bluuebunny/crossref_metadata_2025_split huggingface dataset:
SU‐G‐JeP4‐04: Commissioning and Acceptance Testing of Optical Surface Monitoring System On TrueBEAM STx as Per Task Group 147
Authors: Mhatre V , Patwe P , Dandekar P 
Published: July 2016

Purpose:Optical Surface Monitoring system (OSMS) have been recently introduced by Varian for initial patient positioning and real‐time monitoring during complex radiotherapy treatment. The purpose of this work was to implement TG 147 with OSMS.Methods:Recently we installed OSMS first of its kind in India on trueBEAM STx at our Institue. The OSMS is composed of a three cameras ceiling mounted and a Workstation. The following tests were performed to validate the system a. Calibration b. System reproducibility and drift c. Static localization displacement accuracy and d. Dynamic radiation gating delivery. The Calibration procedure consists of Daily,Monthly and MV Radiation Isocenter Calibration. The reproducibility of system was tested by monitoring the varian gating phantom test pattern for at least 120 min. Each recorded pattern was registered to the reference surface to calculate the required couch adjustment. To measure the static localization displacement accuracy of the system to detect and quantify patient shift relative to a reference image,we compared the shift detected by the surface imaging system with known couch transitions in a phantom study. The phantom was set in a motion and the radiation beam was holded by changing the threshold in the software for different clinical setups to test the dynamic radiation gating capability.Results:Daily calibration was within ±0.5 mm. The MV radiation isocentre with respect to cameras was less than 1 mm in translational axis and less than 0.5° for rotational axis. The reproducibility was found to be 0.4 mm. The maximum static displacement accuracy was 0.75 mm for the three translational axis, and less than 0.5° for rotational axis. The system was able to hold the beam with a minimum threshold of 1 mm.Conclusion:A quality assurance process has been developed as per TG 147 for the clinical implementation of an OSMS in radiation therapy.
SU‐G‐JeP4‐07: Evaluation of Intrafraction Motion Using 3D Surface Guided Radiation Therapy in Lung SBRT
Authors: Jermoumi M , Cao D , Mehta V , Shepard D 
Published: July 2016

Purpose:Surface guided radiation therapy (SGRT) uses stereoscopic video images in combination with patterns projected onto the patient's surface to dynamically capture and reconstruct a 3D surface map. In this work, we used a C‐RAD Catalyst HD system (C‐RAD) to evaluate intrafraction motion in the delivery of lung SBRT.Methods:The surface acquired from the 4DCT images from our preliminary cohort of eight lung cancer patients treated with SBRT were matched to the surface images acquired prior to each treatment. Additionally, a CBCT image set was acquired. A linear regression model was established between the external and internal motion of tumor during pretreatment and used to predict the CBCT deviation during treatment. The shifts determined from CBCT and the shifts from surface map imaging were compared and assessed using Bland‐Altman method. For intrafraction motion, we assessed the percentage of mean errors that fell outside of the threshold of 2 mm, 3 mm, and 5 mm along the translational directions. The required PTV margin was quantified over the course of treatment. The correlation between intrafraction treatment time and mean error of 3D displacement was evaluated using the Pearson coefficient, rResults:A total of 7971 data points were analyzed. Deviations of 2mm, 3mm, and 5mm were observed less than 7%, 2 %, and 0 % of the time along the translational direction. CBCT and Catalyst showed close agreement during patient positioning. Furthermore, the calculated PTV margins were less than our clinical tolerance of 5 mm. Using the Pearson coefficient r,the mean error of 3D displacement showed significant correlation with treatment time (r=0.69, p= 0.000002).Conclusion:SGRT can be used to ensure accurate patient positioning during treatment without an additional delivery of dose to the patient. This study shows that importance of treatment time as a consideration during the treatment planning process.
SU‐G‐TeP4‐07: Automatic EPID‐Based 2D Measurement of MLC Leaf Offset as a Quality Control Tool
Authors: Ritter T , Schultz B , Kim G , Barnes M , Perez M , Farrey K , Popple R , Greer P , Moran J 
Published: July 2016

