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DOE OSTI2012

Emergence of Integrated Urology-Radiation Oncology Practices in the State of Texas

Purpose: Integrated urology-radiation oncology (RO) practices have been advocated as a means to improve community-based prostate cancer care by joining urologic and radiation care in a single-practice environment. However, little is known regarding the scope and actual physical integration of such practices. We sought to characterize the emergence of such practices in Texas, their extent of physical integration, and their potential effect on patient travel times for radiation therapy. Methods and Materials: A telephone survey identified integrated urology-RO practices, defined as practices owned by urologists that offer RO services. Geographic information software was used to determine the proximity of integrated urology-RO clinic sites with respect to the state's population. We calculated patient travel time and distance from each integrated urology-RO clinic offering urologic services to the RO treatment facility owned by the integrated practice and to the nearest nonintegrated (independent) RO facility. We compared these times and distances using the Wilcoxon-Mann-Whitney test. Results: Of 229 urology practices identified, 12 (5%) offered integrated RO services, and 182 (28%) of 640 Texas urologists worked in such practices. Approximately 53% of the state population resides within 10 miles of an integrated urology-RO clinic site. Patients with a diagnosis of prostate cancer at an integrated urology-RO clinic site travel a mean of 19.7 miles (26.1 min) from the clinic to reach the RO facility owned by the integrated urology-RO practice vs 5.9 miles (9.2 min) to reach the nearest nonintegrated RO facility (P<.001). Conclusions: Integrated urology-RO practices are common in Texas and are generally clustered in urban areas. In most integrated practices, the urology clinics and the integrated RO facilities are not at the same location, and driving times and distances from the clinic to the integrated RO facility exceed those from the clinic to the nearest nonintegrated RO facility.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

NASA NTRSDate not supplied

The Impact of Assimilating Large Volumes of GNSS Radio Occultation Observations from Spire’s Commercial Constellation into NASA’s Global Earth Observing System

The upcoming retrospective analysis for the 21st century (R21C) reanalysis product from NASA will include the full dataset of GNSS Radio Occultation (RO) observations collected by Spire with their constellation of smallsats. The Spire RO dataset, which was purchased by NASA for its Commercial Smallsat Data Acquisition (CSDA) archive, has global coverage and includes approximately 6 thousand RO profiles per day during 2019 increasing to nearly 20 thousand in 2022-2023. This more than doubles the volume of RO profiles from all other routinely assimilated RO missions combined during 2023. The increase in the number of RO profiles available is particularly important in the extratropics as the next largest RO constellation, the state-of-the-science Formosa Satellite Mission 7 (FORMOSAT-7)/Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC-2) mission (hereafter COSMIC-2), is focused on the Tropics and only provides approximately 4 thousand RO profiles per day. The large number of observations in the Spire RO dataset have great potential to improve analyses and forecasts of the Earth’s atmosphere produced by numerical weather prediction systems. Their impact is assessed through numerical experiments using NASA’s Global Earth Observing System (GEOS) Atmospheric Data Assimilation System (ADAS) with and without the observations from the COSMIC-2 mission. The ability of the Spire RO observations to make up for the omission of the RO observations from COSMIC-2 is directly assessed over the tropics and the impact of Spire over the extratropics is compared to that of the available RO missions that sample over this region. Finally, the quality of the Spire RO observations is compared to that of the routinely assimilated RO missions using Forecast Sensitivity-based Observation Impact (FSOI).

Michael J. Murphy, Jr.↗

NASA NTRSDate not supplied

The Impact of Assimilating Large Volumes of GNSS Radio Occultation Observations from Spire’s Commercial Constellation into NASA’s GEOS

Michael J. Murphy↗

NASA NTRSDate not supplied

The Impact of Assimilating Large Volumes of GNSS Radio Occultation Observations from Spire’s Commercial Constellation into NASA’s GEOS

