bluuebunny/crossref_metadata_2025_split huggingface dataset:
MO‐FG‐207‐01: Technological Advances and Challenges: Experience with the First Integrated Whole‐Body PET/MRI
Authors: Laforest R. 
Published: June 2015

The use of integrated PET/MRI systems in clinical applications can best benefit from understanding their technological advances and limitations. The currently available clinical PET/MRI systems have their own characteristics. Thorough analyses of existing technical data and evaluation of necessary performance metrics for quality assurances could be conducted to optimize application‐specific PET/MRI protocols. This Symposium will focus on technical advances and limitations of clinical PET/MRI systems, and how this exciting imaging modality can be utilized in applications that can benefit from both PET and MRI.Learning Objectives:

To understand the technological advances of clinical PET/MRI systems
To correctly identify clinical applications that can benefit from PET/MRI
To understand ongoing work to further improve the current PET/MRI technology
Floris Jansen is a GE Healthcare employee.
MO‐FG‐201‐02: High‐Impact Presentations
Authors: Weiker T. 
Published: June 2015

Oral presentations are one of the most important tools to advance education, scientific research, and clinical excellence in medical physics. Medical physicists do not often captivate their audiences like a Steve Jobs keynote or a TED talk, but every physicist can learn to engage their audiences and deliver their message in a memorable way using their own personality and style. This interactive session will teach attendees to discover their own style and voice and to use it to engage and connect with their audiences. Audience reception and response will be reviewed in terms of the speaker's executive presence and content, as well as research on the psychology of audiences and physiology of speakers. Physicists will learn how to organize and mentally prepare themselves as well as their PowerPoint slides.Learning Objectives:

Develop executive presence: poised under pressure to deliver a message in a relaxed, casual, and credible way
Connect with an audience by creating harmony between the content and the visual and audible elements of a presentation
Confidently deliver engaging presentations in the individual's voice and personality
Heidi Weiker and Tanya Weiker are co‐owners of Spherica LLC.
MO‐FG‐210‐03: Intraoperative Ultrasonography‐Guided Positioning of Plaque Brachytherapy in the Treatment of Choroidal Melanoma
Authors: Lamb J. 
Published: June 2015

Ultrasound (US) is one of the most widely used imaging modalities in medical practice. Since US imaging offers real‐time imaging capability, it has becomes an excellent option to provide image guidance for brachytherapy (IGBT). (1) The physics and the fundamental principles of US imaging are presented, and the typical steps required to commission an US system for IGBT is provided for illustration. (2) Application of US for prostate HDR brachytherapy, including partial prostate treatments using MR‐ultrasound co‐registration to enable a focused treatment on the disease within the prostate is also presented. Prostate HDR with US image guidance planning can benefit from real time visualization of the needles, and fusion of the ultrasound images with T2 weighted MR allows the focusing of the treatment to the specific areas of disease within the prostate, so that the entire gland need not be treated. Finally, (3) ultrasound guidance for an eye plaque program is presented. US can be a key component of placement and QA for episcleral plaque brachytherapy for ocular cancer, and the UCLA eye plaque program with US for image guidance is presented to demonstrate the utility of US verification of plaque placement in improving the methods and QA in episcleral plaque brachytherapy.Learning Objectives:

To understand the physics of an US system and the necessary aspects of commissioning US for image guided brachytherapy (IGBT).
To understand real time planning of prostate HDR using ultrasound, and its application in partial prostate treatments using MR‐ultrasound fusion to focus treatment on disease within the prostate.
To understand the methods and QA in applying US for localizing the target and the implant during a episcleral plaque brachytherapy procedures.
MO‐F‐CAMPUS‐T‐02: An Electronic Whiteboard Platform to Manage Treatment Planning Process
Authors: DiCostanzo D , Thompson S , Woollard J , Gupta N , Ayan A 
Published: June 2015

