang L Tags: J Appl Clin Med Phys Source Type: research

Combined application of pharamcokinetic DCE-MRI and IVIM-DWI could improve detection efficiency in early diagnosis of ductal carcinoma in situ.
This study aimed to use pharamcokinetic dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) for the early diagnosis of DCIS. METHODS: Forty-seven patients, including 25 with DCIS (age: 28-70 yr, mean age: 48.7 yr) and 22 with benign disease (age: 25-67 yr, mean age: 43.1 yr) confirmed by pathology, underwent pharamcokinetic DCE-MRI and IVIM-DWI in this study. The quantitative parameters Ktrans , Kep , Ve , Vp , and D, f, D* were obtained by processing of DCE-MRI and IVIM-DWI images with Omni-Kinetics and MITK-Diffusio...
Source: Journal of Applied Clinical Medical Physics - May 23, 2019 Category: Physics Authors: Tao WJ, Zhang HX, Zhang LM, Gao F, Huang W, Liu Y, Zhu Y, Bai GJ Tags: J Appl Clin Med Phys Source Type: research

Evaluation of a commercial Monte Carlo dose calculation algorithm for electron treatment planning.
Abstract The RayStation treatment planning system implements a Monte Carlo (MC) algorithm for electron dose calculations. For a TrueBeam accelerator, beam modeling was performed for four electron energies (6, 9, 12, and 15 MeV), and the dose calculation accuracy was tested for a range of geometries. The suite of validation tests included those tests recommended by AAPM's Medical Physics Practice Guideline 5.a, but extended beyond these tests in order to validate the MC algorithm in more challenging geometries. For MPPG 5.a testing, calculation accuracy was evaluated for square cutouts of various sizes, two cu...
Source: Journal of Applied Clinical Medical Physics - May 23, 2019 Category: Physics Authors: Huang JY, Dunkerley D, Smilowitz JB Tags: J Appl Clin Med Phys Source Type: research

Comparison of pancreatic respiratory motion management with three abdominal corsets for particle radiation therapy: Case study.
CONCLUSION: Abdominal corsets may be effective devices to reduce pancreatic motion. For particle therapy, PE-based corsets are preferred over PU-based corset due to their material homogeneity and constant thickness. PMID: 31120639 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 23, 2019 Category: Physics Authors: Dolde K, Schneider S, Stefanowicz S, Alimusaj M, Flügel B, Saito N, Troost EGC, Pfaffenberger A, Hoffmann AL Tags: J Appl Clin Med Phys Source Type: research

Developing a MLC modifier program to improve fiducial detection for MV/kV imaging during hypofractionated prostate volumetric modulated arc therapy.
Abstract PURPOSE: To develop an Eclipse plug-in (MLC_MODIFIER) that automatically modifies control points to expose fiducials obscured by MLC during VMAT, thereby facilitating tracking using periodic MV/kV imaging. METHOD: Three-dimensional fiducial tracking was performed during VMAT by pairing short-arc (3°) MV digital tomosynthesis (DTS) images to triggered kV images. To evaluate MLC_MODIFIER efficacy, two cohorts of patients were considered. For first 12 patients, plans were manually edited to expose one fiducial marker. Next for 15 patients, plans were modified using MLC_MODIFIER script. MLC_MODIFIER ...
Source: Journal of Applied Clinical Medical Physics - May 22, 2019 Category: Physics Authors: Happersett L, Wang P, Zhang P, Mechalakos J, Li G, Eley E, Zelefsky M, Mageras G, Damato AL, Hunt M Tags: J Appl Clin Med Phys Source Type: research

Development of a rotational set-up correction device for stereotactic head radiation therapy: A performance evaluation.
Abstract We developed a new head supporting device to provide accurate correction of rotational setup during image-guided radiation therapy (IGRT), evaluating its correction performance and the efficacy of dose distribution in stereotactic radiotherapy (SRT) using a helical tomotherapy (HT) system. The accuracy of rotational motion was measured using an electronic inclinometer; we compared device angles and measurement values from 0.0° to 3.0°. The correction accuracy was investigated based on the distance between rotational centers in the device and on megavoltage computed tomography (MVCT); the correctio...
Source: Journal of Applied Clinical Medical Physics - May 21, 2019 Category: Physics Authors: Usui K, Isobe A, Hara N, Muroi T, Sajiki O, Ogawa K, Shikama N, Sasai K Tags: J Appl Clin Med Phys Source Type: research

MR-linac is the best modality for lung SBRT.
PMID: 31112368 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 21, 2019 Category: Physics Authors: Godley A, Zheng D, Rong Y Tags: J Appl Clin Med Phys Source Type: research

Dosimetric comparison of distal esophageal carcinoma plans for patients treated with small-spot intensity-modulated proton versus volumetric-modulated arc therapies.
CONCLUSIONS: Small-spot IMPT decreases doses to heart, liver, and total lung compared to VMAT as well as achieves clinically acceptable plan robustness. Our study supports the use of small-spot IMPT for the treatment of distal esophageal carcinoma. PMID: 31112371 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 21, 2019 Category: Physics Authors: Liu C, Bhangoo RS, Sio TT, Yu NY, Shan J, Chiang JS, Ding JX, Rule WG, Korte S, Lara P, Ding X, Bues M, Hu Y, DeWees T, Ashman JB, Liu W Tags: J Appl Clin Med Phys Source Type: research