The upcoming retrospective analysis for the 21st century (R21C) reanalysis product from NASA will include the full dataset of GNSS Radio Occultation (RO) observations collected by Spire with their constellation of smallsats. The Spire RO dataset, which was purchased by NASA for its Commercial Smallsat Data Acquisition (CSDA) archive, has global coverage and increases in number from approximately 6 thousand RO profiles per day during 2019 to approximately 20 thousand in 2022-2023. This more than doubles the volume of RO profiles from all other routinely assimilated RO missions combined during 2022. The increase in the number of RO profiles available is particularly important in the extratropics as the next largest RO constellation, the state-of-the-science Formosa Satellite Mission 7 (FORMOSAT-7)/Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC-2) mission (hereafter COSMIC-2), is focused on the Tropics and only provides approximately 4 thousand RO profiles per day. The large number of observations in the Spire RO dataset have great potential to improve analyses and forecasts of the Earth’s atmosphere produced by numerical weather prediction systems. Their impact is assessed through numerical experiments using NASA’s Global Earth Observing System (GEOS) Atmospheric Data Assimilation System (ADAS) with and without the observations from the COSMIC-2 mission. The ability of the Spire RO observations to make up for the omission of the RO observations from COSMIC-2 is directly assessed over the tropics and the impact of Spire over the extratropics is compared to that of the available RO missions that sample over this region. Finally, the quality of the Spire RO observations is compared to that of the routinely assimilated RO missions using Forecast Sensitivity-based Observation Impact (FSOI).

Michael J. Murphy↗

NASA NTRS2012

Advances and Limitations of Atmospheric Boundary Layer Observations with GPS Occultation over Southeast Pacific Ocean

The typical atmospheric boundary layer (ABL) over the southeast (SE) Pacific Ocean is featured with a strong temperature inversion and a sharp moisture gradient across the ABL top. The strong moisture and temperature gradients result in a sharp refractivity gradient that can be precisely detected by the Global Positioning System (GPS) radio occultation (RO) measurements. In this paper, the Constellation Observing System for Meteorology, Ionosphere & Climate (COSMIC) GPS RO soundings, radiosondes and the high-resolution ECMWF analysis over the SE Pacific are analyzed. COSMIC RO is able to detect a wide range of ABL height variations (1-2 kilometer) as observed from the radiosondes. However, the ECMWF analysis systematically underestimates the ABL heights. The sharp refractivity gradient at the ABL top frequently exceeds the critical refraction (e.g., −157 N-unit per kilometer) and becomes the so-called ducting condition, which results in a systematic RO refractivity bias (or called N-bias) inside the ABL. Simulation study based on radiosonde profiles reveals the magnitudes of the N-biases are vertical resolution dependent. The N-bias is also the primary cause of the systematically smaller refractivity gradient (rarely exceeding −110 N-unit per kilometer) at the ABL top from RO measurement. However, the N-bias seems not affect the ABL height detection. Instead, the very large RO bending angle and the sharp refractivity gradient due to ducting allow reliable detection of the ABL height from GPS RO. The seasonal mean climatology of ABL heights derived from a nine-month composite of COSMIC RO soundings over the SE Pacific reveals significant differences from the ECMWF analysis. Both show an increase of ABL height from the shallow stratocumulus near the coast to a much higher trade wind inversion further off the coast. However, COSMIC RO shows an overall deeper ABL and reveals different locations of the minimum and maximum ABL heights as compared to the ECMWF analysis. At low latitudes, despite the decreasing number of COSMIC RO soundings and the lower percentage of soundings that penetrate into the lowest 500-m above the mean-sea-level, there are small sampling errors in the mean ABL height climatology. The difference of ABL height climatology between COSMIC RO and ECMWF analysis over SE Pacific is significant and requires further studies.

