bluuebunny/crossref_metadata_2025_split huggingface dataset:
TU‐E‐TOUR‐T‐01: Microdosimeters for Therapy
Authors: Das I. 
Published: July 2016

Tour Leader: Indra Das, NYU Langone Medical Center, New York, NYTour Guides:Hsui Ai, Indiana University School of Medicine, Indianapolis, INAaron Andersen, Indiana University School of Medicine, Indianapolis, INOlga Volotoskova, NYU Langone Medical Center, New York, NYParticipating Vendors:IBAPTW – New YorkRTI Electronics, Inc.Standard Imaging, Inc.Sun Nuclear CorporationSmall fields are increasing used in specialized radiation treatments such as Gammaknife, Cyberknife, Tomotherapy, IMRT, VMAT, SRS and SBRT. Due to small field size electron transport creates lateral electronic disequilibrium and thus dosimetry could be very difficult. Microdetectors are used for small field dosimetry which will be discussed in preface of this tour as below:

Understanding small field e.g. meaning and definition of small field
IAEA definition and approach
Characteristics of microdetectors in terms of perturbation, recombination, correction
Suitability of microdetectors in small field dosimetry
TU‐H‐204‐03: NCRP PAC 4 (Radiation Protection in Medicine)
Authors: Miller D. 
Published: July 2016

Since 1928, the International Commission on Radiological Protection (ICRP) has developed, maintained, and elaborated the International System of Radiological Protection used world‐wide as the common basis for radiological protection standards, legislation, guidelines, programs, and practice. ICRP provides and periodically revises radiation and tissue weighing factors, provides and updates recommended dose limits for occupational and public exposures, recommends dose levels for termination of pregnancy, and estimates threshold doses for tissue reactions (deterministic effects). ICRP developed the dose quantity “effective dose”.NCRP Council Committee 1 (CC‐1) is charged with developing recommendations for revising radiation protection guidance for the United States. Topics to be discussed include a summary of current ICRP guidance, NCRP CC‐1 directions, NRC regulatory changes on the horizon, and potential implications of radiation protection guidance changes on the practice of medicine. The opinions of AAPM members on potential changes are welcomed.NCRP Program Area Committee (PAC) 4 has oversight of activities in radiation protection in medicine, including protection of patients and training of health care workers. Documents have been published recently on diagnostic reference levels and achievable doses, health effects of preconception and prenatal radiation exposure, and administrative policies for quality assurance and peer review of tissue reactions associated with fluoroscopically guided interventions. Additional documents are in preparation.

Learning Objectives:
To understand the international system of radiation protection and learn about the work of the International Commission on Radiological Protection (ICRP) in relation to activities of medical physicists
To understand the ongoing work of NCRP in developing new guidance for radiation protection in the U.S.
To understand the ongoing work of NCRP in developing new recommendations for radiation protection in medicine.
To learn about other national organizations in US whose work plays a useful role in the activities of medical physicists.M. Rehani, Work done as part of being member of ICRP. ICRP is an independent charity.
TU‐H‐201‐01: Introduction
Authors: Curran B. 
Published: July 2016

The New New Symposium is a symposium for members relatively new to the organization to learn about the organizational structure and operational procedures of the society; how decisions are made, how the council and committee leadership is appointed and operates, opportunities for volunteer involvement, and a brief overview of the services and efforts provided by the HQ staff and the website. Attendees will hear from council chairs, key staff and chairs, and members with volunteer experience.After the symposium a social hour ensues with opportunities to interact with key AAPM members. The New Member Symposium is a (free) ticket option when you register online for the Annual Meeting. And don't forget registrants receive one (free) ticket for a beverage of your choice during the social afterwards.
TU‐H‐BRC‐02: Biological Dose Escalation for Liver SBRT Through Spatiotemporal Fractionation
Authors: Unkelbach J , Perko Z , Wolfgang J , Hong T 
Published: July 2016

