Investigating split-filter dual-energy CT for improving liver tumor visibility for radiation therapy.
CONCLUSIONS: Liver tumor contrast was significantly improved using split-filter DECT 40 keV VMIs compared to mixed images. On average, there was no statistical difference in CNR between the mixed images and VMIs, but for individual cases, CNR was greatly increased for the 57 keV and 40 keV VMIs. Therefore, although not universally successful for our patient cohort, split-filter DECT VMIs may provide substantial gains in tumor visibility of certain liver cases for radiation therapy treatment planning. PMID: 32410336 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 15, 2020 Category: Physics Authors: DiMaso LD, Miller JR, Lawless MJ, Bassetti MF, DeWerd LA, Huang J Tags: J Appl Clin Med Phys Source Type: research

Independent calculation-based verification of volumetric-modulated arc therapy-stereotactic body radiotherapy plans for lung cancer.
This study aimed to investigate the feasibility of independent calculation-based verification of volumetric-modulated arc therapy (VMAT)-stereotactic body radiotherapy (SBRT) for patients with lung cancer using a secondary treatment planning system (sTPS). In all, 50 patients with lung cancer who underwent VMAT-SBRT between April 2018 and May 2019 were included in this study. VMAT-SBRT plans were devised using the Collapsed-Cone Convolution in RayStation (primary TPS: pTPS). DICOM files were transferred to Eclipse software (sTPS), which utilized the Eclipse software, and the dose distribution was then recalculated using Ac...
Source: Journal of Applied Clinical Medical Physics - May 11, 2020 Category: Physics Authors: Ono T, Mitsuyoshi T, Shintani T, Tsuruta Y, Iramina H, Hirashima H, Miyabe Y, Nakamura M, Matsuo Y, Mizowaki T Tags: J Appl Clin Med Phys Source Type: research

Image artifacts caused by incorrect bowtie filters in cone-beam CT image-guided radiotherapy.
Abstract Certain models of cone beam computed tomography (CBCT) image-guided radiotherapy (IGRT) systems require manually placing the appropriate bowtie filter according to the relevant imaging protocol. Inadvertently using a wrong bowtie filter or no bowtie filter could cause unexpected image artifacts. In this work, CBCT image artifact patterns caused by different bowtie filter placement were evaluated. CBCT images of CT phantoms, that is, a Body Norm phantom, a Catphan® phantom and an anthropomorphic RANDO® phantom, were acquired at a Varian Trilogy® unit with an On-Board Imager® (OBI) system. T...
Source: Journal of Applied Clinical Medical Physics - May 8, 2020 Category: Physics Authors: Cao Y, Ma T, de Boer SF, Wang IZ Tags: J Appl Clin Med Phys Source Type: research

Technical Note: A step-by-step guide to Temporally Feathered Radiation Therapy planning for head and neck cancer.
CONCLUSIONS: Temporally Feathered Radiation Therapy planning is possible with modern treatment planning systems. Modest dosimetric changes are observed with TFRT planning compared with non-TFRT IMRT planning. We await the results of the current prospective trial to seeking to demonstrate the feasibility of TFRT in the modern clinical workflow (NCT03768856). Further studies will be required to demonstrate the potential benefit of TFRT over non-TFRT IMRT Planning. PMID: 32383296 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 8, 2020 Category: Physics Authors: Parsai S, Qiu RLJ, Qi P, Alfonso JCL, Donaghue J, Murray E, Majkszak D, Dorio N, Fuller CD, Brock K, Koyfman S, Woody N, Joshi N, Scott JG Tags: J Appl Clin Med Phys Source Type: research

Dosimetric impact of tracheostomy devices in head and neck cancer patients.
CONCLUSION: In summary, the tracheostomy flange acts like bolus with a twofold increase in the skin surface dose. Changes in the peristomal apparatus from simulation to treatment needs to be considered to ensure that the simulated dose and coverage is achieved. PMID: 32374922 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 6, 2020 Category: Physics Authors: Lee J, Ramadan S, Kim A, Alayed Y, Ravi A Tags: J Appl Clin Med Phys Source Type: research

