Results for “physicists” — Page 17

DOE OSTI2015

TU-A-210-01: HIFU Physics and Delivery

High-intensity focused ultrasound (HIFU) has developed rapidly in recent years and is used frequently for clinical treatments in Asia and Europe with increasing clinical use and clinical trial activity in the US, making it an important medical technology with which the medical physics community must become familiar. Akin to medical devices that deliver treatments using ionizing radiation, HIFU relies on emitter geometry to non-invasively form a tight focus that can be used to affect diseased tissue while leaving healthy tissue intact. HIFU is unique in that it does not involve the use of ionizing radiation, it causes thermal necrosis in 100% of the treated tissue volume, and it has an immediate treatment effect. However, because it is an application of ultrasound energy, HIFU interacts strongly with tissue interfaces, which makes treatment planning challenging. In order to appreciate the advantages and disadvantages of HIFU as a thermal therapy, it is important to understand the underlying physics of ultrasound tissue interactions. The first lecture in the session will provide an overview of the physics of ultrasound wave propagation; the mechanism for the accumulation of heat in soft-tissue; image-guidance modalities including temperature monitoring; current clinical applications and commercial devices; active clinical trials; alternate mechanisms of action (future of FUS). The second part of the session will compare HIFU to existing ionization radiation techniques. The difficulties in defining a clear concept of absorbed dose for HIFU will be discussed. Some of the technical challenges that HIFU faces will be described, with an emphasis on how the experience of radiation oncology physicists could benefit the field. Learning Objectives: Describe the basic physics and biology of HIFU, including treatment delivery and image guidance techniques. Summarize existing and emerging clinical applications and manufacturers for HIFU. Understand that thermal ablation with HIFU is likely the first of several applications of the technology Learn about some similarities and differences between HIFU and ionizing radiation in terms of physics and biological effects. Learn about some of the technical challenges HIFU faces that might benefit from the experience of radiation oncology physicists including treatment planning improvements, quality assurance procedures, and treatment risk analysis. David Schlesinger receives research support from Elekta Instruments, AB. Matt Eames is an employee of the Focused Ultrasound Foundation which supports research and clinical trials. Dr. Eames conducts research which is supported by the Focused Ultrasound Foundation.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2015

TU-G-201-00: Imaging Equipment Specification and Selection in Radiation Oncology Departments

This session will update therapeutic physicists on technological advancements and radiation oncology features of commercial CT, MRI, and PET/CT imaging systems. Also described are physicists’ roles in every stage of equipment selection, purchasing, and operation, including defining specifications, evaluating vendors, making recommendations, and optimal and safe use of imaging equipment in radiation oncology environment. The first presentation defines important terminology of CT and PET/CT followed by a review of latest innovations, such as metal artifact reduction, statistical iterative reconstruction, radiation dose management, tissue classification by dual energy CT and spectral CT, improvement in spatial resolution and sensitivity in PET, and potentials of PET/MR. We will also discuss important technical specifications and items in CT and PET/CT purchasing quotes and their impacts. The second presentation will focus on key components in the request for proposal for a MRI simulator and how to evaluate vendor proposals. MRI safety issues in radiation Oncology, including MRI scanner Zones (4-zone design), will be discussed. Basic MR terminologies, important functionalities, and advanced features, which are relevant to radiation therapy, will be discussed. In the third presentation, justification of imaging systems for radiation oncology, considerations in room design and construction in a RO department, shared use with diagnostic radiology, staffing needs and training, clinical/research use cases and implementation, will be discussed. The emphasis will be on understanding and bridging the differences between diagnostic and radiation oncology installations, building consensus amongst stakeholders for purchase and use, and integrating imaging technologies into the radiation oncology environment. Learning Objectives: Learn the latest innovations of major imaging systems relevant to radiation therapy Be able to describe important technical specifications of CT, MRI, and PET/CT Understand the process of budget request, equipment justification, comparisons of technical specifications, site visits, vendor selection, and contract development.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2015