Purpose:Stereotactic body radiotherapy (SBRT) has become an established treatment option for liver cancer. For patients with large tumors, the prescription dose is often limited by constraints on the mean liver dose, leading to tumor recurrence. In this work, we demonstrate that spatiotemporal fractionation schemes, ie delivering distinct dose distributions in different fractions, may allow for a 10% increase in biologically effective dose (BED) in the tumor compared to current practice where each fraction delivers the same dose distribution.Methods:We consider rotation therapy delivered with x‐ray beams. Treatment plan optimization is performed using objective functions evaluated for the cumulative BED delivered at the end of treatment. This allows for simultaneously optimizing multiple distinct treatment plans for different fractions.Results:The treatment that optimally exploits fractionation effects is designed such that each fraction delivers a similar dose bath to the uninvolved liver while delivering high single fraction doses to complementary parts of the target volume. Thereby, partial hypofractionation in the tumor is achieved along with near uniform fractionation in the surrounding liver ‐ leading to an improvement in the therapeutic ratio. The benefit of such spatiotemporal fractionation schemes depends on tumor geometry and location as well as the number of fractions. For 5‐fraction treatments (allowing for 5 distinct dose distributions) an improvement in the order of 10% is observed.Conclusion:Delivering distinct dose distributions in different fractions, purely motivated by fractionation effects rather than geometric changes, may improve the therapeutic ratio. For treatment sites where the prescriptions dose is limited by mean dose constraints in the surrounding organ, such as liver cancer, this approach may facilitate biological dose escalation and improved cure rates.
TU‐H‐BRC‐03: Evaluation of Very High‐Energy Electron (VHEE) Beams in Comparison to VMAT and PBS Treatment Plans
Authors: Schueler E , Eriksson K , Hynning E , Loo B , Maxim P 
Published: July 2016

Purpose:The aim of this study was to evaluate the performance of very high‐energy electron (VHEE) beams in comparison to clinically delivered treatment plans generated with volumetric modulated arc therapy (VMAT) and proton pencil beam scanning (PBS) technology.Methods:Three clinical cases were selected (prostate, lung, and pediatric CNS). The VHEE plans were calculated in the Monte Carlo EGSnrc code and pencil beam doses were calculated using the DOSxyznrc MC code for 100 and 200 MeV beams. Treatment plans with VHEE, VMAT, and PBS were optimized in a research version of RayStation using an in house build script in order to minimize operator bias between the different techniques.Results:For the prostate cancer case, the PBS plan showed lower mean organ at risk (OAR) doses compared to the other modalities. An exception was the femoral heads, due to the lateral beam arrangements. The VMAT plan showed lower mean doses to the rectum and the bladder compared to the 100 MeV VHEE plan. The lung cancer case showed minor differences between the three modalities. However, the PBS plan showed a lower contralateral lung dose. The pediatric CNS case showed a better conformity and lower spinal cord dose for the 100 MeV VHEE plan. For all cases, the 200 MeV VHEE plans were found to be similar to or better than the 100 MeV VHEE plans.Conclusion:The present study showed that VHEE plans are similar or superior to VMAT plans with reduced mean OAR dose and increased target conformity for a variety of clinical cases. With increased VHEE energy, better conformity and even higher reductions in mean OAR doses can be achieved.Funding: DoD, Award#:W81XWH‐13‐1‐0165, Weston Havens Foundation, Bio‐X (Stanford University), the Office of the Dean of the Medical School, the Office of the Provost (Stanford University), and the Swedish Childhood Cancer Foundation. BL and PM are founders of TibaRay,Inc. BL and PM have received research grants from Varian and RaySearch Laboratory.
TU‐H‐BRB‐03: The BARDA Chemical/Radiological/Nuclear Countermeasures Effort
Authors: Hu T. 
Published: July 2016

