bluuebunny/crossref_metadata_2025_split huggingface dataset:
SU‐G‐JeP1‐07: Development of a Programmable Motion Testbed for the Validation of Ultrasound Tracking Algorithms
Authors: Shepard A , Matrosic C , Zagzebski J , Bednarz B 
Published: July 2016

Purpose:To develop an advanced testbed that combines a 3D motion stage and ultrasound phantom to optimize and validate 2D and 3D tracking algorithms for real‐time motion management during radiation therapy.Methods:A Siemens S2000 Ultrasound scanner utilizing a 9L4 transducer was coupled with the Washington University 4D Phantom to simulate patient motion. The transducer was securely fastened to the 3D stage and positioned to image three cylinders of varying contrast in a Gammex 404GS LE phantom. The transducer was placed within a water bath above the phantom in order to maintain sufficient coupling for the entire range of simulated motion. A programmed motion sequence was used to move the transducer during image acquisition and a cine video was acquired for one minute to allow for long sequence tracking. Images were analyzed using a normalized cross‐correlation block matching tracking algorithm and compared to the known motion of the transducer relative to the phantom.Results:The setup produced stable ultrasound motion traces consistent with those programmed into the 3D motion stage. The acquired ultrasound images showed minimal artifacts and an image quality that was more than suitable for tracking algorithm verification. Comparisons of a block matching tracking algorithm with the known motion trace for the three features resulted in an average tracking error of 0.59 mm.Conclusion:The high accuracy and programmability of the 4D phantom allows for the acquisition of ultrasound motion sequences that are highly customizable; allowing for focused analysis of some common pitfalls of tracking algorithms such as partial feature occlusion or feature disappearance, among others. The design can easily be modified to adapt to any probe such that the process can be extended to 3D acquisition. Further development of an anatomy specific phantom better resembling true anatomical landmarks could lead to an even more robust validation.This work is partially funded by NIH grant R01CA190298
SU‐G‐JeP1‐08: Dual Modality Verification for Respiratory Gating Using New Real‐ Time Tumor Tracking Radiotherapy System
Authors: Shiinoki T , Kawamura S , Koike M , Yuasa Y , Uehara T , Fujimoto K , Hanazawa H , Shibuya K 
Published: July 2016

Purpose:The respirato ry gating system combined the TrueBeam and a new real‐time tumor‐tracking radiotherapy system (RTRT) was installed. The RTRT system consists of two x‐ray tubes and color image intensifiers. Using fluoroscopic images, the fiducial marker which was implanted near the tumor was tracked and was used as the internal surrogate for respiratory gating. The purposes of this study was to develop the verification technique of the respiratory gating with the new RTRT using cine electronic portal image device images (EPIDs) of TrueBeam and log files of the RTRT. Methods: A patient who underwent respiratory gated SBRT of the lung using the RTRT were enrolled in this study. For a patient, the log files of three‐dimensional coordinate of fiducial marker used as an internal surrogate were acquired using the RTRT. Simultaneously, the cine EPIDs were acquired during respiratory gated radiotherapy. The data acquisition was performed for one field at five sessions during the course of SBRT. The residual motion errors were calculated using the log files (Elog). The fiducial marker used as an internal surrogate into the cine EPIDs was automatically extracted by in‐house software based on the template‐matching algorithm. The differences between the the marker positions of cine EPIDs and digitally reconstructed radiograph were calculated (EEPID).Results:Marker detection on EPID using in‐house software was influenced by low image contrast. For one field during the course of SBRT, the respiratory gating using the RTRT showed the mean ± S.D. of 95th percentile EEPID were 1.3 ± 0.3 mm,1.1 ± 0.5 mm,and those of Elog were 1.5 ± 0.2 mm, 1.1 ± 0.2 mm in LR and SI directions, respectively.Conclusion:We have developed the verification method of respiratory gating combined TrueBeam and new real‐time tumor‐tracking radiotherapy system using EPIDs and log files.
SU‐G‐TeP2‐15: Feasibility Study of Fiber‐Optic Cerenkov Radiation Sensors for in Vivo Measurement: Dosimetric Characterization and Clinical Application in Proton Beams
Authors: Lah J , Son J , Kim G , Shin D 
Published: July 2016

