M. Mi. Zaini, PhD1, N. Boyles, BSc1,2, P. Zencak2, , D. Wenger2, E. M. Craig, PhD21Northwest Medical Physics Center, Lynnwood, WA, 2Central Washington University, Ellensburg, WA Will appear in the Journal of Physics and Chemistry
Mehran Miron Zaini, PhD1, Peter Zencak2, Nicholas Boyles, BSc1,2, Robert Campbell, BSc2, Christian Laurent2, Akshara Saha2, Addison Wenger2, Rex G. Ayers, MEng1 and Erin M Craig, PhD21Northwest Medical Physics Center, Lynnwood, WA, 2Central Washington University, Ellensburg, WA SU300-GPD(A)-LOUNGE-535 – A Tabletop Electron Gun at an Undergraduate University (2024). This project aimed to have undergraduate students at a…
Krista Burton11Northwest Medical Physics Center, Lynnwood, WA American Association of Physics Teachers Annual Winter Meeting, Portland, OR (2023).* Invited presentation * Working in the field of medical physics can take many different forms, with careers including regulatory, industry, clinical, research, and/or teaching responsibilities. Medical physicists work in a variety of specializations, including health physics, imaging…
Jessica M. Fagerstrom1 1Northwest Medical Physics Center, Lynnwood, WA American Association of Physics Teachers Annual Winter Meeting, Portland, OR (2023).* Invited presentation * Physics education research has indicated that students who perceive curricula as relating to real life applications are more engaged with learning materials, and medical physics may provide an absorbing anchoring context. Medical…
Jessica M. Fagerstrom1 1Northwest Medical Physics Center, Lynnwood, WA IUPAP International Conference on Physics Education 2022, Virtual (2022). Medical physics is a diverse and dynamic field in which principles in physics are used in a healthcare setting. Scientists in medical physics often hold graduate degrees after focused studying and research on specific subtopics within medical…
M. M. Zaini,1 E. I. Marshall1, K. M. Hedrick,1 J. M. Fagerstrom,1 D. Zaks,1 T. M. Fitzgerald1 1Northwest Medical Physics Center, Lynnwood, WA IUPESM World Congress on Medical Physics and Biomedical Engineering, Singapore (2022). Our group of about 50 clinical physicists has been engaged in measuring various beam characteristics of more than 50 therapeutic linear accelerators in more than…
T. Brown,1 C. Beck,1 H. Holloway,1 J. Kerns,2 J. Fagerstrom,1 D. Kaurin,1 K. Kielar21Northwest Medical Physics Center, Lynnwood, WA; 2Varian Medical Systems, Palo Alto ESTRO Annual Meeting, Madrid, Spain (2021). Purpose/Objective: A new anthropomorphic head phantom has been designed by Varian Medical Systems for the purposes of commissioning MLC-based SRS treatments on TrueBeam and EDGE linear accelerators. The validation of the phantom prototype…
T. Brown,1 J. Fagerstrom,1 C. Beck,1 C. Holloway,1 J. Kerns,2 D. Kaurin,1 K. Kielar21Northwest Medical Physics Center, Lynnwood, WA; 2Varian Medical Systems, Palo Alto AAPM Annual Scientific Meeting, Virtual (2021). Purpose: An end-to-end procedure for a new anthropomorphic phantom was developed for MLC-based SRS commissioning on a linear accelerator. This procedure was developed and tested by Northwest Medical Physics Center at three independent…
M. M. Zaini,1,2 S. S. Honeywell,2 M. A. Whiton,2 A. P. Mazza,1,2 R. Poortvliet,2 C. Kahnke21Northwest Medical Physics Center, Lynnwood, WA; 2Skagit Valley Hospital, Mount Vernon, WA AAPM/COMP Annual Scientific Meeting, Virtual (2020). Purpose: To evaluate two TPS algorithms and their agreement with in-vivo measurements of a brass bolus VMAT treatment case. Methods: VMAT treatment was prescribed for a young post-mastectomy right breast…
