The Dark Side of the MedPhys Match.
PMID: 28857496 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 30, 2017 Category: Physics Authors: Antolak JA, Solberg TD Tags: J Appl Clin Med Phys Source Type: research

J Appl Clin Med Phys; +146 new citations
146 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results: J Appl Clin Med Phys These pubmed results were generated on 2017/08/23PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites. (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 24, 2017 Category: Physics Tags: Report Source Type: research

IMRT QA using machine learning: A multi-institutional validation.
CONCLUSIONS: We have demonstrated that Virtual IMRT QA can predict passing rates using different measurement techniques and across multiple institutions. Prediction of QA passing rates can have profound implications on the current IMRT process. PMID: 28815994 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 17, 2017 Category: Physics Authors: Valdes G, Chan MF, Lim SB, Scheuermann R, Deasy JO, Solberg TD Tags: J Appl Clin Med Phys Source Type: research

Improved electron collimation system design for Elekta linear accelerators.
Abstract Prototype 10 × 10 and 20 × 20-cm(2) electron collimators were designed for the Elekta Infinity accelerator (MLCi2 treatment head), with the goal of reducing the trimmer weight of excessively heavy current applicators while maintaining acceptable beam flatness (±3% major axes, ±4% diagonals) and IEC leakage dose. Prototype applicators were designed initially using tungsten trimmers of constant thickness (1% electron transmission) and cross-sections with inner and outer edges positioned at 95% and 2% off-axis ratios (OARs), respectively, cast by the upstream collimating component. ...
Source: Journal of Applied Clinical Medical Physics - August 12, 2017 Category: Physics Authors: Pitcher GM, Hogstrom KR, Carver RL Tags: J Appl Clin Med Phys Source Type: research

Characterization of a novel scale maille contralateral breast shield: SMART Armor.
Abstract During breast radiotherapy treatment, the contralateral breast receives radiation doses to the skin and subcutaneous tissue caused mainly from incident electron contamination and low energy photon scatter radiation. Measurements have shown that for a typical hybrid tangential treatment, these dose levels can be up to 17% of maximum applied prescription dose if no shielding is used during the treatment process. This work examined the use of different shielding metals, aluminum, copper, and lead to reduce peripheral radiation dose to evaluate the optimal metal to form the basis of a contralateral breast rad...
Source: Journal of Applied Clinical Medical Physics - August 11, 2017 Category: Physics Authors: Butson M, Carroll S, Butson M, Hill R Tags: J Appl Clin Med Phys Source Type: research

Sensitivity of array detector measurements in determining shifts of MLC leaf positions.
In conclusion, if more than 2 mm MLC leaf shifts were required, the commercial detector array (MatriXX) is able to detect such MLC positioning shifts, otherwise a more sensitive quality assurance method should be used. PMID: 28799273 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 11, 2017 Category: Physics Authors: Shang Q, Godley A, Huang L, Qi P, Xia P Tags: J Appl Clin Med Phys Source Type: research

Fetal dose conversion factor for fetal computed tomography examinations: A mathematical phantom study.
This study aimed to examine the relationship between fetal dose and the dose-length product, and to evaluate the impact of the number of rotations on the fetal doses and maternal effective doses using a 320-row multidetector computed tomography unit in a wide-volume mode. The radiation doses for the pregnant woman and the fetus were estimated using ImPACT CT Patient Dosimetry Calculator software for scan lengths ranging from 176 to 352 mm, using a 320-row unit in a wide-volume mode and an 80-row unit in a helical scanning mode. In the 320-row unit, the fetal doses in all scan lengths ranged from 3.51 to 6.52 mGy;...
Source: Journal of Applied Clinical Medical Physics - August 11, 2017 Category: Physics Authors: Matsunaga Y, Kawaguchi A, Kobayashi M, Suzuki S, Asada Y, Ito K, Chida K Tags: J Appl Clin Med Phys Source Type: research

Beam focal spot position: The forgotten linac QA parameter. An EPID-based phantomless method for routine Stereotactic linac QA.
In this study a novel, phantomless method has been developed using the EPID (Electronic Portal Imaging Device) that utilizes the different heights of the MLC and jaws. The method has been performed on four linear accelerators and benchmarked against an alternate ion chamber-based method. The method has been found to be reproducible to within ±0.012 mm (1 SD) and in agreement with the ion chamber-based method to within 0.001 ± 0.015 mm (1 SD). The method could easily be incorporated into a departmental routine linac QA (Quality Assurance) program. PMID: 28786168 [PubMed - as supplied by publisher] (Source...
Source: Journal of Applied Clinical Medical Physics - August 8, 2017 Category: Physics Authors: Chojnowski JM, Barnes MP, Sykes JR, Thwaites DI Tags: J Appl Clin Med Phys Source Type: research

