bluuebunny/crossref_metadata_2025_split huggingface dataset:
TU‐G‐213‐00: The International Electrotechnical Commission (IEC): What Is It and Why Should Medical Physicists Care?
Authors: Supanich Mark 
Published: June 2015

The International Electrotechnical Commission (IEC) writes standards that manufacturers of electrical equipment must comply with. Medical electrical equipment, such as medical imaging, radiation therapy, and radiation dosimetry devices, fall under Technical Committee 62. Of particular interest to medical physicists are the standards developed within Subcommittees (SC) 62B, which addresses diagnostic radiological imaging equipment, and 62C, which addresses equipment for radiation therapy, nuclear medicine and dosimetry. For example, a Working Group of SC 62B is responsible for safety and quality assurance standards for CT scanners and a Working Group of SC 62C is responsible for standards that set requirements for dosimetric safety and accuracy of linacs and proton accelerators. IEC standards thus have an impact on every aspect of a medical physicist's job, including equipment testing, shielding design, room layout, and workflow. Consequently, it is imperative that US medical physicists know about existing standards, as well as have input on those under development or undergoing revision.The structure of the IEC and current standards development work will be described in detail. The presentation will explain how US medical physicists can learn about IEC standards and contribute to their development.Learning Objectives:

Learn about the structure of the IEC and the influence that IEC standards have on the design of equipment for radiology and radiation therapy.
Learn about the mechanisms by which the US participates in the development and revision of standards.
Understand the specific requirements of several standards having direct relevance to diagnostic and radiation therapy physicists.
TU‐G‐213‐01: IEC and US Committee Activities and Organizational Structure
Authors: Ibbott G. 
Published: June 2015

The International Electrotechnical Commission (IEC) writes standards that manufacturers of electrical equipment must comply with. Medical electrical equipment, such as medical imaging, radiation therapy, and radiation dosimetry devices, fall under Technical Committee 62. Of particular interest to medical physicists are the standards developed within Subcommittees (SC) 62B, which addresses diagnostic radiological imaging equipment, and 62C, which addresses equipment for radiation therapy, nuclear medicine and dosimetry. For example, a Working Group of SC 62B is responsible for safety and quality assurance standards for CT scanners and a Working Group of SC 62C is responsible for standards that set requirements for dosimetric safety and accuracy of linacs and proton accelerators. IEC standards thus have an impact on every aspect of a medical physicist's job, including equipment testing, shielding design, room layout, and workflow. Consequently, it is imperative that US medical physicists know about existing standards, as well as have input on those under development or undergoing revision.The structure of the IEC and current standards development work will be described in detail. The presentation will explain how US medical physicists can learn about IEC standards and contribute to their development.Learning Objectives:

Learn about the structure of the IEC and the influence that IEC standards have on the design of equipment for radiology and radiation therapy.
Learn about the mechanisms by which the US participates in the development and revision of standards.
Understand the specific requirements of several standards having direct relevance to diagnostic and radiation therapy physicists.
TU‐G‐BRD‐01: Quantifying the Effectiveness of the Physics Pre‐Treatment Plan Review for Detecting Errors in Radiation Therapy
Authors: Gopan O , Novak A , Zeng J , Ford E 
Published: June 2015