TU-G-201-02: An MRI Simulator From Proposal to Operation

This session will update therapeutic physicists on technological advancements and radiation oncology features of commercial CT, MRI, and PET/CT imaging systems. Also described are physicists’ roles in every stage of equipment selection, purchasing, and operation, including defining specifications, evaluating vendors, making recommendations, and optimal and safe use of imaging equipment in radiation oncology environment. The first presentation defines important terminology of CT and PET/CT followed by a review of latest innovations, such as metal artifact reduction, statistical iterative reconstruction, radiation dose management, tissue classification by dual energy CT and spectral CT, improvement in spatial resolution and sensitivity in PET, and potentials of PET/MR. We will also discuss important technical specifications and items in CT and PET/CT purchasing quotes and their impacts. The second presentation will focus on key components in the request for proposal for a MRI simulator and how to evaluate vendor proposals. MRI safety issues in radiation Oncology, including MRI scanner Zones (4-zone design), will be discussed. Basic MR terminologies, important functionalities, and advanced features, which are relevant to radiation therapy, will be discussed. In the third presentation, justification of imaging systems for radiation oncology, considerations in room design and construction in a RO department, shared use with diagnostic radiology, staffing needs and training, clinical/research use cases and implementation, will be discussed. The emphasis will be on understanding and bridging the differences between diagnostic and radiation oncology installations, building consensus amongst stakeholders for purchase and use, and integrating imaging technologies into the radiation oncology environment. Learning Objectives: Learn the latest innovations of major imaging systems relevant to radiation therapy Be able to describe important technical specifications of CT, MRI, and PET/CT Understand the process of budget request, equipment justification, comparisons of technical specifications, site visits, vendor selection, and contract development.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2015

TU-G-201-03: Imaging Systems in Radiotherapy: Buying, Installing, and Using

This session will update therapeutic physicists on technological advancements and radiation oncology features of commercial CT, MRI, and PET/CT imaging systems. Also described are physicists’ roles in every stage of equipment selection, purchasing, and operation, including defining specifications, evaluating vendors, making recommendations, and optimal and safe use of imaging equipment in radiation oncology environment. The first presentation defines important terminology of CT and PET/CT followed by a review of latest innovations, such as metal artifact reduction, statistical iterative reconstruction, radiation dose management, tissue classification by dual energy CT and spectral CT, improvement in spatial resolution and sensitivity in PET, and potentials of PET/MR. We will also discuss important technical specifications and items in CT and PET/CT purchasing quotes and their impacts. The second presentation will focus on key components in the request for proposal for a MRI simulator and how to evaluate vendor proposals. MRI safety issues in radiation Oncology, including MRI scanner Zones (4-zone design), will be discussed. Basic MR terminologies, important functionalities, and advanced features, which are relevant to radiation therapy, will be discussed. In the third presentation, justification of imaging systems for radiation oncology, considerations in room design and construction in a RO department, shared use with diagnostic radiology, staffing needs and training, clinical/research use cases and implementation, will be discussed. The emphasis will be on understanding and bridging the differences between diagnostic and radiation oncology installations, building consensus amongst stakeholders for purchase and use, and integrating imaging technologies into the radiation oncology environment. Learning Objectives: Learn the latest innovations of major imaging systems relevant to radiation therapy Be able to describe important technical specifications of CT, MRI, and PET/CT Understand the process of budget request, equipment justification, comparisons of technical specifications, site visits, vendor selection, and contract development.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2015

WE-A-210-00: Educational: Diagnostic Ultrasound QA

This presentation will focus on the present role of ultrasound medical physics in clinical practices. The first part of the presentation will provide an overview of ultrasound QC methodologies and testing procedures. A brief review of ultrasound phantoms utilized in these testing procedures will be presented. The second part of the presentation will summarize ultrasound imaging technical standards and professional guidelines by American College of Radiology (ACR), American Institute of Ultrasound in Medicine (AIUM), American Association of Physicists in Medicine (AAPM) and International Electrotechnical Commission (IEC). The current accreditation requirements by ACR and AIUM for ultrasound practices will be described and the practical aspects of implementing QC programs to be compliant with these requirements will be discussed. Learning Objectives: Achieve familiarity with common ultrasound QC test methods and ultrasound phantoms. Understand the coverage of the existing testing standards and professional guidelines on diagnostic ultrasound imaging. Learn what a medical physicist needs to know about ultrasound program accreditation and be able to implement ultrasound QC programs accordingly.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2015

