bluuebunny/crossref_metadata_2025_split huggingface dataset:
SU‐C‐18C‐04: Evaluation of Effective Dose During Ureteroscopy for Obese and Non‐Obese Patients
Authors: Wang C , Nguyen G , Chung Y , Cabrera F , Shin R , Lipkin M , Yoshizumi T 
Published: July 2014

Purpose:Ureteroscopy involves fluoroscopy which potentially results in considerable amount of radiation dose to the patient. Purpose of this study was two‐fold: (a) to develop the effective dose computational model for obese and non‐obese patients undergoing left and right ureteroscopy, and (b) to evaluate the utility of a commercial Monte Carlo software for dose assessment in ureteroscopy.Methods:Organ dose measurements were performed on an adult male anthropomorphic phantom, representing the non‐obese patients, with 20 high‐sensitivity MOSFET detectors and two 0.18cc ionization chambers placed in selected organs. Fat‐equivalent paddings were placed around the abdominal region to simulate for obese patients. Effective dose (ED) was calculated using ICRP 103 tissue weighting factors and normalized to the effective dose rate in miliSivert per second (mSv/s). In addition, a commercial Monte Carlo (MC) dose estimation program was used to estimate ED for the non‐obese model, with table attenuation correction applied to simulate clinical procedure.Results:For the equipment and protocols involved in this study, the MOSFETderived ED rates for the obese patient model (‘Left’: 0.0092±0.0004 mSv/s; ‘Right’: 0.0086±0.0004 mSv/s) was found to be more than twice as much as that to the non‐obese patient model (‘Left’: 0.0041±0.0003 mSv/s; ‘Right’: 0.0036±0.0007 mSv/s). The MC‐derived ED rates for the non‐obese patient model (‘Left’: 0.0041 mSv/s; ‘Right’: 0.0036 mSv/s; with statistical uncertainty of 1%) showed a good agreement with the MOSFET method.Conclusion:The significant difference in ED rate between the obese and non‐obese patient models shows the limitation of directly applying commercial softwares for obese patients and leading to considerable underestimation of ED. Although commercial softwares offer a convenient means of dose estimation, but the utility may be limited to standard‐man geometry as the software does not account for table attenuation, obese patient geometry, and differences between the anthropomorphic phantom and MC mathematical phantom.
SU‐D‐18A‐03: Markerless Motion Tracking of Lung Tumors Using Dual‐Energy Fluoroscopy
Authors: Patel R , Panfil J , Campana M , Block AM , Harkenrider MM , Surucu M , Roeske JC 
Published: July 2014

Purpose:To evaluate the efficacy of dual energy (DE) vs. single energy (SE) fluoroscopic imaging in lung tumors using a markerless template‐based tracking algorithm.Methods:Ten representative patient breathing patterns were programmed into a Quasar™ motion phantom. The phantom was modified by affixing pork ribs to the surface, and a cedar insert with a small spherical volume was used to simulate lung and tumor, respectively. Gated 60kVp(6mA) and 120kVp(1.5mA) fluoroscopic sequences were acquired using the Varian TrueBeam Integrated Imaging Solution. These high and low energy frames were subsequently aligned by phase and amplitude. Frame‐by‐frame weighted logarithmic subtraction was performed resulting in a DE fluoroscopic image sequence that highlighted soft tissue structures. A template‐based algorithm was then used to track tumor motion throughout the sequence for DE and SE images (120kVp). Tracking coordinates were evaluated against ground truth tumor locations as identified by a physician. A displacement of greater than 3 mm was considered a non‐successful track. The same process was also repeated for images obtained from 3 SBRT lung patients, none of which had implanted fiducials.Results:For phantom imaging, a total of 1925 frames were analyzed. The algorithm successfully tracked the target on 91.6%(1763/1925) of DE frames vs. 74.9%(1441/1923) SE images (p<0.001). The displacement between tracking coordinates and ground truth for the phantom was 1.1mm+/−0.7mm for DE and 1.5mm+/− 0.6mm for SE (p<0.001). Images from 3 patients were analyzed with the tumor tracked on 84.9%(478/563) of frames for DE vs. 53.5%(301/563) for SE (p<0.001). The average difference to ground truth for successfully tracked DE frames was 0.6mm+/−0.6mm vs. 1.7mm+/−0.7mm SE (p<0.001).Conclusion:This work indicates the potential for markerless tumor tracking utilizing DE fluoroscopy. With DE imaging, the algorithm showed improved detectability vs. SE fluoroscopy and was able to accurately track the tumor in a majority of cases.This work was supported by Varian Medical Systems
SU‐D‐18C‐07: Framework for Time‐Dependency Analysis of MRI Data to Visualize and Quantify Lung Ventilation by Using Oxygen as Contrast Media
Authors: Etzel R , Fiebich M 
Published: July 2014