Robust optimization of VMAT for lung cancer: Dosimetric implications of motion compensation techniques.
Abstract In inverse planning of lung radiotherapy, techniques are required to ensure dose coverage of target disease in the presence of tumor motion as a result of respiration. A range of published techniques for mitigating motion effects were compared for dose stability across 5 breath cycles of ±2 cm. Techniques included planning target volume (PTV) expansions, internal target volumes with (OITV) and without tissue override (ITV), average dataset scans (ADS), and mini-max robust optimization. Volumetric arc therapy plans were created on a thorax phantom and verified with chamber and film measurements. Dos...
Source: Journal of Applied Clinical Medical Physics - August 8, 2017 Category: Physics Authors: Archibald-Heeren BR, Byrne MV, Hu Y, Cai M, Wang Y Tags: J Appl Clin Med Phys Source Type: research

Submillimeter alignment of more than three contiguous vertebrae in spinal SRS/SBRT with 6-degree couch.
In conclusion, 6D couch integrated with image guidance is convenient and accurately corrects small rotational shifts. Consequently, more than three contiguous vertebrae can be aligned within 1 mm with immobilization that reliably reproduces the curvature of the thoracic and lumbar spinal column. Ability of accurate setup is becoming less a concern in limiting the use of stereotactic radiosurgery or stereotactic body radiation therapy to treat multilevel spinal target. PMID: 28786235 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 8, 2017 Category: Physics Authors: Wang X, Zhao Z, Luo D, Yang JN, Yang J, Chang EL, Brown PD, Li J, McAleer MF, Ghia AJ Tags: J Appl Clin Med Phys Source Type: research

AAPM-RSS Medical Physics Practice Guideline 9.a. for SRS-SBRT.
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 8,000 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 revision or ren...
Source: Journal of Applied Clinical Medical Physics - August 8, 2017 Category: Physics Authors: Halvorsen PH, Cirino E, Das IJ, Garrett JA, Yang J, Yin FF, Fairobent LA Tags: J Appl Clin Med Phys Source Type: research

Comparison of AAPM Addendum to TG-51, IAEA TRS-398, and JSMP 12: Calibration of photon beams in water.
This study was performed using measurements with flattened photon beams with nominal energies of 6 and 10 MV. Three widely used ionization chambers with different compositions, Exradin A12, PTW 30013, and IBA FC65-P, were employed. Fully corrected charge readings obtained for the three chambers according to AAPM TG-51 and the Addendum to TG-51, which included the correction for the radiation beam profile (Prp ), showed variations of 0.2% and 0.3% at 6 and 10 MV, respectively, from the readings corresponding to IAEA TRS-398 and JSMP 12. The values for the beam quality conversion factor kQ obtained according to the three pro...
Source: Journal of Applied Clinical Medical Physics - August 3, 2017 Category: Physics Authors: Kinoshita N, Oguchi H, Nishimoto Y, Adachi T, Shioura H, Kimura H, Doi K Tags: J Appl Clin Med Phys Source Type: research

Dosimetric and radiobiological comparison for quality assurance of IMRT and VMAT plans.
CONCLUSION: A ≥90% gamma passing criterion at 3%/3 mm cannot assure the radiobiological equivalence between planned and delivered dose. These results agree with the published literature demonstrating the inadequacy of the criterion for dosimetric QA and suggest for a tighter tolerance. PMID: 28771941 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 3, 2017 Category: Physics Authors: Paudel NR, Narayanasamy G, Han EY, Penagaricano J, Mavroidis P, Zhang X, Pyakuryal A, Kim D, Liang X, Morrill S Tags: J Appl Clin Med Phys Source Type: research

Do we need a new CT scan for retreatment of intracranial SRS patients?
CONCLUSIONS: The rMR can be aligned to the iCT to accurately define targets. The skull shows minimal change between scans so the iCT can be used for set-up at repeat treatments. The dosimetry provided by the iCT dose calculation is adequate for repeat SRS. Treatment based on iCT is feasible. PMID: 28771971 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 3, 2017 Category: Physics Authors: Wiant D, Manning M, Koch K, Maurer J, Hayes L, Liu H, Shang Q, Sintay B Tags: J Appl Clin Med Phys Source Type: research

