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NASA NTRS1992

SPIKE: Application for ASTRO-D mission planning

SPIKE is a mission planning software system developed by a team of programmers at the STScI for use with the Hubble Space Telescope (HST). SPIKE has been developed for the purpose of automating observatory scheduling to increase the effective utilization and ultimately, scientific return from orbiting telescopes. High-level scheduling strategies using both rule-based and neural network approaches have been incorporated. Graphical displays of activities, constraints, and schedules are an important feature of the system. Although SPIKE was originally developed for the HST, it can be used for other astronomy missions including ground-based observatories. One of the missions that has decided to use SPIKE is ASTRO-D, a Japanese X-ray satellite for which the U.S. is providing a part of the scientific payload. Scheduled to fly in Feb. 1993, its four telescopes will focus X-rays over a wide energy range onto CCD's and imaging gas proportional counters. ASTRO-D will be the first X-ray imaging mission operating over the 0.5-12 keV band with high energy resolution. This combination of capabilities will enable a varied and exciting program of astronomical research to be carried out. ASTRO-D is expected to observe 5 to 20 objects per day and a total of several thousands per year. This requires the implementation of an efficient planning and scheduling system which SPIKE can provide. Although the version of SPIKE that will be used for ASTRO-D mission is almost identical to that used for the HST, there are a few differences. For example, ASTRO-D will use two ground stations for data downlinks, instead of the TDRSS system for data transmission. As a consequence ASTRO-D is constrained by limited on-board data storage capacity to schedule high data-rate observations during periods of frequent high bit rate observations accordingly. We will demonstrate the ASTRO-D version of SPIKE to show what SPIKE can provide and how efficiently it creates an observational schedule.

Isobe, T.↗

DOE OSTI2016

SU-F-J-103: Assessment of Liver Tumor Contrast for Radiation Therapy: Inter-Patient and Inter-Sequence Variability

Purpose: To determine the variation in tumor contrast between different MRI sequences and between patients for the purpose of MRI-based treatment planning. Methods: Multiple MRI scans of 11 patients with cancer(s) in the liver were included in this IRB-approved study. Imaging sequences consisted of T1W MRI, Contrast-Enhanced T1W MRI, T2W MRI, and T2*/T1W MRI. MRI images were acquired on a 1.5T GE Signa scanner with a four-channel torso coil. We calculated the tumor-to-tissue contrast to noise ratio (CNR) for each MR sequence by contouring the tumor and a region of interest (ROI) in a homogeneous region of the liver using the Eclipse treatment planning software. CNR was calculated (I-Tum-I-ROI)/SD-ROI, where I-Tum and I-ROI are the mean values of the tumor and the ROI respectively, and SD-ROI is the standard deviation of the ROI. The same tumor and ROI structures were used in all measurements for different MR sequences. Inter-patient Coefficient of variation (CV), and inter-sequence CV was determined. In addition, mean and standard deviation of CNR were calculated and compared between different MR sequences. Results: Our preliminary results showed large inter-patient CV (range: 37.7% to 88%) and inter-sequence CV (range 5.3% to 104.9%) of liver tumor CNR, indicating great variations in tumor CNR between MR sequences and between patients. Tumor CNR was found to be largest in CE-T1W (8.5±7.5), followed by T2W (4.2±2.4), T1W (3.4±2.2), and T2*/T1W (1.7±0.6) MR scans. The inter-patient CV of tumor CNR was also the largest in CE-T1W (88%), followed by T1W (64.3%), T1W (56.2%), and T2*/T1W (37.7) MR scans. Conclusion: Large inter-sequence and inter-patient variations were observed in liver tumor CNR. CE-T1W MR images on average provided the best tumor CNR. Efforts are needed to optimize tumor contrast and its consistency for MRI-based treatment planning of cancer in the liver. This project is supported by NIH grant: 1R21CA165384.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2014

SU-E-T-378: Limits and Possibilities of a Simplistic Approach to Whole Breast Radiation Therapy Planning