Purpose:In an effort to improve patient safety and streamline the radiotherapy treatment planning (TP) process, a software based whiteboard had been developed and put in use in our facilityMethods:The electronic whiteboard developed using SQL database (DB) and PHP/JavaScript based web interface, is published via department intranet and login credentials. The DB stores data for each TP process such as patient information, plan type, simulation/start dates, physician, dosimetrist, QA and the current status in planning process. Users interact with the DB per plan and perform status updates in real time as the planning process progresses. All user interactions with the DB are recorded with timestamps so as to calculate statistical information for TP process management such as contouring times, planning and review times, dosimetry, physics and therapist QA times. External beam and brachytherapy plans are categorized according to complexity (ex: IMRT, 3D, HDR, LDR etc) and treatment types and applicators. Each plan category is assigned specific timelines for each planning process. When a plan approaches or passes the predetermined timeline, users are alerted via color coded graphical cues. When certain process items are not completed in time, pre‐determined actions are triggered such as a delay in treatment start date.Results:Our institution has been using the electronic whiteboard for two years. Implementation of pre‐determined actions based on the statistical information collected by the whiteboard improved our TP process. For example, the average time for normal tissue contouring decreased from 0.73±1.37 to 0.24±0.33 days. The average time for target volume contouring decreased from 3.2±2.84 to 2.37±2.54 days. This increase in efficiency allows more time for quality assurance processes, improving patient safety.Conclusion:The electronic whiteboard has been an invaluable tool for streamlining our TP processes. It facilitates timely and accurate communication between all parties involved in the TP process increasing patient safety.
MO‐F‐CAMPUS‐T‐01: Radiosurgery of Multiple Brain Metastases with Single‐Isocenter VMAT: Optimizing Treatment Geometry to Reduce Normal Brain Dose
Authors: Wu Q , Snyder K , Liu C , Huang Y , Li H , Chetty I , Wen N 
Published: June 2015

Purpose:To develop an optimization algorithm to reduce normal brain dose by optimizing couch and collimator angles for single isocenter multiple targets treatment of stereotactic radiosurgery.Methods:Three metastatic brain lesions were retrospectively planned using single‐isocenter volumetric modulated arc therapy (VMAT). Three matrices were developed to calculate the projection of each lesion on Beam's Eye View (BEV) by the rotating couch, collimator and gantry respectively. The island blocking problem was addressed by computing the total area of open space between any two lesions with shared MLC leaf pairs. The couch and collimator angles resulting in the smallest open areas were the optimized angles for each treatment arc. Two treatment plans with and without couch and collimator angle optimization were developed using the same objective functions and to achieve 99% of each target volume receiving full prescription dose of 18Gy. Plan quality was evaluated by calculating each target's Conformity Index (CI), Gradient Index (GI), and Homogeneity index (HI), and absolute volume of normal brain V8Gy, V10Gy, V12Gy, and V14Gy.Results:Using the new couch/collimator optimization strategy, dose to normal brain tissue was reduced substantially. V8, V10, V12, and V14 decreased by 2.3%, 3.6%, 3.5%, and 6%, respectively. There were no significant differences in the conformity index, gradient index, and homogeneity index between two treatment plans with and without the new optimization algorithm.Conclusion:We have developed a solution to the island blocking problem in delivering radiation to multiple brain metastases with shared isocenter. Significant reduction in dose to normal brain was achieved by using optimal couch and collimator angles that minimize total area of open space between any of the two lesions with shared MLC leaf pairs. This technique has been integrated into Eclipse treatment system using scripting API.
MO‐F‐CAMPUS‐J‐05: Using 2D Relative Gamma Analysis From EPID Image as a Predictor of Plan Deterioration Due to Anatomical Changes
Authors: Piron O , Varfalvy N , Archambault L 
Published: June 2015