Purpose:To evaluate the possibility of a fiber‐optic Cerenkov radiation sensor (FCRS) for in vivo dose verification in proton therapy.Methods:The Cerenkov radiation due to the proton beam was measured using a homemade phantom, consisting of a plastic optical fiber (POF, PGSCD1001‐13‐E, Toray, Tokyo, Japan) connected to each channel of a multianode photomultiplier tube (MAPMT:H7546, Hamamatsu Photonics, Shizuoka, Japan). Data were acquired using a multi‐anode photomultiplier tube with the NI‐DAQ system (National Instruments Texas, USA). The real‐time monitoring graphic user interface was programmed using Labview. The FCRS was analyzed for its dosimetrics characteristic in proton beam. To determine the accuracy of the FCRS in proton dose measurements, we compared the ionization chamber dose measurements using a water phantom. We investigated the feasibility of the FCRS for the measurement of dose distributions near the superficial region for proton plans with a varying separation between the target volume and the surface of 3 patients using a humanoid phantom.Results:The dose‐response has good linearity. Dose‐rate and energy dependence were found to be within 1%. Depth‐dose distributions in non‐modulated proton beams obtained with the FCRS was in good agreement with the depth‐dose measurements from the ionization chamber. To evaluate the dosimetric accuracy of the FCRS, the difference of isocenter dose between the delivery dose calculated by the treatment planning system and that measured by the FCRS was within 3%. With in vivo dosimetry using the humanoid phantom, the calculated surface doses overestimated measurements by 4%–8% using FCRS.Conclusion:In previous study, our results indicate that the performance of the array‐type FCRS was comparable to that of the currently used a multi‐layer ion chamber system. In this study, we also believe that the fiber‐optic Cerenkov radiation sensor has considerable potential for use with in vivo patient proton dosimetry.
SU‐G‐IeP3‐03: Dual‐Filament, Multi‐Facet Anode Design to Overcome Small Focal Spot Output Limitations
Authors: Freund E , Rudin S , Bednarek D 
Published: July 2016

Purpose:Demonstrate the advantages of two novel x‐ray tube‐insert designs to overcome tube output limitations for high‐resolution, small field‐of‐view (FOV) angiographic imaging.Methods:High‐spatial resolution with a small focal spot (sfs) is achievable with the microangiographic (MA) detector that we have developed. The two designs explored are a non‐offset design, and an offset design. Both tube‐insert designs include two filaments, L1 and L2, and two focal target tracks. L1 corresponds to an 8° anode region to produce a medium effective focal spot (mfs) to be used with the standard FOV flat‐panel detector (FPD). L2 corresponds to a 2° anode region to produce a small effective focal spot (sfs) to be used with the smaller FOV MA detector, while providing comparable x‐ray output. The non‐offset design has the sfs region closer to the anode rotation axis, and mfs region farther from the axis. The offset design has the mfs region closer to the rotation axis, and sfs region farther from the rotation axis. The sfs region of the offset design has a greater anode track diameter which may further increase output capability. However, in order to avoid limitations on the mfs FOV in this design, the sfs target region of the anode is offset in the anode cathode direction. The geometries of both designs are illustrated and compared.Results:It is shown that the new designs enable increased tube output for the sfs when used with a small FOV detector, while also allowing for increased FOV with the standard FPD and the mfs.Conclusion:A dual track, dual filament x‐ray tube‐insert design provides increased output capability over a small FOV, while enabling an mfs to be used with the lower resolution standard FPD.Toshiba Medical Systems Corp
SU‐G‐IeP3‐05: Effects of Image Receptor Technology and Dose Reduction Software On Radiation Dose Estimates for Fluoroscopically‐Guided Interventional (FGI) Procedures
Authors: Merritt Z , Dave J , Eschelman D , Gonsalves C 
Published: July 2016