Purpose: Challenges for radiation therapy in developing countries include unreliable infrastructure and high patient load. We propose a system to treat whole breast in the prone position without computed tomography and/or planning software. Methods: Six parameters are measured using calipers and levels with the patient prone in the treatment position. (1) The largest separation; (2) the angle that separation makes with the horizontal; (3) the separation 2 cm posterior to the nipple; (4) the vertical distance between these two separations; (5) the sup/inf length and (6) angle of the desired posterior field edge. The data in (5) (6) and (2) provide field length, collimator and gantry angles. Isocenter is set to the midpoint of (1), anterior jaw setting is 20cm (half-beam setup), and the dose is prescribed to a point 1.5 cm anterior to isocenter. MUs and wedge angles are calculated using an MU calculator and by requiring 100% dose at that point and 100-105% at the midpoint of (3). Measurements on 30 CT scans were taken to obtain the data 1-6. To test the resulting MU/wedge combinations, they were entered into Eclipse (Varian) and dose distributions were calculated. The MU/wedge combinations were recorded and tabulated. Results: Performing a dose volume histogram analysis, the contoured breast V95 was 90.5%, and the average V90 was 94.1%. The maximum dose never exceeded 114.5%, (average 108%). The lung V20 was <5% for 96.7%, and the heart V5 was <10% for 93.3% of our sample. Conclusion: A method to provide prone whole breast treatment without CT-planning was developed. The method provides reasonable coverage and normal tissue sparing. This approach is not recommended if imaging and planning capabilities are available; it was designed to specifically avoid the need for CT planning and should be reserved to clinics that need to avoid that step.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2015

SU-E-J-265: Feasibility Study of Texture Analysis for Prognosis of Local Tumor Recurrence Within 5-Years for Pharyngeal-Laryngeal Carcinoma Patients Received Radiotherapy Treatment

Purpose: Pharyngeal and laryngeal carcinomas (PLC) are among the top leading cancers in Asian populations. Typically the tumor may recur and progress in a short period of time if radiotherapy fails to deliver a successful treatment. Here we used image texture features extracted from images of computed tomography (CT) planning and conducted a retrospective study to evaluate whether texture analysis is a feasible approach to predict local tumor recurrence for PLC patients received radiotherapy treatment. Methods: CT planning images of 100 patients with PLC treated by radiotherapy at our facility between 2001 and 2010 are collected. These patients were received two separate CT scans, before and mid-course of the treatment delivery. Before the radiotherapy, a CT scanning was used for the first treatment planning. A total of 30 fractions were used in the treatment and patients were scanned with a second CT around the end of the fifteenth delivery for an adaptive treatment planning. Only patients who were treated with intensity modulated radiation therapy and RapidArc were selected. Treatment planning software of Eclipse was used. The changes of texture parameters between two CT acquisitions were computed to determine whether they were correlated to the local tumor recurrence. The following texture parameters were used in the preliminary assessment: mean, variance, standard deviation, skewness, kurtosis, energy, entropy, inverse difference moment, cluster shade, inertia, cluster prominence, gray-level co-occurrence matrix, and gray-level run-length matrix. The study was reviewed and approved by the committee of our institutional review board. Results: Our calculations suggested the following texture parameters were correlated with the local tumor recurrence: skewness, kurtosis, entropy, and inertia (p<0.0.05). Conclusion: The preliminary results were positive. However some works remain crucial to be completed, including addition of texture parameters for different image features, sensitivity of tumor segmentation variations, and effect of image filtering.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2014

Independent dosimetric assessment of the model EP917 episcleral brachytherapy plaque