Technical note: No increase in effective dose from half compared to full rotation pelvis cone beam CT.
CONCLUSION: The half compared to the full rotation CBCT displays a smaller field-of-view in a transversal slice and no significant difference in the effective dose. Hence, the full rotation CBCT is favorable compared to the half rotation CBCT. However, by using the half rotation protocol, critical volumes in the patient can be spared compared to the full rotation protocol. PMID: 28766828 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 2, 2017 Category: Physics Authors: Hauri P, Hälg RA, Schneider U Tags: J Appl Clin Med Phys Source Type: research

Technical note: TROG 15.01 SPARK trial multi-institutional imaging dose measurement.
CONCLUSIONS: All machines measured agreed to within 20%. Additional dose to the prostate from using KIM is at most 1.3% of the prescribed dose of 36.25 Gy in five fractions delivered during the trial. PMID: 28766904 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 2, 2017 Category: Physics Authors: Legge K, Greer PB, Keall PJ, Booth JT, Arumugam S, Moodie T, Nguyen DT, Martin J, O'Connor DJ, Lehmann J Tags: J Appl Clin Med Phys Source Type: research

Monitoring deep inspiration breath hold for left-sided localized breast cancer radiotherapy with an in-house developed laser distance meter system.
This study aims at evaluating an in-house developed DIBH system. Free-breathing (FB) and DIBH plans were generated for 22 left-sided localized breast cancer patients who had radiation therapy (RT) after breast-conserving surgery. All patients were treated utilizing an in-house laser distance measuring system. 50 Gy was prescribed, and parameters of interest were target coverage, left anterior descending coronary artery, (LAD) and heart doses. Portal images were acquired and the reproducibility and stability of DIBH treatment were compared to FB. The comparing result shows there is a significant reduction in all LAD an...
Source: Journal of Applied Clinical Medical Physics - July 29, 2017 Category: Physics Authors: Jensen CA, Abramova T, Frengen J, Lund JÅ Tags: J Appl Clin Med Phys Source Type: research

Quality assurance in proton beam therapy using a plastic scintillator and a commercially available digital camera.
CONCLUSIONS: This approach offers an effective way to correct for quenching, and could provide a method for rapid, convenient, routine quality assurance for clinical proton beams. Furthermore, the system has the advantage of providing 2D visualization of individual radiation fields, with potential application for quality assurance of complex, time-varying fields. PMID: 28755419 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - July 29, 2017 Category: Physics Authors: Almurayshid M, Helo Y, Kacperek A, Griffiths J, Hebden J, Gibson A Tags: J Appl Clin Med Phys Source Type: research

Dose comparison between Gafchromic film, XiO, and Monaco treatment planning systems in a novel pelvic phantom that contains a titanium hip prosthesis.
This study systematically investigates the perturbation effects of unilateral titanium prosthesis on 6 and 15 MV photon beam dose distributions using Gafchromic EBT2 film measurements in a novel pelvic phantom made out of a stack of nylon slices. Comparisons were also made between the film data and dose calculations made on XiO and Monaco treatment planning systems. The collapsed cone algorithm was chosen for the XiO and the Monte Carlo algorithm used on Monaco is XVMC. Transmission measurements were taken using a narrow-beam geometry to determine the mass attenuation coefficient of nylon = 0.0458 cm(2) /g and for a water-...
Source: Journal of Applied Clinical Medical Physics - July 25, 2017 Category: Physics Authors: Ade N, du Plessis FCP Tags: J Appl Clin Med Phys Source Type: research

Therapeutic analysis of Intrabeam-based intraoperative radiation therapy in the treatment of unicentric breast cancer lesions utilizing a spherical target volume model.
In conclusion, IB-IORT can provide a possible therapeutic advantage on sparing more normal tissue compared with the External Beam IORT (EB-IORT) for shallowly populated unicentric breast lesion. Our data suggest that IB-IORT dose size should be adjusted based on the individual patient's cancer cell infiltrating distance for delivering an effective dose, one dose-fits-all regimen may have undertreated some patients with large cancer infiltrating distance. PMID: 28741896 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - July 25, 2017 Category: Physics Authors: Schwid M, Donnelly ED, Zhang H Tags: J Appl Clin Med Phys Source Type: research

Effects of collimator angle, couch angle, and starting phase on motion-tracking dynamic conformal arc therapy (4D DCAT).
CONCLUSIONS: By selecting collimator angle, couch angle, and starting tracking phase, 4D DCAT plans with the maximal PPS demonstrated less MLC leaf position errors, lower maximal MLC leaf speed, and shorter beam-on time which improved the performance of 4D motion-tracking DCAT delivery. PMID: 28730652 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - July 21, 2017 Category: Physics Authors: Xu Z, Yao R, Podgorsak MB, Wang IZ Tags: J Appl Clin Med Phys Source Type: research