Purpose:One of the side effects of radiotherapy for head and neck (H&N) cancer is the patient's anatomical changes. The changes can strongly affect the planned dose distribution. In this work, our goal is to demonstrate that relative analysis of EPID images is a fast and simple method to detect anatomical changes that can have a strong dosimetric impact on the treatment plan for H&N patients.Methods:EPID images were recorded at every beam and all fractions for 50 H&N patients. Of these, five patients that showed important anatomical changes were selected to evaluate dosimetric impacts of these changes and to correlate them with a 2D relative gamma analysis of EPID images. The planning CT and original contours were deformed onto CBCTs (one mid treatment and one at the end of treatment). By using deformable image registration, it was possible to map accurate CT numbers from the planning CT to the anatomy of the day obtained with CBCTs. Clinical treatment plan were then copied on the deformed dataset and dose was re‐computed. In parallel, EPID images were analysed using the gamma index (3%3mm) relative to the first image.Results:It was possible to divide patients in two distinct, statistically different (p<0.001) categories using an average gamma index of 0.5 as a threshold. Below this threshold no significant dosimetric degradation of the plan are observed. Above this threshold two types of plan deterioration were seen: (1) target dose increases, but coverage remains adequate while dose to at least one OAR increases beyond tolerances; (2) the OAR doses remain low, but the target dose is reduced and coverage becomes inadequate.Conclusion:Relative analysis gamma of EPID images could indeed be a fast and simple method to detect anatomical changes that can potentially deteriorates treatment plan for H&N patients.This work was supported in part by Varian Medical System
MO‐F‐CAMPUS‐I‐03: CT and MR Characteristics of Some Specialty 3D Printing Filaments
Authors: Lam K 
Published: June 2015

Purpose:To quantify the Hounsfield Unit and demonstrate MR signal of specialty 3D printer filaments that are recently made available to fused deposition modeling (FDM) 3D printers as raw materials to print 3D objects such as phantoms and patient specific boluses or shields.Methods:We acquired 2.85mm diameter batches of ColorFabb copperfill metal filament, Soft PLA filaments of different colors (Red, Blue, White, Beige, Black), BendLay filament, Taulman Bridge filament, NinjaFlex water semi‐transparent thermoplastic elastomer filament, Light Cherry Wood LAYWOO‐D3 filament, as well as the more commonly used polylactic acid (PLA) filament and acrylonitrile butadiene styrene (ABS) filament. We also included 2.5mm diameter silicone, polyurethane, neoprene, and nitrile rubber (soft Buna‐N) o‐ring cords for comparison. These filaments were arranged in a 4×4 array in a 5cm × 15cm × 15cm block of UHMW polyethylene. CT scan of 1mm slice thickness was performed with a cranial SRS protocol. MR scan was performed with an ultra‐short echo time point‐wise encoding time reduction with radial acquisition (UTE PETRA) protocol in a water bath. The CT and MR of these different materials were imported into Eclipse. In order to reduce the contribution of partial volume effect, the maximum HU of each material were determined in 4 slices and averaged.Results:The copperfill filament HU was saturated at 2975. Soft PLA filaments had HU in the range of 400–500. PLA and NinjaFlex were 100–200 HU. Taulman Bridge filament was about 63 HU. LAYWOO‐ D3, ABS, and BendLay filaments were between −60 to −30 HU. Overall, the HU of these specialty filaments spanned the range from −60 to >3000. The materials were also visible in the UTE MR image.Conclusion:The wide range of materials available to FDM 3D printing made possible the fabrication of various objects for medical physics to emulate different tissues.
MO‐F‐CAMPUS‐T‐01: IROC Houston QA Center's Anthropomorphic Proton Phantom Program
Authors: Lujano C , Hernandez N , Keith T , Nguyen T , Taylor P , Molineu A , Followill D 
Published: June 2015

Purpose:To describe the proton phantoms that IROC Houston uses to approve and credential proton institutions to participate in NCI‐sponsored clinical trials.Methods:Photon phantoms cannot necessarily be used for proton measurements because protons react differently than photons in some plastics. As such plastics that are tissue equivalent for protons were identified. Another required alteration is to ensure that the film dosimeters are housed in the phantom with no air gap to avoid proton streaming. Proton‐equivalent plastics/materials used include RMI Solid Water, Techron HPV, blue water, RANDO soft tissue material, balsa wood, compressed cork and polyethylene. Institutions wishing to be approved or credentialed request a phantom and are prioritized for delivery. At the institution, the phantom is imaged, a treatment plan is developed, positioned on the treatment couch and the treatment is delivered. The phantom is returned and the measured dose distributions are compared to the institution's electronically submitted treatment plan dosimetry data.Results:IROC Houston has developed an extensive proton phantom approval/credentialing program consisting of five different phantoms designs: head, prostate, lung, liver and spine. The phantoms are made with proton equivalent plastics that have HU and relative stopping powers similar (within 5%) of human tissues. They also have imageable targets, avoidance structures, and heterogeneities. TLD and radiochromic film are contained in the target structures. There have been 13 head, 33 prostate, 18 lung, 2 liver and 16 spine irradiations with either passive scatter, or scanned proton beams. The pass rates have been: 100%, 69.7%, 72.2%, 50%, and 81.3%, respectively.Conclusion:IROC Houston has responded to the recent surge in proton facilities by developing a family of anthropomorphic phantoms that are able to be used for remote audits of proton beams.Work supported by PHS grant CA10953 and CA081647
MO‐F‐CAMPUS‐T‐02: Dosimetric Accuracy of the CrystalBallâ„¢: New Reusable Radiochromic Polymer Gel Dosimeter for Patient QA in Proton Therapy
Authors: Avery S , Kraus J , Lin L , Kassaee A , Maryanski M 
Published: June 2015

