bluuebunny/crossref_metadata_2025_split huggingface dataset:
MO‐G‐BRE‐05: Clinical Process Improvement and Billing in Radiation Oncology: A Case Study of Applying FMEA for CPT Code 77336 (continuing Medical Physics Consultation)
Authors: Spirydovich S , Huq M 
Published: July 2014

Purpose:The improvement of quality in healthcare can be assessed by Failure Mode and Effects Analysis (FMEA). In radiation oncology, FMEA, as applied to the billing CPT code 77336, can improve both charge capture and, most importantly, quality of the performed services.Methods:We created an FMEA table for the process performed under CPT code 77336. For a given process step, each member of the assembled team (physicist, dosimetrist, and therapist) independently assigned numerical values for: probability of occurrence (O, 1–10), severity (S, 1–10), and probability of detection (D, 1–10) for every failure mode cause and effect combination. The risk priority number, RPN, was then calculated as a product of O, S and D from which an average RPN was calculated for each combination mentioned above. A fault tree diagram, with each process sorted into 6 categories, was created with linked RPN. For processes with high RPN recommended actions were assigned. 2 separate R&V systems (Lantis and EMR‐based ARIA) were considered.Results:We identified 9 potential failure modes and corresponding 19 potential causes of these failure modes all resulting in unjustified 77336 charge and compromised quality of care. In Lantis, the range of RPN was 24.5–110.8, and of S values – 2–10. The highest ranking RPN of 110.8 came from the failure mode described as “end‐of‐treatment check not done before the completion of treatment”, and the highest S value of 10 (RPN=105) from “overrides not checked”. For the same failure modes, within ARIA electronic environment with its additional controls, RPN values were significantly lower (44.3 for end‐of‐treatment missing check and 20.0 for overrides not checked).Conclusion:Our work has shown that when charge capture was missed that also resulted in some services not being performed. Absence of such necessary services may result in sub‐optimal quality of care rendered to patients.
MO‐G‐BRE‐09: Validating FMEA Against Incident Learning Data: A Study in Stereotactic Body Radiation Therapy
Authors: Yang F , Cao N , Young L , Howard J , Sponseller P , Logan W , Arbuckle T , Korssjoen T , Meyer J , Ford E 
Published: July 2014

Purpose:Though FMEA (Failure Mode and Effects Analysis) is becoming more widely adopted for risk assessment in radiation therapy, to our knowledge it has never been validated against actual incident learning data. The objective of this study was to perform an FMEA analysis of an SBRT (Stereotactic Body Radiation Therapy) treatment planning process and validate this against data recorded within an incident learning system.Methods:FMEA on the SBRT treatment planning process was carried out by a multidisciplinary group including radiation oncologists, medical physicists, and dosimetrists. Potential failure modes were identified through a systematic review of the workflow process. Failure modes were rated for severity, occurrence, and detectability on a scale of 1 to 10 and RPN (Risk Priority Number) was computed. Failure modes were then compared with historical reports identified as relevant to SBRT planning within a departmental incident learning system that had been active for two years. Differences were identified.Results:FMEA identified 63 failure modes. RPN values for the top 25% of failure modes ranged from 60 to 336. Analysis of the incident learning database identified 33 reported near‐miss events related to SBRT planning. FMEA failed to anticipate 13 of these events, among which 3 were registered with severity ratings of severe or critical in the incident learning system. Combining both methods yielded a total of 76 failure modes, and when scored for RPN the 13 events missed by FMEA ranked within the middle half of all failure modes.Conclusion:FMEA, though valuable, is subject to certain limitations, among them the limited ability to anticipate all potential errors for a given process. This FMEA exercise failed to identify a significant number of possible errors (17%). Integration of FMEA with retrospective incident data may be able to render an improved overview of risks within a process.
MO‐G‐BRF‐09: Investigating Magnetic Field Dose Effects in Mice: A Monte Carlo Study
Authors: Rubinstein A , Guindani M , Followill D , Melancon A , Hazle J , Court L 
Published: July 2014