D. Zaks,1 R. Bassalow,2 O. Volotskova,3 M. Narayanan,1 C. Huntzinger,1 S. Shirvani,1 S. Mazin,1 G. Kuduvalli11RefleXion Medical, Hayward, CA; 2Northwest Medical Physics Center, Silverdale, WA; 3Sutter Health, Berkeley, CA AAPM/COMP Annual Scientific Meeting, Virtual (2020). Purpose: To benchmark the mechanical performance of the RefleXion™ X1 biology-guided radiotherapy (BgRT) machine, which employs a novel architecture with linac, kVCT and PET subsystems in the same treatment gantry,…
D. Zaks,1 M. Narayanan,1 R. Bassalow,2 O. Volotskova,3 Y. Voroneknko,1 D. Pal,4 D. Rigie,1 J. Burns,1 A. Purwar,1 P. Olcott,1 G. Kuduvalli11RefleXion Medical, Hayward, CA; 2Northwest Medical Physics Center, Silverdale, WA; 3Sutter Health, Berkeley, CA; 4GE Healthcare, Menlo Park, CA AAPM/COMP Annual Scientific Meeting, Virtual (2020). Purpose: To characterize the IMRT and SBRT performance of the RefleXion™ X1 biology-guided radiotherapy (BgRT) machine using the ArcCHECK (AC) dosimetry device. Methods: Plans…
D. Zaks,1 R. Bassalow,2 S. Maganti,1 Y. Voroneknko,1 D. Rigie,1 O. Volotskova,3 P. Olcott,1 G. Kuduvalli11RefleXion Medical, Hayward, CA; 2Northwest Medical Physics Center, Silverdale, WA; 3Sutter Health, Berkeley, CA; 4GE Healthcare, Menlo Park, CA AAPM/COMP Annual Scientific Meeting, Virtual (2020). Purpose: To validate the performance of the RefleXion™ X1 biology-guided radiotherapy (BgRT) TPS following the testing methodology outlined in IAEA-TECDOC-1540: Specification and Acceptance Testing of Radiotherapy…
D. Zaks,1 M. Narayanan,1 R. Bassalow,2 O. Volotskova,3 C. Huntzinger,1 S. Shirvani,1 S. Mazin,1 G. Kuduvalli11RefleXion Medical, Hayward, CA; 2Northwest Medical Physics Center, Silverdale, WA; 3Sutter Health, Berkeley, CA; 4GE Healthcare, Menlo Park, CA AAPM/COMP Annual Scientific Meeting, Virtual (2020). Purpose: To validate the ArcCheck (AC) dosimetry device as a dosimetry tool to measure the dose delivered by a the RefleXion™ X1 biology-guided radiotherapy (BgRT) machine….
Jessica M. Fagerstrom,1,2 Jeffrey Marotta,2 Justin Cantley1,21Northwest Medical Physics Center, Lynnwood, WA; 2Kaiser Permanente, Seattle, WA AAPM/COMP Annual Scientific Meeting, Virtual (2020). Purpose: A community hospital developed an MRI-based high dose rate (HDR) brachytherapy program. The program launched treating locally advanced cervical and non-operable endometrial cancer, intending to add other sites in the future. To initiate the program, physics…
Christopher Anderson,1,2 Jose Garcia-Cobian,2 Bing Fang21Pacific Lutheran University, Tacoma, WA; 2Northwest Medical Physics Center, Lynnwood, WA Radiosurgery Society (RSS) Annual Scientific Meeting, Virtual (2020). Purpose: In CyberKnife® (Accuray – Sunnyvale, CA) radiosurgery plans created to treat brain lesions, orienting the ion chamber across the couch instead of longitudinally has been observed to sometimes yield closer agreement between the dose…
R. Alex Hsi,1 Adam Schoen1,21Evergreen Health Cancer Care, Kirkland, WA; 2Northwest Medical Physics Center, Lynnwood, WA ASTRO Annual Scientific Meeting, Chicago, IL (2019). Purpose: To assess the outcomes of intra-fraction prostate motion monitoring using an integrated linear accelerator based KV imaging system. Methods: Between June 2017 and December 2018, 1516 radiation treatment fractions were delivered to 35 prostate cancer…
Jennifer Fisher,1 Darryl Kaurin11Northwest Medical Physics Center, Lynnwood, WA AAPM Southwest Chapter Meeting, Little Rock, AK (2019). Invited presentation at the annual American Association of Physicists in Medicine Southwest Chapter Meeting.