The US government has substantial research and development activities underway for medical countermeasures that will insure the long‐term safety and survival of the country's population after unfortunate large‐scale biological, chemical and radiological and nuclear events. Preparedness includes research and development of medical countermeasures to address radiation‐induced cutaneous and internal injury from radiation and nuclear events as well as for minimizing radiation risks incurred during and after travel in space. Other important research and development efforts include the repurposing of countermeasures and development of radioprotectors and mitigators to improve the outcome of radiation treatment. Participating agencies include NIAID, BARDA, NCI, and NASA, with examples of research and development funding that includes the Centers for Medical Countermeasures against Radiation (CMCR) consortia (NIAID) and primary and sub‐contracts with commercial entities (BARDA). Each of these programs requires substantial medical and health physics effort in collaboration with biology colleagues to provide a range of radiation sources, dosimetry instrumentation and assessment methods, and animal models for specific radiation‐induced effects and injuries. Radiation countermeasure activities for government agencies will be reviewed, the importance of model development will be stressed, example radiation countermeasure research projects will be reviewed, and the roles for medical physicists will be discussed.

Learning Objectives:
Review US national radiation countermeasure activities.
Review the roles for medical physicists in radiation countermeasures research and development.
Understand specific physics challenges in radiation research that need solutions.Research for JD Bourland supported in part by: NIH/NIAID, U19 AI67798 (subcontract 131714). NIH/NCI, R01CA155293. HHSO10020130019C, BARDA/Argentum Medical LLC.; J. Bourland, Research supported in part by:NIH/NIAID, U19 AI67798 (subcontract 131714); NIH/NCI, R01CA155293; HHSO10020130019C, BARDA/Argentum Medical LLC.; P. Prasanna, Supported by the Radiation Research Program, National Cancer Institute
TU‐H‐BRB‐04: Radiation Countermeasures and the NCI Radiation Research Program
Authors: Prasanna P. 
Published: July 2016

The US government has substantial research and development activities underway for medical countermeasures that will insure the long‐term safety and survival of the country's population after unfortunate large‐scale biological, chemical and radiological and nuclear events. Preparedness includes research and development of medical countermeasures to address radiation‐induced cutaneous and internal injury from radiation and nuclear events as well as for minimizing radiation risks incurred during and after travel in space. Other important research and development efforts include the repurposing of countermeasures and development of radioprotectors and mitigators to improve the outcome of radiation treatment. Participating agencies include NIAID, BARDA, NCI, and NASA, with examples of research and development funding that includes the Centers for Medical Countermeasures against Radiation (CMCR) consortia (NIAID) and primary and sub‐contracts with commercial entities (BARDA). Each of these programs requires substantial medical and health physics effort in collaboration with biology colleagues to provide a range of radiation sources, dosimetry instrumentation and assessment methods, and animal models for specific radiation‐induced effects and injuries. Radiation countermeasure activities for government agencies will be reviewed, the importance of model development will be stressed, example radiation countermeasure research projects will be reviewed, and the roles for medical physicists will be discussed.

Learning Objectives:
Review US national radiation countermeasure activities.
Review the roles for medical physicists in radiation countermeasures research and development.
Understand specific physics challenges in radiation research that need solutions.Research for JD Bourland supported in part by: NIH/NIAID, U19 AI67798 (subcontract 131714). NIH/NCI, R01CA155293. HHSO10020130019C, BARDA/Argentum Medical LLC.; J. Bourland, Research supported in part by:NIH/NIAID, U19 AI67798 (subcontract 131714); NIH/NCI, R01CA155293; HHSO10020130019C, BARDA/Argentum Medical LLC.; P. Prasanna, Supported by the Radiation Research Program, National Cancer Institute
TU‐H‐BRB‐05: Radiation Countermeasures and the NASA Space Radiation Program
Authors: Huff J. 
Published: July 2016