Purpose:Physics pre‐treatment plan review is crucial to safe radiation oncology treatments. Studies show that most errors originate in treatment planning, which underscores the importance of physics plan review. As a QA measure the physics review is of fundamental importance and is central to the profession of medical physics. However, little is known about its effectiveness. More hard data are needed. The purpose of this study was to quantify the effectiveness of physics review with the goal of improving it.Methods:This study analyzed 315 “potentially serious” near‐miss incidents within an institutional incident learning system collected over a two‐year period. 139 of these originated prior to physics review and were found at the review or after. Incidents were classified as events that: 1)were detected by physics review, 2)could have been detected (but were not), and 3)could not have been detected. Category 1 and 2 events were classified by which specific check (within physics review) detected or could have detected the event.Results:Of the 139 analyzed events, 73/139 (53%) were detected or could have been detected by the physics review; although, 42/73 (58%) were not actually detected. 45/73 (62%) errors originated in treatment planning, making physics review the first step in the workflow that could detect the error. Two specific physics checks were particularly effective (combined effectiveness of >20%): verifying DRRs (8/73) and verifying isocenter (7/73). Software‐based plan checking systems were evaluated and found to have potential effectiveness of 40%. Given current data structures, software implementations of some tests such as isocenter verification check would be challenging.Conclusion:Physics plan review is a key safety measure and can detect majority of reported events. However, a majority of events that potentially could have been detected were NOT detected in this study, indicating the need to improve the performance of physics review.
TU‐G‐BRA‐05: Predicting Volume Change of the Tumor and Critical Structures Throughout Radiation Therapy by CT‐CBCT Registration with Local Intensity Correction
Authors: Park S , Robinson A , Plishker W , Shekhar R , Kiess A , Quon H , Wong J , Lee J 
Published: June 2015

Purpose:The purpose of this study is to develop an accurate and effective technique to predict and monitor volume changes of the tumor and organs at risk (OARs) from daily cone‐beam CTs (CBCTs).Methods:While CBCT is typically used to minimize the patient setup error, its poor image quality impedes accurate monitoring of daily anatomical changes in radiotherapy. Reconstruction artifacts in CBCT often cause undesirable errors in registration‐based contour propagation from the planning CT, a conventional way to estimate anatomical changes. To improve the registration and segmentation accuracy, we developed a new deformable image registration (DIR) that iteratively corrects CBCT intensities using slice‐based histogram matching during the registration process. Three popular DIR algorithms (hierarchical B‐spline, demons, optical flow) augmented by the intensity correction were implemented on a graphics processing unit for efficient computation, and their performances were evaluated on six head and neck (HN) cancer cases. Four trained scientists manually contoured nodal gross tumor volume (GTV) on the planning CT and every other fraction CBCTs for each case, to which the propagated GTV contours by DIR were compared. The performance was also compared with commercial software, VelocityAI (Varian Medical Systems Inc.).Results:Manual contouring showed significant variations, [‐76, +141]% from the mean of all four sets of contours. The volume differences (mean±std in cc) between the average manual segmentation and four automatic segmentations are 3.70±2.30(B‐spline), 1.25±1.78(demons), 0.93±1.14(optical flow), and 4.39±3.86 (VelocityAI). In comparison to the average volume of the manual segmentations, the proposed approach significantly reduced the estimation error by 9%(B‐spline), 38%(demons), and 51%(optical flow) over the conventional mutual information based method (VelocityAI).Conclusion:The proposed CT‐CBCT registration with local CBCT intensity correction can accurately predict the tumor volume change with reduced errors. Although demonstrated only on HN nodal GTVs, the results imply improved accuracy for other critical structures.This work was supported by NIH/NCI under grant R42CA137886.
TU‐G‐BRA‐07: Characterization of Tumor Proliferation During Successive Cycles of Anti‐Angiogenic Therapy Using [F‐18]FLT PET/CT
Authors: Scarpelli M , Perlman S , Harmon S , Perk T , Scully P , Bruce J , Liu G , Jeraj R 
Published: June 2015