Purpose: To investigate the influence of slot design on dose distributions and dose-volume histograms (DVHs) for the model EP917 plaque for episcleral brachytherapy. Methods: Dimensions and orientations of the slots were measured for three model EP917 plaques and compared to data in the Plaque Simulator (PS) treatment planning software (version 5.7.6). These independently determined coordinates were incorporated into the MCNP Monte Carlo simulation environment to obtain dose from the plaques in a water environment and in a clinical environment with ocular structures. A tumor volume was simulated as 5 mm in apical height and 11 mm in basal diameter. Variations in plaque mass density and composition; slot length, width, and depth; seed positioning; and Ag-marker rod positioning were simulated to examine their influence on plaque central axis (CAX) and planar dose distributions, and DVHs. Results: Seed shifts in a single slot toward the eye and shifts of the{sup 125}I-coated Ag rod within the capsule had the greatest impact on CAX dose distribution. A shift of 0.0994 mm toward the eye increased dose by 14%, 9%, 4.3%, and 2.7% at 1, 2, 5, and 10 mm, respectively, from the inner sclera. When examining the fully-modeled plaque in the ocular geometry, the largest dose variations were caused by shifting the Ag rods toward the sclera and shifting the seeds away from the globe when the slots were made 0.51 mm deeper, causing +34.3% and −69.4% dose changes to the outer sclera, respectively. At points along the CAX, dose from the full plaque geometry using the measured slot design was 2.4% ± 1.1% higher than the manufacturer-provided slot design and 2.2% ± 2.3% higher than the homogeneous calculation of PS treatment planning results. The ratio of D{sub 10} values for the measured slot design to the D{sub 10} values for the manufacturer-provided slot design was higher by 9%, 10%, and 19% for the tumor, inner sclera, and outer sclera, respectively. In comparison to the measured slot design, a theoretical plaque having narrower and deeper slots delivered 30%, 37%, and 62% lower D{sub 10} doses to the tumor, inner sclera, and outer sclera, respectively. Conclusions: While the measured positions of the slots on the model EP917 plaque were in close agreement (<0.7 mm) with the PS values, small differences in the slot shape caused substantial differences in dose distributions and DVH metrics. Increasing slot depth by 0.1 mm decreased outer scleral dose by 20%, yet shifting the Ag rods in the seeds toward the globe by 0.1 mm increased outer scleral dose by 35%. The clinical medical physicist is advised to measure these types of plaques upon acceptance testing before clinical use to inspect slot shape and position for comparison with data used for treatment planning purposes.

60 APPLIED LIFE SCIENCES↗

NASA NTRS2020

PHALANX: Expendable Projectile Sensor Networks for Planetary Exploration

Technologies enabling long-term, wide-ranging measurement in hard-to-reach areas are a critical need for planetary science inquiry. Phenomena of interest include flows or variations in volatiles, gas composition or concentration, particulate density, or even simply temperature. Improved measurement of these processes enables understanding of exotic geologies and distributions or correlating indicators of trapped water or biological activity. However, such data is often needed in unsafe areas such as caves, lava tubes, or steep ravines not easily reached by current spacecraft and planetary robots. To address this capability gap, we have developed miniaturized, expendable sensors which can be ballistically lobbed from a robotic rover or static lander - or even dropped during a flyover. These projectiles can perform sensing during flight and after anchoring to terrain features. By augmenting exploration systems with these sensors, we can extend situational awareness, perform long-duration monitoring, and reduce utilization of primary mobility resources, all of which are crucial in surface missions. We call the integrated payload that includes a cold gas launcher, smart projectiles, planning software, network discovery, and science sensing: PHALANX. In this paper, we introduce the mission architecture for PHALANX and describe an exploration concept that pairs projectile sensors with a rover “mothership.” Science use cases explored include reconnaissance using ballistic cameras, volatiles detection, and building timelapse maps of temperature and illumination conditions. Strategies to autonomously coordinate constellations of deployed sensors to self-discover and localize with peer ranging (i.e. a “local GPS”) are summarized, thus providing communications infrastructure beyond-line-of-sight (BLOS) of the rover. Capabilities were demonstrated through both simulation and physical testing with a terrestrial prototype. The approach to developing a terrestrial prototype is discussed, including design of the launching mechanism, projectile optimization, micro-electronics fabrication, and sensor selection. Results from early testing and characterization of commercial-off-the-shelf (COTS) components are reported. Nodes were subjected to successful burn-in tests over 48 hours at full logging duty cycle. Integrated field tests were conducted in the Roverscape, a half-acre planetary analog environment at NASA Ames, where we tested up to 10 sensor nodes simultaneously coordinating with an exploration rover. Ranging accuracy has been demonstrated to be within +/-10cm over 20m using commodity radios when compared to high-resolution laser scanner ground truthing. Evolution of the design, including progressive miniaturization of the electronics and iterated modifications of the enclosure housing for streamlining and optimized radio performance are described. Finally, lessons learned to date, gaps toward eventual flight mission implementation, and continuing future development plans are discussed.

