CARE Dose 4D combined with sinogram-affirmed iterative reconstruction improved the image quality and reduced the radiation dose in low dose CT of the small intestine.
CONCLUSIONS: Combination of CARE Dose 4D and SAFIRE is shown to decrease the radiation dose while maintaining image quality. PMID: 30508275 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - December 3, 2018 Category: Physics Authors: Wang L, Gong S, Yang J, Zhou J, Xiao J, Gu JH, Yang H, Zhu J, He B Tags: J Appl Clin Med Phys Source Type: research

Organ doses evaluation for chest computed tomography procedures with TL dosimeters: Comparison with Monte Carlo simulations.
CONCLUSIONS: The results obtained in this study measured the impact on the absorbed dose in routine chest CT by changing several scan parameters while the image quality could be potentially preserved. PMID: 30508315 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - December 3, 2018 Category: Physics Authors: Giansante L, Martins JC, Nersissian DY, Kiers KC, Kay FU, Sawamura MVY, Lee C, Gebrim EMMS, Costa PR Tags: J Appl Clin Med Phys Source Type: research

A comprehensive dosimetric study of Monte Carlo and pencil-beam algorithms on intensity-modulated proton therapy for breast cancer.
In this study, we examined 20 patients with breast cancer and systematically investigated the dosimetric impact of MC and PB algorithms on IMPT. Four plans were generated for each patient: (a) a PB plan that optimized and computed the final dose using a PB algorithm; (b) a MC-recomputed plan that recomputed the final dose of the PB plan using a MC algorithm; (c) a MC-renormalized plan that renormalized the MC-recomputed plan to restore the target coverage; and (d) a MC-optimized plan that optimized and computed the final dose using a MC algorithm. The DVH on CTVs and on organ-at-risks (OARs) from each plan were studied. Th...
Source: Journal of Applied Clinical Medical Physics - November 28, 2018 Category: Physics Authors: Liang X, Li Z, Zheng D, Bradley JA, Rutenberg M, Mendenhall N Tags: J Appl Clin Med Phys Source Type: research

Dosimetric evaluation of an atlas-based synthetic CT generation approach for MR-only radiotherapy of pelvis anatomy.
CONCLUSION: We investigated the potential of a multiatlas approach to generate synthetic CT images for the pelvis. Our results demonstrate excellent results in terms of HU value assignment compared to the original CT and dosimetric consistency. PMID: 30474353 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 26, 2018 Category: Physics Authors: Farjam R, Tyagi N, Deasy JO, Hunt MA Tags: J Appl Clin Med Phys Source Type: research

Assessment of scatter radiation dose and absorbed doses in eye lens and thyroid gland during digital breast tomosynthesis.
This study aimed to measure scattered dose and estimate organ dose during mammography under conventional (CM) and Tomo (TM) modes in a specific DBT system. Optically stimulated luminescence dosimeters (OSLDs), whose responses were corrected using a parallel-plate ionization chamber, were pasted on the surface of custom-made polymethyl methacrylate (PMMA) and RANDO phantoms to measure entrance surface air kerma (ESAK). ESAK measurements were also acquired with a 4.5-cm thick breast phantom for a standard mammogram. Organ dose conversion factors (CFD ) were determined as ratio of air kerma at a specific depth to that at the ...
Source: Journal of Applied Clinical Medical Physics - November 24, 2018 Category: Physics Authors: Chusin T, Matsubara K, Takemura A, Okubo R, Ogawa Y Tags: J Appl Clin Med Phys Source Type: research

A dosimetric analysis of a spine SBRT specific treatment planning system.
Abstract PURPOSE: The Brainlab Elements treatment planning system utilizes distinct modules for treatment planning specific to stereotactic treatment sites including single or multiple brain lesions as well as spine. This work investigates the hypothesis that an optimization tailored specifically to spine can in fact create dosimetrically superior plans to those created in more general use treatment planning systems (TPS). METHODS: Ten spine patients at our institution were replanned in Brainlab Elements, Phillips Pinnacle3 , and Elekta Monaco. The planning target volume (PTV) included the vertebral body (in ...
Source: Journal of Applied Clinical Medical Physics - November 20, 2018 Category: Physics Authors: Saenz DL, Crownover R, Stathakis S, Papanikolaou N Tags: J Appl Clin Med Phys Source Type: research