Purpose:In MRI‐linac treatments, radiation dose distributions are affected by magnetic fields, especially at high‐density/low‐density interfaces. Radiobiological consequences of magnetic field dose effects are presently unknown; therefore, preclinical studies are needed to ensure the safe clinical use of MRI‐linacs. This study investigates the optimal combination of beam energy and magnetic field strength needed for preclinical murine studies.Methods:The Monte Carlo code MCNP6 was used to simulate the effects of a magnetic field when irradiating a mouse‐sized lung phantom with a 1.0cmx1.0cm photon beam. Magnetic field effects were examined using various beam energies (225kVp, 662keV[Cs‐137], and 1.25MeV[Co‐60]) and magnetic field strengths (0.75T, 1.5T, and 3T). The resulting dose distributions were compared to Monte Carlo results for humans with various field sizes and patient geometries using a 6MV/1.5T MRI‐linac.Results:In human simulations, the addition of a 1.5T magnetic field caused an average dose increase of 49% (range:36%–60%) to lung at the soft tissue‐to‐lung interface and an average dose decrease of 30% (range:25%–36%) at the lung‐to‐soft tissue interface. In mouse simulations, the magnetic fields had no effect on the 225kVp dose distribution. The dose increases for the Cs‐137 beam were 12%, 33%, and 49% for 0.75T, 1.5T, and 3.0T magnetic fields, respectively while the dose decreases were 7%, 23%, and 33%. For the Co‐60 beam, the dose increases were 14%, 45%, and 41%, and the dose decreases were 18%, 35%, and 35%.Conclusion:The magnetic field dose effects observed in mouse phantoms using a Co‐60 beam with 1.5T or 3T fields and a Cs‐137 beam with a 3T field compare well with those seen in simulated human treatments with an MRI‐linac. These irradiator/magnet combinations are suitable for preclinical studies investigating potential biological effects of delivering radiation therapy in the presence of a magnetic field.Partially funded by Elekta.
MO‐G‐17A‐01: Innovative High‐Performance PET Imaging System for Preclinical Imaging and Translational Researches
Authors: Sun X , Lou K , Deng Z , Shao Y 
Published: July 2014

Purpose:To develop a practical and compact preclinical PET with innovative technologies for substantially improved imaging performance required for the advanced imaging applications.Methods:Several key components of detector, readout electronics and data acquisition have been developed and evaluated for achieving leapfrogged imaging performance over a prototype animal PET we had developed. The new detector module consists of an 8×8 array of 1.5×1.5×30 mm3 LYSO scintillators with each end coupled to a latest 4×4 array of 3×3 mm2 Silicon Photomultipliers (with ∼0.2 mm insensitive gap between pixels) through a 2.0 mm thick transparent light spreader. Scintillator surface and reflector/coupling were designed and fabricated to reserve air‐gap to achieve higher depth‐of‐interaction (DOI) resolution and other detector performance. Front‐end readout electronics with upgraded 16‐ch ASIC was newly developed and tested, so as the compact and high density FPGA based data acquisition and transfer system targeting 10M/s coincidence counting rate with low power consumption. The new detector module performance of energy, timing and DOI resolutions with the data acquisition system were evaluated. Initial Na‐22 point source image was acquired with 2 rotating detectors to assess the system imaging capability.Results:No insensitive gaps at the detector edge and thus it is capable for tiling to a large‐scale detector panel. All 64 crystals inside the detector were clearly separated from a flood‐source image. Measured energy, timing, and DOI resolutions are around 17%, 2.7 ns and 1.96 mm (mean value). Point source image is acquired successfully without detector/electronics calibration and data correction.Conclusion:Newly developed advanced detector and readout electronics will be enable achieving targeted scalable and compact PET system in stationary configuration with >15% sensitivity, ∼1.3 mm uniform imaging resolution, and fast acquisition counting rate capability for substantially improved imaging and quantification performance for small animal imaging and image‐guided radiotherapy applications.This work was supported by a research award RP120326 from Cancer Prevention and Research Institute of Texas.
MO‐G‐17A‐08: Applications of Quantitative PET/CT Imaging of Yttrium‐90: A Tool for Improving Radioembolization
Authors: Pasciak A , Bradley Y 
Published: July 2014