Dille, Michael↗

DOE OSTI2015

SU-E-T-108: An Investigation of Cerenkov Light Production in the Exradin W1 Scintillator Under Various Measurement Conditions

Purpose: To investigate the effects of depth, fiber-optic cable bends, and incident radiation angle on Cerenkov production in the Standard Imaging Exradin W1. Methods: Measurements were completed using a Varian Clinac 21EX linear accelerator with an Exradin W1 scintillator as well as a cable-only scintillator (no scintillation material) to isolate the Cerenkov signal. The effects of cable bend radius and location were investigated by bending the fiber-optic cable into a circle with radii ranging from 1.0 to 10.8 cm and positioning the center of the coil at distances ranging from 10.0 to 175.0 cm from the photodiode. The effects of depth and incident radiation angle were investigated by performing measurements in water at depths ranging from 1.0 cm to 25.0 cm and angles ranging from 0° to 80°. Eclipse treatment-planning software was utilized to ensure a consistent dose was delivered to the W1 regardless of depth or angle. Results: Measured signal in both channels of the cable-only scintillator decreased as the bend radius decreased and as the distance between the bend and photodiode increased. A fiber bend of 1.0 cm radius produced a 17.1% decrease in the green channel response in the cable-only scintillator. The effect of depth was less severe; a maximum increase of 6.6% in the green channel response was observed at a depth of 25.0 cm in the W1. In the angular dependence investigation, the signal in both channels of the W1 peaked at an angle of 40°; which is in agreement with the nominal Cerenkov emission angle of 45°. Conclusion: The green channel response in the W1 (mainly Cerenkov signal) varied with depth, fiber-optic cable bends, and incident radiation angle. Fully characterizing Cerenkov production is essential to ensure it is properly accounted for in scintillator measurements. Research funding and materials received by Standard Imaging, Inc. (Middleton WI)

07 ISOTOPE AND RADIATION SOURCES↗

DOE OSTI2016

First Human Experience with Directly Image-able Iodinated Embolization Microbeads

PurposeTo describe first clinical experience with a directly image-able, inherently radio-opaque microspherical embolic agent for transarterial embolization of liver tumors.MethodologyLC Bead LUMI™ is a new product based upon sulfonate-modified polyvinyl alcohol hydrogel microbeads with covalently bound iodine (~260 mg I/ml). 70–150 μ LC Bead LUMI™ iodinated microbeads were injected selectively via a 2.8 Fr microcatheter to near complete flow stasis into hepatic arteries in three patients with hepatocellular carcinoma, carcinoid, or neuroendocrine tumor. A custom imaging platform tuned for LC LUMI™ microbead conspicuity using a cone beam CT (CBCT)/angiographic C-arm system (Allura Clarity FD20, Philips) was used along with CBCT embolization treatment planning software (EmboGuide, Philips).ResultsLC Bead LUMI™ image-able microbeads were easily delivered and monitored during the procedure using fluoroscopy, single-shot radiography (SSD), digital subtraction angiography (DSA), dual-phase enhanced and unenhanced CBCT, and unenhanced conventional CT obtained 48 h after the procedure. Intra-procedural imaging demonstrated tumor at risk for potential under-treatment, defined as paucity of image-able microbeads within a portion of the tumor which was confirmed at 48 h CT imaging. Fusion of pre- and post-embolization CBCT identified vessels without beads that corresponded to enhancing tumor tissue in the same location on follow-up imaging (48 h post).ConclusionLC Bead LUMI™ image-able microbeads provide real-time feedback and geographic localization of treatment in real time during treatment. The distribution and density of image-able beads within a tumor need further evaluation as an additional endpoint for embolization.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2024