Comprehensive validation of halcyon 2.0 plans and the implementation of patient specific QA with multiple detector platforms.
CONCLUSION: Halcyon plan deliveries were verified with multiple measurement devices. New features of Halcyon 2.0 were also validated. Traditional PSQA techniques and process specific tolerance and action limits were successfully implemented. PMID: 32368862 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 5, 2020 Category: Physics Authors: Laugeman E, Heermann A, Hilliard J, Watts M, Roberson M, Morris R, Goddu S, Sethi A, Zoberi I, Kim H, Mutic S, Hugo G, Cai B Tags: J Appl Clin Med Phys Source Type: research

Personalized setting of plan parameters using feasibility dose volume histogram for auto-planning in Pinnacle system.
Abstract PURPOSE: The personalized setting of plan parameters in the Auto-Planning module of the Pinnacle treatment planning system (TPS) using the PlanIQ feasibility tool was evaluated for lung cancer conventional fractionated radiotherapy (CFRT). MATERIALS AND METHOD: We reviewed the records of ten patients with lung cancer who were treated with volumetric modulated arc therapy (VMAT). Three plans were designed for each patient: the clinically accepted manual plan (MP) and two automatic plans including one generated using the generic plan parameters in technique script (AP1) and the other generated using pe...
Source: Journal of Applied Clinical Medical Physics - May 4, 2020 Category: Physics Authors: Xia W, Han F, Chen J, Miao J, Dai J Tags: J Appl Clin Med Phys Source Type: research

On the complexity of helical tomotherapy treatment plans.
CONCLUSIONS: The proposed metrics and the global score demonstrated to be useful to characterize and quantify the complexity of HT plans of different treatment sites. The reported differences inter- and intra-group may be valuable to guide the planning process aiming at reducing uncertainties and harmonize planning strategies. PMID: 32363800 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - May 4, 2020 Category: Physics Authors: Santos T, Ventura T, Mateus J, Capela M, Lopes MDC Tags: J Appl Clin Med Phys Source Type: research

Impact of interfractional anatomical variation and setup correction methods on interfractional dose variation in IMPT and VMAT plans for pancreatic cancer patients: A planning study.
CONCLUSION: Organ-matching may be a better setup correction technique than BM for both photon therapy and IMPT plans. However, in some beam arrangements of IMPT, the dose distribution may be somewhat worse using OM, due to interfractional anatomical variation. Therefore, it is important to choose beam angles that are less likely to be influenced by changes in the gastrointestinal gas volume, especially in IMPT plans. PMID: 32350969 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 30, 2020 Category: Physics Authors: Ashida R, Nakamura M, Yoshimura M, Mizowaki T Tags: J Appl Clin Med Phys Source Type: research

Survey results of 3D-CRT and IMRT quality assurance practice.
CONCLUSION: The survey provided a snapshot of the current state of dose verification for IMRT radiotherapy. The results showed variability in approaches and that work is still needed to unify and tighten criteria in the medical physics community, especially in reference to TG-218's recommendations. PMID: 32351006 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 30, 2020 Category: Physics Authors: Mehrens H, Taylor P, Followill DS, Kry SF Tags: J Appl Clin Med Phys Source Type: research

Project DEAL - Germany is leading the way in the transition to open access publishing.
PMID: 32352223 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 30, 2020 Category: Physics Authors: Mills M Tags: J Appl Clin Med Phys Source Type: research

Infection prevention and control measures during COVID-19 from medical physics perspective: A single institution experience from China.
PMID: 32346963 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 28, 2020 Category: Physics Authors: Li D, Liu R, Wei S, Li T, Cai J, Ge H Tags: J Appl Clin Med Phys Source Type: research

Dosimetric assessment of patient-specific breath-hold reproducibility on liver motion for SBRT planning.
CONCLUSIONS: Non-negligible intrafractional motion occurs in patients with poor breath-hold reproducibility. To identify this subgroup of patients, acquiring three CTs with active breath-hold during simulation is a feasible practical method. PMID: 32337841 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 26, 2020 Category: Physics Authors: Lu L, Ouyang Z, Lin S, Mastroianni A, Stephans KL, Xia P Tags: J Appl Clin Med Phys Source Type: research

A practical cyberattack contingency plan for radiation oncology.
CONCLUSIONS: The proposed solution can achieve continuation of radiation therapy treatment without treatment breaks in the event of a cyberattack. It also provides cushion time for radiation oncology departments to rebuild their clinical ROIS systems from the enterprise data backup. PMID: 32333513 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 24, 2020 Category: Physics Authors: Zhang B, Chen S, Nichols E, D'Souza W, Prado K, Yi B Tags: J Appl Clin Med Phys Source Type: research

