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All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

SIMULATING ASTRO-H OBSERVATIONS OF SLOSHING GAS MOTIONS IN THE CORES OF GALAXY CLUSTERS

Astro-H will be the first X-ray observatory to employ a high-resolution microcalorimeter, capable of measuring the shift and width of individual spectral lines to the precision necessary for estimating the velocity of the diffuse plasma in galaxy clusters. This new capability is expected to bring significant progress in understanding the dynamics, and therefore the physics, of the intracluster medium. However, because this plasma is optically thin, projection effects will be an important complicating factor in interpreting future Astro-H measurements. To study these effects in detail, we performed an analysis of the velocity field from simulations of a galaxy cluster experiencing gas sloshing and generated synthetic X-ray spectra, convolved with model Astro-H Soft X-ray Spectrometer (SXS) responses. We find that the sloshing motions produce velocity signatures that will be observable by Astro-H in nearby clusters: the shifting of the line centroid produced by the fast-moving cold gas underneath the front surface, and line broadening produced by the smooth variation of this motion along the line of sight. The line shapes arising from inviscid or strongly viscous simulations are very similar, indicating that placing constraints on the gas viscosity from these measurements will be difficult. Our spectroscopic analysis demonstrates that, for adequate exposures, Astro-H will be able to recover the first two moments of the velocity distribution of these motions accurately, and in some cases multiple velocity components may be discerned. The simulations also confirm the importance of accurate treatment of point-spread function scattering in the interpretation of Astro-H/SXS spectra of cluster plasmas.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2016

MAPPING THE GAS TURBULENCE IN THE COMA CLUSTER: PREDICTIONS FOR ASTRO-H

Astro-H will be able for the first time to map gas velocities and detect turbulence in galaxy clusters. One of the best targets for turbulence studies is the Coma cluster, due to its proximity, absence of a cool core, and lack of a central active galactic nucleus. To determine what constraints Astro-H will be able to place on the Coma velocity field, we construct simulated maps of the projected gas velocity and compute the second-order structure function, an analog of the velocity power spectrum. We vary the injection scale, dissipation scale, slope, and normalization of the turbulent power spectrum, and apply measurement errors and finite sampling to the velocity field. We find that even with sparse coverage of the cluster, Astro-H will be able to measure the Mach number and the injection scale of the turbulent power spectrum—the quantities determining the energy flux down the turbulent cascade and the diffusion rate for everything that is advected by the gas (metals, cosmic rays, etc.). Astro-H will not be sensitive to the dissipation scale or the slope of the power spectrum in its inertial range, unless they are outside physically motivated intervals. We give the expected confidence intervals for the injection scale and the normalization of the power spectrum for a number of possible pointing configurations, combining the structure function and velocity dispersion data. Importantly, we also determine that measurement errors on the line shift will bias the velocity structure function upward, and show how to correct this bias.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2012

How Do the ASTRO Consensus Statement Guidelines for the Application of Accelerated Partial Breast Irradiation Fit Intraoperative Radiotherapy? A Retrospective Analysis of Patients Treated at the European Institute of Oncology

Purpose: To verify how the classification according to the American Society for Therapeutic Radiation Oncology (ASTRO) consensus statement (CS) for the application of accelerated partial breast irradiation (APBI) fits patients treated with intraoperative radiotherapy with electrons (ELIOT) at a single institution. Methods and Materials: The study included 1,822 patients treated with ELIOT as the sole radiation modality outside of a clinical trial at the European Institute of Oncology after breast-conserving surgery for invasive breast cancer, who were classified into CS groups of suitable, cautionary, and unsuitable. The outcome in terms of ipsilateral breast recurrence, regional node relapse, distant metastases, progression free-survival, cause-specific survival, and overall survival were assessed. Results: All the 1,822 cases except for 25 could be classified according to ASTRO CS: 294 patients met the criteria for inclusion into the suitable group, 691 patients into the cautionary group, and 812 patients into the unsuitable group. The 5-year rate of ipsilateral breast recurrence for suitable, cautionary, and unsuitable groups were 1.5%, 4.4%, and 8.8%, respectively (p = 0.0003). Whereas the regional node relapse showed no difference, the rate of distant metastases was significantly different in the unsuitable group compared with the suitable and cautionary groups, having a significant impact on survival. Conclusion: In the context of patients treated with ELIOT, the ASTRO guidelines identify well the groups for whom APBI might be considered as an effective alternative to whole breast radiotherapy and also identify groups for whom APBI is not indicated.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2021

A Framework for Patient-Centered Pathways of Care for Radiopharmaceutical Therapy: An ASTRO Consensus Document