COSMIC RO↗

DOE OSTI2012

Geographic Analysis of the Radiation Oncology Workforce

Purpose: To evaluate trends in the geographic distribution of the radiation oncology (RO) workforce. Methods and Materials: We used the 1995 and 2007 versions of the Area Resource File to map the ratio of RO to the population aged 65 years or older (ROR) within different health service areas (HSA) within the United States. We used regression analysis to find associations between population variables and 2007 ROR. We calculated Gini coefficients for ROR to assess the evenness of RO distribution and compared that with primary care physicians and total physicians. Results: There was a 24% increase in the RO workforce from 1995 to 2007. The overall growth in the RO workforce was less than that of primary care or the overall physician workforce. The mean ROR among HSAs increased by more than one radiation oncologist per 100,000 people aged 65 years or older, from 5.08 per 100,000 to 6.16 per 100,000. However, there remained consistent geographic variability concerning RO distribution, specifically affecting the non-metropolitan HSAs. Regression analysis found higher ROR in HSAs that possessed higher education (p = 0.001), higher income (p < 0.001), lower unemployment rates (p < 0.001), and higher minority population (p = 0.022). Gini coefficients showed RO distribution less even than for both primary care physicians and total physicians (0.326 compared with 0.196 and 0.292, respectively). Conclusions: Despite a modest growth in the RO workforce, there exists persistent geographic maldistribution of radiation oncologists allocated along socioeconomic and racial lines. To solve problems surrounding the RO workforce, issues concerning both gross numbers and geographic distribution must be addressed.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2012

Physician Beliefs and Practices for Adjuvant and Salvage Radiation Therapy After Prostatectomy

Purpose: Despite results of randomized trials that support adjuvant radiation therapy (RT) after radical prostatectomy (RP) for prostate cancer with adverse pathologic features (APF), many clinicians favor selective use of salvage RT. This survey was conducted to evaluate the beliefs and practices of radiation oncologists (RO) and urologists (U) regarding RT after RP. Methods and Materials: We designed a Web-based survey of post-RP RT beliefs and policies. Survey invitations were e-mailed to a list of 926 RO and 591 U. APF were defined as extracapsular extension, seminal vesicle invasion, or positive surgical margin. Differences between U and RO in adjuvant RT recommendations were evaluated by comparative statistics. Multivariate analyses were performed to evaluate factors predictive of adjuvant RT recommendation. Results: Analyzable surveys were completed by 218 RO and 92 U (overallresponse rate, 20%). Adjuvant RT was recommended based on APF by 68% of respondents (78% RO, 44% U, p <0.001). U were less likely than RO to agree that adjuvant RT improves survival and/or biochemical control (p < 0.0001). PSA thresholds for salvage RT were higher among U than RO (p < 0.001). Predicted rates of erectile dysfunction due to RT were higher among U than RO (p <0.001). On multivariate analysis, respondent specialty was the only predictor of adjuvant RT recommendations. Conclusions: U are less likely than RO to recommend adjuvant RT. Future research efforts should focus on defining the toxicities of post-RP RT and on identifying the subgroups of patients who will benefit from adjuvant vs. selective salvage RT.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2013

Diversity Based on Race, Ethnicity, and Sex, of the US Radiation Oncology Physician Workforce

Purpose: To assess the current diversity of the US radiation oncology (RO) physician workforce by race, ethnicity, and sex. Methods and Materials: Publicly available American Medical Association, American Association of Medical Colleges, and US census registries were used to assess differences by race, ethnicity, and sex for 2010 among RO practicing physicians, academic faculty, residents, and residency applicants. RO resident diversity was compared to medical school graduates and medical oncology (MO) fellows. Significant differences in diversity of RO residents by race, ethnicity, and sex were evaluated between 2003 and 2010 academic years. Results: Females and traditionally underrepresented minorities in medicine (URM), blacks, Hispanics, American Indians, Alaska Natives, Native Hawaiian, and Pacific Islanders are underrepresented as RO residents (33.3% and 6.9%, respectively), faculty (23.8%, 8.1%), and practicing physicians (25.5%, 7.2%) levels compared with the US population (50.8%, 30.0%; P<.01). Although females and URMs remain underrepresented at the resident trainee level compared with their proportions as medical school graduates (48.3%, 15.6%) and MO fellows (45.0%, 10.8%; P<.01), females are significantly increased in proportion as RO residents compared with RO practicing physicians (P<.01), whereas representation of individual URM groups as RO residents is no different than current practicing physicians. There is no trend toward increased diversification for female or URM trainees over 8 years, suggesting underrepresentation is not diminishing. Conclusions: Females and URM are underrepresented in the RO physician workforce. Given existing cancer disparities, further research and efforts are needed to ensure that the field is equipped to meet the needs of an increasingly diverse society.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

