267 results match your criteria phantom conformity


Dosimetric evaluation of different planning techniques based on flattening filter-free beams for central and peripheral lung stereotactic body radiotherapy.

Biomed Phys Eng Express 2021 Oct 12. Epub 2021 Oct 12.

Department of Radiotherapy, Government Medical College Patiala, Sangrur Road, Patiala, Punjab, 147001, INDIA.

This study aimed to dosimetrically compare and evaluate the flattening filter-free (FFF) photon beam-based three-dimensional conformal radiotherapy (3DCRT), intensity-modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT) for lungstereotactic body radiotherapy (SBRT). RANDO phantom computed tomography (CT) images were used for treatment planning. Gross tumor volumes (GTVs) were delineated in the central and peripheral lung locations. Read More

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October 2021

Spatiotemporal Distribution of Nanodroplet Vaporization in a Proton Beam Using Real-Time Ultrasound Imaging for Range Verification.

Ultrasound Med Biol 2021 Oct 8. Epub 2021 Oct 8.

Department of Medical Imaging, TU Delft, Delft, The Netherlands.

The potential of proton therapy to improve the conformity of the delivered dose to the tumor volume is currently limited by range uncertainties. Injectable superheated nanodroplets have recently been proposed for ultrasound-based in vivo range verification, as these vaporize into echogenic microbubbles on proton irradiation. In previous studies, offline ultrasound images of phantoms with dispersed nanodroplets were acquired after irradiation, relating the induced vaporization profiles to the proton range. Read More

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October 2021

Dosimetric Validation of a System to Treat Moving Tumors Using Scanned Ion Beams That Are Synchronized With Anatomical Motion.

Front Oncol 2021 8;11:712126. Epub 2021 Sep 8.

Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany.

Purpose: The purpose of this study was to validate the dosimetric performance of scanned ion beam deliveries with motion-synchronization to heterogenous targets.

Methods: A 4D library of treatment plans, comprised of up to 10 3D sub-plans, was created with robust and conventional 4D optimization methods. Each sub-plan corresponded to one phase of periodic target motion. Read More

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September 2021

Efficient uncertainty quantification for Monte Carlo dose calculations using importance (re-)weighting.

Phys Med Biol 2021 Oct 7;66(20). Epub 2021 Oct 7.

German Cancer Research Center-DKFZ, Department of Medical Physics in Radiation Oncology, Heidelberg, Germany.

. To present an efficient uncertainty quantification method for range and set-up errors in Monte Carlo (MC) dose calculations. Further, we show that uncertainty induced by interplay and other dynamic influences may be approximated using suitable error correlation models. Read More

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October 2021

On the interplay effect for moving targets treated with the CyberKnife static tracking system.

Phys Med 2021 Sep 13;90:30-39. Epub 2021 Sep 13.

Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland. Electronic address:

Purpose: To assess the interplay effect amplitude between different planned MU distributions and respiratory patterns in the CyberKnife system when treating moving targets with static tracking technique.

Methods: Small- and Large-Respiratory Motions (SRM and LRM) differing in amplitude and frequency were simulated in a semi-anthropomorphic dynamic thorax phantom. The interplay effect was evaluated for both respiration motions in terms of GTV coverage and conformity for three plans designed with an increasing range of MU per beam (small, medium and large). Read More

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September 2021

Double-vertebral segment SBRT via novel ring-mounted Halcyon Linac: Plan quality, delivery efficiency and accuracy.

Med Dosim 2021 Aug 16. Epub 2021 Aug 16.

University of Kentucky, Department of Radiation Medicine, Lexington, KY, USA.

To evaluate the plan quality, treatment delivery efficiency, and accuracy of single-isocenter/multi-target (SIMT) volumetric modulated arc therapy (VMAT) of double-vertebral segments stereotactic body radiation therapy (SBRT) on Halcyon ring delivery system (RDS). In-house multi-target end-to-end phantom testing and independent dose verification using the MD Anderson's single-isocenter/multi-target (lung/spine targets) thorax phantom were completed. Six previously treated patients with 2-vertebral segments on thoracic and/or lumber spine were replanned on Halcyon RDS with 6MV-FFF beam using a single-isocenter placed between the vertebral segments. Read More

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MVCT versus kV-CBCT for targets subject to respiratory motion: A phantom study.

J Appl Clin Med Phys 2021 Sep 16;22(9):143-152. Epub 2021 Jul 16.

Department of Radiation Oncology, Karmanos Cancer Institute and Wayne State University, Detroit, MI, USA.