Purpose:Yttrium‐90 (Y90) PET/CT post‐treatment imaging of radioembolization has fostered significant interest from both the interventional radiology and nuclear medicine communities over the past few years. Recent literature has demonstrated high quantitative accuracy of Y90 PET at the activity concentrations common in radioembolization. However, few have explored methods in which this information can be clinically applied toward improving patient care.Methods:IRB approval and informed consent was obtained for over 35 Y90 post‐treatment imaging studies, performed under 2 distinct protocols. In protocol 1, Y90 PET/CT provided quantitative post‐treatment imaging, which was then converted into 3D maps of absorbed‐dose. Both images and absorbed dose maps were used to manage patient care. In protocol 2, tumor absorbed‐dose measurements from Y90 PET/CT were compared to known tumoricidal thresholds. If insufficient absorbed dose was delivered to the tumor, the patient would have an additional Y90 infusion the same day, providing truly patient‐specific Y90 PET/CT based treatment‐planning.Results:Y90 PET/CT allowed for a superior post‐radioembolization evaluation of technical success compared with conventional Y90 bremsstrahlung SPECT. Due to the exceptional resolution of PET, a direct comparison between the distribution of radioembolization and pre‐treatment planning intentions can be made. Further, quantification of tumor absorbed‐dose directly from PET/CT imaging allows for the prediction of treatment efficacy based on a comparison with known tumoricidal thresholds. This immediate evaluation allowed treating physicians to consider additional or alternate therapies before discovering clinical failure weeks later. One protocol 2 patient was found to have a subtumoricidal absorbed dose following radioembolization. This patient received a same‐day infusion of additional Y90 with identical catheter placement to the first infusion. A robust treatment response was seen on follow‐up imaging.Conclusion:Y90 PET/CT produces quantifiable image sets, which can be transformed into 3D maps of absorbed dose. This information can be utilized to improve patient care. SIRTeX Medical, Surefire Medical
MO‐G‐17A‐09: Quantitative Autoradiography of Biopsy Specimens Extracted Under PET/CT Guidance
Authors: Fanchon L , Carlin S , Burger I , Schmidtlein C , Humm J , Yorke E , Solomon S , Deasy J , Kirov A 
Published: July 2014

Purpose:To develop a procedure for accurate determination of PET tracer co ncentration with high spatial accuracy in situ by performing Quantitative Autoradiography of Biopsy Specimens (QABS) extracted under PET/CT guidance.Methods:Autoradiography (ARG) standards were produced from a gel loaded with a known co ncentration of FDG biopsied with 18G and 20G biopsy needles. Specimens obtained with these needles are generally cylindrical: up to 18 mm in length and about 0.8 and 0.6 mm in diameter respectively. These standards, with similar shape and density as biopsy specimens were used to generate ARG calibration curves.Quantitative ARG was performed to measure the activity co ncentration in biopsy specimens extracted from ten patients. The biopsy sites were determined acco rding to PET/CT's obtained in the operating room. Additional CT scans were acquired with the needles in place to co nfirm co rrect needle placements. The ARG images were aligned with the needle tip in the PET/CT images using the open source CERR software. The mean SUV calculated from the specimen activities (SUVarg) were co mpared to that from PET (SUVpet) at the needle locations.Results:Calibration curves show that the relation between ARG signal and activity co ncentration in those standards is linear for the investigated range (up to 150 kBq/ml). The co rrelation co efficient of SUVarg with SUVpet is 0.74. Discrepancies between SUVarg and SUVpet can be attributed to the small size of the biopsy specimens compared to PET resolution.Conclusion:The calibration procedure using surrogate biopsy specimens provided a method for quantifying the activity within the biopsy cores obtained under FDG‐PET guidance. QABS allows mapping the activity concentration in such biopsy specimens with a resolution of about 1mm. QABS is a promising tool for verification of biopsy adequacy by comparing specimen activity to that expected from the PET image.A portion of this research was funded by a research grant from Biospace Lab, 13 rue Georges Auric 75019 Paris, FRANCE.
MO‐G‐18C‐02: Flow Quantification Quality Assurance for Multiple MR Scanners Using Power Injector
Authors: Ai H , Zhou Y , Clevenger T , Lin C 
Published: July 2014