Calibration strategies for use of the nanoDot OSLD in CT applications.
Abstract Aluminum oxide based optically stimulated luminescent dosimeters (OSLD) have been recognized as a useful dosimeter for measuring CT dose, particularly for patient dose measurements. Despite the increasing use of this dosimeter, appropriate dosimeter calibration techniques have not been established in the literature; while the manufacturer offers a calibration procedure, it is known to have relatively large uncertainties. The purpose of this work was to evaluate two clinical approaches for calibrating these dosimeters for CT applications, and to determine the uncertainty associated with measurements using ...
Source: Journal of Applied Clinical Medical Physics - November 13, 2018 Category: Physics Authors: Scarboro SB, Cody D, Stingo FC, Alvarez P, Followill D, Court L, Zhang D, McNitt-Gray M, Kry SF Tags: J Appl Clin Med Phys Source Type: research

A complete workflow for utilizing Monte Carlo toolkits in clinical cases for a double-scattering proton therapy system.
Abstract The methods described in this paper allow end users to utilize Monte Carlo (MC) toolkits for patient-specific dose simulation and perform analysis and plan comparisons for double-scattering proton therapy systems. The authors aim to fill two aspects of this process previously not explicitly published. The first one addresses the modeling of field-specific components in simulation space. Patient-specific compensator and aperture models are exported from treatment planning system and converted to STL format using a combination of software tools including Matlab and Autodesk's Netfabb. They are then loaded i...
Source: Journal of Applied Clinical Medical Physics - November 13, 2018 Category: Physics Authors: Muller L, Prusator M, Ahmad S, Chen Y Tags: J Appl Clin Med Phys Source Type: research

Diffusion-weighted MRI of the lung at 3T evaluated using echo-planar-based and single-shot turbo spin-echo-based acquisition techniques for radiotherapy applications.
CONCLUSIONS: Diffusion-weighted turbo spin-echo shows better geometrical accuracy compared to DWI-EPI. Mean ADC values were similar with both acquisitions but the shape of the histograms was different based on the skewness and kurtosis values. The impact of differences in respiratory technique on ADC values requires further investigation. PMID: 30421496 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 12, 2018 Category: Physics Authors: Tyagi N, Cloutier M, Zakian K, Deasy JO, Hunt M, Rimner A Tags: J Appl Clin Med Phys Source Type: research

A study of positioning orientation effect on segmentation accuracy using convolutional neural networks for rectal cancer.
CONCLUSIONS: Orientation affects the accuracy for CTV and bladder, but has negligible effect on the femurs. The model trained from data combining both orientations performs as well as a model trained with data from the same orientation for all the organs. These observations can offer guidance on the choice of training data for accurate segmentation. PMID: 30418701 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 12, 2018 Category: Physics Authors: Men K, Boimel P, Janopaul-Naylor J, Cheng C, Zhong H, Huang M, Geng H, Fan Y, Plastaras JP, Ben-Josef E, Xiao Y Tags: J Appl Clin Med Phys Source Type: research

The effectiveness of 4DCT in children and adults: A pooled analysis.
CONCLUSIONS: Overall variability is smaller in children than in adults, indicating that respiratory motion is more regular in children than in adults. This implies that a single pretreatment 4DCT could be a good representation of daily respiratory motion in children and will be at least equally beneficial for planning purposes as it is in adults. PMID: 30414252 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 9, 2018 Category: Physics Authors: Huijskens SC, van Dijk IWEM, Visser J, Balgobind BV, Rasch CRN, Alderliesten T, Bel A Tags: J Appl Clin Med Phys Source Type: research

Steeper dose gradients resulting from reduced source to target distance-a planning system independent study.
CONCLUSION: Stereotactic treatments of spherical targets delivered at reduced SAD of 70 or 55 cm using MLC spare healthy tissue around the target at least as good as treatments at SAD 100 cm using circular collimators. The steeper beam penumbra at reduced SAD seems to be as important as perfect target conformity. The authors argue therefore that the beam penumbra width should be addressed in the stereotactic studies. PMID: 30412346 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 9, 2018 Category: Physics Authors: Bratengeier K, Holubyev K, Wegener S Tags: J Appl Clin Med Phys Source Type: research