Statistical process control and verifying positional accuracy of a cobra motion couch using step-wedge quality assurance tool.
This study utilizes process control techniques to identify action limits for TomoTherapy couch positioning quality assurance tests. A test was introduced to monitor accuracy of the applied couch offset detection in the TomoTherapy Hi-Art treatment system using the TQA "Step-Wedge Helical" module and MVCT detector. Individual X-charts, process capability (cp), probability (P), and acceptability (cpk) indices were used to monitor a 4-year couch IEC offset data to detect systematic and random errors in the couch positional accuracy for different action levels. Process capability tests were also performed on the retr...
Source: Journal of Applied Clinical Medical Physics - July 21, 2017 Category: Physics Authors: Binny D, Lancaster CM, Trapp JV, Crowe SB Tags: J Appl Clin Med Phys Source Type: research

Technical Note: Using k-means clustering to determine the number and position of isocenters in MLC-based multiple target intracranial radiosurgery.
Abstract PURPOSE: To present the k-means clustering algorithm as a tool to address treatment planning considerations characteristic of stereotactic radiosurgery using a single isocenter for multiple targets. METHODS: For 30 patients treated with stereotactic radiosurgery for multiple brain metastases, the geometric centroids and radii of each met were determined from the treatment planning system. In-house software used this as well as weighted and unweighted versions of the k-means clustering algorithm to group the targets to be treated with a single isocenter, and to position each isocenter. The algorithm r...
Source: Journal of Applied Clinical Medical Physics - July 20, 2017 Category: Physics Authors: Yock AD, Kim GY Tags: J Appl Clin Med Phys Source Type: research

Adapting VMAT plans optimized for an HD120 MLC for delivery with a Millennium MLC.
We present the dosimetric results of our adaptation method for head-and-neck, brain, lung, and prostate VMAT plans. The delivery of the adapted plans was verified using standard phantom measurements. PMID: 28727285 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - July 20, 2017 Category: Physics Authors: French SB, Bhagroo S, Nazareth DP, Podgorsak MB Tags: J Appl Clin Med Phys Source Type: research

Initial testing of a pixelated silicon detector prototype in proton therapy.
Abstract As technology continues to develop, external beam radiation therapy is being employed, with increased conformity, to treat smaller targets. As this occurs, the dosimetry methods and tools employed to quantify these fields for treatment also have to evolve to provide increased spatial resolution. The team at the University of Wollongong has developed a pixelated silicon detector prototype known as the dose magnifying glass (DMG) for real-time small-field metrology. This device has been tested in photon fields and IMRT. The purpose of this work was to conduct the initial performance tests with proton radiat...
Source: Journal of Applied Clinical Medical Physics - July 18, 2017 Category: Physics Authors: Wroe AJ, McAuley G, Teran AV, Wong J, Petasecca M, Lerch M, Slater JM, Rozenfeld AB Tags: J Appl Clin Med Phys Source Type: research

Re: Effect of beam profile measurement on arc therapy plan quality assurance: A case study.
PMID: 28707776 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - July 14, 2017 Category: Physics Authors: Kim LH, Juneja B Tags: J Appl Clin Med Phys Source Type: research

A novel and independent method for time-resolved gantry angle quality assurance for VMAT.
Abstract Volumetric-modulated arc therapy (VMAT) treatment delivery requires three key dynamic components; gantry rotation, dose rate modulation, and multi-leaf collimator motion, which are all simultaneously varied during the delivery. Misalignment of the gantry angle can potentially affect clinical outcome due to the steep dose gradients and complex MLC shapes involved. It is essential to develop independent gantry angle quality assurance (QA) appropriate to VMAT that can be performed simultaneously with other key VMAT QA testing. In this work, a simple and inexpensive fully independent gantry angle measurement ...
Source: Journal of Applied Clinical Medical Physics - July 13, 2017 Category: Physics Authors: Fuangrod T, Greer PB, Zwan BJ, Barnes MP, Lehmann J Tags: J Appl Clin Med Phys Source Type: research