Purpose:To visualize and quantify lung ventilation by analyzing MRI data time‐dependent an eligible framework is capable to use the contrast enhancing characteristic of oxygen in functional lung MRI.Methods:A framework was developed and programmed by using the tool Fiji, which is an image processing package based on ImageJ. The analysis was performed on previously recorded 1.5T magnetic resonance images of narcotized and mechanically ventilated pigs in both dorsal and transversal plane, with a slice thickness of 8 mm and 32 pictures per slice. The oxygen rate of the pigs' breathing was alternated periodically from 21 to 100 percent and backwards within an eight seconds interval. Several lung areas were blocked mechanically. After importing the MR sequence into Fiji the framework could be started automatically with pre‐set or manually adjusted parameters. The framework analyzed all pixels of each picture temporally to detect the variation of gray values related to the temporal change in oxygen rate.Results:The software is able to detect time‐dependent changes in signal intensity during dynamic examination of the lung. Change of pixel intensities and time‐to‐peak of the output signal showed a significant relation between oxygen rate and gray value of the stored data and the generated images and curves. The blocked lung areas could be identified in the resultimages since pixels located in these regions representing less signal in contrast with other regions.Conclusion:This work confirmed the ability of oxygen to be used as contrast media in magnetic resonance imaging. The developed and tested framework for time‐dependent analysis of MRI data has demonstrated the significance of a quantification of lung ventilation based on oxygen‐induced change in output signal.
SU‐D‐9A‐05: IBEX: An Open Software Infrastructure Platform to Accelerate Collaborative Work On Quantitative Image Features and Predictive Models
Authors: Zhang L , Hunter L , Fried D , Fave X , Yang J , Court L 
Published: July 2014

Purpose:Quantitative imaging analysis has great potential to improve the accuracy and efficiency of cancer research, but the lack of software infrastructure prohibits progress from developing and using its methods. We have developed a software platform to flexibly support common quantitative imaging analysis tasks such as multimodality image data import and review, feature algorithm development, predictive model design, and consistent data sharing among multi‐institutions.Methods:The IBEX(Imaging Biomarker Explorer) software package was developed under Matlab and C/C++. The software architecture deploys the modern Model‐View‐Controller (MVC) and unit testing programming concepts to isolate each task and to validate if their relevant data and algorithms are fit for use. The View component represents multimodality images with delineated structures (if available), which are imported using DICOM, CERR, or other native formats. Non‐image data, such as patient performance status can also be entered. The Controller component represents image pre‐processing and feature extraction algorithms. The Model component represents the predictive model formula and coefficients. Thanks to the unit testing implementation, the user has the option of reviewing the corresponding result to check the quality of data and algorithms at each stage. While IBEX itself is self‐contained and has implemented typical algorithms and models, it is an open system and additional algorithms and models can be easily added by defining them in library files. Also, a complete external model can be imported, including necessary data about pre‐processing algorithms, feature algorithms, model formula, and model coefficients. This greatly helps maintain data consistency when institutions attempt to validate external models.Results:Testers found the IBEX software to be intuitive and easy to use. All import, pre‐processing algorithms, and feature algorithms were fully validated.Conclusion:We have successfully implemented an open software infrastructure platform to accelerate work on quantitative imaging analysis and collaborative research activities.This work was funded by the NCI(1R03CA178495‐01)
SU‐D‐9A‐07: Imaging Dose and Cancer Risk in Image‐Guided Radiotherapy of Cancers
Authors: Zhou L , Bai S , Zhang Y , Ming X , Zhang Y , Deng J 
Published: July 2014