Monte Carlo and analytic modeling of an Elekta Infinity linac with Agility MLC: Investigating the significance of accurate model parameters for small radiation fields.
CONCLUSION: Accurate modeling of the full-width-half-maximum (FWHM) of the primary photon source as well as the MLC leaf design (leaf bank rotation, etc.) is essential for accurate calculations of dose delivered by small radiation fields when using virtual source or MC models of the beam. PMID: 30408308 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 8, 2018 Category: Physics Authors: Gholampourkashi S, Cygler JE, Belec J, Vujicic M, Heath E Tags: J Appl Clin Med Phys Source Type: research

Voices for gender equity in medical physics.
PMID: 30408312 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 8, 2018 Category: Physics Authors: Pollard-Larkin JM, Paradis KC, Moran JM, Martel MK, Rong Y Tags: J Appl Clin Med Phys Source Type: research

Development and evaluation of a novel MR-compatible pelvic end-to-end phantom.
Abstract MR-only treatment planning and MR-IGRT leverage MRI's powerful soft tissue contrast for high-precision radiation therapy. However, anthropomorphic MR-compatible phantoms are currently limited. This work describes the development and evaluation of a custom-designed, modular, pelvic end-to-end (PETE) MR-compatible phantom to benchmark MR-only and MR-IGRT workflows. For construction considerations, subject data were assessed for phantom/skeletal geometry and internal organ kinematics to simulate average male pelvis anatomy. Various materials for the bone, bladder, and rectum were evaluated for utility within...
Source: Journal of Applied Clinical Medical Physics - November 8, 2018 Category: Physics Authors: Cunningham JM, Barberi EA, Miller J, Kim JP, Glide-Hurst CK Tags: J Appl Clin Med Phys Source Type: research

A dosimetric study on the use of 3D-printed customized boluses in photon therapy: A hydrogel and silica gel study.
CONCLUSIONS: Silica gel and hydrogel boluses were not only good for fit and a high level of comfort and repeatability, but also had better parameters in IMRT plans. They could replace the commercial bolus for clinical use. PMID: 30402935 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 7, 2018 Category: Physics Authors: Kong Y, Yan T, Sun Y, Qian J, Zhou G, Cai S, Tian Y Tags: J Appl Clin Med Phys Source Type: research

Assessment of beam-matched linacs quality/accuracy for interchanging SBRT or SRT patient using VMAT without replanning.
CONCLUSION: Minimal differences in beam parameters, point doses, and passing rates among three linacs proved the viability of swapping SBRT/SRT using VMAT among beam-matched linacs. The effect of plan complexity on passing rate difference among beam-matched linacs is not statistically significant. PMID: 30402983 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 7, 2018 Category: Physics Authors: Xu Z, Warrell G, Lee S, Colussi V, Zheng Y, Ellis R, Machtay M, Podder T Tags: J Appl Clin Med Phys Source Type: research

Longitudinal assessment of anchored transponder migration following lung stereotactic body radiation therapy.
CONCLUSION: No significant difference in the rates of fiducial marker retention and migration were noted when comparing patients who had anchored transponders placed into small airways and a 2:1 matched cohort of patients who had other commercially available lung fiducial markers placed. In both groups, no late or chronic toxicity appeared to be related to the implanted fiducial markers. PMID: 30387242 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 1, 2018 Category: Physics Authors: McDonald AM, Colvin T, Boggs DH, Spencer SA, Popple RA, Clayton R, Minnich D, Dobelbower MC Tags: J Appl Clin Med Phys Source Type: research

Commissioning of a respiratory gating system involving a pressure sensor in carbon-ion scanning radiotherapy.
This study reports the commissioning methodology and results of a respiratory gating system [AZ - 733 V/733 VI (Anzai Medical Co., Japan)] using a pressure sensor in carbon-ion scanning radiotherapy. Commissioning includes choosing a location and method for pressure sensor installation, delay time measurement of the system, and the final flow test. Additionally, we proposed a methodology for the determination of a threshold level of generating an on/off gate for the beam to the respiratory waveform, which is important for clinical application. Regarding the location and method for installation of the pressure sensor, ...
Source: Journal of Applied Clinical Medical Physics - November 1, 2018 Category: Physics Authors: Mizuno H, Saito O, Tajiri M, Kimura T, Kuroiwa D, Shirai T, Inaniwa T, Fukahori M, Miki K, Fukuda S Tags: J Appl Clin Med Phys Source Type: research