Purpose:Studies have shown cessation of anti‐angiogenic treatment during the first cycle of therapy resulted in rebound of tumor proliferation (flare). This study characterized proliferation dynamics during the first and third cycle of anti‐angiogenic treatment using [F‐18]FLT PET.Methods:Thirteen patients with various solid cancers were treated with Axitinib (Pfizer, Inc) at a dose of 5mg orally, twice daily, on contiguous three‐week cycles with intermittent dosing (two‐weeks‐on/one‐week‐off). All patients received three FLT PET/CT scans during cycle 1 (C1): at baseline (C1D0), peak Axitinib concentration (C1D14), and the end of washout (C1D21). Ten patients received up to an additional three scans at corresponding time points during cycle 3 (C3). Lesions were identified by a nuclear medicine physician and manually contoured. Tumor burden was quantified using standard SUV metrics. Correlations between imaging metrics across C1 and C3 were calculated using the Spearman correlation.Results:At C1 peak drug concentration 11/13 patients had decreases in SUVtotal, with median decrease of 50% (change from C1D0 to C1D14). At C3 peak drug concentration 7/7 patients had decreases in SUVtotal, with median decrease of 20% (C3D0 to C3D14). Proliferative flare during C1 washout (>20% increase from C1D14 to C1D21) occurred in 9/13 patients, with median SUVtotal increase of 190%. Flare was also seen in C3 for 5/5 patients, with median SUVtotal increase of 70% (change from C3D14 to C3D21). Correlations were found between changes in imaging metrics across C1 and C3, notably the change in SUVtotal from C1D0 to C1D21 and the change in SUVtotal from C1D0 to C3D0 (ρ = 0.80).Conclusion:Measurements of SUVtotal showed that both patient response to treatment and flare were evident in both cycles of treatment. Correlation between changes in SUVtotal across C1 and C3 suggest early time points could be used to characterize patient response in later cycles.Research funded in part by Pfizer.
TU‐G‐BRA‐08: BEST IN PHYSICS (JOINT IMAGING‐THERAPY): Hybrid PET‐MRI Imaging of Acute Radiation Induced Cardiac Toxicity
Authors: El‐Sherif O , Xhaferllari I , Sykes J , Butler J , Wisenberg G , Prato F , Gaede S 
Published: June 2015

Purpose:To identify the presence of low‐dose radiation induced cardiac toxicity in a canine model using hybrid positron emission tomography (PET) and magnetic resonance imaging (MRI).Methods:Research ethics board approval was obtained for a longitudinal imaging study of 5 canines after cardiac irradiation. Animals were imaged at baseline, 1 week post cardiac irradiation, and 1 month post cardiac irradiation using a hybrid PET‐ MRI system (Biograph mMR, Siemens Healthcare). The imaging protocol was designed to assess acute changes in myocardial perfusion and inflammation. Myocardial perfusion imaging was performed using N13‐ammonia tracer followed by a dynamic PET acquisition scan. A compartmental tracer kinetic model was used for absolute perfusion quantification. Myocardial inflammation imaging was performed using F18‐fluorodeoxyglucose (FDG) tracer. The standard uptake value (SUV) over a region encompassing the whole heart was used to compare FDG scans. All animals received a simulation CT scan (GE Medical Systems) for radiation treatment planning. Radiation treatment plans were created using the Pinncale3 treatment planning system (Philips Radiation Oncology Systems) and designed to resemble the typical cardiac exposure during left‐sided breast cancer radiotherapy. Cardiac irradiations were performed in a single fraction using a TrueBeam linear accelerator (Varian Medical Systems).Results:The delivered dose (mean ± standard deviation) to heart was 1.8±0.2 Gy. Reductions in myocardial stress perfusion relative to baseline were observed in 2 of the 5 animals 1 month post radiation. A global inflammatory response 1 month post radiation was observed in 4 of the 5 animals. The calculated SUV at 1 month post radiation was significantly higher (p=0.05) than the baseline SUV.Conclusion:Low doses of cardiac irradiation (< 2 Gy) may lead to myocardial perfusion defects and a global inflammatory response that can be detectable as early as 1 month post irradiation using hybrid PET‐MRI imaging techniques.
TU‐G‐201‐00: Imaging Equipment Specification and Selection in Radiation Oncology Departments
Authors: Hua Chia‐Ho 
Published: June 2015