Purpose:To evaluate a flow quantification QA method on multiple MR scanners with different magnetic field strength from different manufacturer.Methods:Our previous study proposed a low‐cost, reliable and convenient MRI flow quantification QA method based on a simple and compact flow contrast phantom and a power injector. Five different MR scanners (Siemens MAGNETOM Espree 1.5T, Aera 1.5T and Skyra 3T; GE Optima MR450w 1.5T and Discovery MR750w 3T) were used to test the reproducibility and sensitivity of the QA method. Flow phantom phase contrast images were acquired at magnetic field isocenter for all the MR scanners. Eight repeated acquisitions and measurements were performed on each scanner. In addition, off‐center effects were tested on Siemens Espree and two GE scanners.Results:The positive flow rates measured at isocenter of five MR scanners range from +1.84± 0.01 mL/s to +2.01± 0.02 mL/s, within 8% difference from the 2mL/s flow rate provided by the power injector. The negative flow rate measured at isocenter range from −1.89± 0.01 mL/s to ‐2.14± 0.03 mL/s, within 7% difference from 2mL/s flow rate. Flow rate measures were most affected by off‐center effect when the flow phantom was shifted 12 cm transversely and 12 cm longitudinally from the isocenter. For GE Optima scanner, positive flow of +1.53± 0.01 mL/s was measured, which is 24.5% difference from power injector flow rate. For GE Discovery scanner, negative flow of −2.68± 0.02 mL/s was measured, which is 34% difference from 2mL/s flow rate.Conclusion:This QA method was sensitive enough to detect flow quantification difference between scanners. Flow quantification errors at locations away from magnetic field isocenter due to the worse gradient fidelity can be detected by our flow quantification QA method. In conclusion, flow phantom coupled with power injector is presented to be a widely available, consistent and low cost flow quantification method.
MO‐G‐18C‐04: Improved Synthetic 4D‐MRI Using Linear Polynomial Fitting Model
Authors: Yang J , Yin F , Wang H , Chang Z , Czito B , Bashir M , Palta M , Cai J 
Published: July 2014

Purpose:To reduce deformable image registration error by fitting the displacement vector field (DVF) to smooth the motion trajectory of each pixel in synthetic 4D‐MRI.Methods:Five patients with cancers in the liver were enrolled in this study. For a 4D MR image data set, the DVF matrices relative to a specific reference phase were calculated using an in‐house deformable image registration based on b‐spline. The displacement trajectory of each voxel throughout the respiratory cycle was constituted by concatenating the corresponding displacement values from all DVF matrices. A linear polynomial fitting model was then used to fit the DVFs in three spatial and the temporal dimension, respectively. By warpping the source MR images using the remodeled DVFs, we synthesized MR images at selected phases. Tumor motion trajectories were derived from source 4DMRI, original synthetic images and improved synthetic images. These were analyzed in the superior‐inferior (SI), anterior‐posterior (AP), and mediallateral (ML) directions, respectively. Correlation coefficients (CC) and differences in motion amplitude (D) were calculated for comparison.Results:For all patients, tumor motion trajectories were strongly correlated between source 4D‐MRI images and improved synthetic 4D‐MRI (mean CC 0.98±0.01). Differences in motion amplitude were small (mean D 0.46±0.14 mm) in all directions. Correlation between source 4D‐MRI and original synthetic 4D‐MRI was slightly less strong (mean CC 0.97±0.01) and motion amplitude differences were slightly larger (0.55±0.19 mm).Conclusion:The feasibility of synthesizing T2w 4D‐MRI using remodeled DVFs has been investigated in this study. Preliminary results in oncologic patients demonstrated the potential of reducing inaccuracies in original synthetic 4DMRI caused by registration errors using the linear polynomial fitting model without much loss of respiratory motion information.NIH (1R21CA165384‐01A1), Golfers Against Cancer (GAC) Foundation, The China Scholarship Council (CSC)
MO‐G‐9A‐01: Imaging Refresher for Standard of Care Radiation Therapy
Authors: Labby Z , Sensakovic W , Hipp E , Altman M 
Published: July 2014