Purpose:To systematically evaluate the imaging doses and cancer risks associated with various imaging procedures involving ionizing radiation during image‐guided radiotherapy of an increasingly large number of cancer patients.Methods:141 patients (52 brain cases, 47 thoracic cases, 42 abdominal cases, aged 3 to 91 years old) treated between October 2009 and March 2010 were included in this IRB‐approved retrospective study. During the whole radiotherapy course, each patient underwent at least one type of imaging procedures, i.e., kV portal, MV portal and kVCBCT, besides CT simulations. Based on Monte Carlo modeling and particle transport in human anatomy of various dimensions, the correlations between the radiation doses to the various organs‐at‐risk (OARs) at the head, the thoracic and the abdominal regions and one's weight, circumference, scan mAs and kVp have been obtained and used to estimate the radiation dose from a specific imaging procedure. The radiation‐induced excess relative risk (ERR) was then estimated with BEIR VII formulism based on one's gender, age and radiation dose. 1+ ERR was reported in this study as relative cancer risk.Results:For the whole cohort of 141 patients, the mean imaging doses from various imaging procedures were 8.3 cGy to the brain, 10.5 cGy to the lungs and 19.2 cGy to the red bone marrow, respectively. Accordingly, the cancer risks were 1.140, 1.369 and 2.671, respectively. In comparison, MV portal deposited largest doses to the lungs while kVCBCT delivered the highest doses to the red bone marrow.Conclusion:The compiled imaging doses to a patient during his/her treatment course were patient‐specific and site‐dependent, varying from 1.2 to 263.5 cGy on average, which were clinically significant and should be included in the treatment planning and overall decision‐making. Our results indicated the necessity of personalized imaging to maximize its clinical benefits while reducing the associated cancer risks.Sichuan University Scholarship
SU‐E‐E‐04: Hurtles and Benefits to Establishing An Academic/industry Diagnostic Medical Physics Residency Collaboration
Authors: Nye J , Cuddy M , Heathcock G 
Published: July 2014

Purpose:Funding and administration of diagnostic residencies presents a barrier to the expansion of these programs. In this work, the authors detail elements included in establishing an academic and industry collaboration to share the training and finances of a new residency program.Methods:The goals of each partner were prioritized and strengths and weaknesses in expertise were identified as well as their potential benefit to each. Many of the hurtles concerning the broader program administration were addressed through an affiliation agreement. Aspects of program management specific to each resident such as deviations to the approved training plan were addressed through sub‐agreements. Some priorities identified may need to be actively managed throughout the resident's training period.Results:Several hurtles were identified in the administration and training of residents including conflicts between training and service, protection of proprietary materials/knowledge, intellectual property rights, funding and payment models, remote management, resident placement/scheduling and non‐compete agreements. Several benefits may be realized through an academic/industry collaboration including mentorship and teaching experience, scholarship, enhancement of the partner's reputation, marketing advantages, minimization of the administrative burden and training of future qualified staff. These hurtles and benefits should be well understood as some may not be negotiable due to institutional or company policies governing the operation of each partner.Conclusion:Residency collaborations between academic and industry environments present a unique set of hurtles but clear advantages to each stakeholder. The benefit to the future resident is an innovative educational experience comprised of hospital‐ and consultingbased medical practices.
SU‐E‐P‐05: Is Routine Treatment Planning System Quality Assurance Necessary?
Authors: Alaei P 
Published: July 2014