Radiation therapy considerations during the COVID-19 Pandemic: Literature review and expert opinions.
Abstract COVID-19 is an unprecedented pandemic that has already reached over 2 million confirmed cases globally, with at least 140,000 deaths as reported by the World Health Organization (WHO) as of April 16, 2020 1 . More than 662,000 cases have been reported in the United States with more than 29,000 deaths2 . The overall crude mortality rate now stands at 6.6% (may possibly be lower due to under-testing and under-reporting of total confirmed cases), and is highly dependent on age group, comorbidities, and the locoregional resources medically1 . A report from the United States presented age-stratified COVID-19 a...
Source: Journal of Applied Clinical Medical Physics - April 23, 2020 Category: Physics Authors: Mohindra P, Buckey CR, Chen S, Sio TN, Rong Y Tags: J Appl Clin Med Phys Source Type: research

Improvement in MR quality control workflow and outcomes with a web-based database.
Abstract PURPOSE: To describe a custom-built, web-based MR Quality Control (QC) database, and to assess its impact on the QC workflow and outcomes in a large U.S. academic medical center. METHODS: The MR QC database was built with Microsoft Access 2010 and published on a Microsoft Sharepoint website owned and maintained by the authors' institution. Authorized users can access the database remotely with mainstream web browsers on any institutional computers. QC technologists were granted access to add, review, and print daily and weekly QC records. Qualified medical physicists (QMPs) were granted additional ac...
Source: Journal of Applied Clinical Medical Physics - April 19, 2020 Category: Physics Authors: Yang X, Little K, Jiang X, Hintenlang D Tags: J Appl Clin Med Phys Source Type: research

A novel and clinically useful dynamic conformal arc (DCA)-based VMAT planning technique for lung SBRT.
We describe and compare a clinically useful dynamic conformal arc (DCA)-based VMAT (d-VMAT) technique for lung SBRT using flattening filter free (FFF) beams to minimize these effects. MATERIALS AND METHODS: Ten solitary early-stage I-II non-small-cell lung cancer (NSCLC) patients were treated with a single dose of 30 Gy using 3-6 non-coplanar VMAT arcs (clinical VMAT) with 6X-FFF beams in our clinic. These clinically treated plans were re-optimized using a novel d-VMAT planning technique. For comparison, d-VMAT plans were recalculated using DCA with user-controlled field aperture shape before VMAT optimization. I...
Source: Journal of Applied Clinical Medical Physics - April 19, 2020 Category: Physics Authors: Pokhrel D, Visak J, Sanford L Tags: J Appl Clin Med Phys Source Type: research

Development and evaluation of machine learning models for voxel dose predictions in online adaptive magnetic resonance guided radiation therapy.
CONCLUSION: Machine learning prediction models for treatment plan 3D dose distributions in online adaptive MRgRT were developed and tested. Clinical integration of the models requires minimal effort, producing 3D dose predictions for a new patient's plan using only target and OAR structures as inputs. These models can enable improved workflows for MRgRT through more informed plan optimization and plan quality assessment in real time. PMID: 32306535 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 19, 2020 Category: Physics Authors: Thomas MA, Fu Y, Yang D Tags: J Appl Clin Med Phys Source Type: research

Technical Note: A novel dosimeter improves total skin electron therapy surface dosimetry workflow.
CONCLUSION: Scintillators have been shown to report dose nearly twice as fast as OSLDs with substantially less manual work and reduced chances of human error. Scintillator dose measurements are automatically saved to an electronic patient file and images contain a permanent record of the dose delivered during treatment. PMID: 32306551 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 19, 2020 Category: Physics Authors: Tendler II, Bruza P, Jermyn M, Soter J, Sharp G, Williams B, Jarvis LA, Pogue B, Gladstone DJ Tags: J Appl Clin Med Phys Source Type: research

An efficient fusion algorithm combining feature extraction and variational optimization for CT and MR images.
Abstract In medical image processing, image fusion is the process of combining complementary information from different or multimodality images to obtain an informative fused image in order to improve clinical diagnostic accuracy. In this paper, we propose a two-stage fusion framework for computed tomography (CT) and magnetic resonance (MR) images. First, the intensity and geometric structure features in both CT and MR images are extracted by the saliency detection method and structure tensor, respectively, and an initial fused image is obtained. Then, the initial fused image is optimized by a variational model wh...
Source: Journal of Applied Clinical Medical Physics - April 19, 2020 Category: Physics Authors: Wang Q, Yang X Tags: J Appl Clin Med Phys Source Type: research