ORNL Package Testing Program Software Quality Assurance Plan

The Oak Ridge National Laboratory (ORNL) Package Testing Program (PTP) uses commercial off-the-shelf (COTS) software in performing data collection of thermal test results for package designs that contain radioactive materials. Specifically, this software is used to collect temperature data from the furnace, packages, and ambient air to prepare and execute the thermal test specified in 10 CFR 71.73, “Thermal Test.” This software quality assurance (SQA) plan sets forth the guidelines, standards, and procedures that shall be used to provide SQA for PTP software applications. This is a living document that will be maintained for the lifecycle of the PTP program. The SQA plan follows the requirements set forth in ORNL Standards Based Management System (SBMS): Information Technology; Subject Area: Software Quality Assurance. When applicable to the requirements as described in ORNL SBMS, Software Quality Assurance, the software shall be listed in the ORNL Software Registration System (SRS). Exemptions to this SBMS are COTS and firmware that are not modified; spreadsheet applications and personal productivity tools that do not have a utility or safety application, research applications, legacy software, system software, vendor-supplied software used to interface with the vendor’s services, software used within the organization to facilitate processing or management of information, and software developed for applications not specific to the US Department of Energy (DOE).

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2016

Practice Patterns Analysis of Ocular Proton Therapy Centers: The International OPTIC Survey

Purpose: To assess the planning, treatment, and follow-up strategies worldwide in dedicated proton therapy ocular programs. Methods and Materials: Ten centers from 7 countries completed a questionnaire survey with 109 queries on the eye treatment planning system (TPS), hardware/software equipment, image acquisition/registration, patient positioning, eye surveillance, beam delivery, quality assurance (QA), clinical management, and workflow. Results: Worldwide, 28,891 eye patients were treated with protons at the 10 centers as of the end of 2014. Most centers treated a vast number of ocular patients (1729 to 6369). Three centers treated fewer than 200 ocular patients. Most commonly, the centers treated uveal melanoma (UM) and other primary ocular malignancies, benign ocular tumors, conjunctival lesions, choroidal metastases, and retinoblastomas. The UM dose fractionation was generally within a standard range, whereas dosing for other ocular conditions was not standardized. The majority (80%) of centers used in common a specific ocular TPS. Variability existed in imaging registration, with magnetic resonance imaging (MRI) rarely being used in routine planning (20%). Increased patient to full-time equivalent ratios were observed by higher accruing centers (P=.0161). Generally, ophthalmologists followed up the post–radiation therapy patients, though in 40% of centers radiation oncologists also followed up the patients. Seven centers had a prospective outcomes database. All centers used a cyclotron to accelerate protons with dedicated horizontal beam lines only. QA checks (range, modulation) varied substantially across centers. Conclusions: The first worldwide multi-institutional ophthalmic proton therapy survey of the clinical and technical approach shows areas of substantial overlap and areas of progress needed to achieve sustainable and systematic management. Future international efforts include research and development for imaging and planning software upgrades, increased use of MRI, development of clinical protocols, systematic patient-centered data acquisition, and publishing guidelines on QA, staffing, treatment, and follow-up parameters by dedicated ocular programs to ensure the highest level of care for ocular patients.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2024

Digital bead modeling for wire-arc directed energy deposition

Prediction of 2D cross-section and full 3D geometry for stacked weld beads is critical for the outcome of wire-arc directed energy deposition (DED) parts; however, most additive path planning software packages model beads as extrusions of a rectangle. Weld beads are not rectangular, and the resulting shape is dependent upon physics effects at the moment of deposition. Physics phenomena such as the geometry of the underlying surface, the heat input of the welding mode, and the direction of gravity contribute to bead shape. Here, this paper presents a novel implicit modeling method that discretizes a 2D area or 3D volume of space into pixels or voxels and constructs fields based on these physics phenomena. The fields are combined using a weighting scheme trained on 3D scan measurements of welds and wire-arc DED prints. Pixels or voxels are added until the known amount of deposited volume has been achieved. Thereby, a strong conservation of mass principle is applied to the process. Utilizing machine learning techniques, the present model can be trained on a database of scans allowing for the representation of a wide variety of prints. Results show that this method can produce predictions with realistic bead morphology and sub-millimeter form error.