NASA NTRS1992

Effects of COMT inhibitors on striatal dopamine metabolism: A microdialysis study

In vivo microdialysis was used to examine the effect of two new catechol-O-methyltransferase (COMT) inhibitors, Ro 40-7592 and OR-611, on extracellular levels of dopamine, dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) in rat striatum. The interactions of the COMT inhibitors with nomifensine, clorgyline, and deprenyl were also studied. Ro 40-7592 (3-30 mg/kg. i.p.) decreased dose-dependently the efflux of HVA, increased that of DOPAC, and tended to increase that of dopamine. Higher doses of OR-611 (30-100 mg/kg, i.p.) also decreased the dialysate level of HVA, increased that of DOPAC, and tended to increase that of dopamine. Ro 40-7592 was about ten-fold as potent as OR-611. Neither of the COMT inhibitors changed dialysate levels of 6-HIAA. An OR-611 dose of 10 mg/kg i.p. had no significant effect, in contrast to Ro 40-7592, on any of the parameters studied; this dose was thus used to differentiate between the effects of central and peripheral COMT inhibition. Both nomifensine (15 mg/kg, i.p.) and clorgyline (4 mg/kg, i.p.) alone elevated extracellular dopamine levels, and lowered those of DOPAC and HVA, though there were quantitative and temporal differences between the drugs. L-deprenyl (1 mg/kg, i.p.) alone had no significant effect on any of the compounds measured. Ro 40-7592 (10 mg/kg, i.p.) potentiated the effect of nomifensine on dopamine efflux, and it tended to increase clorgyline-induced dopamine efflux. DOPAC levels in dialysates were significantly increased by combinations of Ro 40-7592 and nomifensine or clorgyline, whereas HVA remained about as low as they were after Ro 40-7592 alone. Ro 40-7592 had no significant interactions with L-deprenyl. OR-611 (10 mg/kg, i.p.) did not modify the effects on dopamine metabolism of nomifensine, clorgyline, or L-deprenyl. These data show that Ro 40-7592 is a potent centrally active COMT inhibitor, whereas OR-611 is principally a peripherally active inhibitor. Use of drugs which inhibit brain COMT can considerably modify dopamine metabolism. COMT inhibitors may be of clinical significance in treating Parkinson's disease.

Kaakkola, S.↗

DOE OSTI2016

A comparison between radiation therapists and medical specialists in the use of kilovoltage cone-beam computed tomography scans for potential lung cancer radiotherapy target verification and adaptation

Target volume matching using cone-beam computed tomography (CBCT) is the preferred treatment verification method for lung cancer in many centers. However, radiation therapists (RTs) are trained in bony matching and not soft tissue matching. The purpose of this study was to determine whether RTs were equivalent to radiation oncologists (ROs) and radiologists (RDs) in alignment of the treatment CBCT with the gross tumor volume (GTV) defined at planning and in delineating the GTV on the treatment CBCT, as may be necessary for adaptive radiotherapy. In this study, 10 RTs, 1 RO, and 1 RD performed a manual tumor alignment and correction of the planning GTV to a treatment CBCT to generate an isocenter correction distance for 15 patient data sets. Participants also contoured the GTV on the same data sets. The isocenter correction distance and the contoured GTVs from the RTs were compared with the RD and RO. The mean difference in isocenter correction distances was 0.40 cm between the RO and RD, 0.51 cm between the RTs, and RO and 0.42 cm between the RTs and RD. The 95% CIs were smaller than the equivalence limit of 0.5 cm, indicating that the RTs were equivalent to the RO and RD. For GTV delineation comparisons, the RTs were not found to be equivalent to the RD or RO. The alignment of the planning defined GTV and treatment CBCT using soft tissue matching by the RTs has been shown to be equivalent to those by the RO and RD. However, tumor delineation by the RTs on the treatment CBCT was not equivalent to that of the RO and RD. Thus, it may be appropriate for RTs to undertake soft tissue alignment based on CBCT; however, further investigation may be necessary before RTs undertake delineation for adaptive radiotherapy purposes.