The US government has substantial research and development activities underway for medical countermeasures that will insure the long‐term safety and survival of the country's population after unfortunate large‐scale biological, chemical and radiological and nuclear events. Preparedness includes research and development of medical countermeasures to address radiation‐induced cutaneous and internal injury from radiation and nuclear events as well as for minimizing radiation risks incurred during and after travel in space. Other important research and development efforts include the repurposing of countermeasures and development of radioprotectors and mitigators to improve the outcome of radiation treatment. Participating agencies include NIAID, BARDA, NCI, and NASA, with examples of research and development funding that includes the Centers for Medical Countermeasures against Radiation (CMCR) consortia (NIAID) and primary and sub‐contracts with commercial entities (BARDA). Each of these programs requires substantial medical and health physics effort in collaboration with biology colleagues to provide a range of radiation sources, dosimetry instrumentation and assessment methods, and animal models for specific radiation‐induced effects and injuries. Radiation countermeasure activities for government agencies will be reviewed, the importance of model development will be stressed, example radiation countermeasure research projects will be reviewed, and the roles for medical physicists will be discussed.

Learning Objectives:
Review US national radiation countermeasure activities.
Review the roles for medical physicists in radiation countermeasures research and development.
Understand specific physics challenges in radiation research that need solutions.Research for JD Bourland supported in part by: NIH/NIAID, U19 AI67798 (subcontract 131714). NIH/NCI, R01CA155293. HHSO10020130019C, BARDA/Argentum Medical LLC.; J. Bourland, Research supported in part by:NIH/NIAID, U19 AI67798 (subcontract 131714); NIH/NCI, R01CA155293; HHSO10020130019C, BARDA/Argentum Medical LLC.; P. Prasanna, Supported by the Radiation Research Program, National Cancer Institute
TU‐H‐BRA‐03: Performance of a Clinical Gridded Electron Gun in Magnetic Fields: Implications for MRI‐Linac Therapy
Authors: Whelan B , Bazalova‐Carter M , Oborn B , Constantin D , Holloway L , Fahrig R , Keall P 
Published: July 2016

Purpose:Recent advances towards MRI Linac radiotherapy have motivated a wide range of studies characterizing electromagnetic interactions between the two devices. One of the most sensitive components is the linac electron gun. To data, only non gridded (diode) guns have been investigated however, most linac vendors utilize gridded (triode) guns, which enable efficient and robust beam gating. The purpose of this study was to develop a realistic model of a gridded gun used clinically, and to characterize its performance in magnetic fields.Methods:The gridded electron gun used on Varian high energy machines was measured using 3D laser scanning quoted as accurate to 0.1mm. Based on the scane, a detailed CAD mode was developed. From this, key geometry was extracted and a FEM model was developed (Opera/SCALA). Next, the high voltage (HV), grid voltage, and emission current were read from six dose matched TrueBeam linacs for the 6X, 10X and 15X photon modes (0 B‐field). The mean values were used to represent each mode, which was simulated I constant magnetic fields from 0–200G in‐line, and 0–35G perpendicular.Results:Experimentally measured HV, grid voltage, and emission current from 6X, 10X and 15X modes were respectively: 15±.03kV, 10±.08kV, 11±.03kV; 93±7V, 41±3V, and 70±6V; 327±27mA, 129±10mA, and 214±19mA. The error in simulated emission current of each mode was 3%,6%, and 3%. For in‐line fields, 50% beam loss occurred at 114, 96, and 97G; for perpendicular; at 12, 13 and 14G. Sensitivity for a given geometry is primarily determined by HV setting.Conclusion:Future MRI‐Linac systems will almost certainly use gridded guns. We present the first model of a clinical gridded gun, and match the experimental emission current to within 6% across three different operating modes. This clinical gun shows increased sensitivity to magnetic fields than previous work,and different modes show different sensitivity.
TU‐H‐BRA‐06: Characterization of a Linear Accelerator Operating in a Compact MRIGuided Radiation Therapy System
Authors: Green O , Mutic S , Low D , Li H , Chmielewski T , Fought G , Hernandez M , Kawrakow I , Sharma A , Shvartsman S , Dempsey J 
Published: July 2016