This session will update therapeutic physicists on technological advancements and radiation oncology features of commercial CT, MRI, and PET/CT imaging systems. Also described are physicists’ roles in every stage of equipment selection, purchasing, and operation, including defining specifications, evaluating vendors, making recommendations, and optimal and safe use of imaging equipment in radiation oncology environment.The first presentation defines important terminology of CT and PET/CT followed by a review of latest innovations, such as metal artifact reduction, statistical iterative reconstruction, radiation dose management, tissue classification by dual energy CT and spectral CT, improvement in spatial resolution and sensitivity in PET, and potentials of PET/MR. We will also discuss important technical specifications and items in CT and PET/CT purchasing quotes and their impacts.The second presentation will focus on key components in the request for proposal for a MRI simulator and how to evaluate vendor proposals. MRI safety issues in radiation Oncology, including MRI scanner Zones (4‐zone design), will be discussed. Basic MR terminologies, important functionalities, and advanced features, which are relevant to radiation therapy, will be discussed.In the third presentation, justification of imaging systems for radiation oncology, considerations in room design and construction in a RO department, shared use with diagnostic radiology, staffing needs and training, clinical/research use cases and implementation, will be discussed. The emphasis will be on understanding and bridging the differences between diagnostic and radiation oncology installations, building consensus amongst stakeholders for purchase and use, and integrating imaging technologies into the radiation oncology environment.Learning Objectives:

Learn the latest innovations of major imaging systems relevant to radiation therapy
Be able to describe important technical specifications of CT, MRI, and PET/CT
Understand the process of budget request, equipment justification, comparisons of technical specifications, site visits, vendor selection, and contract development
TU‐G‐210‐03: Acoustic Simulations in Transcranial MRgFUS: Treatment Prediction and Analysis
Authors: Vyas U. 
Published: June 2015

Modeling can play a vital role in predicting, optimizing and analyzing the results of therapeutic ultrasound treatments. Simulating the propagating acoustic beam in various targeted regions of the body allows for the prediction of the resulting power deposition and temperature profiles. In this session we will apply various modeling approaches to breast, abdominal organ and brain treatments. Of particular interest is the effectiveness of procedures for correcting for phase aberrations caused by intervening irregular tissues, such as the skull in transcranial applications or inhomogeneous breast tissues. Also described are methods to compensate for motion in targeted abdominal organs such as the liver or kidney.Douglas Christensen – Modeling for Breast and Brain HIFU Treatment PlanningTobias Preusser – TRANS‐FUSIMO ‐ An Integrative Approach to Model‐Based Treatment Planning of Liver FUSUrvi Vyas – Acoustic Simulations in Transcranial MRgFUS: Treatment Prediction and AnalysisLearning Objectives:

Understand the role of acoustic beam modeling for predicting the effectiveness of therapeutic ultrasound treatments.
Apply acoustic modeling to specific breast, liver, kidney and transcranial anatomies.
Determine how to obtain appropriate acoustic modeling parameters from clinical images.
Understand the separate role of absorption and scattering in energy delivery to tissues.
See how organ motion can be compensated for in ultrasound therapies.
Compare simulated data with clinical temperature measurements in transcranial applications.
Supported by NIH R01 HL172787 and R01 EB013433 (DC); EU Seventh Framework Programme (FP7/2007‐2013) under 270186 (FUSIMO) and 611889 (TRANS‐FUSIMO)(TP); and P01 CA159992, GE, FUSF and InSightec (UV).
TU‐F‐CAMPUS‐J‐01: Inference of Prostate PTV Margins in VMAT Delivery From Intra‐Fraction Prostate Motion During SBRT Delivery
Authors: Thind K , Wong R , Wong D , Gerdes C , Chow T 
Published: June 2015