Feasibility of CBCT-based dose with a patient-specific stepwise HU-to-density curve to determine time of replanning.
Abstract PURPOSE: (a) To investigate the accuracy of cone-beam computed tomography (CBCT)-derived dose distributions relative to fanbeam-based simulation CT-derived dose distributions; and (b) to study the feasibility of CBCT dosimetry for guiding the appropriateness of replanning. METHODS AND MATERIALS: Image data corresponding to 40 patients (10 head and neck [HN], 10 lung, 10 pancreas, 10 pelvis) who underwent radiation therapy were randomly selected. Each patient had both intensity-modulated radiation therapy and volumetric-modulated arc therapy plans; these 80 plans were subsequently recomputed on the CB...
Source: Journal of Applied Clinical Medical Physics - July 13, 2017 Category: Physics Authors: Chen S, Le Q, Mutaf Y, Lu W, Nichols EM, Yi BY, Leven T, Prado KL, D'Souza WD Tags: J Appl Clin Med Phys Source Type: research

Comparison between electromagnetic transponders and radiographic imaging for prostate localization: A pelvic phantom study with rotations and translations.
Abstract The aim of this study was to evaluate the differences in target localization between Calypso(®) , kV orthogonal imaging and cone-beam computed tomography (CBCT) for combined translations and rotations of an anthropomorphic pelvic phantom. The phantom was localized using all three systems in 50 different positions, with applied translational and rotational offsets randomly sampled from representative normal distributions of prostate motion. Lin's concordance correlation coefficient (ρc) and 95% confidence intervals were calculated to assess the agreement between the localization systems. Mean diffe...
Source: Journal of Applied Clinical Medical Physics - July 12, 2017 Category: Physics Authors: Hamilton DG, McKenzie DP, Perkins AE Tags: J Appl Clin Med Phys Source Type: research

Clinical usefulness of MLCs in robotic radiosurgery systems for prostate SBRT.
The objective of this study was to assess the clinical usefulness of MLCs in prostate SBRT by comparing the effectiveness of treatment plans using fixed collimators, variable collimators, and MLCs and by ensuring delivery quality assurance (DQA) for each. For each patient who underwent conventional radiation therapy for localized prostate cancer, mock SBRT plans were created using a fixed collimator, a variable collimator, and an MLC. The total MUs, treatment times, and dose-volume histograms of the planning target volumes and organs at risk for each treatment plan were compared. For DQA, a phantom with a radiochromic film...
Source: Journal of Applied Clinical Medical Physics - July 10, 2017 Category: Physics Authors: Tomida M, Kamomae T, Suzuki J, Ohashi Y, Itoh Y, Oguchi H, Okuda T Tags: J Appl Clin Med Phys Source Type: research

Efficacy of robust optimization plan with partial-arc VMAT for photon volumetric-modulated arc therapy: A phantom study.
This study investigated position dependence in planning target volume (PTV)-based and robust optimization plans using full-arc and partial-arc volumetric modulated arc therapy (VMAT). The gantry angles at the periphery, intermediate, and center CTV positions were 181°-180° (full-arc VMAT) and 181°-360° (partial-arc VMAT). A PTV-based optimization plan was defined by 5 mm margin expansion of the CTV to a PTV volume, on which the dose constraints were applied. The robust optimization plan consisted of a directly optimized dose to the CTV under a maximum-uncertainties setup of 5 mm. The prescription dose was n...
Source: Journal of Applied Clinical Medical Physics - July 10, 2017 Category: Physics Authors: Miura H, Ozawa S, Nagata Y Tags: J Appl Clin Med Phys Source Type: research

Mixed integer programming with dose-volume constraints in intensity-modulated proton therapy.
CONCLUSIONS: The treatment plans from our MIP model with dose-volume constraints can meet all dose-volume constraints for OARs and targets without any tedious trial-and-error process. This model has the potential to automatically generate IMPT plans with consistent plan quality among different treatment planners and across institutions and better protection for important parallel OARs in an effective way. PMID: 28681976 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - July 6, 2017 Category: Physics Authors: Zhang P, Fan N, Shan J, Schild SE, Bues M, Liu W Tags: J Appl Clin Med Phys Source Type: research

"Evaluation of a combined respiratory-gating system comprising the TrueBeam linear accelerator and a new real-time tumor-tracking radiotherapy system: A preliminary study" [JACMP, 17(4), 2016].
"Evaluation of a combined respiratory-gating system comprising the TrueBeam linear accelerator and a new real-time tumor-tracking radiotherapy system: A preliminary study" [JACMP, 17(4), 2016]. J Appl Clin Med Phys. 2017 Jul;18(4):238 Authors: Shiinoki T, Kawamura S, Uehara T, Yuasa Y, Fujimoto K, Koike M, Sera T, Emoto Y, Hanazawa H, Shibuya K PMID: 28681447 [PubMed - in process] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - July 1, 2017 Category: Physics Authors: Shiinoki T, Kawamura S, Uehara T, Yuasa Y, Fujimoto K, Koike M, Sera T, Emoto Y, Hanazawa H, Shibuya K Tags: J Appl Clin Med Phys Source Type: research