WE-A-210-01: Overview of Methods and Accreditation Updates

This presentation will focus on the present role of ultrasound medical physics in clinical practices. The first part of the presentation will provide an overview of ultrasound QC methodologies and testing procedures. A brief review of ultrasound phantoms utilized in these testing procedures will be presented. The second part of the presentation will summarize ultrasound imaging technical standards and professional guidelines by American College of Radiology (ACR), American Institute of Ultrasound in Medicine (AIUM), American Association of Physicists in Medicine (AAPM) and International Electrotechnical Commission (IEC). The current accreditation requirements by ACR and AIUM for ultrasound practices will be described and the practical aspects of implementing QC programs to be compliant with these requirements will be discussed. Learning Objectives: Achieve familiarity with common ultrasound QC test methods and ultrasound phantoms. Understand the coverage of the existing testing standards and professional guidelines on diagnostic ultrasound imaging. Learn what a medical physicist needs to know about ultrasound program accreditation and be able to implement ultrasound QC programs accordingly.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2015

WE-G-BRA-02: SafetyNet: Automating Radiotherapy QA with An Event Driven Framework

Purpose: Quality assurance is an essential task in radiotherapy that often requires many manual tasks. We investigate the use of an event driven framework in conjunction with software agents to automate QA and eliminate wait times. Methods: An in house developed subscription-publication service, EventNet, was added to the Aria OIS to be a message broker for critical events occurring in the OIS and software agents. Software agents operate without user intervention and perform critical QA steps. The results of the QA are documented and the resulting event is generated and passed back to EventNet. Users can subscribe to those events and receive messages based on custom filters designed to send passing or failing results to physicists or dosimetrists. Agents were developed to expedite the following QA tasks: Plan Revision, Plan 2nd Check, SRS Winston-Lutz isocenter, Treatment History Audit, Treatment Machine Configuration. Results: Plan approval in the Aria OIS was used as the event trigger for plan revision QA and Plan 2nd check agents. The agents pulled the plan data, executed the prescribed QA, stored the results and updated EventNet for publication. The Winston Lutz agent reduced QA time from 20 minutes to 4 minutes and provided a more accurate quantitative estimate of radiation isocenter. The Treatment Machine Configuration agent automatically reports any changes to the Treatment machine or HDR unit configuration. The agents are reliable, act immediately, and execute each task identically every time. Conclusion: An event driven framework has inverted the data chase in our radiotherapy QA process. Rather than have dosimetrists and physicists push data to QA software and pull results back into the OIS, the software agents perform these steps immediately upon receiving the sentinel events from EventNet. Mr Keranen is an employee of Varian Medical Systems. Dr. Moran’s institution receives research support for her effort for a linear accelerator QA project from Varian Medical Systems. Other quality projects involving her effort are funded by Blue Cross Blue Shield of Michigan, Breast Cancer Research Foundation, and the NIH.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2015

WE-G-BRA-08: Failure Modes and Effects Analysis (FMEA) for Gamma Knife Radiosurgery