Purpose:To evaluate the accuracy of monoexponential normalization in a new class of commercial, reusable, human‐soft‐tissue‐equivalent, radiochromic polymer gel dosimeters for patient‐specific QA in proton therapy.Methods:Eight formulations of the dosimeter (sealed in glass spheres of 166 mm OD), were exposed to a 150 MeV proton beam (5 cm × 5 cm square field, range 15 cm, modulation10 cm), with max dose ranging from 2.5 Gy to 20 Gy, depending on formulation. Exposed dosimeters were promptly placed in the commercial OCTOPUS™ laser CT scanner which was programmed to scan the central slice every 5 minutes for 20 hours (15 seconds per slice scan). This procedure was repeated several times. Reconstructed data were analyzed using the log‐lin scale to determine the time range over which a monoexponential relaxation model could be applied. Next, a simple test plan was devised and delivered to each dosimeter. The OCTOPUS™ was programmed to rescan the central slice at the end of each volume scan, for signal relaxation reference. Monoexponential normalization was applied to sinograms before FBP reconstruction. Dose calibration was based on a volume‐lookup table built within the central spherical volume of 12 cm diameter. 3D gamma and sigma passing rates were measured at 3%/3mm criteria down to 50% isodose.Results:Approximately monoexponential signal relaxation time ranges from 25 minutes to 3.5 hours, depending on formulation, followed by a slower‐relaxation component. Noise in reconstructed OD/cm images is less than 0.5%. Dose calibration accuracy is better than 99%. Measured proton PDDs demonstrate absence of Bragg‐peak quenching. Estimated number of useful cycles is at least 20, with a theoretical limit above 100. 3D gamma and sigma passing rates exceed 95%.Conclusion:Monoexponential normalization was found to yield adequate dosimetric accuracy in the new class of commercial radiochromic polymer gel dosimeters for patient QA in proton therapy.
MO‐F‐CAMPUS‐T‐04: Utilization of Optical Dosimeter for Modulated Spot‐Scanning Particle Beam
Authors: Hsi W , Li Y , Huang Z , Sheng Y , Deng Y , Zhao J , Zhao F , Sun L , Moyers M 
Published: June 2015

Purpose:To present the utilization of an optical dosimeter for modulated spot‐scanning carbon‐ion and proton beams during the acceptance test of Siemens IONTRIS system.Method and Materials:An optical dosimeter using phosphor scintillation was developed to map and interactively analyze the shapes and sizes of spots over 190 energies for ProTom modulated‐scanning system. The dose response to proton had been characterized with proper pixel calibration at ProTom system. The dose response was further studied at 0.7 cm depths by uniform 8cm in‐diameter fields of 424.89 MeV/u (E290) carbon‐ions and 215.18MeV (E282) protons at IONTRIS system. The virtual source axial distances (vSAD) of carbonions and protons of IONTRIS system was investigated by measuring either variations of spot position or field size at five different locations to Isocenter. By measuring lateral profiles of uniform doses with varied thin‐thicknesses of chest‐board pattern and placing the scintillation plate at near to the distal edge, range variations at different off‐axis‐distances (rOAD) were examined. Relative accuracy and reproducibility of beam range were measured for three beam ranges with a ramping block at front of scintillation plate.Results:Similar dose response was observed for high energies of carbon ions and protons. Mean vSAD at X and Y axes were 744.1 cm and 807.4cm with deviation of 7.4cm and 7.7cm, respectively. Variation of rOAD was within 0.35 mm over 10cm for both protons and carbon ions. Accuracy of measuring relative distal range using the ramping block was 0.2mm. Measured range over repeated three times for each range were within 0.25mm at same room, and within 1.0mm between four rooms.Conclusions:The optical dosimeter could efficiently measure the virtual source distance. And, to measure small range variation at different off‐axial locations, and for the relative beam range between rooms during acceptance test of a modulated spot‐scanning particle system.
TU‐A‐304‐02: Treatment Simulation, Planning and Delivery for SBRT
Authors: Yang Y. 
Published: June 2015