Comparison of treatment planning approaches for spatially fractionated irradiation of deep tumors.
CONCLUSION: Our results present, for the first time, preliminary evidence comparing IMRT-GRID approaches which result in high-dose "islands" within a target, mimicking what is achieved with a conventional GRID block but without high-dose "tail" regions outside of the target. These approaches differ modestly in their ability to achieve high peak-to-edge ratios and also differ in delivery times. PMID: 31112629 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 21, 2019 Category: Physics Authors: Sheikh K, Hrinivich WT, Bell LA, Moore JA, Laub W, Viswanathan AN, Yan Y, McNutt TR, Meyer J Tags: J Appl Clin Med Phys Source Type: research

Quantitative evaluation of breast density using a dual-energy technique on a digital breast tomosynthesis system.
CONCLUSION: The dual-energy technique could be used to measure breast density with a margin of error of 
Source: Journal of Applied Clinical Medical Physics - May 20, 2019 Category: Physics Authors: Lu KM, Yeh DM, Cao BH, Lin CY, Liang CY, Zhou YB, Tsai CJ Tags: J Appl Clin Med Phys Source Type: research

The role of clinical medical physicists in the future: Quality, safety, technology implementation, and enhanced direct patient care.
PMID: 31099457 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 17, 2019 Category: Physics Authors: Wang B, White G Tags: J Appl Clin Med Phys Source Type: research

iCONE-SRS: Development of inverse treatment planning for cone-based stereotactic radiosurgery.
Abstract PURPOSE: At present, commercially available treatment planning systems (TPS) only offer manual planning functionality for cone-based stereotactic radiosurgery (SRS) leading to labor intensive treatment planning. Our objective was to reduce treatment planning time through development of a simple inverse TPS for cone-based SRS. METHODS: The iCONE TPS was developed using MATLAB (R2015a, The MathWorks Inc.) and serves as an inverse planning adjunct to a commercially available TPS. Simulated annealing is used to determine optimal table angle, gantry start and stop angles, and cone sizes for a user-defined...
Source: Journal of Applied Clinical Medical Physics - May 16, 2019 Category: Physics Authors: Lausch A, Nghiem B, Nielsen M Tags: J Appl Clin Med Phys Source Type: research

Optical surface guidance for submillimeter monitoring of patient position during frameless stereotactic radiotherapy.
CONCLUSION: Ongoing improvements in software and calibration procedures have decreased reporting of false offsets at non-zero table angles. However, the median magnitude for non-zero table angles is larger than that observed at the end of treatment, indicating that accuracy remains better when the table is not rotated. PMID: 31095866 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 16, 2019 Category: Physics Authors: Covington EL, Fiveash JB, Wu X, Brezovich I, Willey CD, Riley K, Popple RA Tags: J Appl Clin Med Phys Source Type: research

Comparison of testing of collimator and beam alignment, focal spot size with slit camera, and tube current consistency using computed radiography and conventional screen-film systems.
Abstract Conversion to a filmless technique of physical performance testing is becoming a topic of much interest to researchers. We assessed the use of a computed radiography (CR) system with postprocessing software as an alternative tool for performing the three physical performance tests of an x-ray tube. Collimator and beam alignment, focal spot size, and milliampere second (mAs) linearity, were performed using a CR system. Results were then compared with those obtained from a conventional screen-film (SF) system. The distances of collimator misalignment measured by the SF system were decreased while peak tube ...
Source: Journal of Applied Clinical Medical Physics - May 16, 2019 Category: Physics Authors: Meechai T, Chousangsuntorn K, Owasirikul W, Mongkolsuk M, Iampa W Tags: J Appl Clin Med Phys Source Type: research

In regards to Bogue J, Wan J, Lavey RS, Parsai EI. Dosimetric comparison of VMAT with integrated skin flash to 3D field-in-field tangents for left breast irradiation. Journal of applied clinical medical physics. 2019 Feb;20(2):24-9.
PMID: 31087768 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 14, 2019 Category: Physics Authors: Sarkar B, Ganesh T, Munshi A, Bansal K, Rastogi K, Tiwari S, Manikandan A, Mohanti BK Tags: J Appl Clin Med Phys Source Type: research

Transit and non-transit 3D EPID dosimetry versus detector arrays for patient specific QA.
CONCLUSION: Transit and non-transit EPID dosimetry are equivalent in dosimetric terms to conventional detector arrays for patient specific QA. Non-transit 3D EPID dosimetry can be readily used for pre-treatment patient specific QA of IMRT and VMAT, eliminating the need of phantom positioning. PMID: 31083776 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 13, 2019 Category: Physics Authors: Olaciregui-Ruiz I, Vivas-Maiques B, Kaas J, Perik T, Wittkamper F, Mijnheer B, Mans A Tags: J Appl Clin Med Phys Source Type: research