A novel dynamic robotic moving phantom system for patient-specific quality assurance in real-time tumor-tracking radiotherapy.
In this study, we assess a developed novel dynamic moving phantom system that can reproduce patient three-dimensional (3D) tumor motion and patient anatomy, and perform patient-specific quality assurance (QA) of respiratory-gated radiotherapy using SyncTraX. Three patients with lung cancer were enrolled in a study. 3D printing technology was adopted to obtain individualized lung phantoms using CT images. A water-equivalent phantom (WEP) with the 3D-printed plate lung phantom was set at the tip of the robotic arm. The log file that recorded the 3D positions of the lung tumor was used as the input to the dynamic robotic movi...
Source: Journal of Applied Clinical Medical Physics - April 13, 2020 Category: Physics Authors: Shiinoki T, Fujii F, Fujimoto K, Yuasa Y, Sera T Tags: J Appl Clin Med Phys Source Type: research

Some thoughts on health insurance in the United States.
PMID: 32282102 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 13, 2020 Category: Physics Authors: Mills M Tags: J Appl Clin Med Phys Source Type: research

Automated quality control in nuclear medicine using the structured noise index.
CONCLUSION: An SNI-based QC program provides a robust quantification of the performance of gamma camera uniformity. It operates seamlessly across a fleet of multiple camera models and, additionally, provides effective workflow among the clinical staff. The reliability of this process could eliminate the need for visual inspection of each image, saving valuable time, while enabling quantitative analysis of inter- and intrasystem performance. PMID: 32277546 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 11, 2020 Category: Physics Authors: Nelson JS, Samei E Tags: J Appl Clin Med Phys Source Type: research

The effect of stereotactic body radiotherapy (SBRT) using flattening filter-free beams on cardiac implantable electronic devices (CIEDs) in clinical situations.
CONCLUSIONS: The study showed that caution should be paid to managing CIED patients when they undergo SBRT using FFF beams, as it is recommended by AAPM TG-203. Correspondingly, it was found that for FFF beams although there is small risk from dose-rate effects, delivering high dose of radiation with beam energy greater than 6 MV and high-dose rate to CIEDs positioned in close vicinity of the PTV may present issues. PMID: 32277741 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 11, 2020 Category: Physics Authors: Aslian H, Kron T, Watts T, Akalanli C, Hardcastle N, Lonski P, Montaseri A, Hay B, Korte J, Berk K, Longo F, Severgnini M Tags: J Appl Clin Med Phys Source Type: research

Quality assurance of VMAT on flattened and flattening filter-free accelerators using a high spatial resolution detector.
CONCLUSIONS: The investigation on the use of solid-state detectors in combination with an inclinometer has demonstrated the capability to provide efficient and independent verification of DR, GS, and MLC leaf speed during dynamic VMAT delivery. Good agreement with machine log files suggests the detector/inclinometer system is a useful tool for machine-specific VMAT QA. PMID: 32277745 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 11, 2020 Category: Physics Authors: Matar FS, Wilkinson D, Davis J, Biasi G, Causer T, Fuduli I, Brace O, Stansook N, Carolan M, Rosenfeld AB, Petasecca M Tags: J Appl Clin Med Phys Source Type: research

Automated planning through robust templates and multicriterial optimization for lung VMAT SBRT of lung lesions.
CONCLUSION: The automation of the planning process for lung SBRT using robust templates and MCO was demonstrated to be feasible and more efficient. PMID: 32275353 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 10, 2020 Category: Physics Authors: Marrazzo L, Arilli C, Pellegrini R, Bonomo P, Calusi S, Talamonti C, Casati M, Compagnucci A, Livi L, Pallotta S Tags: J Appl Clin Med Phys Source Type: research

TomoMQA: Automated analysis program for MVCT quality assurance of helical tomotherapy.
CONCLUSION: We successfully developed a new automated analysis program for MVCT QA of a helical tomotherapy platform, called TomoMQA. The developed program will be made freely downloadable from the TomoMQA-dedicated website. PMID: 32268003 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 8, 2020 Category: Physics Authors: Han MC, Hong CS, Chang KH, Kim J, Han SC, Kim DW, Park K, Kim MJ, Shin HB, Lee SH, Kim JS Tags: J Appl Clin Med Phys Source Type: research