The use of kilovoltage cone-beam computed tomography (kV-CBCT) or megavoltage computed tomography (MVCT) for image guidance prior to lung stereotactic body radiation therapy (SBRT) is common clinical practice. We demonstrate that under equivalent respiratory conditions, image guidance using both kV-CBCT and MVCT may result in the inadequate estimation of the range of target motion under free-breathing (FB) conditions when standard low-density window and levels are used. Two spherical targets within a respiratory motion phantom were imaged using both long-exhale (LE) and sinusoidal respiratory traces. Read More

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September 2021

The feasibility of an approximate irregular field dose distribution simulation program applied to a respiratory motion compensation system.

Phys Med 2021 Aug 5;88:117-126. Epub 2021 Jul 5.

Department of Mechanical Engineering, National Taipei University of Technology, Taipei, Taiwan. Electronic address:

Purpose: This study optimized our previously proposed simulation program for the approximate irregular field dose distribution (SPAD) and applied it to a respiratory motion compensation system (RMCS) and respiratory motion simulation system (RMSS). The main purpose was to rapidly analyze the two-dimensional dose distribution and evaluate the compensation effect of the RMCS during radiotherapy.

Methods: This study modified the SPAD to improve the rapid analysis of the dose distribution. Read More

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Pre-clinical dosimetry of a new six-channel applicator for high-dose-rate treatment of esophageal cancer.

J Contemp Brachytherapy 2021 Jun 12;13(3):318-324. Epub 2021 May 12.

Department of Radiation Oncology, Cleveland Clinic, Cleveland, USA.

Purpose: To evaluate the dosimetry of a six-channel high-dose-rate (HDR) applicator for treatment of esophageal cancer with respect to lateral directionality and heterogeneous media.

Material And Methods: A computed tomography (CT)- and magnetic resonance imaging (MRI)-compatible esophageal applicator consisting of 2 inflatable portions (anchor and therapeutic balloons) with 6 longitudinal treatment catheters equally spaced circumferentially was constructed. Treatment plans were prepared using Oncentra 4. Read More

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Quality assurance method for monitoring of lateral pencil beam positions in scanned carbon-ion radiotherapy using tracking of secondary ions.

Med Phys 2021 Aug 28;48(8):4411-4424. Epub 2021 Jun 28.

Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany.

Purpose: Ion beam radiotherapy offers enhances dose conformity to the tumor volume while better sparing healthy tissue compared to conventional photon radiotherapy. However, the increased dose gradient also makes it more sensitive to uncertainties. While the most important uncertainty source is the patient itself, the beam delivery is also subject to uncertainties. Read More

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Automation and integration of a novel restricted single-isocenter stereotactic body radiotherapy (a-RESIST) method for synchronous two lung lesions.

J Appl Clin Med Phys 2021 Jul 25;22(7):56-65. Epub 2021 May 25.

Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, 40508, USA.

Synchronous treatment of two lung lesions using a single-isocenter volumetric modulated arc therapy (VMAT) stereotactic body radiation therapy (SBRT) plan can decrease treatment time and reduce the impact of intrafraction motion. However, alignment of both lesions on a single cone beam CT (CBCT) can prove difficult and may lead to setup errors and unacceptable target coverage loss. A Restricted Single-Isocenter Stereotactic Body Radiotherapy (RESIST) method was created to minimize setup uncertainties and provide treatment delivery flexibility. Read More

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SBRT treatment of abdominal and pelvic oligometastatic lymph nodes using ring-mounted Halcyon Linac.

J Appl Clin Med Phys 2021 Jun 25;22(6):162-171. Epub 2021 May 25.

Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA.

Purpose/objectives: This work seeks to evaluate the plan quality, treatment delivery efficiency, and accuracy of single-isocenter volumetric modulated arc therapy (VMAT) of abdominal/pelvic oligometastatic lymph nodes (LNs) stereotactic body radiation therapy (SBRT) on Halcyon Linac.

Materials And Methods: After completing the in-house multitarget end-to-end phantom testing and independent dose verification using MD Anderson's single-isocenter/multi-target (lung and spine target inserts) thorax phantom, eight patients with two to three abdominal/pelvic oligometastatic LNs underwent highly conformal single-isocenter VMAT-SBRT treatment using the Halcyon Linac 6MV flattening filter free (FFF) beam. Targets were identified using an Axumin PET/CT scan co-registered with planning CT images and a single-isocenter was placed between/among the targets. Read More

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Effect of treatment planning system parameters on beam modulation complexity for treatment plans with single-layer multi-leaf collimator and dual-layer stacked multi-leaf collimator.