Radiopharmaceutical therapy (RPT) is an area of projected growth and importance with several agents in clinical use, new agents in late-phase clinical trials, and many others under testing and development. This article proposes a framework for developing pathways of care that can be broadly applied to all RPTs, representing the current status of RPT. It suggests foundational elements for many pathways of care for patients with cancer and concludes with areas in active development and the future horizon for RPT treatment centers. Developing a framework for patient-centered pathways of care is a critical step in establishing RPT as standard therapy for patients with a diverse spectrum of cancers. This expected increase in RPT treatment options will affect a much larger population of patients with complex cancer. It will also require enhanced coordination and collaboration among appropriately qualified personnel with diverse expertise in image acquisition, image interpretation, quantitative imaging, dosimetry calculation, radiation quality assurance and safety as well as oncology care and RPT-induced sequelae and response assessment. The essential role of this evolving RPT care team within multidisciplinary oncology care is a cornerstone of this framework for a patient-centered pathway of care for RPT. Given the status of current RPT practice and the horizon for future applications, this patient-centered pathway of care guidance is timely and should help inform future clinical RPT practice paradigms. A task force was recruited from the Theranostic Working Group of the American Society for Radiation Oncology (ASTRO) in May 2019 with equal representation from the nuclear medicine community. The task force expanded on a framework that was originally conceived by the Working Group for patient-centered care. This framework was developed to incorporate the strengths of both radiation oncologists and nuclear medicine physicians. The manuscript was then developed by the task force and posted on the ASTRO website for a 6-week public comment period ending in July 2020. Comments were adjudicated, and the draft was sent to external organizations for potential endorsement. This document was sent to the ASTRO Board of Directors in October 2020 for approval.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Impact of the SSO-ASTRO Margin Guideline on Rates of Re-excision After Lumpectomy for Breast Cancer: A Meta-analysis

Background: One in five patients undergoing initial lumpectomy for invasive breast cancer subsequently undergoes re-excision or mastectomy. A lack of clarity of when to re-excise based on lumpectomy margin width contributes to this high rate of reoperation. We sought to determine the impact of the Society of Surgical Oncology (SSO) and American Society of Radiation Oncologist (ASTRO) margin guideline on reoperation rates after lumpectomy. The guideline recommended omission of routine re-excision in specimens with “no ink on tumor”. Methods: A systematic literature review was performed. For eligible studies, a random-effects model was used for a meta-analysis of lumpectomy re-excision prevalence before and after publication of the SSO-ASTRO margin guideline. Study heterogeneity was measured by the Cochran’s Q test. Results: Five institutional, one population-based, and one national registry study met inclusion requirements. Sample size per study ranged from 237 to 26,102. There was significant interstudy heterogeneity (Q = 19.779; p = 0.003). Pooled re-excision prevalence was 22% (confidence interval [CI] 20–23) before and 14% (CI 12–15) after guideline publication. With the pre-guideline re-excision prevalence used as the reference value, the associated odds ratio for re-excision after the guideline was 0.65 (CI 0.54–0.78; p < 0.0001). Conclusions: The findings of a 35% reduction in the odds of re-excision after the guideline publication and a reduction in re-excision prevalence from 22 to 14% supports the notion that the SSO-ASTRO margin guideline was impactful. These findings are congruent with the projected reductions in re-excision at the time of guideline publication.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2022

ASTRO: Facilitating Advancements in Low-Impact Solar Research, Deployment, and Dissemination

The U.S. Department of Energy's (DOE) InSPIRE project evaluates opportunities for cost reductions and assesses the environmental compatibility of solar energy technologies through low environmental impact designs and approaches. To achieve the project's aim, DOE brings together researchers from the National Renewable Energy Laboratory, Argonne National Laboratory, universities, local governments, environmental groups, and solar industry partners to conduct field-based research complemented by foundational analytical studies. The Agriculture and Solar Together: Research Opportunities (ASTRO) advisory group members come from across the United States and represent leading solar industry partners, state agencies, vegetation management companies, and other organizations focused on research, food and agriculture, and the environment. The ASTRO group of engaged advisors is a complementary combination of organizations creating positive feedback loops that spark and solidify new connections, accelerate information dissemination, and magnify the impact of the InSPIRE project and associated low-impact solar research initiatives.