Bead geometry modeling↗

DOE OSTI2014

SU-E-T-594: Preliminary Active Scanning Results of KHIMA

Purpose: To verify the design criteria on heavy ion beam irradiation, developing a proto type active scanning system was purposed. The active scanning system consists of scanning magnet, power supplies, beam monitors, energy modulation system, and irradiation control system. Methods: Each components of the active scanning system was designed for carbon beam first. For the fast ramping a laminated yoke was purposed. To measure incoming dose and profile, a plate and strip type of ion chambers were designed. Also, ridge filter and range shifter was manufactured. And, the scanning system was modified to adopt 45 MeV of proton beam because of the absence of carbon ion beam in Korea. The system was installed in a beam line at MC-50, KIRAMS. Also, the irradiation control system and planning software was provided. Results: The scanning experiment was performed by drawing KHIMA logo on GaF film. The logo was scanned by 237 scanning points through time normalized intensity modulation. Also, a grid points scanning was performed to measure the scanning resolution and intensity resolution. Conclusion: A prototype active scanning system was successfully designed and manufactured. Also, an initial experiment to print out a drawing on GaF film through the scanning system was completed. More experiments would be required to specify the system performance.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2015

Geometric validation of self-gating k-space-sorted 4D-MRI vs 4D-CT using a respiratory motion phantom

Purpose: MRI is increasingly being used for radiotherapy planning, simulation, and in-treatment-room motion monitoring. To provide more detailed temporal and spatial MR data for these tasks, we have recently developed a novel self-gated (SG) MRI technique with advantage of k-space phase sorting, high isotropic spatial resolution, and high temporal resolution. The current work describes the validation of this 4D-MRI technique using a MRI- and CT-compatible respiratory motion phantom and comparison to 4D-CT. Methods: The 4D-MRI sequence is based on a spoiled gradient echo-based 3D projection reconstruction sequence with self-gating for 4D-MRI at 3 T. Respiratory phase is resolved by using SG k-space lines as the motion surrogate. 4D-MRI images are reconstructed into ten temporal bins with spatial resolution 1.56 × 1.56 × 1.56 mm{sup 3}. A MRI-CT compatible phantom was designed to validate the performance of the 4D-MRI sequence and 4D-CT imaging. A spherical target (diameter 23 mm, volume 6.37 ml) filled with high-concentration gadolinium (Gd) gel is embedded into a plastic box (35 × 40 × 63 mm{sup 3}) and stabilized with low-concentration Gd gel. The phantom, driven by an air pump, is able to produce human-type breathing patterns between 4 and 30 respiratory cycles/min. 4D-CT of the phantom has been acquired in cine mode, and reconstructed into ten phases with slice thickness 1.25 mm. The 4D images sets were imported into a treatment planning software for target contouring. The geometrical accuracy of the 4D MRI and CT images has been quantified using target volume, flattening, and eccentricity. The target motion was measured by tracking the centroids of the spheres in each individual phase. Motion ground-truth was obtained from input signals and real-time video recordings. Results: The dynamic phantom has been operated in four respiratory rate (RR) settings, 6, 10, 15, and 20/min, and was scanned with 4D-MRI and 4D-CT. 4D-CT images have target-stretching, partial-missing, and other motion artifacts in various phases, whereas the 4D-MRI images are visually free of those artifacts. Volume percentage difference for the 6.37 ml target ranged from 5.3% ± 4.3% to 10.3% ± 5.9% for 4D-CT, and 1.47 ± 0.52 to 2.12 ± 1.60 for 4D-MRI. With an increase of respiratory rate, the target volumetric and geometric deviations increase for 4D-CT images while remaining stable for the 4D-MRI images. Target motion amplitude errors at different RRs were measured with a range of 0.66–1.25 mm for 4D-CT and 0.2–0.42 mm for 4D-MRI. The results of Mann–Whitney tests indicated that 4D-MRI significantly outperforms 4D-CT in phase-based target volumetric (p = 0.027) and geometric (p < 0.001) measures. Both modalities achieve equivalent accuracy in measuring motion amplitude (p = 0.828). Conclusions: The k-space self-gated 4D-MRI technique provides a robust method for accurately imaging phase-based target motion and geometry. Compared to 4D-CT, the current 4D-MRI technique demonstrates superior spatiotemporal resolution, and robust resistance to motion artifacts caused by fast target motion and irregular breathing patterns. The technique can be used extensively in abdominal targeting, motion gating, and toward implementing MRI-based adaptive radiotherapy.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