Purpose:The MLC dosimetric leaf gap (DLG) and transmission are measured parameters which impact the dosimetric accuracy of IMRT and VMAT plans. This investigation aims to develop an efficient and accurate routine constancy check of the physical DLG in two dimensions.Methods:The manufacturer's recommended DLG measurement method was modified by using 5 fields instead of 11 and by utilizing the Electronic Portal Imaging Device (EPID). Validations were accomplished using an ion chamber (IC) in solid water and a 2D IC array. EPID data was collected for 6 months on multiple TrueBeam linacs using both Millennium and HD MLCs at 5 different clinics in an international consortium. Matlab code was written to automatically analyze the images and calculate the 2D results. Sensitivity was investigated by introducing deliberate leaf position errors. MLC calibration and initialization history was recorded to allow quantification of their impact. Results were analyzed using statistical process control (SPC).Results:The EPID method took approximately 5 minutes. Due to detector response, the EPID measured DLG and transmission differed from the IC values but were reproducible and consistent with changes measured using the ICs. For the Millennium MLC, the EPID measured DLG and transmission were both consistently lower than IC results. The EPID method was implemented as leaf offset and transmission constancy tests (LOC and TC). Based on 6 months of measurements, the initial leaf‐specific action thresholds for changes from baseline were set to 0.1 mm. Upper and lower control limits for variation were developed for each machine.Conclusion:Leaf offset and transmission constancy tests were implemented on Varian HD and Millennium MLCs using an EPID and found to be efficient and accurate. The test is effective for monitoring MLC performance using dynamic delivery and performing process control on the DLG in 2D, thus enhancing dosimetric accuracy.This work was supported by a grant from Varian Medical Systems.
SU‐G‐TeP4‐08: Automating the Verification of Patient Treatment Parameters
Authors: DiCostanzo D , Ayan A , Woollard J , Gupta N 
Published: July 2016

Purpose:To automate the daily verification of each patient's treatment by utilizing the trajectory log files (TLs) written by the Varian TrueBeam linear accelerator while reducing the number of false positives including jaw and gantry positioning errors, that are displayed in the Treatment History tab of Varian's Chart QA module.Methods:Small deviations in treatment parameters are difficult to detect in weekly chart checks, but may be significant in reducing delivery errors, and would be critical if detected daily. Software was developed in house to read TLs. Multiple functions were implemented within the software that allow it to operate via a GUI to analyze TLs, or as a script to run on a regular basis. In order to determine tolerance levels for the scripted analysis, 15,241 TLs from seven TrueBeams were analyzed. The maximum error of each axis for each TL was written to a CSV file and statistically analyzed to determine the tolerance for each axis accessible in the TLs to flag for manual review. The software/scripts developed were tested by varying the tolerance values to ensure veracity. After tolerances were determined, multiple weeks of manual chart checks were performed simultaneously with the automated analysis to ensure validity.Results:The tolerance values for the major axis were determined to be, 0.025 degrees for the collimator, 1.0 degree for the gantry, 0.002cm for the y‐jaws, 0.01cm for the x‐jaws, and 0.5MU for the MU. The automated verification of treatment parameters has been in clinical use for 4 months. During that time, no errors in machine delivery of the patient treatments were found.Conclusion:The process detailed here is a viable and effective alternative to manually checking treatment parameters during weekly chart checks.
SU‐G‐TeP4‐13: Interfraction Treatment Monitoring Using Integrated Invivo EPID Images
Authors: Defoor D , Papanikolaou N , Stathakis S 
Published: July 2016