Increased use of SBRT and hypo fractionation in radiation oncology practice has posted a number of challenges to medical physicist, ranging from planning, image‐guided patient setup and on‐treatment monitoring, to quality assurance (QA) and dose delivery. This symposium is designed to provide updated knowledge necessary for the safe and efficient implementation of SBRT in various linac platforms, including the emerging digital linacs equipped with high dose rate FFF beams. Issues related to 4D CT, PET and MRI simulations, 3D/4D CBCT guided patient setup, real‐time image guidance during SBRT dose delivery using gated/un‐gated VMAT or IMRT, and technical advancements in QA of SBRT (in particular, strategies dealing with high dose rate FFF beams) will be addressed. The symposium will help the attendees to gain a comprehensive understanding of the SBRT workflow and facilitate their clinical implementation of the state‐of‐art imaging and planning techniques.Learning Objectives:

Present background knowledge of SBRT, describe essential requirements for safe implementation of SBRT, and discuss issues specific to SBRT treatment planning and QA.
Update on the use of multi‐dimensional (3D and 4D) and multi‐modality (CT, beam‐level X‐ray imaging, pre‐ and on‐treatment 3D/4D MRI, PET, robotic ultrasound, etc.) for reliable guidance of SBRT.
Provide a comprehensive overview of emerging digital linacs and summarize the key geometric and dosimetric features of the new generation of linacs for substantially improved SBRT.
Discuss treatment planning and quality assurance issues specific to SBRT.
Research grant from Varian Medical Systems
TU‐AB‐BRD‐00: Task Group 100
Authors: Huq M. Saiful 
Published: June 2015

Current quality assurance and quality management guidelines provided by various professional organizations are prescriptive in nature, focusing principally on performance characteristics of planning and delivery devices. However, published analyses of events in radiation therapy show that most events are often caused by flaws in clinical processes rather than by device failures. This suggests the need for the development of a quality management program that is based on integrated approaches to process and equipment quality assurance. Industrial engineers have developed various risk assessment tools that are used to identify and eliminate potential failures from a system or a process before a failure impacts a customer. These tools include, but are not limited to, process mapping, failure modes and effects analysis, fault tree analysis. Task Group 100 of the American Association of Physicists in Medicine has developed these tools and used them to formulate an example risk‐based quality management program for intensity‐modulated radiotherapy. This is a prospective risk assessment approach that analyzes potential error pathways inherent in a clinical process and then ranks them according to relative risk, typically before implementation, followed by the design of a new process or modification of the existing process. Appropriate controls are then put in place to ensure that failures are less likely to occur and, if they do, they will more likely be detected before they propagate through the process, compromising treatment outcome and causing harm to the patient. Such a prospective approach forms the basis of the work of Task Group 100 that has recently been approved by the AAPM. This session will be devoted to a discussion of these tools and practical examples of how these tools can be used in a given radiotherapy clinic to develop a risk based quality management program.Learning Objectives:

Learn how to design a process map for a radiotherapy process
Learn how to perform failure modes and effects analysis analysis for a given process
Learn what fault trees are all about
Learn how to design a quality management program based upon the information obtained from process mapping, failure modes and effects analysis and fault tree analysis.
Dunscombe: Director, TreatSafely, LLC and Center for the Assessment of Radiological Sciences; Consultant to IAEA and VarianThomadsen: President, Center for the Assessment of Radiological SciencesPalta: Vice President of the Center for the Assessment of Radiological Sciences