4D-CT scans reveal reduced magnitude of respiratory liver motion achieved by different abdominal compression plate positions in patients with intrahepatic tumors undergoing helical tomotherapy

Purpose: While abdominal compression (AC) can be used to reduce respiratory liver motion in patients receiving helical tomotherapy for hepatocellular carcinoma, the nature and extent of this effect is not well described. The purpose of this study was to evaluate the changes in magnitude of three-dimensional liver motion with abdominal compression using four-dimensional (4D) computed tomography (CT) images of several plate positions. Methods: From January 2012 to October 2015, 72 patients with intrahepatic carcinoma and divided into four groups underwent 4D-CT scans to assess respiratory liver motion. Of the 72 patients, 19 underwent abdominal compression of the cephalic area between the subxiphoid and umbilicus (group A), 16 underwent abdominal compression of the caudal region between the subxiphoid area and the umbilicus (group B), 11 patients underwent abdominal compression of the caudal umbilicus (group C), and 26 patients remained free breathing (group D). 4D-CT images were sorted into ten-image series, according to the respiratory phase from the end inspiration to the end expiration, and then transferred to treatment planning software. All liver contours were drawn by a single physician and confirmed by a second physician. Liver relative coordinates were automatically generated to calculate the liver respiratory motion in different axial directions to compile the 10 ten contours into a single composite image. Differences in respiratory liver motion were assessed with a one-way analysis of variance test of significance. Results: The average respiratory liver motion in the Y axial direction was 4.53 ± 1.16, 7.56 ± 1.30, 9.95 ± 2.32, and 9.53 ± 2.62 mm in groups A, B, C, and D, respectively, with a significant change among the four groups (p < 0.001). Abdominal compression was most effective in group A (compression plate on the subxiphoid area), with liver displacement being 2.53 ± 0.93, 4.53 ± 1.16, and 2.14 ± 0.92 mm on the X-, Y-, and Z-axes, respectively. There was no significant difference in respiratory liver motion between group C (displacement: 3.23 ± 1.47, 9.95 ± 2.32, and 2.92 ± 1.10 mm on the X-, Y-, and Z-axes, respectively) and group D (displacement: 3.35 ± 1.55, 9.53 ± 2.62, and 3.35 ± 1.73 mm on the X-, Y-, and Z-axes, respectively). Abdominal compression was least effective in group C (compression on caudal umbilicus), with liver motion in this group similar to that of free-breathing patients (group D). Conclusions: 4D-CT scans revealed significant liver motion control via abdominal compression of the subxiphoid area; however, this control of liver motion was not observed with compression of the caudal umbilicus. The authors, therefore, recommend compression of the subxiphoid area in patients undergoing external radiotherapy for intrahepatic carcinoma.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

SU-C-207B-05: Tissue Segmentation of Computed Tomography Images Using a Random Forest Algorithm: A Feasibility Study