D. G. Kaurin,1 A. Eagle,1 A. Hart,1 C. Holloway,1 G. J. Courlas,1 P. Stevens,1 O. Gopan,1 A. Schoen11Northwest Medical Physics Center, Lynnwood, WA ASTRO Annual Scientific Meeting, Chicago, IL (2018). Purpose: For calibration of flattening filter-free (FFF) linac beams, one needs to either use a chamber small enough to avoid volume averaging that occurs with the conventional Farmer-type chamber, or apply a gradient…
G. Johnson,1 J. F. Raymond,1 R. Moore,2 H. Nottingham,2 M. Quiles,2 D. G. Kaurin11Northwest Medical Physics Center, Lynnwood, WA; 2Providence RadiantCare Radiation Oncology, Lacey, WA ASTRO Annual Scientific Meeting, San Antonio, TX (2018). Purpose: To investigate dosimetric clinical appropriateness of on-board kV cone beam computed tomography patient simulation (CBCT-Sim) for palliative treatment plans at a remote satellite clinic having no conventional computed…
K. Wake,1 S. Mahendra11Northwest Medical Physics Center, Lynnwood, WA AAPM Annual Scientific Meeting, Nashville, TN (2018). Purpose: To explore observed dose discrepancies between photon and electron irradiated OSLDs and determine the optimum procedure for creating and using linear and nonlinear microSTARii calibration files based on specific dose range and energy source of clinical relevance. Methods: Commercial dosimeters (Landauer…
G. Johnson,1 C. Malmer,1 B. Owen,1 J. Garci-Cobian,1 S. Small,1 D. King,2 D. Siergiej31Northwest Medical Physics Center, Lynnwood, WA; 2Madigan Army Medical Center, Joint Base Lewis-McChord, WA; 3University of New Mexico, Albuquerque, NM AAPM Annual Scientific Meeting, Nashville, TN (2018). Purpose: To investigate different detectors for relative dosimetry of small fields using a traditional linear accelerator and following the International Atomic Energy Agency (IAEA)…
G. Johnson,1 E. Marshall11Northwest Medical Physics Center, Lynnwood, WA AAPM Annual Scientific Meeting, Nashville, TN (2018). Purpose: To develop a jaw calibration technique and independent jaw test tolerances, accounting for fluctuation of position for a Varian C-series linac. Methods: The jaws were tested to determine how much their position fluctuates in three different scenarios. Motion direction was tested…
D. McFadden,1 P. Jewell,2 N. McIlmoil,2 K. Wake21Northwest Medical Physics Center, Lynnwood, WA; 2Olympic Medical Cancer Center, Sequim, WA AAPM Annual Scientific Meeting, Nashville, TN (2018). Purpose: To shield the fetus from radiation exposure during an IMRT treatment to the brain, per TG 36 and TG 158. Methods: A mobile shield on wheels was designed to straddle the treatment couch and…
Brianna Owen,1 Saikanth Mahendra,1 Bryan Jackson11Northwest Medical Physics Center, Lynnwood, WA AAPM Spring Clinical Meeting, Las Vegas, NV (2018). Purpose: The purpose of this work is to characterize annealing and decay characteristics of OSLD’s using the NMPC annealer and ambient clinical light. This required commissioning a new MicroSTAR ii system. Methods: To commission the MicroSTAR ii system, calibration OSLD’s…
Saikanth Mahendra,1 Adam Schoen,1 Karla D. Thrall21Northwest Medical Physics Center, Lynnwood, WA; 2SNBL USA, Ltd., Everett, WA Radiation Research Society (RRS) Annual Meeting, Cancun, Mexico (2017). Cutaneous radiation injury (CRI) studies in guinea pigs are considered a good small animal model to assess the human dermal response to low-penetrating acute irradiation exposures for prospective medical countermeasures (MCMs). The…