14 SOLAR ENERGY↗
DOE OSTI2011

Outcomes After Accelerated Partial Breast Irradiation in Patients With ASTRO Consensus Statement Cautionary Features

Purpose: To evaluate outcomes among women with American Society for Radiation Oncology (ASTRO) consensus statement cautionary features treated with brachytherapy-based accelerated partial breast irradiation (APBI). Methods and Materials: Between March 2001 and June 2006, 322 consecutive patients were treated with high-dose-rate (HDR) APBI at the University of Wisconsin. A total of 136 patients were identified who met the ASTRO cautionary criteria. Thirty-eight (27.9%) patients possessed multiple cautionary factors. All patients received 32 to 34 Gy in 8 to 10 twice-daily fractions using multicatheter (93.4%) or Mammosite balloon (6.6%) brachytherapy. Results: With a median follow-up of 60 months, there were 5 ipsilateral breast tumor recurrences (IBTR), three local, and two loco-regional. The 5-year actuarial rate of IBTR was 4.8% {+-} 4.1%. The 5-year disease-free survival was 89.6%, with a cause-specific survival and overall survival of 97.6% and 95.3%, respectively. There were no IBTRs among 32 patients with ductal carcinoma in situ (DCIS) vs. 6.1% for patients with invasive carcinoma (p = 0.24). Among 104 patients with Stage I or II invasive carcinoma, the IBTR rate for patients considered cautionary because of age alone was 0% vs. 12.7% in those deemed cautionary due to histopathologic factors (p = 0.018). Conclusions: Overall, we observed few local recurrences among patients with cautionary features. Women with DCIS and patients 50 to 59 years of age with Stage I/II disease who otherwise meet the criteria for suitability appear to be at a low risk of IBTR. Patients with tumor-related cautionary features will benefit from careful patient selection.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

American Society for Radiation Oncology (ASTRO) 2012 Workforce Study: The Radiation Oncologists' and Residents' Perspectives

Purpose: The American Society for Radiation Oncology (ASTRO) conducted the 2012 Radiation Oncology Workforce Survey to obtain an up-to-date picture of the workforce, assess its needs and concerns, and identify quality and safety improvement opportunities. The results pertaining to radiation oncologists (ROs) and residents (RORs) are presented here. Methods: The ASTRO Workforce Subcommittee, in collaboration with allied radiation oncology professional societies, conducted a survey study in early 2012. An online survey questionnaire was sent to all segments of the radiation oncology workforce. Respondents who were actively working were included in the analysis. This manuscript describes the data for ROs and RORs. Results: A total of 3618 ROs and 568 RORs were surveyed. The response rate for both groups was 29%, with 1047 RO and 165 ROR responses. Among ROs, the 2 most common racial groups were white (80%) and Asian (15%), and the male-to-female ratio was 2.85 (74% male). The median age of ROs was 51. ROs averaged 253.4 new patient consults in a year and 22.9 on-treatment patients. More than 86% of ROs reported being satisfied or very satisfied overall with their career. Close to half of ROs reported having burnout feelings. There was a trend toward more frequent burnout feelings with increasing numbers of new patient consults. ROs' top concerns were related to documentation, reimbursement, and patients' health insurance coverage. Ninety-five percent of ROs felt confident when implementing new technology. Fifty-one percent of ROs thought that the supply of ROs was balanced with demand, and 33% perceived an oversupply. Conclusions: This study provides a current snapshot of the 2012 radiation oncology physician workforce. There was a predominance of whites and men. Job satisfaction level was high. However a substantial fraction of ROs reported burnout feelings. Perceptions about supply and demand balance were mixed. ROs top concerns reflect areas of attention for the healthcare sector as a whole.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

Hitomi (ASTRO-H) X-ray Astronomy Satellite

The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. Finally, the paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2017

The State-of-the-art HST Astro-photometric Analysis of the Core of ω Centauri. I. The Catalog

We have constructed the most comprehensive catalog of photometry and proper motions ever assembled for a globular cluster (GC). The core of ω Cen has been imaged over 650 times through WFC3's UVIS and IR channels for the purpose of detector calibration. There exist from 4 to over 60 exposures through each of 26 filters stretching continuously from F225W in the UV to F160W in the infrared. Furthermore, the 11 yr baseline between these data and a 2002 ACS survey has allowed us to more than double the proper-motion accuracy and triple the number of well-measured stars compared to our previous groundbreaking effort. This totally unprecedented complete spectral coverage of over 470,000 stars within the cluster’s core, from the tip of the red giant branch down to the white dwarfs, provides the best astro-photometric observational database yet to understand the multiple-population phenomenon in any GC. In this first paper of the series, we describe in detail the data-reduction processes and deliver the astro-photometric catalog to the astronomical community.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2011