Impact of different treatment techniques for pediatric Ewing sarcoma of the chest wall: IMRT, 3DCPT, and IMPT with/without beam aperture.
CONCLUSION: Compared to IMRT, proton therapy delivers significant lower dose to almost all OARs and much lower healthy tissue integral dose. Compared to 3DCPT, IMPT with small beam spot size or using beam aperture has better dose conformity to the target. PMID: 32268008 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 8, 2020 Category: Physics Authors: Su Z, Indelicato DJ, Mailhot RB, Bradley JA Tags: J Appl Clin Med Phys Source Type: research

Intensity-modulated radiation therapy for multiple targets with tomotherapy using multiple sets of static ports from different angles.
CONCLUSION: The pDJDC technique allows treatment of multiple targets in almost half the time of the HDJ technique. The pDJDC plans were comparable to the HDJ plans in dose distribution, although the conformity index deteriorated. PMID: 32250015 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 6, 2020 Category: Physics Authors: Manabe Y, Shibamoto Y, Murai T, Torii A, Niwa M, Kondo T, Okazaki D, Sugie C Tags: J Appl Clin Med Phys Source Type: research

SpaceOAR © hydrogel rectal dose reduction prediction model: a decision support tool.
SpaceOAR© hydrogel rectal dose reduction prediction model: a decision support tool. J Appl Clin Med Phys. 2020 Apr 06;: Authors: Paetkau O, Gagne IM, Alexander A Abstract Prostate cancer external beam radiation therapy can result in toxicity due to organ at risk (OAR) dose, potentially impairing quality of life. A polyethylene glycol-based spacer, SpaceOAR© hydrogel (SOH), implanted between prostate gland and rectum may significantly reduce dose received by the rectum and hence risk of rectal toxicity. SOH implant is not equally effective in all patients. Determining patients in which the im...
Source: Journal of Applied Clinical Medical Physics - April 6, 2020 Category: Physics Authors: Paetkau O, Gagne IM, Alexander A Tags: J Appl Clin Med Phys Source Type: research

Quantifying the impact of optical surface guidance in the treatment of cancers of the head and neck.
This study investigated the improvement of patient setup accuracy and reduction of setup time for SGRT compared to a conventional setup. A total of 60 H&N cancer patients were retrospectively included. Patients were categorized into three groups: oral cavity, oropharynx and nasopharynx/sinonasal sites with 20 patients in each group. They were further separated into two (2) subgroups, depending on whether they were set up with the aid of SGRT. The Align-RT™ system was used for SGRT in this work. Positioning was confirmed by daily kV-kV imaging in conjunction with weekly CBCT scans. Translational and rotational cou...
Source: Journal of Applied Clinical Medical Physics - April 6, 2020 Category: Physics Authors: Wei W, Ioannides PJ, Sehgal V, Daroui P Tags: J Appl Clin Med Phys Source Type: research

Patient size matters: Effect of tube current modulation on size-specific dose estimates (SSDE) and image quality in low-dose lung cancer screening CT.
Abstract PURPOSE: We compare the effect of tube current modulation (TCM) and fixed tube current (FTC) on size-specific dose estimates (SSDE) and image quality in lung cancer screening with low-dose CT (LDCT) for patients of all sizes. METHODS: Initially, 107 lung screening examinations were performed using FTC, which satisfied the Centers for Medicare & Medicaid Services' volumetric CT dose index (CTDIvol ) limit of 3.0 mGy for standard-sized patients. Following protocol modification, 287 examinations were performed using TCM. Patient size and examination parameters were collected and water-equivalen...
Source: Journal of Applied Clinical Medical Physics - April 6, 2020 Category: Physics Authors: Barreto I, Verma N, Quails N, Olguin C, Correa N, Mohammed TL Tags: J Appl Clin Med Phys Source Type: research

A simple, yet novel hybrid-dynamic conformal arc therapy planning via flattening filter-free beam for lung stereotactic body radiotherapy.
CONCLUSION: Due to no beam modulation through the target, h-DCA plans avoid small-field dosimetry and MLC interplay effects and resulting in enhanced target coverage by improving tumor dose (characteristic of FFF-beam). The h-DCA simplifies treatment planning and beam on time significantly compared to clinical VMAT plans. Additionally, h-DCA allows for the real time target verification and eliminates patient-specific VMAT quality assurance; potentially offering cost-effective, same or next day SBRT treatments. Moreover, this technique can be easily adopted to other disease sites and small clinics with less extensive physic...
Source: Journal of Applied Clinical Medical Physics - April 3, 2020 Category: Physics Authors: Pokhrel D, Halfman M, Sanford L Tags: J Appl Clin Med Phys Source Type: research