An analysis of the ArcCHECK-MR diode array's performance for ViewRay quality assurance.
Abstract The ArcCHECK-MR diode array utilizes a correction system with a virtual inclinometer to correct the angular response dependencies of the diodes. However, this correction system cannot be applied to measurements on the ViewRay MR-IGRT system due to the virtual inclinometer's incompatibility with the ViewRay's multiple simultaneous beams. Additionally, the ArcCHECK's current correction factors were determined without magnetic field effects taken into account. In the course of performing ViewRay IMRT quality assurance with the ArcCHECK, measurements were observed to be consistently higher than the ViewRay TP...
Source: Journal of Applied Clinical Medical Physics - July 1, 2017 Category: Physics Authors: Ellefson ST, Culberson WS, Bednarz BP, DeWerd LA, Bayouth JE Tags: J Appl Clin Med Phys Source Type: research

Proposed changes to the American Association of Physicists in Medicine governance.
PMID: 28681449 [PubMed - in process] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - July 1, 2017 Category: Physics Authors: Pawlicki T, Ayers RG, Brock KK, Clements JB, Curran BH, Dobbins JT, Samei E, Adams E, Martin MC, Schober L Tags: J Appl Clin Med Phys Source Type: research

"The optimization of superficial planning target volumes (PTVs) with helical tomotherapy". [JACMP, 15 (6), 2014].
"The optimization of superficial planning target volumes (PTVs) with helical tomotherapy". [JACMP, 15 (6), 2014]. J Appl Clin Med Phys. 2017 Jul;18(4):237 Authors: Ashburner M, Tudor GS PMID: 28681450 [PubMed - in process] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - July 1, 2017 Category: Physics Authors: Ashburner M, Tudor GS Tags: J Appl Clin Med Phys Source Type: research

Estimation of lung tumor position from multiple anatomical features on 4D-CT using multiple regression analysis.
Abstract To estimate the lung tumor position from multiple anatomical features on four-dimensional computed tomography (4D-CT) data sets using single regression analysis (SRA) and multiple regression analysis (MRA) approach and evaluate an impact of the approach on internal target volume (ITV) for stereotactic body radiotherapy (SBRT) of the lung. Eleven consecutive lung cancer patients (12 cases) underwent 4D-CT scanning. The three-dimensional (3D) lung tumor motion exceeded 5 mm. The 3D tumor position and anatomical features, including lung volume, diaphragm, abdominal wall, and chest wall positions, were measur...
Source: Journal of Applied Clinical Medical Physics - June 29, 2017 Category: Physics Authors: Ono T, Nakamura M, Hirose Y, Kitsuda K, Ono Y, Ishigaki T, Hiraoka M Tags: J Appl Clin Med Phys Source Type: research

Impacts of lung and tumor volumes on lung dosimetry for nonsmall cell lung cancer.
Abstract The purpose of this study was to determine the impacts of lung and tumor volumes on normal lung dosimetry in three-dimensional conformal radiotherapy (3DCRT), step-and-shoot intensity-modulated radiotherapy (ssIMRT), and single full-arc volumetric-modulated arc therapy (VMAT) in treatment of nonsmall cell lung cancers (NSCLC). All plans were designed to deliver a total dose of 66 Gy in 33 fractions to PTV for the 32 NSCLC patients with various total (bilateral) lung volumes, planning target volumes (PTVs), and PTV locations. The ratio of the lung volume (total lung volume excluding the PTV volume) to the ...
Source: Journal of Applied Clinical Medical Physics - June 28, 2017 Category: Physics Authors: Lei W, Jia J, Cao R, Song J, Hu L Tags: J Appl Clin Med Phys Source Type: research