Karla D. Thrall,1, Saikanth Mahendra,2 Thomas J MacVittie31SNBL USA, Ltd., Everett, WA; 2Northwest Medical Physics Center, Lynnwood, WA; 3Department Of Radiation Oncology, University of Maryland, School of Medicine, Baltimore, MD Radiation Research Society (RRS) Annual Meeting, Cancun, Mexico (2017). Concerns over nuclear and radiological threats have prompted the need to improve methods to protect the general population from…
Saikanth Mahendra,1 Karla D. Thrall21Northwest Medical Physics Center, Lynnwood, WA; 2SNBL USA, Ltd., Everett, WA Radiation Research Society (RRS) Annual Meeting, Puako, HI (2016). The characteristics of a linear accelerator generated 6MeV radiation beam are well suited for development of radiation-induced skin injury models. Based on literature, swine has been widely accepted as the closest skin model…
M. M. Zaini,1 A. R. Schoen,1 L. M. Arvan,1 E. I. Marshall,1 G. E. Robertson,1 C. G Beck,1 A. L. Eagle,1 L. E. Sweeney11Northwest Medical Physics Center, Lynnwood, WA World Congress on Medical Physics and Biomedical Engineering, Toronto, Canada (2015). NMPC also chaired this scientific session. The application of low energy X-rays has recently increased in the dermatology workspace, with the generating tube potential…
E. Marshall,1 M. Zaini,1 A. Schoen,1 L. Arvan,1 G. Robertson11Northwest Medical Physics Center, Lynnwood, WA NWAAPM Spring 2015 meeting, Young Investigator Presentation. Portland, Oregon (2015).
S. Robertson,1 D. Kaurin,1,2 J. Kim,2,3 L. Fang,2,3 L. Sweeney,1,2 K. Halloway,2 A. Tran2,31Northwest Medical Physics Center, Lynnwood, WA; 2Seattle Cancer Care Alliance, Seattle, WA; 3University of Washington Medical Center, Seattle, WA AAPM Annual Scientific Meeting, Austin, TX (2014). Purpose: Our institution uses a manual laser-based system for primary localization and verification during radiation treatment of left-sided breast cancer patients using deep inspiration breath hold (DIBH). This primary system was…
K. Hedrick,1 T. Fitzgerald,1 R. Miller11Northwest Medical Physics Center, Lynnwood, WA AAPM Annual Scientific Meeting, Austin, TX (2014). Purpose: To standardize output constancy check procedures in a large medical physics practice group covering multiple sites, in order to identify and reduce small systematic errors caused by differences in equipment and the procedures of multiple physicists. Methods: A standardized machine…
A. Nguyen,1,3 P. Rajaguru,1 D. Kaurin,2 T. Paul,3 R. He,2,3 A. Plowman,4 C. Yang11University of Mississippi Medical Center, Jackson, MS; 2Northwest Medical Physics Center, Lynnwood, WA; 3Ironwood CRC, Phoeniz, AZ; 4Remote Dosimetry Services, Lucedale, MS AAPM Annual Scientific Meeting, Austin, TX (2014). Purpose: To establish a set of tests based on the iCOM software that can be used to commission and perform periodic QA of VMAT…
M. M. Zaini,1 A. R. Schoen11Northwest Medical Physics Center, Lynnwood, WA ASTRO Annual Scientific Meeting, San Francisco, CA (2014). Purpose/Objectives: To commission and analyze a new low energy high dose rate electronic brachytherapy system. Materials/Methods: Half-value layer (HVL), absolute dose output, beam profiles, and insert factors of an electronic brachytherapy system (EBT) were measured and analyzed. A thimble-shaped parallel-plate…
J. Mathews,1,2 P. Stevens,1,2 M. Zaini1,21Northwest Medical Physics Center, Lynnwood, WA; 2Skagit Valley Regional Health Center, Mount Vernon, WA ASTRO Annual Scientific Meeting, San Francisco, CA (2014). Purpose/Objectives: To measure output factors produced by the liquid-filled ion chamber at different field sizes and use the data to evaluate the liquid-filled ion chamber’s performance in a clinical setting compared to its gas-filled…