Imaging techniques and technology which were previously the domain of diagnostic medicine are becoming increasingly integrated and utilized in radiation therapy (RT) clinical practice. As such, there are a number of specific imaging topics that are highly applicable to modern radiation therapy physics. As imaging becomes more widely integrated into standard clinical radiation oncology practice, the impetus is on RT physicists to be informed and up‐to‐date on those imaging modalities relevant to the design and delivery of therapeutic radiation treatments. For example, knowing that, for a given situation, a fluid attenuated inversion recovery (FLAIR) image set is most likely what the physician would like to import and contour is helpful, but may not be sufficient to providing the best quality of care. Understanding the physics of how that pulse sequence works and why it is used could help assess its utility and determine if it is the optimal sequence for aiding in that specific clinical situation. It is thus important that clinical medical physicists be able to understand and explain the physics behind the imaging techniques used in all aspects of clinical radiation oncology practice. This session will provide the basic physics for a variety of imaging modalities for applications that are highly relevant to radiation oncology practice: computed tomography (CT) (including kV, MV, cone beam CT [CBCT], and 4DCT), positron emission tomography (PET)/CT, magnetic resonance imaging (MRI), and imaging specific to brachytherapy (including ultrasound and some brachytherapy specific topics in MR). For each unique modality, the image formation process will be reviewed, trade‐offs between image quality and other factors (e.g. imaging time or radiation dose) will be clarified, and typically used cases for each modality will be introduced. The current and near‐future uses of these modalities and techniques in radiation oncology clinical practice will also be discussed.Learning Objectives:
To review the basic physical science principles of CT, PET, MR, and ultrasound imaging.
To understand how the images are created, and present their specific role in patient management and treatment planning for therapeutic radiation (both external beam and brachytherapy).
To discuss when and how each specific imaging modality is currently used in clinical practice, as well as how they may come to be used in the near future.
MO‐H‐19A‐03: Patient Specific Bolus with 3D Printing Technology for Electron Radiotherapy
Authors: Zou W , Fisher T , Swann B , Siderits R , McKenna M , Khan A , Yue N , Zhang M 
Published: July 2014

Purpose:Bolus is widely used in electron radiotherapy to achieve desired dose distribution. 3D printing technologies provide clinicians with easy access to fabricate patient specific bolus accommodating patient body surface irregularities and tissue inhomogeneity. This study presents the design and the clinical workflow of 3D printed bolus for patient electron therapy in our clinic.Methods:Patient simulation CT images free of bolus were exported from treatment planning system (TPS) to an in‐house developed software package. Bolus with known material properties was designed in the software package and then exported back to the TPS as a structure. Dose calculation was carried out to examine the coverage of the target. After satisfying dose distribution was achieved, the bolus structure was transferred in Standard Tessellation Language (STL) file format for the 3D printer to generate the machine codes for printing. Upon receiving printed bolus, a quick quality assurance was performed with patient resimulated with bolus in place to verify the bolus dosimetric property before treatment started.Results:A patient specific bolus for electron radiotherapy was designed and fabricated in Form 1 3D printer with methacrylate photopolymer resin. Satisfying dose distribution was achieved in patient with bolus setup. Treatment was successfully finished for one patient with the 3D printed bolus.Conclusion:The electron bolus fabrication with 3D printing technology was successfully implemented in clinic practice.
MO‐H‐19A‐04: Multichannel CW Ultrasonic Thermometry for Imaging Therapeutic Dose Fields in Water
Authors: Tosh R 
Published: July 2014

Purpose:To develop a scalable, multichannel ultrasonic thermometry system suitable for imaging clinical‐beam dose distributions in a water phantom.Method:A small, glass‐walled rectangular water phantom (15 cm × 20 cm × 30 cm) was filled with distilled water, and two ultrasonic transducers were placed on the outside, against opposing walls, approximately 5 cm below the water line, and were aligned to optimize transmission/reception of ultrasound between them. Two synchronized lock‐in amplifiers were connected to the transducers to enable full‐duplex operation of two separate ultrasonic frequency channels configured to transmit simultaneously through the same volume of water and thereby provide independent measurements of the temperature‐dependent ultrasonic phase lag. Controlled heating of the water via immersed power resistors provided a means to study dependence of measured phase lag on temperature change for both channels; cross‐correlation of the phase outputs enabled much smaller temperature fluctuations in the phantom to be used to ascertain the noise floor and achievable temperature resolution.Results:Temperature measurements from both channels, converted from phase measurements via polynomials available in the literature, exhibited the expected linear dependence of ultrasonic phase on temperature change (measured via calibrated thermistor probe). Cross‐correlation analysis of phase fluctuations yielded rms noise estimates of approximately 1‐2 microKelvin, comparable to that observed in standard water calorimeters.Conclusion:Phase‐sensitive detection of cw ultrasound has been shown to provide temperature sensitivity needed for calorimetry of external treatment beams, and the present simple demonstration establishes that multiple channels may be run simultaneously without phase disturbances that currently affect time‐of‐flight techniques utilizing phase‐detection. Immediate plans include doubling the number of sensors, to enable a simple tomographic reconstruction, and to test the system in Clinac x‐rays and electron beams.