Retrospective quality metrics review of stereotactic radiosurgery plans treating multiple targets using single-isocenter volumetric modulated arc therapy.
CONCLUSION: The benchmark data on key plan quality metrics were established for single-isocenter multi-target SRS planning. It is feasible to use this knowledge to guide VMAT planning and reduce high V12Gy outliers. PMID: 32239746 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 2, 2020 Category: Physics Authors: Cui Y, Gao H, Zhang J, Kirkpatrick JP, Yin FF Tags: J Appl Clin Med Phys Source Type: research

Assessment of error in the MV radiation isocenter position calculated with the Elekta XVI software.
Abstract The assessment of the coincidence of imaging and radiation isocenters is an important task of regular quality assurance of medical linear accelerators (linacs) as recommended in national and international quality assurance guidelines. A previously reported investigation of the accuracy of the Elekta XVI software to localize the linac radiation isocenter, by comparing statistically with other independent software, has shown some discrepancies at the sub-mm level. A further investigation is carried out here using a set of reference images and mathematical operations to observe how the Elekta XVI software an...
Source: Journal of Applied Clinical Medical Physics - April 2, 2020 Category: Physics Authors: Chojnowski JM, Warr GB, Sykes JR, Thwaites DI Tags: J Appl Clin Med Phys Source Type: research

The effect of the horizontal metallic drive on reference dosimetry in the SNC 3D scanner water tank.
Abstract Accurate quantification of absorbed radiation dose is important for safe and effective delivery of radiation therapy. An important aspect to this is reference dosimetry, which is performed under reference conditions specified by international codes of practice. Such measurements are usually performed in a water phantom. In the Sun Nuclear Corporation (SNC) three-dimensional (3D) scanner water tank system the detector holder is fixed to a horizontal metallic drive rail (MDR) which is in close proximity to the active volume of the detector. In this project, the dosimetric effects of the MDR on reference dos...
Source: Journal of Applied Clinical Medical Physics - April 1, 2020 Category: Physics Authors: Aftab S, Barnes MP, Doebrich M, Lehmann J Tags: J Appl Clin Med Phys Source Type: research

The impact of corrected field output factors based on IAEA/AAPM code of practice on small-field dosimetry to the calculated monitor unit in eclipse ™ treatment planning system.
The objective of this study was to investigate the effect of field output factors (FOFs) according to the current protocol for small-field dosimetry in conjunction to treatment planning system (TPS) commissioning. The calculated monitor unit (MU) for intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans in Eclipse™ TPS were observed. Micro ion chamber (0.01 CC) (CC01), photon field diode (shielded diode) (PFD), and electron field diode (unshielded diode) (EFD) were used to measure percentage depth doses, beam profiles, and FOFs from 1 × 1 cm2 to 10 &t...
Source: Journal of Applied Clinical Medical Physics - April 1, 2020 Category: Physics Authors: Mamesa S, Oonsiri S, Sanghangthum T, Yabsantia S, Suriyapee S Tags: J Appl Clin Med Phys Source Type: research

A longitudinal evaluation of improvements in treatment plan quality for lung cancer with volumetric modulated arc therapy.
CONCLUSION: Increasing the number of optimizations was associated with significantly improved sparing of OARs with slight effects on the dose coverage and homogeneity of target volume. Generally, based on the designed planning strategy, there was no significant improvement of the plan quality for more than three optimizations. PMID: 32237271 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - April 1, 2020 Category: Physics Authors: Xia W, Liu Z, Yan L, Han F, Hu Z, Tian Y, Cui W, Ren W, Guo C, Miao J, Dai J Tags: J Appl Clin Med Phys Source Type: research