American Society for Radiation Oncology (ASTRO) and American College of Radiology (ACR) Practice Guideline for the Transperineal Permanent Brachytherapy of Prostate Cancer

Transperineal permanent prostate brachytherapy is a safe and efficacious treatment option for patients with organ-confined prostate cancer. Careful adherence to established brachytherapy standards has been shown to improve the likelihood of procedural success and reduce the incidence of treatment-related morbidity. A collaborative effort of the American College of Radiology (ACR) and American Society for Therapeutic Radiation Oncology (ASTRO) has produced a practice guideline for permanent prostate brachytherapy. The guideline defines the qualifications and responsibilities of all the involved personnel, including the radiation oncologist, physicist and dosimetrist. Factors with respect to patient selection and appropriate use of supplemental treatment modalities such as external beam radiation and androgen suppression therapy are discussed. Logistics with respect to the brachtherapy implant procedure, the importance of dosimetric parameters, and attention to radiation safety procedures and documentation are presented. Adherence to these practice guidelines can be part of ensuring quality and safety in a successful prostate brachytherapy program.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

American Society for Radiation Oncology (ASTRO) and American College of Radiology (ACR) Practice Guideline for the Performance of High-Dose-Rate Brachytherapy

High-Dose-Rate (HDR) brachytherapy is a safe and efficacious treatment option for patients with a variety of different malignancies. Careful adherence to established standards has been shown to improve the likelihood of procedural success and reduce the incidence of treatment-related morbidity. A collaborative effort of the American College of Radiology (ACR) and American Society for Therapeutic Radiation Oncology (ASTRO) has produced a practice guideline for HDR brachytherapy. The guideline defines the qualifications and responsibilities of all the involved personnel, including the radiation oncologist, physicist and dosimetrists. Review of the leading indications for HDR brachytherapy in the management of gynecologic, thoracic, gastrointestinal, breast, urologic, head and neck, and soft tissue tumors is presented. Logistics with respect to the brachytherapy implant procedures and attention to radiation safety procedures and documentation are presented. Adherence to these practice guidelines can be part of ensuring quality and safety in a successful HDR brachytherapy program.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2014

International Outreach: What Is the Responsibility of ASTRO and the Major International Radiation Oncology Societies?

In this era of globalization and rapid advances in radiation oncology worldwide, the American Society for Radiation Oncology (ASTRO) is committed to help decrease profound regional disparities through the work of the International Education Subcommittee (IES). The IES has expanded its base, reach, and activities to foster educational advances through a variety of educational methods with broad scope, in addition to committing to the advancement of radiation oncology care for cancer patients around the world, through close collaboration with our sister radiation oncology societies and other educational, governmental, and organizational groups.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

In-flight verification of the calibration and performance of the ASTRO-H (Hitomi) Soft X-ray Spectrometer

The Soft X-ray Spectrometer onboard the Astro-H (Hitomi) orbiting x-ray observatory featured an array of 36 silicon thermistor x-ray calorimeters optimized to perform high spectral resolution x-ray imaging spectroscopy of astrophysical sources in the 0.3- to 12-keV band. Extensive preflight calibration measurements are the basis for our modeling of the pulse height–energy relation and energy resolution for each pixel and event grade, telescope collecting area, detector efficiency, and pulse arrival time. Because of the early termination of mission operations, we needed to extract the maximum information from observations performed only days into the mission when the onboard calibration sources had not yet been commissioned and the dewar was still coming into thermal equilibrium, so our technique for reconstructing the per-pixel time-dependent pulse height–energy relation had to be modified. The gain scale was reconstructed using a combination of an absolute energy scale calibration at a single time using a fiducial from an onboard radioactive source and calibration of a dominant time-dependent gain drift component using a dedicated calibration pixel, as well as a residual time-dependent variation using spectra from the Perseus cluster of galaxies. The energy resolution was also measured using the onboard radioactive sources. It is consistent with instrument-level measurements accounting for the modest increase in noise due to spacecraft systems interference. We use observations of two pulsar wind nebulae to validate our models of the telescope area and detector efficiency and to derive a more accurate value for the thickness of the gate-valve Be window, which had not been opened by the time mission operations ceased. We use observations of the Crab nebula to refine the pixel-to-pixel timing and validate the absolute timing.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2018

Design and performance of Soft Gamma-ray Detector onboard the Hitomi (ASTRO-H) satellite