External dosimetry audit for quality assurance of carbon-ion radiation therapy clinical trials.
CONCLUSIONS: The audit demonstrated that the dose at a single point in the water phantom was within tolerance, but it is a big step to say that all doses are correct. In addition, this external dosimetry audit encouraged centers to improve the quality of their dosimetry systems. PMID: 30387294 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 1, 2018 Category: Physics Authors: Mizuno H, Fukumura A, Kanematsu N, Yonai S, Shirai T, Yusa K, Yanou T, Suga M, Mizota M, Minohara S, Kanai T, Kamada T Tags: J Appl Clin Med Phys Source Type: research

Re-irradiation volumetric modulated arc therapy optimization based on cumulative biologically effective dose objectives.
The objective of this note is to introduce a clinical tool that generates ideal base plan dose distributions to enable re-irradiation volumetric modulated arc therapy (VMAT) optimization based on cumulative biological effective dose objectives for specific organs at risk (OARs). The tool is demonstrated with a lung cancer case that required re-irradiation at our clinic. First, previous treatment dose is deformed onto the retreatment computed tomography (CT) using commercial software. Then, the in-house Matlab tool alters the deformed previous dose using radiobiological concepts on a voxel-by-voxel manner to generate an ide...
Source: Journal of Applied Clinical Medical Physics - October 29, 2018 Category: Physics Authors: McVicar N, Thomas S, Liu M, Carolan H, Bergman A Tags: J Appl Clin Med Phys Source Type: research

Comparison of intensity modulated radiotherapy plan optimisation methods for a 1.5 T MR-Linac.
CONCLUSION: The use of MC calculations compared to PB, for stage 1 fluence optimisation, results in increased planning time without clinical improvement in plan quality or reduction in complexity and is therefore not necessary. PMID: 30371972 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 29, 2018 Category: Physics Authors: Chuter R, van Herk M, Akhiat H, Voet P, MacKay R, Choudhury A, McWilliam A Tags: J Appl Clin Med Phys Source Type: research

Quantitative variations in texture analysis features dependent on MRI scanning parameters: A phantom model.
Abstract OBJECTIVES: To evaluate the influence of MRI scanning parameters on texture analysis features. METHODS: Publicly available data from the Reference Image Database to Evaluate Therapy Response (RIDER) project sponsored by The Cancer Imaging Archive included MRIs on a phantom comprised of 18 25-mm doped, gel-filled tubes, and 1 20-mm tube containing 0.25 mM Gd-DTPA (EuroSpinII Test Object5, Diagnostic Sonar, Ltd, West Lothian, Scotland). MRIs performed on a 1.5 T GE HD, 1.5 T Siemens Espree (VB13), or 3.0 T GE HD with TwinSpeed gradients with an eight-channel head coil included T1WIs...
Source: Journal of Applied Clinical Medical Physics - October 27, 2018 Category: Physics Authors: Buch K, Kuno H, Qureshi MM, Li B, Sakai O Tags: J Appl Clin Med Phys Source Type: research

Clinical implementation of Dosimetry Check ™ for TomoTherapy® delivery quality assurance.
CONCLUSION: We have clinically implemented DC for the DQA of TomoTherapy® -based helical IMRT treatment plans. DC carried out the accurate DQA results as performed with the conventional cheese phantom method. This new DQA system provided more information in verifying the dose delivery to patients, while simplifying the DQA process. PMID: 30354001 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 24, 2018 Category: Physics Authors: Chung E, Kwon D, Park T, Kang H, Chung Y Tags: J Appl Clin Med Phys Source Type: research

Using C-Arm X-ray images from marker insertion to confirm the gold fiducial marker identification in an MRI-only prostate radiotherapy workflow.
Abstract Prostate cancer radiotherapy workflows, solely based on magnetic resonance imaging (MRI), are now in clinical use. In these workflows, intraprostatic gold fiducial markers (GFM) show similar signal behavior as calcifications and bleeding in T2-weighted MRI-images. Accurate GFM identification in MRI-only radiotherapy workflows is therefore a major challenge. C-arm X-ray images (CkV-images), acquired at GFM implantation, could provide GFM position information and be used to confirm correct identification in T2-weighted MRI-images. This would require negligible GFM migration between implantation and MRI-imag...
Source: Journal of Applied Clinical Medical Physics - October 24, 2018 Category: Physics Authors: Gustafsson C, Persson E, Gunnlaugsson A, Olsson LE Tags: J Appl Clin Med Phys Source Type: research