Purpose:To investigate inter‐fraction differences of dose delivery by analyzing portal images acquired during treatment and implement an automated system to generate a report for each fraction. Large differences in images between fractions can alert the physicist of possible machine performance issues or patient set‐up errors.Methods:A Varian Novalis Tx equipped with a HD120 MLC and aS1000 electronic portal imaging device (EPID) was used in our study. EPID images are acquired in continuous acquisition mode for 32 volumetric arc therapy (VMAT) patients. The images are summed to create an image for each arc and a single image for each fraction. The first fraction is designated as the reference unless a machine error prevented acquisition of all images. The images for each beam as well as the fraction image are compared using gamma analysis at 1%/1mm, 2%/2mm and 3%/3mm. A report is then generated using an in house MatLab program containing the comparison for the current fraction as well as a history of previous fractions. The reports are automatically sent via email to the physicist for review. Fractions in which the total number of images was not within 5% of the reference number of images were not included in the results.Results:91 of the 182 fractions recorded an image count within 5% of the reference. Gamma averages over all fractions and patients were 96.2% ±0.8% at 3%/3mm, 92.9% ±1% at 2%/2mm and 80.6% ±1.8% at 1%/1mm. The SD between fractions for each patient ranged from .004% to 10.4%. Of the 91 fractions 3 flagged due to low gamma values. After further investigation no significant errors were found.Conclusion:This toolkit can be used for in‐vivo monitoring of treatment plan delivery an alert the physics staff of any inter‐fraction discrepancies that may require further investigation.
SU‐G‐TeP4‐15: The Roucoulette: A Set of Quality Control Tests for Dynamic Trajectory (4Pi) Treatment Delivery Techniques
Authors: Teke T 
Published: July 2016

Purpose:To present and validate a set of quality control tests for trajectory treatment delivery using synchronized dynamic couch (translation and rotation), MLC and collimator motion.Methods:The quality control tests are based on the Picket fence test, which consist of 5 narrow band 2mm width spaced at 2.5cm intervals, and adds progressively synchronized dynamic motions. The tests were exposed on GafChromic EBT3 films. The first test is a regular (no motion and MLC static while beam is on) Picket Fence test used as baseline. The second test includes simultaneous collimator and couch rotation, each stripe corresponding to a different rotation speed. Errors in these tests were introduced (0.5 degree and 1 degree error in rotation synchronization) to assess the error sensitivity of this test. The second test is similar to the regular Picket Fence but now including dynamic MLC motion and couch translation (including acceleration during delivery) while the beam is on. Finally in the third test, which is a combination of the first and second test, the Picket Fence pattern is delivered using synchronized collimator and couch rotation and synchronized dynamic MLC and couch translation including acceleration. Films were analyzed with FilmQA Pro.Results:The distance between the peaks in the dose profile where measured (18.5cm away from the isocentre in the inplane direction where non synchronized rotation would have the largest effect) and compared to the regular Picket Fence tests. For well synchronized motions distances between peaks where between 24.9–25.4 mm identical to the regular Picket Fence test. This range increased to 24.4–26.4mm and 23.4–26.4mm for 0.5 degree and 1 degree error respectively. The amplitude also decreased up to 15% when errors are introduced.Conclusion:We demonstrated that the Roucoulette tests can be used as a quality control tests for trajectory treatment delivery using synchronized dynamic motion.
MO‐AB‐204‐00: Interoperability in Radiation Oncology: IHE‐RO Committee Update
Authors: Hadley Scott 
Published: July 2016

You've experienced the frustration: vendor A's device claims to work with vendor B's device, but the practice doesn't match the promise. Getting devices working together is the hidden art that Radiology and Radiation Oncology staff have to master. To assist with that difficult process, the Integrating the Healthcare Enterprise (IHE) effort was established in 1998, with the coordination of the Radiological Society of North America.Integrating the Healthcare Enterprise (IHE) is a consortium of healthcare professionals and industry partners focused on improving the way computer systems interconnect and exchange information. This is done by coordinating the use of published standards like DICOM and HL7. Several clinical and operational IHE domains exist in the healthcare arena, including Radiology and Radiation Oncology. The ASTRO‐sponsored IHE Radiation Oncology (IHE‐RO) domain focuses on radiation oncology specific information exchange. This session will explore the IHE Radiology and IHE RO process for;