Purpose:To retrospectively quantify the intra‐fraction prostate motion during stereotactic body radiation therapy (SBRT) treatment using CyberKnife's target tracking system, which may provide insight into expansion margins from GTV to PTV used in gantry‐based treatments. CyberKnife is equipped with an active tracking system (InTempo) that tracks the four fiducials placed in the prostate gland. The system acquires intra‐fraction orthogonal kV images at 45° and 315° in a sequential fashion.Methods:A total of 38 patients treated with SBRT using CyberKnife between 2011 and 2013 were studied. Dose‐regime was 36.25 Gy in 5 fractions (7.25 Gy/fraction, twice per week) as per RTOG 0938 guidelines. The CyberKnife image tracking logs for all SBRT treatments using InTempo were examined. A total of 13663 images were examined for the superior/inferior (SI), anterior/posterior (AP) and left/right (LR) translation as well as roll, pitch and yaw rotations for the target position relative to the last known model position.Results:The mean ± 2 SD of intra‐fraction motion was contained within 3 mm for SI and LR and 4.5 mm for AP directions at 5 minutes into the treatment delivery. It was contained within 4 mm for SI and LR and 5 mm for AP at 10 minutes. At 15 minutes into delivery, all translations were contained within 5 mm. The mean ± 2 SD of prostate roll, pitch and yaw increased with time but were contained within 5 degree at 5, 10 and 15 minutes into treatment. Additionally, target translations and rotations were within ± 1 mm and ± 1 degree for 90% and 78% of the time.Conclusion:The organ motion component of PTV margin for 10 minute VMAT delivery is contained within 4 mm in SI and LR direction and within 5 mm in the AP direction.
TU‐F‐CAMPUS‐J‐02: Mooney‐Rivlin Biomechanical Modeling of Lung with Inhomogeneous Material Property
Authors: Tehrani J Nasehi , Guo X , Wang J 
Published: June 2015

Purpose:The Mooney‐Rivlin material with hyperelastic strain energy has been proposed for realistic biomechanical modeling of lung. In this study, the lung is modeled as an inhomogeneous Mooney‐Rivlin material with the incompressibility factors being optimized to improve the tumor center of mass (TCM) motion simulation accuracy during respiration.Method:ITK‐SNAP was used to segment lungs of eight lung cancer patients from the 4D‐CT images and tetrahedral volume meshes of the lungs in phase 50% were created by using adaptive mesh generation toolkit. The interphase deformation vector fields (DVFs) are calculated by demons deformable registration algorithm and the barycentric coordinate system of tetrahedral elements is obtained from the resulted DVFs. Mooney‐Rivlin hyperelastic material is used to model the lung volume. Each element is considered unique where the incompressibility factor (k‐factor) for each element is assumed to be proportional to the magnitude of normalized DVF. The incompressibility factor for each element was optimized by minimizing the tumor center of mass motion simulation error.Results:If lung is considered as a homogenous material in Mooney‐Rivlin modeling, the average TCM motion simulation error is 2.26 mm. By considering inhomogeneous properties of lung in the proposed strategy, the average TCM motion simulation error is reduced to 2.04 mm.Conclusions:We proposed a method for assigning the inhomogeneous biomechanical material in the Mooney‐Rivlin model of lung based on the lung regional deformation vector fields. Inhomogeneous material property of lung improves the simulation accuracy.
WE‐E‐BRB‐02: Knowledge Modeling For Clinical Treatment Planning
Authors: Wu Q. 
Published: June 2015

The knowledge‐based treatment planning automation has evolved from academic research from the clinical application with the involvement of the major industry TPS vendors. Previous work proved the concept that IMRT or VMAT plans can be designed without or with minimal human intervention. Recently, the major industry vendors start releasing the automatic planning product such as Philips automatic treatment planning, Varian's Rapidplan, and RaySearch's autoplan. Many centers start to evaluate and use the automatic planning products from TPS vendors. It is more and more becoming evident that automatic planning will be routinely used in the clinic.The first presentation will focus on the knowledge modeling for clinical treatment planning. The presenter will introduce the algorithm and theory for developing the dose volume histogram (DVH) model, summarize the results on the validation of the DVH model, and discuss the application of DVH for the automatic treatment planning. The second presenter will focus on the clinical use of the automatic treatment planning. The presenter will give an overview of the several automatic treatment planning tools including the tools developed commercially and in‐house, present the early experience of using those tools, and discuss the application of the tools in the routine clinical use and in the quality control of the treatment planning.Learning Objectives:

Describe the algorithm and theory behind the knowledge based treatment planning automation.
Clinical experience of using automatic planning in clinical trial and patient treatment
Early clinical experience of using commercial automatic planning approach
The application of automatic planning approach to perform quality assurance of treatment plan.
XD obtain the research funding from Varian Medical System, Philips Medical System and Funding support form Sister Institution Network Fund of MD Anderson, XD is also a founder of Global Oncology One