Assessment of specific versus combined purpose knowledge based models in prostate radiotherapy.
Abstract Knowledge-based planning (KBP) can be used to improve plan quality, planning speed, and reduce the inter-patient plan variability. KPB may also identify and reduce systematic variations in VMAT plans, something very important in multi-institutional clinical trials. Training of a KBP library is a complex and difficult process, and models must be validated prior to their clinical use. The purpose of this work is to assess the quality of the treatment plans generated using a specific versus combined purpose model KBP library for prostate cancer. Seven KBP model libraries were created from a set of patients t...
Source: Journal of Applied Clinical Medical Physics - October 19, 2018 Category: Physics Authors: Bossart E, Duffy M, Simpson G, Abramowitz M, Pollack A, Dogan N Tags: J Appl Clin Med Phys Source Type: research

AAPM medical physics practice guideline 10.a.: Scope of practice for clinical medical physics.
Abstract The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education, and professional practice of medical physics. The AAPM has more than 8000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for the purpose of r...
Source: Journal of Applied Clinical Medical Physics - October 19, 2018 Category: Physics Authors: Clements J Tags: J Appl Clin Med Phys Source Type: research

A measurement of the attenuation of radiation from F-18 by a PET/MR scanner.
Abstract The attenuation of 511 keV photons by the structure of a PET/MR scanner was measured prior to energizing the magnet. The exposure rate from a source of fluorine-18 was measured in air and, with the source placed at the isocenter of the instrument, at various points outside of the scanner. In an arc from 45 to 135 degrees relative to the long axis of the scanner and at a distance of 1.5 m from the isocenter, the attenuation by the scanner is at least 5.6 half-value layers from the MR component alone and at least 6.6 half-value layers with the PET insert installed. This information could inform better desig...
Source: Journal of Applied Clinical Medical Physics - October 19, 2018 Category: Physics Authors: Wendt RE, Ai HA, Meier JG, Lopez BP, Fahrenholtz SJ, Mawlawi OR Tags: J Appl Clin Med Phys Source Type: research

Cone-Beam CT image contrast and attenuation-map linearity improvement (CALI) for brain stereotactic radiosurgery procedures.
n M Abstract A Contrast and Attenuation-map Linearity Improvement (CALI) framework is proposed for cone-beam CT (CBCT) images used for brain stereotactic radiosurgery (SRS). The proposed framework is tailored to improve soft tissue contrast of a new point-of-care image-guided SRS system that employs a challenging half cone beam geometry, but can be readily reproduced on any CBCT platform. CALI includes a pre- and post-processing step. In pre-processing we apply a shading and beam hardening artifact correction to the projections, and in post-processing step we correct the dome/capping artifact on reconstructed imag...
Source: Journal of Applied Clinical Medical Physics - October 19, 2018 Category: Physics Authors: Hashemi S, Huynh C, Sahgal A, Song WY, Nordström H, Eriksson M, Mainprize JG, Lee Y, Ruschin M Tags: J Appl Clin Med Phys Source Type: research

An algorithm for automated modulation transfer function measurement using an edge of a PMMA phantom: Impact of field of view on spatial resolution of CT images.
CONCLUSION: An automated MTF method was successfully developed using an edge phantom, the PMMA phantom. The method is easy to implement in a clinical environment and is not influenced by user experience. PMID: 30338920 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 19, 2018 Category: Physics Authors: Anam C, Fujibuchi T, Budi WS, Haryanto F, Dougherty G Tags: J Appl Clin Med Phys Source Type: research

Assessment of combined use of ArcCheck ® detector and portal dosimetry for delivery quality assurance of head and neck and prostate volumetric-modulated arc therapy.
CONCLUSION: The combined use of the two measurement processes did not statistically improve the detectability of technical errors compared to use of single process. PMID: 30338922 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 19, 2018 Category: Physics Authors: Moliner G, Sorro L, Verstraet R, Daviau PA, Casas M, Piron B, Dubois K, Debrigode C, Barrau C, Bons F, Greffier J Tags: J Appl Clin Med Phys Source Type: research