61 RADIATION PROTECTION AND DOSIMETRY↗

DOE OSTI2024

Reactive Modified Epoxy Resin and Its Miscible Blends Based on Recycled Oligomers from Solvolysis

Chemical depolymerization of fully cured epoxy resin with 20% reactive modifier was successfully performed via a solvent-assisted solvolysis process into low molecular weight recyclable oligomers (RO) at 240 °C in a pressure vessel at 650 psi for 4 h. The thermoset epoxy resin was depolymerized into transparent brown viscous fluid with a higher viscosity than the uncured epoxy resin with approximately 93% yield. Different concentrations of the RO were homogeneously mixed with the pure epoxy resin, and their curing kinetics, viscosity, FTIR, mechanical properties, DMA, and cross-link density were investigated. The curing kinetics of the pure reactive modified epoxy resin (baseline) and its mixtures with RO of different concentrations were investigated under both isothermal and nonisothermal conditions using small amplitude oscillatory shear flow. The elastic and viscous moduli (G′ and G″), complex viscosity (η*), and tan δ values were evaluated at different curing times and temperatures. The G′, G″, and η* increased dramatically, while tan δ decreased strongly by several orders of magnitude at the gel point. The zero-shear viscosity (η 0 ) was determined from the angular frequency dependent on η* based on the Cross model for different blend compositions in the liquid state before curing. The composition dependence of η 0 showed a positive deviation from the linear mixing rule and was well described by the Lecyar model. Here, the apparent activation energy of curing (E a ) was also evaluated according to the Arrhenius equation and was found to be 46 ± 2 kJ/mol regardless of the different contents of RO. For all blends up to 40 wt % RO, only one tan δ peak systematically shifting to lower temperatures with increasing content of RO was observed in the DMA measurements, indicating that the epoxy resin and the RO are miscible with up to 40 wt % RO.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2015

Differential rotation in magnetized and non-magnetized stars

The effects of magnetic field on stellar differential rotation (DR) are studied by comparing magnetohydrodynamic (MHD) models and their hydrodynamic (HD) counterparts in the broad range of rotation rates and across varying initial rotation profiles. Fully compressible MHD simulations of rotating penetrative convection are performed in a full-spherical shell geometry. Critical conditions for the transition of the DR between a faster equator (solar type) and a slower equator (anti-solar type) are explored by focusing on the “Rossby number (Ro)” and the “convective Rossby number (Ro{sub conv}).” It is confirmed that the transition is more gradual and the critical value for it is higher in the MHD model than in the HD model in view of the Ro{sub conv} dependence. As observed in earlier studies, the rotation profile shows a bistability near the transition in the HD model, whereas it disappears when allowing the growth of magnetic fields except in the model taking the anti-solar-type solution as the initial condition. We find that the transition occurs at Ro≃1 both in the MHD and HD models independently of the hysteresis. Not only the critical value but also the sharpness of the transition is similar between the two models in view of the Ro dependence. The influences of the dynamo-generated magnetic field and/or the hysteresis on convective motion are reflected by Ro. This is why the transition is unified in view of the Ro dependence. We also discuss the Ro dependence of magnetic dynamo activities with emphasis on their possible relation to the kinetic helicity profile.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2016

SU-F-T-186: A Treatment Planning Study of Normal Tissue Sparing with Robustness Optimized IMPT, 4Pi IMRT, and VMAT for Head and Neck Cases