C. Holloway,1 S. Mahendra,1 D. Kaurin,1 Larry E. Sweeney11Northwest Medical Physics Center, Lynnwood, WA AAPM Annual Scientific Meeting, Indianapolis, IN (2013). Purpose: To adequately monitor the doses for Total Body Irradiation (TBI) patients using opposed fields, we carry out both active and passive in vivo dosimetry, with the passive dosimeter being Optically Stimulated Luminescence (OSL) detectors. The OSLs are embedded in hemispherical brass buildup caps with the OSL/flat surface…
M. Fredrickson,1 L. Arvan,1 G. Courlas,1 L. Sweeney,1 D. Kaurin11Northwest Medical Physics Center, Lynnwood, WA AAPM Annual Scientific Meeting, Charlotte, NC (2012). Purpose: This limited study determines the fraction of prostate IMRT patients who do not need setup adjustments, following initial setup, for their first 5 and last 5 fractions. For patients needing setup adjustments during their first or last 5…
M. M. Zaini,1,2 G.A. Sandison21Northwest Medical Physics Center, Lynnwood, WA; 2University of Washington, Seattle, WA ASTRO Annual Scientific Meeting, Boston, MA (2012). Purpose/Objectives: Cancer patients undergoing highly fractionated radiation therapy may experience changes in the relative position of their tumor and surrounding normal tissues during the course of their therapy. These temporal changes impact the planned distribution of radiation, and…
Darryl Kaurin,1,2 Edward Marshall,1 M. M. Zaini,1,2 Larry Sweeney,1,2 Saikanth Mahendra1,21Northwest Medical Physics Center, Lynnwood, WA; 2Seattle Cancer Care Alliance, Seattle, WA ASTRO Annual Scientific Meeting, Miami Beach, FL (2011). Purpose/Objective(s): Our institution has two accelerators that are beam matched, one having a kevlar couch and the other carbon-fiber. We were concerned about couch attenuation for volumetric modulated arc therapy (VMAT), as well…
M. M. Zaini,1,2 W. Bryan Jackson,1,2 Kellen K. Thuo11Northwest Medical Physics Center, Lynnwood, WA; 2Skagit Valley Regional Health Center, Mount Vernon, WA RSNA Annual Scientific Meeting, Chicago, IL (2011). Purpose: Daily cone-beam CT-based 3D dosimetry allows the observation of anatomical and dosimetric changes in the patients undergoing radiation therapy. To derive meaningful anatomical and dosimetric information from the daily changes to…
M. M. Zaini,1,2 W. B. Jackson,1,2 K. K. Thuo,1 G. A. Sandison,3 H. P. Patel,1,2 M. T. Luckstead,1,2 M. A. Whiton,2 L. E. Sweeney11Northwest Medical Physics Center, Lynnwood, WA; 2Skagit Valley Regional Health Center, Mount Vernon, WA; 3University of Washington, Seattle, WA ASTRO Cancer Imaging and Radiation Therapy Symposium, Atlanta, GA (2011). Purpose/Objective(s): To introduce a method that allows for inter-fraction modifications to a treatment…
A. Eagle,1 M. Mann1, J. Washington,2 L. Sweeney,2 D. Kaurin,2 S. Qui,3 W. Simon,4 F. Newman5 1Lutheran Medical Center, Wheat Ridge, CO; 2Northwest Medical Physics Center, Lynnwood, WA; 3University Of Colorado, Denver, Aurora, CO; 4Sun Nuclear Corporation, Melbourne, FL, 5University of Colorado Health Science, Aurora, CO AAPM/COMP Annual Scientific Meeting, Vancouver, BC (2011). Purpose: To characterize the activation of the Sun Nuclear MapCheck2 diode array when…
M. R. Zaini,1,2 T. A. Blackwell1,21Northwest Medical Physics Center, Lynnwood, WA; 2Skagit Valley Regional Health Center, Mount Vernon, WA ASTRO Annual Scientific Meeting, Chicago, IL (2009). Purpose/Objective(s): Volumetric Modulated Arc Therapy (VMAT) is a new treatment modality in radiation therapy marketed by Elekta. VMAT uses both temporal and spatial modulation in delivering large arcs of radiation to patients. The aim…