Medical Physics 3.0, physics for every patient.
PMID: 30338923 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 19, 2018 Category: Physics Authors: Samei E, Mills MD Tags: J Appl Clin Med Phys Source Type: research

Small-spot intensity-modulated proton therapy and volumetric-modulated arc therapies for patients with locally advanced non-small-cell lung cancer: A dosimetric comparative study.
CONCLUSIONS: Small-spot IMPT improves cord, heart, and lung sparing compared to VMAT and achieves clinically acceptable plan robustness at least for the patients included in this study with motion amplitude less than 11 mm. Our study supports the usage of IMPT to treat some lung cancer patients. PMID: 30328674 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 17, 2018 Category: Physics Authors: Liu C, Sio TT, Deng W, Shan J, Daniels TB, Rule WG, Lara PR, Korte SM, Shen J, Ding X, Schild SE, Bues M, Liu W Tags: J Appl Clin Med Phys Source Type: research

A program to train medical physicists for direct patient care responsibilities.
CONCLUSIONS: The training program that we have developed incorporates an array of established education techniques and provides a comprehensive, accessible, means of improving medical physicists' patient communication skills. PMID: 30328675 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 17, 2018 Category: Physics Authors: Brown DW, Atwood T, Moore K, MacAulay R, Murphy J, Mundt A, Pawlicki T Tags: J Appl Clin Med Phys Source Type: research

A clinical 3D/4D CBCT-based treatment dose monitoring system.
In conclusion, we have demonstrated the feasibility and effectiveness of a treatment dose verification system in our clinical setting. PMID: 30306710 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 10, 2018 Category: Physics Authors: Qin A, Gersten D, Liang J, Liu Q, Grill I, Guerrero T, Stevens C, Yan D Tags: J Appl Clin Med Phys Source Type: research

Electrometer offset current due to scattered radiation.
Abstract Relative dose measurements with small ionization chambers in combination with an electrometer placed in the treatment room ("internal electrometer") show a large dependence on the polarity used. While this was observed previously for percent depth dose curves (PDDs), the effect has not been understood or preventable. To investigate the polarity dependence of internal electrometers used in conjunction with a small-volume ionization chamber, we placed an internal electrometer at a distance of 1 m from the isocenter and exposed it to different amounts of scattered radiation by varying the fiel...
Source: Journal of Applied Clinical Medical Physics - October 9, 2018 Category: Physics Authors: Wegener S, Sauer OA Tags: J Appl Clin Med Phys Source Type: research

Occupational radiation exposure to nursing staff during cardiovascular fluoroscopic procedures: A review of the literature.
CONCLUSIONS: The review has highlighted a lack of published literature focussing on dose to nurses. There is a need for future research in this area to inform nursing staff of factors which may contribute to high occupational doses and of methods for minimizing the risk of exposure, particularly regarding the importance of utilizing radiation protective equipment. PMID: 30294978 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 8, 2018 Category: Physics Authors: Wilson-Stewart K, Shanahan M, Fontanarosa D, Davidson R Tags: J Appl Clin Med Phys Source Type: research

On the improvement of CBCT image quality for soft tissue-based SRS localization.
CONCLUSIONS: Our results indicate that optimization of the imaging protocol, and thereby an increase in the imaging dose, is warranted for improved soft-tissue visualization for intracranial SRS. PMID: 30294838 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 7, 2018 Category: Physics Authors: Mao W, Gardner SJ, Snyder KC, Wen NW, Zhong H, Li H, Jackson P, Shah M, Chetty IJ Tags: J Appl Clin Med Phys Source Type: research

Merging images with different central frequencies reduces banding artifacts in balanced steady-state free precession magnetic resonance cisternography.
CONCLUSIONS: The maximum magnitude merging of images with different central frequencies makes it possible to reduce banding artifacts on bSSFP images without the need for special pulse sequences and image processing programs. PMID: 30288917 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 5, 2018 Category: Physics Authors: Matsumoto K, Yokota H, Mukai H, Masuda Y, Uno T, Miyati T Tags: J Appl Clin Med Phys Source Type: research