Purpose: To perform a failure modes and effects analysis (FMEA) study for Gamma Knife (GK) radiosurgery processes at our institution based on our experience with the treatment of more than 13,000 patients. Methods: A team consisting of medical physicists, nurses, radiation oncologists, neurosurgeons at the University of Pittsburgh Medical Center and an external physicist expert was formed for the FMEA study. A process tree and a failure mode table were created for the GK procedures using the Leksell GK Perfexion and 4C units. Three scores for the probability of occurrence (O), the severity (S), and the probability of no detection (D) for failure modes were assigned to each failure mode by each professional on a scale from 1 to 10. The risk priority number (RPN) for each failure mode was then calculated (RPN = OxSxD) as the average scores from all data sets collected. Results: The established process tree for GK radiosurgery consists of 10 sub-processes and 53 steps, including a sub-process for frame placement and 11 steps that are directly related to the frame-based nature of the GK radiosurgery. Out of the 86 failure modes identified, 40 failure modes are GK specific, caused by the potential for inappropriate use of the radiosurgery head frame, the imaging fiducial boxes, the GK helmets and plugs, and the GammaPlan treatment planning system. The other 46 failure modes are associated with the registration, imaging, image transfer, contouring processes that are common for all radiation therapy techniques. The failure modes with the highest hazard scores are related to imperfect frame adaptor attachment, bad fiducial box assembly, overlooked target areas, inaccurate previous treatment information and excessive patient movement during MRI scan. Conclusion: The implementation of the FMEA approach for Gamma Knife radiosurgery enabled deeper understanding of the overall process among all professionals involved in the care of the patient and helped identify potential weaknesses in the overall process.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

Technical Report: Reference photon dosimetry data for Varian accelerators based on IROC-Houston site visit data

Purpose: Accurate data regarding linear accelerator (Linac) radiation characteristics are important for treatment planning system modeling as well as regular quality assurance of the machine. The Imaging and Radiation Oncology Core-Houston (IROC-H) has measured the dosimetric characteristics of numerous machines through their on-site dosimetry review protocols. Photon data are presented and can be used as a secondary check of acquired values, as a means to verify commissioning a new machine, or in preparation for an IROC-H site visit. Methods: Photon data from IROC-H on-site reviews from 2000 to 2014 were compiled and analyzed. Specifically, data from approximately 500 Varian machines were analyzed. Each dataset consisted of point measurements of several dosimetric parameters at various locations in a water phantom to assess the percentage depth dose, jaw output factors, multileaf collimator small field output factors, off-axis factors, and wedge factors. The data were analyzed by energy and parameter, with similarly performing machine models being assimilated into classes. Common statistical metrics are presented for each machine class. Measurement data were compared against other reference data where applicable. Results: Distributions of the parameter data were shown to be robust and derive from a student’s t distribution. Based on statistical and clinical criteria, all machine models were able to be classified into two or three classes for each energy, except for 6 MV for which there were eight classes. Quantitative analysis of the measurements for 6, 10, 15, and 18 MV photon beams is presented for each parameter; supplementary material has also been made available which contains further statistical information. Conclusions: IROC-H has collected numerous data on Varian Linacs and the results of photon measurements from the past 15 years are presented. The data can be used as a comparison check of a physicist’s acquired values. Acquired values that are well outside the expected distribution should be verified by the physicist to identify whether the measurements are valid. Comparison of values to this reference data provides a redundant check to help prevent gross dosimetric treatment errors.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

SU-F-E-07: Web-Based Training for Radiosurgery: Methods and Metrics for Global Reach

Purpose: Webinars have become an evolving tool with greater or lesser success in reaching health care providers (HCPs). This study seeks to assess best practices and metrics for success in webinar deployment for optimal global reach. Methods: Webinars have been developed and launched to reach practicing health care providers in the field of radiation oncology and radiosurgery. One such webinar was launched in early February 2016. “Multiple Brain Metastases & Volumetric Modulated Arc Radiosurgery: Refining the Single-Isocenter Technique to Benefit Surgeons and Patients” presented by Drs. Fiveash and Thomas from UAB was submitted to and accredited by the Institute for Medical Education as qualifying for CME as well as MDCB for educational credit for dosimetrists, in order to encourage participation. MedicalPhysicsWeb was chosen as the platform to inform attendees regarding the webinar. Further IME accredited the activity for 1 AMA PRA Category 1 credit for physicians & medical physicists. The program was qualified by the ABR in meeting the criteria for self-assessment towards fulfilling MOC requirements. Free SAMs credits were underwritten by an educational grant from Varian Medical Systems. Results: The webinar in question attracted 992 pre-registrants from 66 countries. Outside the US and Canada; 11 were from the Americas; 32 were from Europe; 9 from the Middle East and Africa. Australasia and the Indian subcontinent represented the remaining 14 countries. Pre-registrants included 423 Medical Physicists, 225 Medical Dosimetrists, 24 Radiation Therapists, 66 Radiation Oncologists & other. Conclusion: The effectiveness of CME and SAM-CME programs such as this can be gauged by the high rate of respondents who state an intention to change practice habits, a primary goal of continuing medical education and self-assessment. This webinar succeeded in being the most successful webinar on Medical Physics Web as measured by pre-registration, participation and participation to pre-registration ratio. R.A. Schulz is an employee of Varian Medical Systems.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