Br J Radiol 2021 Jun 29;94(1122):20201011. Epub 2021 Apr 29.

Medical Physics Service, Castle Hill Hospital, Hull University Teaching Hospitals NHS Trust, Hull, UK.

Objective: High levels of beam modulation complexity (MC) and monitor units (MU) can compromise the plan deliverability of intensity-modulated radiotherapy treatments. Our study evaluates the effect of three treatment planning system (TPS) parameters on MC and MU using different multi-leaf collimator (MLC) architectures.

Methods: 192 volumetric modulated arc therapy plans were calculated using one virtual prostate phantom considering three main settings: (1) three TPS-parameters (Convergence; Aperture Shape Controller, ASC; and Dose Calculation Resolution, DCR) selected from Eclipse v15. Read More

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Split-VMAT technique to control the deep inspiration breath hold time for breast cancer radiotherapy.

Radiat Oncol 2021 Apr 20;16(1):77. Epub 2021 Apr 20.

Medical Physics Department, Institut Jules Bordet - Université Libre de Bruxelles, Brussels, Belgium.

Background: To improve split-VMAT technique by optimizing treatment delivery time for deep-inspiration breath hold (DIBH) radiotherapy in left-sided breast cancer patients, when automatic beam-interruption devices are not available.

Methods: Ten consecutive patients were treated with an eight partial arcs (8paVMAT) plan, standard of care in our center. A four partial arcs (4paVMAT) plan was also created and actual LINAC outputs were measured, to evaluate whether there was a dosimetric difference between both techniques and potential impact on the delivered dose. Read More

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Commissioning cranial single-isocenter multi-target radiosurgery for the Versa HD.

J Appl Clin Med Phys 2021 Apr 23;22(4):108-114. Epub 2021 Mar 23.

Department of Radiation Oncology, Beaumont Health, Royal Oak, MI, 48073, USA.

Purpose: Brainlab's Elements Multiple Brain Mets SRS (MBMS) is a dedicated treatment planning system for single-isocenter multi-target (SIMT) cranial stereotactic radiosurgery (SRS) treatments. The purpose of this study is to present the commissioning experience of MBMS on an Elekta Versa HD.

Methods: MBMS was commissioned for 6 X, 6 FFF, and 10 FFF. Read More

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Development and validation of the Dynamic Collimation Monte Carlo simulation package for pencil beam scanning proton therapy.

Med Phys 2021 Jun 9;48(6):3172-3185. Epub 2021 Apr 9.

Department of Human Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WI, 53792, USA.

Purpose: The aim of this work was to develop and experimentally validate a Dynamic Collimation Monte Carlo (DCMC) simulation package specifically designed for the simulation of collimators in pencil beam scanning proton therapy (PBS-PT). The DCMC package was developed using the TOPAS Monte Carlo platform and consists of a generalized PBS source model and collimator component extensions.

Methods: A divergent point-source model of the IBA dedicated nozzle (DN) at the Miami Cancer Institute (MCI) was created and validated against on-axis commissioning measurements taken at MCI. Read More

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[Dosimetric analysis of LINAC based stereotactic irradiation of brain tumours in CIRS SHANE phantom].

Magy Onkol 2021 Mar 17;65(1):23-29. Epub 2020 Jul 17.

Sugárterápiás Központ, Országos Onkológiai Intézet, Budapest, Hungary.

The aim of the study was to compare the different stereotactic treatment plans and dose calculation algorithms for small targets with film dosimetry in anthropomorphic phantom. Treatment plans were prepared for multiple targets with single setup isocenter. Plans for three different irradiation techniques were generated using conformal arc with four non-coplanar arcs, RapidArc with two coplanar full arcs and RapidArc with four non-coplanar arcs in the Varian Eclipse v13. Read More

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Ninjaflex vs Superflab: A comparison of dosimetric properties, conformity to the skin surface, Planning Target Volume coverage and positional reproducibility for external beam radiotherapy.

J Appl Clin Med Phys 2021 Apr 10;22(4):26-33. Epub 2021 Mar 10.

Radiotherapy Department, Ninewells Hospital & Medical School, NHS Tayside, Dundee, UK.

Background And Purpose: When planning and delivering radiotherapy, ideally bolus should be in direct contact with the skin surface. Varying air gaps between the skin surface and bolus material can result in discrepancies between the intended and delivered dose. This study assessed a three-dimensional (3D) printed flexible bolus to determine whether it could improve conformity to the skin surface, reduce air gaps, and improve planning target volume coverage, compared to a commercial bolus material, Superflab. Read More

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Volume-based algorithm of lung dose optimization in novel dynamic arc radiotherapy for esophageal cancer.