GammaKnife versus VMAT radiosurgery plan quality for many brain metastases.
Abstract The purpose of this work was to compare dose distributions between two radiosurgery modalities, single-isocenter volumetric modulated arc therapy (VMAT), and GammaKnife Perfexion (GK), in the treatment of a large number (≥7) of brain metastases. Twelve patients with 103 brain metastases were analyzed. The median number of targets per patient was 8 (range: 7-14). GK plans were compared to noncoplanar VMAT plans using both 6-MV flattening filter-free (FFF) and 10-MV FFF modes. Parameters analyzed included radiation therapy oncology group conformity index (CI), 12, 6, and 3 Gy isodose volumes (V12&nb...
Source: Journal of Applied Clinical Medical Physics - October 4, 2018 Category: Physics Authors: Potrebko PS, Keller A, All S, Sejpal S, Pepe J, Saigal K, Kandula S, Sensakovic WF, Shridhar R, Poleszczuk J, Biagioli M Tags: J Appl Clin Med Phys Source Type: research

Use of a commercial ion chamber detector array for the measurement of high spatial-resolution photon beam profiles.
Abstract Linear accelerator (linac) commissioning and quality assurance measurements are time-consuming tasks that often require a water tank scanning system to acquire profile scans for full characterization of dosimetric beam properties. To increase efficiency, a method is demonstrated to acquire variable resolution, photon beam profile data using a commercially available ion chamber array (0.5 cm detector spacing). Field sizes of 2 × 2, 5 × 5, 10 × 10, and 15 × 15 cm2 were acquired at depths in solid water of dmax , 5 cm, and 10 ...
Source: Journal of Applied Clinical Medical Physics - October 4, 2018 Category: Physics Authors: Karimnia V, Belley MD, Rodgers R, Price M Tags: J Appl Clin Med Phys Source Type: research

Evaluation of offline adaptive planning techniques in image-guided brachytherapy of cervical cancer.
This study examines offline adaptive planning techniques that may reduce intrafraction uncertainties by shortening the time between the planning CT and treatment delivery. Eight patients who received EBRT followed by HDR boosts were retrospectively reviewed. A CT scan was obtained for each insertion. Four strategies were simulated: (A) plans based on the current treatment day CT; (B) plans based on the first fraction CT; (C) plans based on the CT from the immediately preceding fraction; (D) plans based on the closest anatomically matched previous CT, using all prior plans as a library. Strategies B, C, and D allow plans to...
Source: Journal of Applied Clinical Medical Physics - October 3, 2018 Category: Physics Authors: Liu H, Kinard J, Maurer J, Shang Q, Vanderstraeten C, Hayes L, Sintay B, Wiant D Tags: J Appl Clin Med Phys Source Type: research

A hybrid planning strategy for stereotactic body radiation therapy of early stage non-small-cell lung cancer.
Abstract Currently dynamic conformal arcs (DCA) and volumetric modulated arc therapy (VMAT) are two popular planning techniques to treat lung stereotactic body radiation therapy (SBRT) patients. Of the two, DCA has advantages in terms of multi-leaf collimator (MLC) motion, positioning error, and delivery efficiency. However, VMAT is often the choice when critical organ sparing becomes important. We developed a hybrid strategy to incorporate DCA component into VMAT planning, results were compared with DCA and VMAT plans. Four planning techniques were retrospectively simulated for 10 lung SBRT patients: DCA, Hybrid-...
Source: Journal of Applied Clinical Medical Physics - October 3, 2018 Category: Physics Authors: Liu H, Sintay B, Pearman K, Shang Q, Hayes L, Maurer J, Vanderstraeten C, Wiant D Tags: J Appl Clin Med Phys Source Type: research

A snapshot of medical physics practice patterns.
Abstract A large number of surveys have been sent to the medical physics community addressing many clinical topics for which the medical physicist is, or may be, responsible. Each survey provides an insight into clinical practice relevant to the medical physics community. The goal of this study was to create a summary of these surveys giving a snapshot of clinical practice patterns. Surveys used in this study were created using SurveyMonkey and distributed between February 6, 2013 and January 2, 2018 via the MEDPHYS and MEDDOS listserv groups. The format of the surveys included questions that were multiple choice ...
Source: Journal of Applied Clinical Medical Physics - October 1, 2018 Category: Physics Authors: Kisling KD, Ger RB, Netherton TJ, Cardenas CE, Owens CA, Anderson BM, Lee J, Rhee DJ, Edward SS, Gay SS, He Y, David SD, Yang J, Nitsch PL, Balter PA, Urbauer DL, Peterson CB, Court LE, Dube S Tags: J Appl Clin Med Phys Source Type: research