SU-F-E-12: Elective International Rotations in Medical Physics Residency Programs

Purpose: The purpose of this educational program is to motivate talented, intelligent individuals to become stakeholders in the global effort to improve access to radiotherapy. Methods: The need to improve global access to radiotherapy has been clearly established and several organizations are making substantial progress in securing funding and developing plans to achieve this worthwhile goal. The incorporation of elective international rotations in residency programs may provide one possible mechanism to promote and support this future investment. We recently incorporated an elective 1-month international rotation into our CAMPEP accredited Medical Physics residency program, with our first rotation taking place in Vietnam. A unique aspect of this rotation was that it was scheduled collaboratively with our Radiation Oncology residency program such that Radiation Oncology and Medical Physics residents traveled to the same clinic at the same time. Results: We believe the international rotation substantially enhances the educational experience, providing additional benefits to residents by increasing cross-disciplinary learning and offering a shared learning experience. The combined international rotation may also increase benefit to the host institution by modeling positive multidisciplinary working relationships between Radiation Oncologists and Medical Physicists. Our first resident returned with several ideas designed to improve radiotherapy in resource-limited settings – one of which is currently being pursued in collaboration with a vendor. Conclusion: The elective international rotation provides a unique learning experience that has the potential to motivate residents to become stakeholders in the global effort to improve access to radiotherapy. What better way to prepare the next generation of Medical Physicists to meet the challenges of improving global access to radiotherapy than to provide them with training experiences that motivate them to be socially conscious and equip them with the clinical and problem solving skills required to deliver effective treatments in resource limited settings?.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

SU-F-J-116: Clinical Experience-Based Verification and Improvement of a 4DCT Program

Purpose: To demonstrate the role of continuous improvement fulfilled by the Medical Physicist in clinical 4DCT and CBCT scanning. Methods: Lung (SABR and Standard) patients’ 4D respiratory motion and image data were reviewed over a 3, 6 and 12 month period following commissioning testing. By identifying trends of clinically relevant parameters and respiratory motions, variables were tested with a programmable motion phantom and assessed. Patient traces were imported to a motion phantom and 4DCT and CBCT imaging were performed. Cos6 surrogate and sup-inf motion was also programmed into the phantom to simulate the long exhale of patients for image contrast tests. Results: Patient surrogate motion amplitudes were 9.9+5.2mm (3–35) at 18+6bpm (6–30). Expiration/Inspiration time ratios of 1.4+0.5second (0.6–2.9) showed image contrast effects evident in the AveCT and 3DCBCT images. Small differences were found for patients with multiple 4DCT data sets. Patient motion assessments were simulated and verified with the phantom within 2mm. Initial image reviews to check for reconstructed artefacts and data loss identified a small number of patients with irregularities in the automatic placement of inspiration and expiration points. Conclusion: The Physicist’s involvement in the continuous improvements of a clinically commissioned technique, processes and workflows continues beyond the commissioning stage of a project. Our experience with our clinical 4DCT program shows that Physics presence is required at the clinical 4DCT scan to assist with technical aspects of the scan and also for clinical image quality assessment prior to voluming. The results of this work enabled the sharing of information from the Medical Physics group with the Radiation Oncologists and Radiation Therapists. This results in an improved awareness of clinical patient respiration variables and how they may affect 4D simulation images and also may also affect the treatment verification images.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