Estimation of the shielding ability of a tungsten functional paper for diagnostic x-rays and gamma rays.
Abstract Tungsten functional paper (TFP) is a novel paper-based radiation-shielding material. We measured the shielding ability of TFP against x-rays and gamma rays. The TFP was supplied in 0.3-mm-thick sheets that contained 80% tungsten powder and 20% cellulose (C6 H10 O5 ) by mass. In dose measurements for x-rays (60, 80, 100, and 120 kVp), we measured doses after through 1, 2, 3, 5, 10, and 12 TFP sheets, as well as 0.3 and 0.5 mm of lead. In lead equivalence measurements, we measured doses after through 2 and 10 TFP sheets for x-rays (100 and 150 kVp), and 0, 7, 10, 20, and 30 TFP sheets for gamma rays from ce...
Source: Journal of Applied Clinical Medical Physics - June 28, 2017 Category: Physics Authors: Monzen H, Kanno I, Fujimoto T, Hiraoka M Tags: J Appl Clin Med Phys Source Type: research

Potential benefits of crawl position for prone radiation therapy in breast cancer.
CONCLUSIONS: Radiation therapy for breast and regional lymph nodes in crawl position is feasible. Good comfort and set-up precision were demonstrated. Planning results support the hypothesis that breast and regional lymph nodes can be treated in crawl position with less dose to organs at risk and equal or better dose distribution in the target volumes than in supine position. The crawl technique is a candidate methodology for further investigation for patients requiring breast and regional lymph node irradiation. PMID: 28649708 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - June 26, 2017 Category: Physics Authors: Boute B, De Neve W, Speleers B, Van Greveling A, Monten C, Van Hoof T, Van de Velde J, Paelinck L, De Gersem W, Vercauteren T, Detand J, Veldeman L Tags: J Appl Clin Med Phys Source Type: research

Comparison of DVH-based plan verification methods for VMAT: ArcCHECK-3DVH system and dynalog-based dose reconstruction.
Abstract The purpose of this study was comparing dose-volume histogram (DVH)-based plan verification methods for volumetric modulated arc therapy (VMAT) pretreatment QA. We evaluated two 3D dose reconstruction systems: ArcCHECK-3DVH system (Sun Nuclear corp.) and Varian dynalog-based dose reconstruction (DBDR) system, developed in-house. Fifteen prostate cancer patients (67.6 Gy/26 Fr), four head and neck cancer patient (66 Gy/33 Fr), and four esophagus cancer patients (60 Gy/30 Fr) treated with VMAT were studied. First, ArcCHECK measurement was performed on all plans; simultaneously, the Varian dyn...
Source: Journal of Applied Clinical Medical Physics - June 26, 2017 Category: Physics Authors: Saito M, Kadoya N, Sato K, Ito K, Dobashi S, Takeda K, Onishi H, Jingu K Tags: J Appl Clin Med Phys Source Type: research

The more IGRT systems, the merrier?
PMID: 28649749 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - June 26, 2017 Category: Physics Authors: Sun B, Chang J, Rong Y Tags: J Appl Clin Med Phys Source Type: research

Development of the breast immobilization system in prone setup: The effect of bra in prone position to improve the breast setup error.
CONCLUSION: The use of an immobilizing bra reduced the setup margin for prone position fixation of breast tumors. PMID: 28594079 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - June 8, 2017 Category: Physics Authors: Kawamura M, Maeda Y, Yamamoto K, Takamatsu S, Sato Y, Minami H, Saga Y, Kume K, Tameshige Y, Sasaki M, Tamamura H, Ohta K, Itoh Y, Naganawa S Tags: J Appl Clin Med Phys Source Type: research

Preliminary study of clinical application on IMRT three-dimensional dose verification-based EPID system.
Abstract The three-dimensional dose (3D) distribution of intensity-modulated radiation therapy (IMRT) was verified based on electronic portal imaging devices (EPIDs), and the results were analyzed. Thirty IMRT plans of different lesions were selected for 3D EPID-based dose verification. The gamma passing rates of the 3D dose verification-based EPID system (Edose, Version 3.01, Raydose, Guangdong, China) and Delta4 measurements were then compared with treatment planning system (TPS) calculations using global gamma criteria of 5%/3 mm, 3%/3 mm, and 2%/2 mm. Furthermore, the dose-volume histograms (DVHs) for planning...
Source: Journal of Applied Clinical Medical Physics - June 8, 2017 Category: Physics Authors: Huang M, Huang D, Zhang J, Chen Y, Xu B, Chen L Tags: J Appl Clin Med Phys Source Type: research

Technical Note: Monte Carlo calculations of the AAPM TG-43 brachytherapy dosimetry parameters for a new titanium-encapsulated Yb-169 source.
In this study, the original MC source model was modified to accurately match the specifications of the manufactured Yb-169 source. The modified MC model was then used to obtain a complete set of the AAPM TG-43 parameters for the new titanium-encapsulated Yb-169 source. The MC-calculated dose rate constant for this titanium-encapsulated Yb-169 source was 1.19 ± 0.03 cGy·h-1·U-1, indicating no significant change from the values reported for stainless steel-encapsulated Yb-169 sources. The source anisotropy and radial dose function for the new source were also found similar to those reported for the stain...
Source: Journal of Applied Clinical Medical Physics - June 6, 2017 Category: Physics Authors: Reynoso FJ, Munro Iii JJ, Cho SH Tags: J Appl Clin Med Phys Source Type: research