Clinical commissioning of a new patient positioning system, SyncTraX FX4, for intracranial stereotactic radiotherapy.
CONCLUSION: Our results demonstrate a competent performance of the SyncTraX FX4 system in terms of the localization accuracy for intracranial SRT. PMID: 30273444 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 1, 2018 Category: Physics Authors: Tanabe S, Umetsu O, Sasage T, Utsunomiya S, Kuwabara R, Kuribayashi T, Takatou H, Kawaguchi G, Aoyama H Tags: J Appl Clin Med Phys Source Type: research

Study of dosimetric properties of flattened and unflattened megavoltage x ray beam on high Z implant materials.
CONCLUSION: The dosimetric properties of x ray photon beam were studied comprehensively in the presence of high Z material like stainless steel and titanium alloy using both flattened and UF beams to understand and incorporate the findings of various parameters in clinical condition due to the variation in energy spectrum from FF to UF x ray beam. PMID: 30267468 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - September 28, 2018 Category: Physics Authors: Rajamanickam T, Muthu S, Murugan P, Pathokonda M, Senthilnathan K, Arunai Nambi Raj N, Ramesh Babu P Tags: J Appl Clin Med Phys Source Type: research

Dosimetric effects of a repositioning head frame system and treatment planning system dose calculation accuracy.
Abstract This work aims to study the effect on surface dose and dose distribution caused by the Elekta Fraxion cranial immobilization system. The effect of Fraxion inclusion in Elekta Monaco treatment planning system and its calculation accuracy is also checked. To study the dose attenuation, a cylindrical phantom was located over the Elekta Fraxion with an IBA CC13 ionization chamber placed in the central insert at the linac isocenter. Dose measurements at multiple gantry angles were performed for three open fields, 10 × 10 cm, 5 × 5 cm and other smaller 2 × 2 cm. Measured doses were compared wi...
Source: Journal of Applied Clinical Medical Physics - September 25, 2018 Category: Physics Authors: Ferrer C, Huertas C, Plaza R, Aza Z, Corredoira E Tags: J Appl Clin Med Phys Source Type: research

Implementation and operation of incident learning across a newly-created health system.
CONCLUSIONS: We have developed an ILS that identifies issues related to the entire process of care delivery in radiation oncology, as evidenced by frequent and varied reported events. By identifying a broad spectrum of issues in a department, opportunities for improvement can be identified. PMID: 30225861 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - September 17, 2018 Category: Physics Authors: Schubert L, Petit J, Vinogradskiy Y, Peters R, Towery J, Stump B, Westerly D, Ridings J, Kneeland P, Liu A Tags: J Appl Clin Med Phys Source Type: research

Development of a dedicated phantom for multi-target single-isocentre stereotactic radiosurgery end to end testing.
CONCLUSION: A novel, versatile and cost-effective phantom for comprehensive E2E testing of MTSI SRS treatments was developed, incorporating multiple detector types and fiducial markers. The phantom is capable of quantifying the accuracy of each step in the MTSI SRS planning and treatment process. PMID: 30221462 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - September 16, 2018 Category: Physics Authors: Poder J, Brown R, Porter H, Gupta R, Ralston A Tags: J Appl Clin Med Phys Source Type: research

Partially ablative radiotherapy (PAR) for large mass tumors using simultaneous integrated boost: A dose-escalation feasibility study.
CONCLUSION: A modified SIB technique is dosimetrically feasible for large tumors, where doses higher than the tolerance dose of healthy tissues are necessary to increase the therapeutic gain. PMID: 30220111 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - September 15, 2018 Category: Physics Authors: Cilla S, Deodato F, Ianiro A, Macchia G, Picardi V, Buwenge M, Cammelli S, Zamagni A, Valentini V, Morganti AG Tags: J Appl Clin Med Phys Source Type: research