Sci Rep 2021 Feb 23;11(1):4360. Epub 2021 Feb 23.

Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan.

This study aims to develop a volume-based algorithm (VBA) that can rapidly optimize rotating gantry arc angles and predict the lung V preceding the treatment planning. This phantom study was performed in the dynamic arc therapy planning systems for an esophageal cancer model. The angle of rotation of the gantry around the isocenter as defined as arc angle (θ), ranging from 360° to 80° with an interval of 20°, resulting in 15 different θ of treatment plans. Read More

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February 2021

Personalized automation of treatment planning in head-neck cancer: A step forward for quality in radiation therapy?

Phys Med 2021 Feb 25;82:7-16. Epub 2021 Jan 25.

Radiation Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Italy; DIMES, Alma Mater Studiorum Bologna University, Italy.

Purpose: To perform a comprehensive dosimetric and clinical evaluation of the new Pinnacle Personalized automated planning system for complex head-and-neck treatments.

Methods: Fifteen consecutive head-neck patients were enrolled. Radiotherapy was prescribed using VMAT with simultaneous integrated boost strategy. Read More

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February 2021

Development and clinical validation of a robust knowledge-based planning model for stereotactic body radiotherapy treatment of centrally located lung tumors.

J Appl Clin Med Phys 2021 Jan 7;22(1):146-155. Epub 2020 Dec 7.

Medical Physics Graduate Program, Department of Radiation Medicine, University Kentucky, Lexington, KY, USA.

Purpose: To develop a robust and adaptable knowledge-based planning (KBP) model with commercially available RapidPlan for early stage, centrally located non-small-cell lung tumors (NSCLC) treated with stereotactic body radiotherapy (SBRT) and improve a patient's"simulation to treatment" time.

Methods: The KBP model was trained using 86 clinically treated high-quality non-coplanar volumetric modulated arc therapy (n-VMAT) lung SBRT plans with delivered prescriptions of 50 or 55 Gy in 5 fractions. Another 20 independent clinical n-VMAT plans were used for validation of the model. Read More

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January 2021

Dosimetric Comparison of Intensity-Modulated Radiotherapy, Volumetric Modulated Arc Therapy and Hybrid Three-Dimensional Conformal Radiotherapy/Intensity-Modulated Radiotherapy Techniques for Right Breast Cancer.

J Clin Med 2020 Nov 29;9(12). Epub 2020 Nov 29.

Department of Medical Imaging and Radiological Technology, Yuanpei University of Medical Technology, Hsinchu 30015, Taiwan.

This study aimed to compare different types of right breast cancer radiotherapy planning techniques and to estimate the whole-body effective doses and the critical organ absorbed doses. The three planning techniques are intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT; two methods) and hybrid 3D-CRT/IMRT (three-dimensional conformal radiotherapy/intensity-modulated radiotherapy). The VMAT technique includes two methods to deliver a dose: non-continuous partial arc and continuous partial arc. Read More

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November 2020

Dosimetric feasibility of brain stereotactic radiosurgery with a 0.35 T MRI-guided linac and comparison vs a C-arm-mounted linac.

Med Phys 2020 Nov 18;47(11):5455-5466. Epub 2020 Oct 18.

Radiation and Cellular Oncology, University of Chicago, Chicago, IL, 60637, USA.

Purpose: MRI is the gold-standard imaging modality for brain tumor diagnosis and delineation. The purpose of this work was to investigate the feasibility of performing brain stereotactic radiosurgery (SRS) with a 0.35 T MRI-guided linear accelerator (MRL) equipped with a double-focused multileaf collimator (MLC). Read More

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November 2020

Application of 3D-print silica bolus for nasal NK/T-cell lymphoma radiation therapy.

J Radiat Res 2020 Nov;61(6):920-928

Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.

The aim of the study was to evaluate the clinical feasibility of a 3D-print silica bolus for nasal NK/T-cell lymphoma radiation therapy. Intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) plans were designed using an anthropomorphic head phantom with a 3D-print silica bolus and other kinds of bolus used clinically, and the surface dose was measured by a metal oxide semiconductor field-effect transistor (MOSFET) dosimeter. Four nasal NK/T patients with or without 3D-print silica bolus were treated and the nose surface dose was measured using a MOSFET dosimeter during the first treatment. Read More

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November 2020

The potential of Gantry beamline large momentum acceptance for real time tumour tracking in pencil beam scanning proton therapy.