Effect of VERO pan-tilt motion on the dose distribution.
Abstract Tumor tracking is an option for intra-fractional motion management in radiotherapy. The VERO gimbal tracking system creates a unique beam geometry and understanding the effect of the gimbal motion in terms of dose distribution is important to assess the dose deviation from the reference conditions. Beam profiles, output factors (OF) and percentage depth doses (PDD) were measured and evaluated to investigate this effect. In order to find regions affected by the pan-tilt motion, synthesized 2D dose distributions were generated. An evaluation of the 2D dose distribution with the reference position was done u...
Source: Journal of Applied Clinical Medical Physics - June 6, 2017 Category: Physics Authors: Prasetio H, Yohannes I, Bert C Tags: J Appl Clin Med Phys Source Type: research

Investigation of error detection capabilities of phantom, EPID and MLC log file based IMRT QA methods.
In this study, we will compare the ability of three QA methods (Delta(4) ®, MU-EPID, Dynalog QA) to detect specific errors. Multileaf collimator (MLC) errors, gantry angle, and dose errors were introduced into five volumetric modulated arc therapy (VMAT) plans for a total of 30 plans containing errors. The original plans (without errors) were measured five times with each method to set a threshold for detectability using two standard deviations from the mean and receiver operating characteristic (ROC) derived limits. Gamma passing percentages as well as percentage error of planning target volume (PTV) were used for pas...
Source: Journal of Applied Clinical Medical Physics - June 6, 2017 Category: Physics Authors: Defoor DL, Stathakis S, Roring JE, Kirby NA, Mavroidis P, Obeidat M, Papanikolaou N Tags: J Appl Clin Med Phys Source Type: research

MR-safe personal radiation dosimeters.
Abstract Magnetic resonance imaging (MRI) is being rapidly integrated for cancer treatments-such systems are referred to as MRI-guided radiation therapy (MRIgRT). As the magnet of an MRI scanner is always on, the presence of a strong static magnetic field from the MRI scanner during radiotherapy delivery presents new challenges. One of the challenges is that a personal radiation dosimeter used to estimate the radiation dose deposited in an individual wearing the device must be MR-safe. No such devices, however, are currently available. In this work we first modified an existing personal dosimeter (by removing a me...
Source: Journal of Applied Clinical Medical Physics - June 6, 2017 Category: Physics Authors: Tchistiakova E, Kim A, Song WY, Pang G Tags: J Appl Clin Med Phys Source Type: research

Does liver resection/transplantation affect respiratory induced liver motion in patients with hepatocellular carcinoma?
Abstract The purpose of this study was to evaluate the changes in magnitude of three-dimensional (3D) liver motion after liver resection/transplantation in patients with hepatocellular carcinoma (HCC) using four-dimensional (4D)-computed tomography (CT) images. From January 2012 to April 2016, 74 HCC patients underwent 4D-CT scans under a free-breathing state to assess respiratory liver motion. Of the 74 patients, 40 did not have a liver resection/transplantation (Group A), 34 with liver resection/transplantation. 15 underwent major or minor resection in the right liver lobe (Group B), 14 underwent major or minor ...
Source: Journal of Applied Clinical Medical Physics - June 6, 2017 Category: Physics Authors: Hu Y, Zhou YK, Chen YX, Ye LX, Zeng ZC Tags: J Appl Clin Med Phys Source Type: research

Assessment of volumetric absorbed dose for mobile fluoroscopic 3D image acquisition.
Abstract Mobile fluoroscopy (c-arm) units offering 3D image reconstruction are becoming more common in surgical settings. Although these images are "CT-like" and sometimes replace the postoperative CT, the acquisition is technically very different from a traditional CT acquisition. Dose assessment is complicated by a large beam width, automatic exposure rate control, and a rotation of less than 360°. The purpose of this work was to explore the impact of these factors on the volumetric dose calculation and to provide practical recommendations for clinical physicists assessing dose from these units usi...
Source: Journal of Applied Clinical Medical Physics - June 6, 2017 Category: Physics Authors: Leon S Tags: J Appl Clin Med Phys Source Type: research