Hitomi (ASTRO-H) was the sixth Japanese x-ray satellite that carried instruments with exquisite energy resolution of <7 eV and broad energy coverage of 0.3 to 600 keV. The Soft Gamma-ray Detector (SGD) was the Hitomi instrument that observed the highest energy band (60 to 600 keV). The SGD design achieves a low background level by combining active shields and Compton cameras where Compton kinematics is utilized to reject backgrounds coming from outside of the field of view. A compact and highly efficient Compton camera is realized using a combination of silicon and cadmium telluride semiconductor sensors with a good energy resolution. Compton kinematics also carries information for gamma-ray polarization, making the SGD an excellent polarimeter. Following several years of development, the satellite was successfully launched on February 17, 2016. After proper functionality of the SGD components were verified, the nominal observation mode was initiated on March 24, 2016. The SGD observed the Crab Nebula for approximately two hours before the spacecraft ceased to function on March 26, 2016. We present concepts of the SGD design followed by detailed description of the instrument and its performance measured on ground and in orbit.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2014

MO-E-BRF-01: Research Opportunities in Technology for Innovation in Radiation Oncology (Highlight of ASTRO NCI 2013 Workshop)

Radiotherapy is one of the most effective treatments for solid tumors, in large part due to significant technological advances associated with, for instance, the ability to target tumors to very high levels of accuracy (within millimeters). Technological advances have played a central role in the success of radiation therapy as an oncologic treatment option for patients. ASTRO, AAPM and NCI sponsored a workshop “Technology for Innovation in Radiation Oncology” at the NCI campus in Bethesda, MD on June 13–14, 2013. The purpose of this workshop was to bring together expert clinicians and scientists to discuss the role of disruptive technologies in radiation oncology, in particular with regard to how they are being developed and translated to clinical practice in the face of current and future challenges and opportunities. The technologies discussed encompassed imaging and delivery aspects, along with methods to enable/facilitate application of them in the clinic. Measures for assessment of the performance of these technologies, such as techniques to validate quantitative imaging, were reviewed. Novel delivery technologies, incorporating efficient and safe delivery mechanisms enabled by development of tools for process automation and the associated field of oncology informatics formed one of the central themes of the workshop. The discussion on disruptive technologies was grounded in the need for evidence of efficacy. Scientists in the areas of technology assessment and bioinformatics provided expert views on different approaches toward evaluation of technology efficacy. Clinicians well versed in clinical trials incorporating disruptive technologies (e.g. SBRT for early stage lung cancer) discussed the important role of these technologies in significantly improving local tumor control and survival for these cohorts of patients. Recommendations summary focused on the opportunities associated with translating the technologies into the clinic and assessing their efficacy, and provided a glimpse into the future. Learning Objectives: To understand the impact of technology on the field of radiation therapy To learn about the trends of technology development for the field of radiation oncology To understand the opportunities for in innovative technology research.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

WE-H-BRB-01: Overview of the ASTRO-NIH-AAPM 2015 Workshop On Exploring Opportunities for Radiation Oncology in the Era of Big Data

Big Data in Radiation Oncology: (1) Overview of the NIH 2015 Big Data Workshop, (2) Where do we stand in the applications of big data in radiation oncology?, and (3) Learning Health Systems for Radiation Oncology: Needs and Challenges for Future Success The overriding goal of this trio panel of presentations is to improve awareness of the wide ranging opportunities for big data impact on patient quality care and enhancing potential for research and collaboration opportunities with NIH and a host of new big data initiatives. This presentation will also summarize the Big Data workshop that was held at the NIH Campus on August 13–14, 2015 and sponsored by AAPM, ASTRO, and NIH. The workshop included discussion of current Big Data cancer registry initiatives, safety and incident reporting systems, and other strategies that will have the greatest impact on radiation oncology research, quality assurance, safety, and outcomes analysis. Learning Objectives: To discuss current and future sources of big data for use in radiation oncology research To optimize our current data collection by adopting new strategies from outside radiation oncology To determine what new knowledge big data can provide for clinical decision support for personalized medicine L. Xing, NIH/NCI Google Inc.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

High-level support for simulations in astro- and elementary particle physics

To fully exploit the potential of modern supereomputing systems, when performing particle and astrophysics simulations, the special user support unite called simulation laboratory “Elementary- and Astro-Particle Physics” (Sim-Lab E&A Particle) is established at Steinbuch Centre for Computing of the Karlsruhe Institute for Technology. SimLab is providing advanced support to scientific groups in developing the simulation software and porting them into up-to-date super-computing infrastructures. Some details of how the SimLab is governed and cooperation with developers and users of codes are presented in this work in progress paper including examples about code THiSMPI for simulation of particle accelerations in supernovae shock fronts and the KB3D code for solving quantum kinematic equations that could be used in simulations of heavy ion collisions or laser excited semiconductor systems.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