SU-F-T-96: A New Paradigm of Weekly Chart Checking for Radiation Therapy Clinics

Purpose: To put forth an innovative clinical paradigm for weekly chart checking so that treatment status is periodically checked accurately and efficiently. This study also aims to help optimize the chart checking clinical workflow in a busy radiation therapy clinic. Methods: It is mandated by the Texas Administrative code to check patient charts of radiation therapy once a week or every five fractions, however it varies drastically among institutions in terms of when and how it is done. Some do it every day, but a lot of efforts are wasted on opening ineligible charts; some do it on a fixed day but the distribution of intervals between subsequent checks is not optimal. To establish an optimal chart checking procedure, a new paradigm was developed to achieve 1) charts are checked more accurately and more efficiently; 2) charts are checked on optimal days without any miss; 3) workload is evened out throughout a week when multiple physicists are involved. All active charts will be accessed by querying the R&V system. Priority is assigned to each chart based on the number of days before the next due date followed by sorting and workload distribution steps. New charts are also taken into account when distributing the workload so it is reasonably even throughout the week. Results: Our clinical workflow became more streamlined and smooth. In addition, charts get checked in a more timely fashion so that errors would get caught earlier should they occur. Conclusion: We developed a new weekly chart checking diagram. It helps physicists check charts in a timely manner, saves their time in busy clinics, and consequently reduces possible errors.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

SU-F-T-247: Collision Risks in a Modern Radiation Oncology Department: An Efficient Approach to Failure Modes and Effects Analysis

Purpose: Collisions between treatment equipment and patients are potentially catastrophic. Modern technology now commonly involves automated remote motion during imaging and treatment, yet a systematic assessment to identify and mitigate collision risks has yet to be performed. Failure modes and effects analysis (FMEA) is a method of risk assessment that has been increasingly used in healthcare, yet can be resource intensive. This work presents an efficient approach to FMEA to identify collision risks and implement practical interventions within a modern radiation therapy department. Methods: Potential collisions (e.g. failure modes) were assessed for all treatment and simulation rooms by teams consisting of physicists, therapists, and radiation oncologists. Failure modes were grouped into classes according to similar characteristics. A single group meeting was held to identify implementable interventions for the highest priority classes of failure modes. Results: A total of 60 unique failure modes were identified by 6 different teams of physicists, therapists, and radiation oncologists. Failure modes were grouped into four main classes: specific patient setups, automated equipment motion, manual equipment motion, and actions in QA or service mode. Two of these classes, unusual patient setups and automated machine motion, were identified as being high priority in terms severity of consequence and addressability by interventions. The two highest risk classes consisted of 33 failure modes (55% of the total). In a single one hour group meeting, 6 interventions were identified. Those interventions addressed 100% of the high risk classes of failure modes (55% of all failure modes identified). Conclusion: A class-based approach to FMEA was developed to efficiently identify collision risks and implement interventions in a modern radiation oncology department. Failure modes and interventions will be listed, and a comparison of this approach against traditional FMEA methods will be presented.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

SU-F-T-462: Lessons Learned From a Machine Incident Reporting System

Purpose: Linear accelerators must operate with minimal downtime. Machine incident logs are a crucial tool to meet this requirement. They providing a history of service and demonstrate whether a fix is working. This study investigates the information content of a large department linear accelerator incident log. Methods: Our department uses an electronic reporting system to provide immediate information to both key department staff and the field service department. This study examines reports for five linac logs during 2015. The report attributes for analysis include frequency, level of documentation, who solved the problem, and type of fix used. Results: Of the reports, 36% were documented as resolved. In another 25% the resolution allowed treatment to proceed although the reported problem recurred within days. In 5% only intermediate troubleshooting was documented. The remainder lacked documentation. In 60% of the reports, radiation therapists resolved the problem, often by clearing the appropriate faults or reinitializing a software or hardware service. 22% were resolved by physics and 10% by field service engineers. The remaining 8% were resolved by IT, Facilities, or resolved spontaneously. Typical fixes, in order of scope, included clearing the fault and moving on, closing and re-opening the patient session or software, cycling power to a sub-unit, recalibrating a device (e.g., optical surface imaging), and calling in Field Service (usually resolving the problem through maintenance or component replacement). Conclusion: The reports with undocumented resolution represent a missed opportunity for learning. Frequency of who resolves a problem scales with the proximity of the person’s role (therapist, physicist, or service engineer), which is inversely related to the permanence of the resolution. Review of lessons learned from machine incident logs can form the basis for guidance to radiation therapists and medical physicists to minimize equipment downtime and ensure safe operation.