The potential of an optical surface tracking system in non-coplanar single isocenter treatments of multiple brain metastases.
n F Abstract To evaluate the accuracy of a commercial optical surface tracking (OST) system and to demonstrate how it can be implemented to monitor patient positioning during non-coplanar single isocenter stereotactic treatments of brain metastases. A 3-camera OST system was used (Catalyst HD™, C-RAD) on a TruebeamSTx with a 6DoF couch. The setup accuracy and agreement between the OST system, and CBCT and kV-MV imaging at couch angles 0° and 270°, respectively, were examined. Film measurements at 3 depths in the Rando-Alderson phantom were performed using a single isocenter non-coplanar VMAT plan con...
Source: Journal of Applied Clinical Medical Physics - April 1, 2020 Category: Physics Authors: Swinnen ACC, Öllers MC, Loon Ong C, Verhaegen F Tags: J Appl Clin Med Phys Source Type: research

Evaluation of a neural network-based photon beam profile deconvolution method.
CONCLUSIONS: The ANN-based deconvolution method can be effectively applied to beams of different energies and modalities measured with ICs of various sizes. Separate ANNs yielded marginally better results than combined ANNs. An IC-specific, combined ANN can provide clinically acceptable results as long as the training data includes data of each beam energy and modality. PMID: 32227629 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - March 30, 2020 Category: Physics Authors: Mund K, Wu J, Liu C, Yan G Tags: J Appl Clin Med Phys Source Type: research

Recommendations of megavoltage computed tomography settings for the implementation of adaptive radiotherapy on helical tomotherapy units.
e; WA Abstract Megavoltage computed tomography (MVCT) image quality metrics were evaluated on an Accuray Radixact unit to recommend scan settings for the implementation of a consistent adaptive radiotherapy program. Megavoltage computed tomography image quality was evaluated and compared to a kilovoltage CT (kVCT) simulator using a commercial cone beam computed tomography image quality phantom. Megavoltage computed tomographies were acquired on the Accuray Radixact using fine, normal, and coarse pitches, with all available reconstruction slice thicknesses, each of which were reconstructed using standard and iterat...
Source: Journal of Applied Clinical Medical Physics - March 26, 2020 Category: Physics Authors: Velten C, Boyd R, Jeong K, Garg MK, Tomé WA Tags: J Appl Clin Med Phys Source Type: research

Dosimetric evaluation of synthetic CT generated with GANs for MRI-only proton therapy treatment planning of brain tumors.
CONCLUSIONS: This work demonstrated the feasibility of using sCT generated with a GAN-based deep learning method for MRI-only treatment planning of patients with brain tumor in intensity-modulated proton therapy. PMID: 32216098 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - March 26, 2020 Category: Physics Authors: Kazemifar S, Barragán Montero AM, Souris K, Rivas ST, Timmerman R, Park YK, Jiang S, Geets X, Sterpin E, Owrangi A Tags: J Appl Clin Med Phys Source Type: research

Clinical impact of the VOLO optimizer on treatment plan quality and clinical treatment efficiency for CyberKnife.
g L Abstract With the recent CyberKnife treatment planning system (TPS) upgrade from Precision 1.0 to Precision 2.0, the new VOLO optimizer was released for plan optimization. The VOLO optimizer sought to overcome some of the limitations seen with the Sequential optimizer from previous TPS versions. The purpose of this study was to investigate the clinical impact of the VOLO optimizer on treatment plan quality and clinical treatment efficiency as compared to the Sequential optimizer. Treatment plan quality was evaluated in four categories of patients: Brain Simple (BS), Brain Complex (BC), Spine Complex (SC), and ...
Source: Journal of Applied Clinical Medical Physics - March 25, 2020 Category: Physics Authors: Schüler E, Lo A, Chuang CF, Soltys SG, Pollom EL, Wang L Tags: J Appl Clin Med Phys Source Type: research

Efficiency and safety increases after the implementation of a multi-institutional automated plan check tool at our institution.
Abstract PURPOSE: The plan check tool (PCT) is the result of a multi-institutional collaboration to jointly develop a flexible automated plan checking framework designed with the versatility to be shared across collaborating facilities while supporting the individual differences between practices. We analyze the effect that PCT has had on the efficiency and effectiveness of initial chart checks at our institution. METHODS AND MATERIALS: Data on errors identified during initial chart checks were acquired during two time periods: before the introduction of PCT in the clinic (6/24/2015 to 7/31/2015, 187 checks) ...
Source: Journal of Applied Clinical Medical Physics - March 20, 2020 Category: Physics Authors: Berry SL, Zhou Y, Pham H, Elguindi S, Mechalakos JG, Hunt M Tags: J Appl Clin Med Phys Source Type: research