Purpose: We performed a retrospective dosimetric comparison study between the robustness optimized Intensity Modulated Proton Therapy (RO-IMPT), volumetric-modulated arc therapy (VMAT), and the non-coplanar 4? intensity modulated radiation therapy (IMRT). These methods represent the most advanced radiation treatment methods clinically available. We compare their dosimetric performance for head and neck cancer treatments with special focus on the OAR sparing near the tumor volumes. Methods: A total of 11 head and neck cases, which include 10 recurrent cases and one bilateral case, were selected for the study. Different dose levels were prescribed to tumor target depending on disease and location. Three treatment plans were created on commercial TPS systems for a novel noncoplanar 4π method (20 beams), VMAT, and RO-IMPT technique (maximum 4 fields). The maximum patient positioning error was set to 3 mm and the maximum proton range uncertainty was set to 3% for the robustness optimization. Line dose profiles were investigated for OARs close to tumor volumes. Results: All three techniques achieved 98% coverage of the CTV target and most photon plans had less than 110% of the hot spots. The RO-IMPT plans show superior tumor dose homogeneity than 4? and VMAT plans. Although RO-IMPT has greater R50 dose spillage to the surrounding normal tissue than 4π and VMAT, the RO-IMPT plans demonstrate better or comparable OAR (parotid, mandible, carotid, oral cavity, pharynx, and etc.) sparing for structures closely abutting tumor targets. Conclusion: The RO-IMPT’s ability of OAR sparing is benchmarked against the C-arm linac based non-coplanar 4π technique and the standard VMAT method. RO-IMPT consistently shows better or comparable OAR sparing even for tissue structures closely abutting treatment target volume. RO-IMPT further reduces treatment uncertainty associated with proton therapy and delivers robust treatment plans to both unilateral and bilateral head and neck cancer patients with desirable treatment time.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2024

HERO WEC V1.0 2024 - WEC-Sim Detailed Simulation Runs and Summary Data

This dataset includes results from simulations of NREL's hydraulic and electric reverse osmosis wave energy converter (HEREO WEC). Simulation runs include 135 wave cases that were based on the updated WEC-Sim model, which is linked below. The data represented in this repository is based on an updated WEC-Sim model using laboratory data to tune and refine the original WEC-Sim model for the V1.0 HERO WEC. The 135 wave cases represent waves with the following wave height and wave period ranges: - Significant Wave Height: 0.25 - 3.75m in 0.25m increments - Wave Period: 5 - 13 sec in 1 sec increments Each run was simulated using a Pierson-Moskowitz irregular wave spectrum with a 100 second ramp time, a total simulation time of 3,100 seconds, and a simulation time-step of 0.005s. A reference table has been included to map each multi condition run (MCR) case with each wave condition. Summary data set includes a spreadsheet and image files with matrices that are associated with data from simulation runs. All matrices cover the same significant wave height and wave periods from the simulation runs, in the same increments. The following matrices are included: - Power Abs: The average absorbed power from the WEC (calculated from anchor reaction force and heave velocity) - Power Hyd: The average hydraulic power output at pump (calculated from pump output flow and pressure) - Power - Hyd ROi: The average hydraulic power measured at the RO system inlet (calculated from RO system pressure and flow (pre-accumulator)) - Flow - Pump out: The average flowrate measured at the pump outlet - Flow - Perm: The average permeate (clean water) production - Flow - RO (pre): The average flowrate measured at the inlet of the RO system before the accumulators - Flow - RO (post): The average flowrate measured after the accumulator bank in the RO system - Pressure - RO: The average pressure measured at the inlet of the RO system This data set has been developed by the National Renewable Energy Laboratory, operated by the Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Funding provided by the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Water Power Technologies Office.

16 TIDAL AND WAVE POWER↗

DOE OSTI2017

Fast frequency divider circuit using combinational logic

The various technologies presented herein relate to performing on-chip frequency division of an operating frequency of a ring oscillator (RO). Per the various embodiments herein, a conflict between RO size versus operational frequency can be addressed by dividing the output frequency of the RO to a frequency that can be measured on-chip. A frequency divider circuit (comprising NOR gates and latches, for example) can be utilized in conjunction with the RO on the chip. In an embodiment, the frequency divider circuit can include a pair of latches coupled to the RO to facilitate dividing the oscillating frequency of the RO by 2. In another embodiment, the frequency divider circuit can include four latches (operating in pairs) coupled to the RO to facilitate dividing the oscillating frequency of the RO by 4. A plurality of ROs can be MUXed to the plurality of ROs by a single oscillation-counting circuit.