Tolerance levels of mass density for CT number calibration in photon radiation therapy.
Abstract Computed tomography (CT) data are required to calculate the dose distribution in a patient's body. Generally, there are two CT number calibration methods for commercial radiotherapy treatment planning system (RTPS), namely CT number-relative electron density calibration (CT-RED calibration) and CT number-mass density calibration (CT-MD calibration). In a previous study, the tolerance levels of CT-RED calibration were established for each tissue type. The tolerance levels were established when the relative dose error to local dose reached 2%. However, the tolerance levels of CT-MD calibration are not estab...
Source: Journal of Applied Clinical Medical Physics - May 13, 2019 Category: Physics Authors: Nakao M, Ozawa S, Yogo K, Miura H, Yamada K, Hosono F, Hayata M, Miki K, Nakashima T, Ochi Y, Kawahara D, Morimoto Y, Yoshizaki T, Nozaki H, Habara K, Nagata Y Tags: J Appl Clin Med Phys Source Type: research

Automation, regulation, and collaboration: Threats and opportunities for clinical medical physics careers in diagnostic imaging and nuclear medicine.
PMID: 31081249 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 13, 2019 Category: Physics Authors: Jordan DW, Gingold EL, Samei E Tags: J Appl Clin Med Phys Source Type: research

Evaluation of video compression methods for cone-beam computerized tomography.
CONCLUSIONS: Video compression algorithms could provide a higher compression ratio comparing to static image compression algorithm. Although the loss of CBCT image due to compression its impact on registration accuracy of patient positioning is almost negligible. Video compression method is an effective way to substantially reduce the size of CBCT images for storage. PMID: 31074197 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 9, 2019 Category: Physics Authors: Yan H, Li Y, Dai J Tags: J Appl Clin Med Phys Source Type: research

The impact of the three degrees-of-freedom fiducial marker-based setup compared to soft tissue-based setup in hypofractionated intensity-modulated radiotherapy for prostate cancer.
CONCLUSIONS: The setup accuracy of the 3DOF-FM-based setup has the potential to be interchangeable with a ST-based setup. Our data are likely to be useful in clinical practice along with the popularization of the hypofractionated IMRT in prostate cancer. PMID: 31054217 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 4, 2019 Category: Physics Authors: Tanabe S, Utsunomiya S, Abe E, Sato H, Ohta A, Sakai H, Yamada T, Kaidu M, Aoyama H Tags: J Appl Clin Med Phys Source Type: research

A new frontier of image guidance: Organs at risk avoidance with MRI-guided respiratory-gated intensity modulated radiotherapy: Technical note and report of a case.
Abstract The case of a 50-year-old man affected by a rhabdomiosarcoma metastatic lesion in the left flank Is reported. The patient was addressed to 50.4 Gy radiotherapy with concomitant chemotherapy in order to locally control the lesion. A Tri-60-Co magnetic resonance hybrid radiotherapy unit was used for treatment delivery and a respiratory gating protocol was applied for the different breathing phases (Free Breathing, Deep Inspiration Breath Hold and Final Expiration Breath Hold). Three intensity modulated radiation therapy (IMRT) plans were calculated and Final Expiration Breath Hold plan was finally selected ...
Source: Journal of Applied Clinical Medical Physics - May 4, 2019 Category: Physics Authors: Massaccesi M, Cusumano D, Boldrini L, Dinapoli N, Fionda B, Teodoli S, Azario L, Mattiucci GC, Balducci M, Cellini F, Valentini V Tags: J Appl Clin Med Phys Source Type: research

Characterization and validation of an intra-fraction motion management system for masked-based radiosurgery.
Abstract PURPOSE: Characterize the intra-fraction motion management (IFMM) system found on the Gamma Knife Icon (GKI), including spatial accuracy, latency, temporal performance, and overall effect on delivered dose. METHODS: A phantom was constructed, consisting of a three-axis translation mount, a remote motorized flipper, and a thermoplastic sphere surrounding a radiation detector. An infrared marker was placed on the translation mount secured to the flipper. The spatial accuracy of the IFMM was measured via the translation mount in all Cartesian planes. The detector was centered at the radiation focal poin...
Source: Journal of Applied Clinical Medical Physics - May 4, 2019 Category: Physics Authors: Knutson NC, Hawkins BJ, Bollinger D, Goddu SM, Kavanaugh JA, Santanam L, Mitchell TJ, Zoberi JE, Tsien C, Huang J, Robinson CG, Perkins SM, Dowling JL, Chicoine MR, Rich KM, Dunn GP, Mutic S Tags: J Appl Clin Med Phys Source Type: research

Estimation of primary radiation output for wide-beam computed tomography scanner.
CONCLUSIONS: A method for describing the in-air primary radiation output in a wide-beam CT scanner was proposed that provides a means to characterize the scatter-to-primary ratio of the CT scanner. PMID: 31050131 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 2, 2019 Category: Physics Authors: Fukuda A, Lin PP, Ichikawa N, Matsubara K Tags: J Appl Clin Med Phys Source Type: research