Sci Rep 2020 09 18;10(1):15325. Epub 2020 Sep 18.

Center for Proton Therapy, WMSA/C14, Paul Scherrer Institute, 5232, Villigen, Switzerland.

Tumour tracking is an advanced radiotherapy technique for precise treatment of tumours subject to organ motion. In this work, we addressed crucial aspects of dose delivery for its realisation in pencil beam scanning proton therapy, exploring the momentum acceptance and global achromaticity of a Gantry beamline to perform continuous energy regulation with a standard upstream degrader. This novel approach is validated on simulation data from three geometric phantoms of increasing complexity and one liver cancer patient using 4D dose calculations. Read More

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September 2020

Characterization and clinical validation of patient-specific three-dimensional printed tissue-equivalent bolus for radiotherapy of head and neck malignancies involving skin.

Phys Med 2020 Sep 20;77:138-145. Epub 2020 Aug 20.

University of California Davis Comprehensive Cancer Center, Department of Radiation Oncology, Sacramento, CA, United States. Electronic address:

Purpose: Megavoltage radiotherapy to irregular superficial targets is challenging due to the skin sparing effect. We developed a three-dimensional bolus (3DB) program to assess the clinical impact on dosimetric and patient outcomes.

Materials And Methods: Planar commercial bolus (PCB) and 3DB density, clarity, and net bolus effect were rigorously evaluated prior to clinical implementation. Read More

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September 2020

A modular dose delivery system for treating moving targets with scanned ion beams: Performance and safety characteristics, and preliminary tests.

Phys Med 2020 Aug 30;76:307-316. Epub 2020 Jul 30.

Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany. Electronic address:

Purpose: The purpose of this study was to develop a modular dose-delivery system (DDS) for scanned-ion radiotherapy that mitigates against organ motion artifacts by synchronizing the motion of the beam with that of the moving anatomy.

Methods: We integrated a new motion synchronization system and an existing DDS into two centers. The modular approach to integration utilized an adaptive layer of software and hardware interfaces. Read More

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Dosimetric benefits of gantry-static couch-motion (GsCM) technique for breast boost radiation therapy: Reduced dose to organs-at-risk and improved dosimetric indices.

J Appl Clin Med Phys 2020 Sep 5;21(9):71-81. Epub 2020 Jul 5.

Department of Radiation Medicine, Center for Advanced Medicine, Northwell Health, New York, NY, USA.

To evaluate the clinical feasibility and dosimetric benefits of a novel gantry-static couch-motion (GsCM) technique for external beam photon boost treatment of lumpectomy cavity in patients with early-stage breast cancer in comparison to three-dimensional conformal radiotherapy (3D-CRT), wedge pair in supine position (WPS), and wedge pair in decubitus position (WPD) techniques. A retrospective review was conducted on breast patients (right breast, n = 10 and left breast, n = 10) who received 10 Gy boost after 50 Gy to whole breast. The treatment plans were generated using an isocentric-based GsCM technique (a VMAT type planning approach) integrating couch rotational motion at static gantry positions. Read More

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September 2020

Intracranial Stereotactic Radiation Therapy With a Jawless Ring Gantry Linear Accelerator Equipped With New Dual Layer Multileaf Collimator.

Adv Radiat Oncol 2020 May-Jun;5(3):482-489. Epub 2020 Jan 28.

Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri.

Purpose: To test the feasibility of a simplified, robust, workflow for intracranial stereotactic radiation therapy (SRT) using a ring gantry linear accelerator (RGLA) equipped with a dual-layer stacked, staggered, and interdigitating multileaf collimator.

Materials And Methods: Twenty recent clinical SRT cases treated using a radiosurgery c-arm linear accelerator were anonymized. From these data sets, a new planning workflow was developed and used to replan these cases, which then were compared to their clinical counterparts. Read More

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January 2020

Feasibility study for marker-based VMAT plan optimization toward tumor tracking.

J Appl Clin Med Phys 2020 Jul 11;21(7):84-99. Epub 2020 Jun 11.

Division of Medical Physics, CancerCare Manitoba, Winnipeg, MB, Canada.

This work investigates the incorporation of fiducial marker-based visibility parameters into the optimization of volumetric modulated arc therapy (VMAT) plans. We propose that via this incorporation, one may produce treatment plans that aid real-time tumor tracking approaches employing exit imaging of the therapeutic beam (e.g. Read More

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