47 OTHER INSTRUMENTATION↗

DOE OSTI2016

Close to Home: Employment Outcomes for Recent Radiation Oncology Graduates

Purpose: To characterize the practice type and location of radiation oncology (RO) residents graduating in 2013. Methods and Materials: Graduates completing RO residency in 2013 were identified, and for each, postgraduate practice setting (academic vs private practice) and location were identified. Characteristics of the graduates, including details regarding their institutions of medical school and residency education, were collected and analyzed. Results: Data were obtained from 146 of the 154 RO graduates from the class of 2013. Employment data were available for 142 graduates. Approximately one-third of graduates were employed in the same state as residency (36.6%), approximately two-thirds (62.0%) in the same region as residency, and nearly three-fourths (73.9%) in the same region as medical school or residency completion. Of the 66 graduates (46.5%) working in academics, 40.9% were at the same institution where they completed residency. Most trainees (82.4%) attended medical schools with RO residency programs. Conclusions: Although personal factors may attract students to train in a particular area, the location of medical school and residency experiences may influence RO graduate practice location choice. Trends in the geographic distribution of graduating radiation oncologists can help identify and better understand disparities in access to RO care. Steps to improve access to RO care may include interventions at the medical student or resident level, such as targeting students at medical schools without associated residency programs and greater resident exposure to underserved areas.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2013

Molecular composition of recycled organic wastes, as determined by solid-state {sup 13}C NMR and elemental analyses

Highlights: • Model estimated the molecular C components well for most RO wastes. • Molecular nature of organic matter in RO wastes varied widely. • Molecular composition by NMR modelling preferable to extraction techniques. • Some model shortcomings in estimating molecular composition of biochars. • Waste molecular composition important for carbon/nutrient outcomes in soil. - Abstract: Using solid state {sup 13}C NMR data and elemental composition in a molecular mixing model, we estimated the molecular components of the organic matter in 16 recycled organic (RO) wastes representative of the major materials generated in the Sydney basin area. Close correspondence was found between the measured NMR signal intensities and those predicted by the model for all RO wastes except for poultry manure char. Molecular nature of the organic matter differed widely between the RO wastes. As a proportion of organic C, carbohydrate C ranged from 0.07 to 0.63, protein C from <0.01 to 0.66, lignin C from <0.01 to 0.31, aliphatic C from 0.09 to 0.73, carbonyl C from 0.02 to 0.23, and char C from 0 to 0.45. This method is considered preferable to techniques involving imprecise extraction methods for RO wastes. Molecular composition data has great potential as a predictor of RO waste soil carbon and nutrient outcomes.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2015

TU-E-213-03: Tools for Ensuring Quality and Safety

Purpose: To develop the first 4D robust optimization (RO) method accounting for respiratory motion and evaluate its potential to improve plan robustness and optimality compared to 3D RO and PTV-based optimization. Methods: A set of 4D CT images are used to track respiratory motion and deformation of tumors and organs. For each of 10 respiration phases, dose distributions for nine different uncertainty scenarios including the nominal one, those incorporating ±5mm setup uncertainties long x, y and z directions and ±3.5% range uncertainties are calculated. All 90 dose distributions are simultaneously optimized to achieve full dose coverage of 10 CTVs and sparing of normal structures. ITV-based 3D RO and PTV-based optimization based on the average CT are also carried for the same patient using same dose volume constrains. After optimization, 4D robustness evaluation was performed for all resulting plans. The CTV coverage and the sparing of normal tissue in 10 phases are evaluated and compared among the three methods. The widths of DVH bands represent the robustness of dose distributions in the structures. Results: For one patient studied so far, the worst case CTV coverage by the prescription dose among all 90 scenarios is: 99% for 4D RO; 88.9% for 3D RO, and 85.2% for PTV based optimization. 4D RO also results in best robustness with the narrowest DVH’ bandwidths for the CTV. 4D and 3D RO have similar organ sparing while PTV based optimization results in worst organ sparing. Conclusion: 4D robust optimization which accounts for anatomy motion and deformation in the optimization process, significantly improves plan robustness and achieves higher quality treatment plans for lung cancer patients. The method is being evaluated for multiple patients with different tumor and motion characteristics.

60 APPLIED LIFE SCIENCES↗