Purpose:To investigate the effects of image receptor technology and dose reduction software on radiation dose estimates for most frequently performed fluoroscopically‐guided interventional (FGI) procedures at a tertiary health care center.Methods:IRB approval was obtained for retrospective analysis of FGI procedures performed in the interventional radiology suites between January‐2011 and December‐2015. This included procedures performed using image‐intensifier (II) based systems which were subsequently replaced, flat‐panel‐detector (FPD) based systems which were later upgraded with ClarityIQ dose reduction software (Philips Healthcare) and relatively new FPD system already equipped with ClarityIQ. Post procedure, technologists entered system‐reported cumulative air kerma (CAK) and kerma‐area product (KAP; only KAP for II based systems) in RIS; these values were analyzed. Data pre‐processing included correcting typographical errors and cross‐verifying CAK and KAP. The most frequent high and low dose FGI procedures were identified and corresponding CAK and KAP values were compared.Results:Out of 27,251 procedures within this time period, most frequent high and low dose procedures were chemo/immuno‐embolization (n=1967) and abscess drainage (n=1821). Mean KAP for embolization and abscess drainage procedures were 260,657, 310,304 and 94,908 mGycm2, and 14,497, 15,040 and 6307 mGycm2 using II‐, FPD‐ and FPD with ClarityIQ‐ based systems, respectively. Statistically significant differences were observed in KAP values for embolization procedures with respect to different systems but for abscess drainage procedures significant differences were only noted between systems with FPD and FPD with ClarityIQ (p<0.05). Mean CAK reduced significantly from 823 to 308 mGy and from 43 to 21 mGy for embolization and abscess drainage procedures, respectively, in transitioning to FPD systems with ClarityIQ (p<0.05).Conclusion:While transitioning from II‐ to FPD‐ based systems was not associated with dose reduction for the most frequently performed FGI procedures, substantial dose reduction was noted with relatively newer systems and dose reduction software.
SU‐G‐IeP3‐15: Cloud Based Monitoring of X‐Ray Angiography Equipment Performance Based On Automated Daily Sampling of Key Performance Indicators
Authors: Sjoeberg J , Omar A , Bujila R , Nowik P , Olafsson I , Poludniowski G 
Published: July 2016

Purpose:To investigate the feasibility of deploying a novel method for the daily monitoring of x‐ray Angiography (XA) equipment performance as a cloud‐based service.Methods:From previous work, we have developed a novel image based method of testing the performance of XA equipment on a daily basis. A pre‐programmed protocol on an XA system is used and images are automatically analyzed using software developed in‐house, resulting in a set of Key Performance Indicators (KPI's) that can be tracked over time. The analysis software was deployed in the cloud and a routing rule was set up to automatically transfer images from the XA systems to the cloud. A web based user interface was developed with access to the KPI's for studying auto generated reports, trends and anomalies. Technologists were instructed on how to perform the daily scans with a remotely hosted instructional video and have actively participated in this endeavor for the last 7 months.Results:Quantitative performance tests have been automated including data aggregation, management, analysis and visualization which enables sampling of KPI's on a daily basis and the developed solution has been migrated to the cloud. The daily performance check routine takes ∼6 minutes per XA system in total including the transfer of images, analysis and reporting. In one instance a significant artifact and a defective pixel has been identified. A generally stable system performance has otherwise been observed as indicated by the process control charts.Conclusion:A cloud based solution for monitoring the performance of XA equipment has been developed. The solution facilitates efficient data collection, enabling useful trend analysis on large data sets.This project was funded by Vinnova (Swedish Innovation Agency), grant number 2012‐03693, and was carried out in collaboration with Image Owl, Inc. (Reykjavik, Iceland).
SU‐G‐JeP3‐06: Lower KV Image Dose Are Expected From a Limited‐Angle Intra‐Fractional Verification (LIVE) System for SBRT Treatments
Authors: Ding G , Yin F , Ren L 
Published: July 2016