Use of surface-guided radiation therapy in combination with IGRT for setup and intrafraction motion monitoring during stereotactic body radiation therapy treatments of the lung and abdomen.
This study analyzes the accuracy of 3D surface mapping with Surface-guided radiation therapy (SGRT) in detecting interfraction setup error and intrafraction motion during SBRT treatments of the lung and abdomen. MATERIALS AND METHODS: Seventy-one patients with 85 malignant thoracic or abdominal tumors treated with SBRT were analyzed. For initial patient setup, an alternating scheme of kV/kV imaging or SGRT was followed by cone beam computed tomography (CBCT) for more accurate tumor volumetric localization. The CBCT six degree shifts after initial setup with each method were recorded to assess interfraction setup error...
Source: Journal of Applied Clinical Medical Physics - March 20, 2020 Category: Physics Authors: Heinzerling JH, Hampton CJ, Robinson M, Bright M, Moeller BJ, Ruiz J, Prabhu R, Burri SH, Foster RD Tags: J Appl Clin Med Phys Source Type: research

The impact of isocentric shifts on delivery accuracy during the irradiation of small cerebral targets-Quantification and possible corrections.
CONCLUSION: Mechanical deviations during gantry, collimator, and table rotation may adversely affect the treatment of small stereotactic lesions. Adjustments of beam isocenters in the treatment planning system (TPS) can be used to both quantify their impact and for prospective correction of treatment plans. PMID: 32196950 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - March 20, 2020 Category: Physics Authors: Wack LJ, Exner F, Wegener S, Sauer OA Tags: J Appl Clin Med Phys Source Type: research

A plan template-based automation solution using a commercial treatment planning system.
CONCLUSION: An automated planning platform to interface with Monaco was developed, and our reported tests showed preliminary results for prostate and head and neck cases. PMID: 32180351 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - March 16, 2020 Category: Physics Authors: Huang X, Quan H, Zhao B, Zhou W, Chen C, Chen Y Tags: J Appl Clin Med Phys Source Type: research

Intrafractional relationship changes between an external breathing signal and fiducial marker positions in pancreatic cancer patients.
CONCLUSION: On average, 2 mm of treatment delivery accuracy was lost due to IRC. Periodical intrafractional imaging is needed to safely deliver respiratory-guided SBRT. PMID: 32170900 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - March 14, 2020 Category: Physics Authors: Pettersson N, Oderinde OM, Murphy J, Simpson D, Cerviño LI Tags: J Appl Clin Med Phys Source Type: research

Set-up error and dosimetric analysis of HexaPOD evo RT 6D couch combined with cone beam CT image-guided intensity-modulated radiotherapy for primary malignant tumor of the cervical spine.
Abstract PURPOSE: To investigate the set-up error and consequent dosimetric change in HexaPOD evo RT 6D couch under image-guided intensity-modulated radiotherapy (IG-IMRT) for primary malignant tumor of the cervical spine. METHODS: Ten cases with primary malignant tumor of the cervical spine were treated with intensity-modulated radiotherapy (IMRT) in our hospital from August 2013 to November 2014. The X-ray volumetric images (XVI) were scanned and obtained by cone-beam CT (CBCT). The six directions (6D) of set-up errors of translation and rotation were obtained by planned CT image registration. HexaPOD evo R...
Source: Journal of Applied Clinical Medical Physics - March 14, 2020 Category: Physics Authors: Jiang P, Zhang X, Wei S, Zhao T, Wang J Tags: J Appl Clin Med Phys Source Type: research

Measurement-based study on characterizing symmetric and asymmetric respiratory motion interplay effect on target dose distribution in the proton pencil beam scanning.
This study evaluated the measurements of proton pencil beam scanning delivery made with a 2D ion chamber array in solid water on a 1D motion platform, where respiratory motion was simulated using sine and cosine4 waves representing sinusoidal symmetric and realistic asymmetric breathing motions, respectively. Motion amplitudes were 0.5 cm and 1 cm corresponding to 1 cm and 2 cm of maximum respiratory excursions, respectively, with 5 sec fixed breathing cycle. The treatment plans were created to mimic spherical targets of 3 cm or 10 cm diameter located at 5 cm or 1 cm depth in so...
Source: Journal of Applied Clinical Medical Physics - March 14, 2020 Category: Physics Authors: Lee E, Perry D, Speth J, Zhang Y, Xiao Z, Mascia A Tags: J Appl Clin Med Phys Source Type: research