Purpose:To evaluate the variation of dose calculations using a treatment planning system (TPS) over a two year period and assessment of the need for TPS QA on regular intervals.Methods:Two phantoms containing solid water and lung‐ and bone‐equivalent heterogeneities were constructed in two different institutions for the same brand treatment planning system. Multiple plans, consisting of photons and electron beams, including IMRT and VMAT ones, were created and calculated on the phantoms. The accuracy of dose computation in the phantoms was evaluated at the onset by dose measurements within the phantoms. The dose values at up to 24 points of interest (POI) within the solid water, lung, and bone slabs, as well as mean doses to several regions of interest (ROI), were re‐calculated over a two‐year period which included two software upgrades. The variations in POI and ROI dose values were analyzed and evaluated.Results:The computed doses vary slightly month‐over‐month. There are noticeable variations at the times of software upgrade, if the upgrade involves remodeling and/or re‐commissioning of the beams. The variations are larger in certain points within the phantom, usually in the buildup region or near interfaces, and are almost non‐existent for electron beams.Conclusion:Routine TPS QA is recommended by AAPM and other professional societies, and is often required by accreditation organizations. The frequency and type of QA, though, is subject to debate. The results presented here demonstrate that the frequency of these tests could be at longer intervals than monthly. However, it is essential to perform TPS QA at the time of commissioning and after each software upgrade.
SU‐E‐P‐06: A Novel Hybrid Planning Approach to Allow More Patients Benefited by the Intensity Modulated Proton Therapy
Authors: Jiang S , Liao L , Li Y , Wang X , Li H , Zhu X , Sahoo N , Gillin M , Hojo Y , Sun J , Chang J , Liao Z , Grosshans D , Frank S , Zhang X 
Published: July 2014

Purpose:We report a hybrid scattering and scanning beam delivery approach, termed as (HimpsPT), which demonstrated that majority IMPT delivery can be potentially replaced with hybrid IMPT and PSPT delivery with similar or better plan quality.Methods:Three representative clinical cases, including head and neck (HN), skull base chordoma (CNS) and lung cancer, treated in MDACC Proton Therapy Center with IMPT were retrospectively redesigned using HimpsPT. The PSPT plans are designed with the same prescriptions as those of IMPT plans. The whole treatment can be delivered by either alternating or sequential PSPT and IMPT delivery. The dosimetric data and dose distributions of HimpsPT plans are compared with those of IMPT plans. We also performed a worst‐case robust analysis for all plans.Results:The target coverages for all cases are comparable. For the HN case, the mean dose of esophagus larynx, left parotid and right submandibular, oral cavity V20, the max dose of cord is 18.0, 36.1, 23.6, 47.2, 0.1, 31.7 Gy in HimpsPT plan, and 25.5, 33.8, 24.9, 49.1, 0.2, 33.8 Gy in IMPT plan. For the lung case, the lung V5, V20, V30, mean lung dose, heart V40, esophagus V70, cord maximum dose are 50.5%, 37.0%, 31.7%, 21.3 Gy, 7.2%, 4.9%, 35.5 Gy in HimpsPT plan, and 55.4%, 36.7%, 30.1%, 21.3 Gy, 7.7%, 8.4%, 36.8Gy in IMPT plans. For the CNS case, brainstem maximum dose is 50.5 Gy in HimpsPT plan and 55.4 Gy in IMPT plan due to sharp penumbra offered by the aperture of the PSPT plan in HimpsPT technique.Conclusion:For majority disease sites, the dosimetric advantage of IMPT technique can be achieved by the hybrid PSPT and IMPT technique, which enables the centers equipped with both scattering and scanning beam facilities to treat more patients which can be benefited by the scanning beam.
SU‐E‐I‐04: A Mammography Phantom to Measure Mean Glandular Dose and Image Quality
Authors: Lopez‐Pineda E , Ruiz‐Trejo C , E Brandan M 
Published: July 2014

Purpose:To evaluate mean glandular dose (MGD) and image quality in a selection of mammography systems using a novel phantom based on thermoluminescent dosemeters and the ACR wax insert.Methods:The phantom consists of two acrylic, 19 cm diameter, 4.5 cm thick, semicircular modules, used in sequence. The image quality module contains the ACR insert and is used to obtain a quality control image under automatic exposure conditions. The dosimetric module carries 15 TLD‐100 chips, some under Al foils, to determine air kerma and half‐value‐layer. TL readings take place at our laboratory under controlled conditions. Calibration was performed using an ionization chamber and a Senographe 2000D unit for a variety of beam qualities, from 24 to 40 kV, Mo and Rh anodes and filters. Phantom MGD values agree, on the average, within 3% with ionization chamber data, and their precision is better than 10% (k=1).Results:MGD and image quality have been evaluated in a selection of mammography units currently used in Mexican health services. The sample includes analogic (screen/film), flexible digital (CR), and full‐field digital image receptors. The highest MDG are associated to the CR technology. The most common image quality failure is due to artifacts (dust, intensifying screen scratches, and processor marks for film/screen, laser reader defects for CR).Conclusion:The developed phantom permits the MGD measurement without the need of a calibrated ionization chamber at the mammography site and can be used by a technician without the presence of a medical physicist. The results indicate the urgent need to establish quality control programs for mammography.
SU‐E‐I‐07: An Improved Technique for Scatter Correction in PET
Authors: Lin S , Wang Y , Lue K , Lin H , Chuang K 
Published: July 2014