Purpose:In order to track the tumor movement for patient positioning verification during arc treatment delivery or in between 3D/IMRT beams for stereotactic body radiation therapy (SBRT), the limited‐angle kV projections acquisition simultaneously during arc treatment delivery or in‐between static treatment beams as the gantry moves to the next beam angle was proposed. The purpose of this study is to estimate additional imaging dose resulting from multiple tomosynthesis acquisitions in‐between static treatment beams and to compare with that of a conventional kV‐CBCT acquisition.Methods:kV imaging system integrated into Varian TrueBeam accelerators was modeled using EGSnrc Monte Carlo user code, BEAMnrc and DOSXYZnrc code was used in dose calculations. The simulated realistic kV beams from the Varian TrueBeam OBI 1.5 system were used to calculate dose to patient based on CT images. Organ doses were analyzed using DVHs. The imaging dose to patient resulting from realistic multiple tomosynthesis acquisitions with each 25–30 degree kV source rotation between 6 treatment beam gantry angles was studied.Results:For a typical lung SBRT treatment delivery much lower (20–50%) kV imaging doses from the sum of realistic six tomosynthesis acquisitions with each 25–30 degree x‐ray source rotation between six treatment beam gantry angles were observed compared to that from a single CBCT image acquisition.Conclusion:This work indicates that the kV imaging in this proposed Limited‐angle Intra‐fractional Verification (LIVE) System for SBRT Treatments has a negligible imaging dose increase. It is worth to note that the MV imaging dose caused by MV projection acquisition in‐between static beams in LIVE can be minimized by restricting the imaging to the target region and reducing the number of projections acquired. For arc treatments, MV imaging acquisition in LIVE does not add additional imaging dose as the MV images are acquired from treatment beams directly during the treatment.
SU‐G‐JeP3‐07: Real‐Time Image Guided Radiation Therapy for Heterotopic Ossification in Patients After Hip Replacement
Authors: Le A , Jiang S , Timmerman R , Choy H , Pompos A 
Published: July 2016

Purpose:To demonstrate the feasibility of using CBCT in a real‐time image guided radiation therapy (IGRT) for single fraction heterotopic ossification (HO) in patients after hip replacement. In this real‐time procedure, all steps, from simulation, imaging, planning to treatment delivery, are performed at the treatment unit in one appointment time slot. This work promotes real‐time treatment to create a paradigm shift in the single fraction radiation therapy.Methods:An integrated real‐time IGRT for HO was developed and tested for radiation treatment of heterotopic ossification for patient after hip replacement. After CBCT images are acquired at the linac, and sent to the treatment planning system, the physician determines the field and/or draws a block. Subsequently, a simple 2D AP/PA plan with prescription of 700 cGy is created on‐the‐fly for physician to review. Once the physician approves the plan, the patient is treated on the same simulation position. This real‐time treatment requires the team of attending physician, physicist, therapists, and dosimetrist to work in harmony to achieve all the steps in a timely manner.Results:Ten patients have been treated with this real‐time treatment, having the same beams arrangement treatment plan and prescription as our clinically regular CT‐based 2D plans. The average time for these procedures are 52.9 ±10.7 minutes from the time patient entered the treatment room until s/he exited, and 37.7 ±8.6 minutes from starting CBCT until last beam delivered.Conclusion:The real‐time IGRT for HO treatment has been tested and implemented to be a clinically accepted procedure. This one‐time appointment greatly enhances the waiting time, especially when patients in high level of pain, and provides a convenient approach for the whole clinical staff. Other disease sites will be also tested with this new technology.
SU‐G‐JeP3‐11: Use of an Easily‐Modified Simple Phantom to Perform the Daily and Monthly Localization QA Tasks for a Video‐Based Surface Imaging System
Authors: Kim C , Furhang E , Devick C 
Published: July 2016

Purpose:To describe a simple, easily fabricated, Styrofoam phantom used in conjunction with a commonly available OBI phantom, to QA a video‐surface imaging system according to TG147, using minimal effort.Methods:Styrofoam, a common packaging material, reflects the speckled AlignRT light very well. A Styrofoam block was used as a partial cap to attach onto a standard Varian Marker Match phantom. The cap was engraved with two sets crosshairs on each surface, one at the ‘zero’(center) and the other an ‘off‐centered’ position, 2 cm in all three orthogonal directions. A reference image is obtained at ‘zero’ position. For the daily test, static localization check is performed by aligning the phantom with room lasers at ‘off‐centered’ position and then the couch is shifted to match the ‘zero’ with the lasers. For the monthly test, plate calibration is recommended to define a relationship between an image point on the camera and that of the isocenter in the treatment room. Static localization accuracy is checked using a hidden‐target test, which is an extension of daily static localization procedure. The phantom positioned at ‘off‐centered’ is shifted to make the readings 0.0 cm for all orientations. The location of the hidden target is then verified by taking orthogonal kV images or CBCT.Results:The AlignRT tests required by TG147 are quite similar to those performed on on‐board imaging (OBI). Overall alignment of the system is maintained with RMS < 1 mm and any potential problems were identified. The system's static location is maintained within ± 1 mm. The same accuracy can be obtained for a monthly hidden target test which is integrated with an OBI QA.Conclusion:A customized phantom is tested and a routine QA program for surface‐imaging system is introduced. By dealing with a single phantom, the procedure can achieve similar goals efficiently.
SU‐G‐TeP3‐10: Radiation Induces Prompt Live‐Cell Metabolic Fluxes
Authors: Campos D , Peeters W , Nickel K , Burkel B , Bussink J , Kimple R , van der Kogel A , Eliceiri K , Kissick M 
Published: July 2016