IHE solicitation process for new profiles.
Improving the way computer systems interconnect and exchange information in the healthcare enterprise
Supporting interconnectivity descriptions and proof of adherence by vendors
Testing and assuring the vendor solutions to connectivity problems.
Including IHE profiles in RFPs for future software and hardware purchases.
Learning Objectives:
Understand IHE role in improving interoperability in health care.
Understand process of profile development and implantation.
Understand how vendors prove adherence to IHE RO profiles.S. Hadley, ASTRO Supported Activity
MO‐AB‐204‐01: IHE RO Overview
Authors: Hadley S. 
Published: July 2016

You've experienced the frustration: vendor A's device claims to work with vendor B's device, but the practice doesn't match the promise. Getting devices working together is the hidden art that Radiology and Radiation Oncology staff have to master. To assist with that difficult process, the Integrating the Healthcare Enterprise (IHE) effort was established in 1998, with the coordination of the Radiological Society of North America.Integrating the Healthcare Enterprise (IHE) is a consortium of healthcare professionals and industry partners focused on improving the way computer systems interconnect and exchange information. This is done by coordinating the use of published standards like DICOM and HL7. Several clinical and operational IHE domains exist in the healthcare arena, including Radiology and Radiation Oncology. The ASTRO‐sponsored IHE Radiation Oncology (IHE‐RO) domain focuses on radiation oncology specific information exchange. This session will explore the IHE Radiology and IHE RO process for;

IHE solicitation process for new profiles.
Improving the way computer systems interconnect and exchange information in the healthcare enterprise
Supporting interconnectivity descriptions and proof of adherence by vendors
Testing and assuring the vendor solutions to connectivity problems.
Including IHE profiles in RFPs for future software and hardware purchases.
Learning Objectives:
Understand IHE role in improving interoperability in health care.
Understand process of profile development and implantation.
Understand how vendors prove adherence to IHE RO profiles.S. Hadley, ASTRO Supported Activity
MO‐AB‐BRA‐07: Low Dose Imaging with Avalanche Amorphous Selenium Flat Panel Imager
Authors: Scheuermann J , Howansky A , Goldan A , Leveille S , Tousignant O , Tanioka K , Zhao W 
Published: July 2016

Purpose:We present the first active matrix flat panel imager (AMFPI) capable of producing x‐ray quantum noise limited images at low doses by overcoming the electronic noise through signal amplification by photoconductive avalanche gain (gav). The indirect detector fabricated uses an optical sensing layer of amorphous selenium (a‐Se) known as High‐Gain Avalanche Rushing Photoconductor (HARP). The detector design is called Scintillator HARP (SHARP)‐AMFPI. This is the first image sensor to utilize solid‐state HARP technology.Methods:The detector's electronic readout is a 24 × 30 cm2 array of thin film transistors (TFT) with a pixel pitch of 85 µm. The HARP structure consists of a 15 µm layer of a‐Se isolated from the high voltage (HV) and signal electrode by a 2 µm thick hole blocking layer and electron blocking layer, respectively, to reduce dark current. A 150 µm thick structured CsI scintillator with reflective backing and a fiber optic faceplate (FOP) was coupled to the semi‐transparent HV bias electrode of the HARP structure. Images were acquired using a 30 kVp Mo/Mo spectrum typically used in mammography.Results:Optical sensitivity measurements demonstrate that gav = 76 ± 5 can be achieved over the entire active area of the detector. At a constant dose to the detector of 6.67 µGy, image quality increases with gav until the effective electronic noise is negligible. Quantum noise limited images can be obtained with doses as low as 0.18 µGy.Conclusion:We demonstrate the feasibility of utilizing avalanche gain to overcome electronic noise. The indirect detector fabricated is the first solid‐state imaging sensor to use HARP, and the largest active area HARP sensor to date. Our future work is to improve charge transport within the HARP structure and utilize a transparent HV electrode.
MO‐AB‐206‐01: PET Physics
Authors: Turkington T. 
Published: July 2016