Purpose: Develop an automated Random Forest algorithm for tissue segmentation of CT examinations. Methods: Seven materials were classified for segmentation: background, lung/internal gas, fat, muscle, solid organ parenchyma, blood/contrast, and bone using Matlab and the Trainable Weka Segmentation (TWS) plugin of FIJI. The following classifier feature filters of TWS were investigated: minimum, maximum, mean, and variance each evaluated over a pixel radius of 2n, (n = 0–4). Also noise reduction and edge preserving filters, Gaussian, bilateral, Kuwahara, and anisotropic diffusion, were evaluated. The algorithm used 200 trees with 2 features per node. A training data set was established using an anonymized patient’s (male, 20 yr, 72 kg) chest-abdomen-pelvis CT examination. To establish segmentation ground truth, the training data were manually segmented using Eclipse planning software, and an intra-observer reproducibility test was conducted. Six additional patient data sets were segmented based on classifier data generated from the training data. Accuracy of segmentation was determined by calculating the Dice similarity coefficient (DSC) between manual and auto segmented images. Results: The optimized autosegmentation algorithm resulted in 16 features calculated using maximum, mean, variance, and Gaussian blur filters with kernel radii of 1, 2, and 4 pixels, in addition to the original CT number, and Kuwahara filter (linear kernel of 19 pixels). Ground truth had a DSC of 0.94 (range: 0.90–0.99) for adult and 0.92 (range: 0.85–0.99) for pediatric data sets across all seven segmentation classes. The automated algorithm produced segmentation with an average DSC of 0.85 ± 0.04 (range: 0.81–1.00) for the adult patients, and 0.86 ± 0.03 (range: 0.80–0.99) for the pediatric patients. Conclusion: The TWS Random Forest auto-segmentation algorithm was optimized for CT environment, and able to segment seven material classes over a range of body habitus and CT protocol parameters with an average DSC of 0.86 ± 0.04 (range: 0.80–0.99).

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

SU-F-T-213: Commissioning Results of the Prototype Active Scanning Irradiation System of Korea Heavy Ion Medical Accelerator

Purpose: A prototype actives scanning beam delivery system was designed, manufactured and installed as a part of the Korea Heavy Ion Medical Accelerator Project. The prototype system includes the most components for steering, modulating, detecting incident beam to patient. The system was installed in MC-50 cyclotron beam line and tested to extract the normal operation conditions. Methods: The commissioning process was completed by using 45 MeV of proton beam. To measure the beam position accuracy along the scanning magnet power supply current, 25 different spots were scanning and measured. The scanning results on GaF film were compared with the irradiation plan. Also, the beam size variation and the intensity reduction using range shifter were measured and analyzed. The results will be used for creating a conversion factors for asymmetric behavior of scanning magnets and a dose compensation factor for longitudinal direction. Results: The results show asymmetry operations on both scanning × and y magnet. In case of scanning magnet × operation, the current to position conversion factors were measured 1.69 mm/A for positive direction and 1.74 mm/A for negative direction. The scanning magnet y operation shows 1.38mm/A and 1.48 mm/A for both directions. The size of incoming beam which was 18 mm as sigma becomes larger up to 55 mm as sigma while using 10 mm of the range shifter plate. As the beam size becomes large, the maximum intensity of the was decreased. In case of using 10 mm of range shifter, the maximum intensity was only 52% compared with no range shifter insertion. Conclusion: For the appropriate operation of the prototype active scanning system, the commissioning process were performed to measure the beam characteristics variation. The obtained results would be applied on the irradiation planning software for more precise dose delivery using the active scanning system.

43 PARTICLE ACCELERATORS↗

DOE OSTI2020

Coupled TD Simulation project (Final Report)

This project implements coupled simulation of electric power grid transmission and distribution (T&D) by instantiating the co-simulation platform HELICS using a commercial distribution planning software CYMDIST1 by Eaton Inc., a power management company, and by leveraging the open-source transmission grid simulator GridDyn and LLNL’s High Performance Computing (HPC). The project is funded by DOE’s Technology Commercialization Funding (TCF) and supported by DOE Office of Technology Transitions (OTT).

14 SOLAR ENERGY↗

DOE OSTI2024

GRACE Final Technical Report

The GRACE project (Grid that is Risk-Aware for Clean Electricity) was a five-year research initiative funded by the U.S. Department of Energy's Advanced Research Projects Agency- Energy (ARPA-E) under the PERFORM program. Led by Duke University's Nicholas School of the Environment, with contributions from The Ohio State University, North Carolina State University, Dartmouth College, and Pacific Northwest National Laboratory, the project addressed a fundamental challenge in grid management: conventional software plans for a single most-likely outcome and relies on reserves as a buffer, leaving utilities poorly equipped for the growing variability introduced by renewable energy. GRACE demonstrated a better approach: explicitly representing thousands of plausible future scenarios and choosing operating schedules that perform well across all of them.

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