Purpose:To describe the performance of a linear accelerator operating in a compact MRI‐guided radiation therapy system.Methods:A commercial linear accelerator was placed in an MRI unit that is employed in a commercial MR‐based image guided radiation therapy (IGRT) system. The linear accelerator components were placed within magnetic field‐reducing hardware that provided magnetic fields of less than 40 G for the magnetron, gun driver, and port circulator, with 1 G for the linear accelerator. The system did not employ a flattening filter. The test linear accelerator was an industrial 4 MV model that was employed to test the ability to run an accelerator in the MR environment. An MR‐compatible diode detector array was used to measure the beam profiles with the accelerator outside and inside the MR field and with the gradient coils on and off to examine if there was any effect on the delivered dose distribution. The beam profiles and time characteristics of the beam were measured.Results:The beam profiles exhibited characteristic unflattened Bremsstrahlung features with less than ±1.5% differences in the profile magnitude when the system was outside and inside the magnet and less than 1% differences with the gradient coils on and off. The central axis dose rate fluctuated by less than 1% over a 30 second period when outside and inside the MRI.Conclusion:A linaccompatible MR design has been shown to be effective in not perturbing the operation of a commercial linear accelerator. While the accelerator used in the tests was 4MV, there is nothing fundamentally different with the operation of a 6MV unit, implying that the design will enable operation of the proposed clinical unit.Research funding provided by ViewRay, Inc.
TU‐H‐202‐00: CT Ventilation Imaging: The New Clinical Reality of Functional Avoidance and Response Assessment in Lung Cancer Radiation Therapy
Authors: Keall Paul 
Published: July 2016

CT ventilation imaging is an exciting functional imaging modality that combines four‐dimensional computed tomography (4DCT) and deformable image registration (DIR) to provide exquisite ventilation maps of the lung. CT ventilation imaging can be used for:

Functional avoidance in thoracic radiation therapy,
Imaging longitudinal changes in regional lung function for treatment assessment and adaptation,
Image‐assisted diagnosis of non‐oncologic respiratory diseases.CT ventilation imaging uses CT, a predominantly anatomic imaging modality, and through imaging processing creates functional images. CT ventilation imaging provides functional images that are higher resolution, faster and cheaper to perform than the clinical standard, SPECT. Indeed the number of CT ventilation abstracts presented at the AAPM meeting has been doubling every two years. With the world's‐first clinical trial of CT ventilation functional image‐guided radiation therapy now underway, the first dedicated scientific symposium will educate and stimulate AAPM members from both radiology and radiation oncology.This symposium will compare the foundations of CT ventilation imaging with competing MRI, PET and SPECT ventilation imaging methods, and details the first clinical trial of CT ventilation imaging for functional avoidance in lung cancer radiation therapy. The spatial‐temporal nature of pulmonary ventilation, response maps to radiation and the design of predictive models will be presented. Validation efforts and challenges will also be discussed, from clinical outcome correlations in single time point and longitudinal studies, to cross‐modality image comparisons in the first multi‐institutional CT ventilation imaging challenge.The panel will discuss the future role of CT ventilation imaging, and what level of physiologic validation is needed for applications in radiation oncology and beyond.

Learning Objectives:
Learn the principles of CT ventilation imaging and how ventilation images are acquired with MRI, PET and SPECT
Understand the methods used to benchmark CT ventilation and the correlations between CT ventilation imaging and clinical outcomes
Recognize the clinical applications of CT ventilation imaging in radiation oncology and beyondAustralian NHMRC Fellowship. Australian NSW Cancer Institute Fellowship.; Y. Vinogradskiy, The authors acknowledge NIH R01CA200817 grant and Stat of Colorado grant.; T. Yamamoto, This study was supported in part by the American Cancer Society and the Dean of the University of California Davis School of Medicine (ACS IRG‐95‐125‐13). Philips Radiation Oncology Systems loaned us a research version of the Pinnacle3 treatment planning system.; J. Bayouth, Funding support from NCIR01 CA166703; J. Kipritidis, This work has been supported by a Cancer Institute NSW Early Career Fellowship and an NHMRC Australia Fellowship.No commercial funding was received for this work.