Purpose:To compare metabolic dynamics and HIF‐1α expression following radiation between a cancerous cell line (UM‐SCC‐22B) and a normal, immortalized cell line, NOK (Normal Oral Keratinocyte). HIF‐1 is a key factor in metabolism and radiosensitivity. A better understanding of how radiation affects the interplay of metabolism and HIF‐1 might give a better understanding of the mechanisms responsible for radiosensitivity.Methods:Changes in cellular metabolism in response to radiation are tracked by fluorescence lifetime of NADH. Expression of HIF‐1α was measured by immunofluorescence for both cell lines with and without irradiation. Radiation response is also monitored with additional treatment of a HIF‐1α inhibitor (chrysin) as well as a radical scavenger (glutathione). Changes in oxygen consumption and respiratory capacity are also monitored using the Seahorse XF analyzer.Results:An increase in HIF‐1α was found to be in response to radiation for the cancer cell line, but not the normal cell line. Radiation was found to shift metabolism toward glycolytic pathways in cancer cells as measured by oxygen consumption and respiratory capacity. Radiation response was found to be muted by addition of glutathione to cell media. HIF‐1α inhibition similarly muted radiation response in cancer.Conclusion:The HIF‐1 protein complex is a key regulator cellular metabolism through the regulation of glycolysis and glucose transport enzymes. Moreover, HIF‐1 has shown radio‐protective effects in tumor vascular endothelia, and has been implicated in metastatic aggression. Monitoring interplay between metabolism and the HIF‐1 protein complex can give a more fundamental understanding of radiotherapy response.
SU‐G‐IeP4‐05: Experience with a Practical Approach to the Release of Radioactive Patients from Radiation Safety Isolation
Authors: Wendt R , Erwin W , Fisher A , Jones S , Jimenez S , Wong F , Jessop A 
Published: July 2016

Purpose:The radioactive patient releases of the nuclear medicine department in a large cancer center were analyzed to compare the estimated doses to others to the regulatory limit and institutional targets and to gauge how onerous the patients’ instructions were.Methods:In‐house software that implements the NUREG 1556 approach and further considers fellow travelers, children and pregnant women and members of the public following Siegel, et al., is used to calculate release timing and to provide patients with individualized instructions. A retrospective analysis of the 218 releases in 2015 that required instructions included all I‐131 and Lu‐177 treatments.Results:There were 87 male and 131 female patients. They were 45.5±16.5 (8‐84) years old, weighed 83.3±21.8 kg and stood 168±10 cm tall with a body mass index of 29.3±6.7 kg/m2. 195 patients received 2.96±2.23 GBq of I‐131‐NaI for differentiated thyroid carcinoma and eight received 636±231 MBq of I‐131‐NaI for hyperthyroidism. There were eight administrations of 18.5 GBq of I‐131‐mIBG and seven administrations of 7.4 GBq of Lu‐177‐DOTATATE. The dose to the most exposed person was 1.67±1.05 (mode=0.60, median=1.15) mSv. The dose to a fellow traveler was 0.31±0.31 (mode=0.1, median=0.17) mSv. The dose to children and pregnant women was 0.51±0.34 (mode=1.0, median=0.42) mSv. The duration of isolation was 7.7±17.3 (mode=2, median=1.7) hours. The duration of sleeping alone was 60.4±127 (mode=0, median=15.5) hours. The time to delay traveling was 12.2±11 (mode=median=0) hours. The time to completely avoid children and pregnant women was 23.3±26.5 (0–254, mode=median=24) hours followed by limited contact for 20.6±68.1 (0–491, mode=median=0) hours. The time to avoid others (e.g., to wait to return to work) was 12.1±101 (0–1465, mode=median=0) hours.Conclusion:The estimated doses to others were often well below the limits set by regulation, 5 mSv, or prudent practice, 1 mSv. Most patients’ instructions were not hard to comply with.