Purpose:In positron emission tomography (PET), the single scatter simulation (SSS) algorithm is widely used for scatter estimation in clinical scans. However, bias usually occurs at the essential steps of scaling the computed SSS distribution to real scatter amounts by employing the scatter‐only projection tail. The bias can be amplified when the scatter‐only projection tail is too small, resulting in incorrect scatter correction. To this end, we propose a novel scatter calibration technique to accurately estimate the amount of scatter using pre‐determined scatter fraction (SF) function instead of the employment of scatter‐only tail information.Methods:As the SF depends on the radioactivity distribution and the attenuating material of the patient, an accurate theoretical relation cannot be devised. Instead, we constructed an empirical transformation function between SFs and average attenuation coefficients based on a serious of phantom studies with different sizes and materials. From the average attenuation coefficient, the predicted SFs were calculated using empirical transformation function. Hence, real scatter amount can be obtained by scaling the SSS distribution with the predicted SFs. The simulation was conducted using the SimSET. The Siemens Biograph™ 6 PET scanner was modeled in this study. The Software for Tomographic Image Reconstruction (STIR) was employed to estimate the scatter and reconstruct images. The EEC phantom was adopted to evaluate the performance of our proposed technique.Results:The scatter‐corrected image of our method demonstrated improved image contrast over that of SSS. For our technique and SSS of the reconstructed images, the normalized standard deviation were 0.053 and 0.182, respectively; the root mean squared errors were 11.852 and 13.767, respectively.Conclusion:We have proposed an alternative method to calibrate SSS (C‐SSS) to the absolute scatter amounts using SF. This method can avoid the bias caused by the insufficient tail information and therefore improve the accuracy of scatter estimation.
SU‐E‐I‐08: An Inpaint‐Based Interpolation Technique to Recover Blocked Information for Cone Beam CT with a Synchronized Moving Grid (SMOG)
Authors: Kong V , Zhang H , Ren L , Jin J 
Published: July 2014

Purpose:Synchronized moving grid (SMOG) is a promising technique to reduce scatter and ghost artifacts in cone beam computed tomography (CBCT). However, the grid blocks part of image information in each projection, and multiple projections at the same gantry angle have to been taken to obtain full information. Because of the continuity of a patient's anatomy in the projection, the blocked information may be estimated by interpolation. This study aims to evaluate an inpainting‐based interpolation approach to recover the missing information for CBCT reconstruction.Method:We used a simple region‐based inpainting approach to interpolate the missing information. For a pixel to be interpolated, we divided the nearby regions having image information into 6 sub‐regions: up‐left, up‐middle, up‐right, down‐left, down‐middle, and down‐right, each with 9 pixels. The average pixel value of each sub‐region was calculated. These average values, along with the pixel location, were used to determine the interpolated pixel value. We compared our approach with the Criminisi Exemplar (CE) and total variation (TV) based inpainting techniques. Projection images of Catphan and a head phantom were used for the comparison. The SMOG was simulated by erasing the information (filling with “0”) of the areas in each projection corresponding to the grid.Results:For the Catphan, the processing time was 178, 45 and 0.98 minutes for CE, TV and our approach, respectively. The signal to noise ratio (SNR) was 19.4, 18.5 and 26.4 db, correspondingly. For the head phantom, the processing time was 222, 45 and 0.93 minutes for CE, TV and our approach, respectively. The SNR was 24.6, 20.2 and 26.2db correspondingly.Conclusion:We have developed a simple inpainting based interpolation approach, which can recover some of the image information for the SMOG‐based CBCT imaging.This study is supported by NIH/NCI grant 1R01CA166948‐01