This education session will cover the physics and operation principles of gamma cameras and PET scanners.The first talk will focus on PET imaging. An overview of the principles of PET imaging will be provided, including positron decay physics, and the transition from 2D to 3D imaging. More recent advances in hardware and software will be discussed, such as time‐of‐flight imaging, and improvements in reconstruction algorithms that provide for options such as depth‐of‐interaction corrections. Quantitative applications of PET will be discussed, as well as the requirements for doing accurate quantitation. Relevant performance tests will also be described.

Learning Objectives:
Be able to describe basic physics principles of PET and operation of PET scanners.
Learn about recent advances in PET scanner hardware technology.
Be able to describe advances in reconstruction techniques and improvements
Be able to list relevant performance tests.The second talk will focus on gamma cameras. The Nuclear Medicine subcommittee has charged a task group (TG177) to develop a report on the current state of physics testing of gamma cameras, SPECT, and SPECT/CT systems. The report makes recommendations for performance tests to be done for routine quality assurance, annual physics testing, and acceptance tests, and identifies those needed satisfy the ACR accreditation program and The Joint Commission imaging standards. The report is also intended to be used as a manual with detailed instructions on how to perform tests under widely varying conditions.Learning Objectives:At the end of the presentation members of the audience will:

Be familiar with the tests recommended for routine quality assurance, annual physics testing, and acceptance tests of gamma cameras for planar imaging.
Be familiar with the tests recommended for routine quality assurance, annual physics testing, and acceptance tests of SPECT systems.
Be familiar with the tests of a SPECT/CT system that include the CT images for SPECT reconstructions.
Become knowledgeable of items to be included in annual acceptance testing reports including CT dosimetry and PACS monitor measurements.T. Turkington, GE Healthcare
MO‐A‐209‐02: A Tale of Two Journals: Open‐Access and Subscription‐Based Publications
Authors: Bourland J. 
Published: July 2016

Scientific publishing is a major endeavor of the AAPM. Although publishing requires substantial resources, it has the potential to generate both reputation and revenue to further the missions of our society. The AAPM owns and publishes two journals: Medical Physics and the Journal of Applied Clinical Medical Physics (JACMP). Medical Physics, with the tagline “The international journal of medical physics research and practice,” publishes research concerned with the application of physics and mathematics to the solution of problems in medicine and human biology, with an emphasis on theoretical and experimental approaches. The JACMP is an applied journal that publishes papers designed to help clinical medical physicists perform their responsibilities more effectively and efficiently for the greater benefit of patients. The two journals reflect two different missions, reach two different (yet often overlapping) audiences, engage two different publication approaches, and operate under two different financial models. A journal must serve both “producers” (authors who submit manuscripts to – and ultimately have their work published in – the journal) and “consumers” (readers – either individuals who access journal content or subscribing institutions that make the journal's content available to its members). Any viable publication model and cost‐recovery structure must satisfy the interests of both groups without sacrificing the needs of the scientific community. The purpose of this symposium is to explore the roles of the AAPM's two journals in advancing the scientific and clinical missions of the society and to understand the complex interplay of economic factors that impact financial decisions governing the journals and the returns they bring to the AAPM.

Learning Objectives:
Appreciate the complementary roles of Medical Physics and JACMP in advancing the scientific and clinical missions of the AAPM.
Understand AAPM resources committed to the two journals and the return on these investments.
Understand the role of the AAPM's Journals Business Management Committee in the financial stability of the two journals.
Explore the potential benefits and pitfalls of various economic and publication models for the two journals.J. Bourland, Member, Journals Business Management Committee, AAPM.