61 RADIATION PROTECTION AND DOSIMETRY↗

DOE OSTI2016

SU-G-TeP4-06: An Integrated Application for Radiation Therapy Treatment Plan Directives, Management, and Reporting

Purpose: With electronic medical records, patient information for the treatment planning process has become disseminated across multiple applications with limited quality control and many associated failure modes. We present the development of a single application with a centralized database to manage the planning process. Methods: The system was designed to replace current functionalities of (i) static directives representing the physician intent for the prescription and planning goals, localization information for delivery, and other information, (ii) planning objective reports, (iii) localization and image guidance documents and (iv) the official radiation therapy prescription in the medical record. Using the Eclipse Scripting Application Programming Interface, a plug-in script with an associated domain-specific SQL Server database was created to manage the information in (i)–(iv). The system’s user interface and database were designed by a team of physicians, clinical physicists, database experts, and software engineers to ensure usability and robustness for clinical use. Results: The resulting system has been fully integrated within the TPS via a custom script and database. Planning scenario templates, version control, approvals, and logic-based quality control allow this system to fully track and document the planning process as well as physician approval of tradeoffs while improving the consistency of the data. Multiple plans and prescriptions are supported along with non-traditional dose objectives and evaluation such as biologically corrected models, composite dose limits, and management of localization goals. User-specific custom views were developed for the attending physician review, physicist plan checks, treating therapists, and peer review in chart rounds. Conclusion: A method was developed to maintain cohesive information throughout the planning process within one integrated system by using a custom treatment planning management application that interfaces directly with the TPS. Future work includes quantifying the improvements in quality, safety and efficiency that are possible with the routine clinical use of this system. Supported in part by NIH-P01-CA-059827.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

SU-G-TeP4-13: Interfraction Treatment Monitoring Using Integrated Invivo EPID Images

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.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

MO-A-BRC-02: TG167 Report - Detailed Description

Although a multicenter, Phase III, prospective, randomized trial is the gold standard for evidence-based medicine, it is rarely used to evaluate innovative radiotherapy devices because of many practical and ethical reasons. It is usually sufficient to compare the dose distributions and dose rates for determining equivalence of the innovative device to an existing one. Thus, quantitative evaluation of the dosimetric characteristics of an innovative brachytherapy device or application is a critical part in which physicists are actively involved. The physicist’s role, along with physician colleagues, in this process is highlighted for innovative products or applications and includes evaluation of 1) dosimetric considerations for clinical implementation (including calibrations, dose calculations, and radiobiological aspects) to comply with existing societal dosimetric prerequisites for sources in routine clinical use, 2) risks and benefits from regulatory and safety perspectives, and 3) resource assessment and preparedness. Further, calibration methods should be traceable to a primary standards dosimetry laboratory such as NIST in the U.S. or to other primary standards dosimetry laboratory located elsewhere. Clinical users should follow standards as approved by their country’s regulatory agencies that approved such a brachytherapy device. Integration of this system into the medical source calibration infrastructure of secondary standard dosimetry laboratories such as the ADCLs is encouraged before a source is introduced into widespread routine clinical use. The AAPM and GEC-ESTRO have developed guidelines for the safe and consistent application of brachytherapy using innovative brachytherapy devices and applications. The current report covers regulatory approvals, calibration, dose calculations, radiobiological issues, and overall safety concerns that should be addressed during the commissioning stage preceding clinical use. These guidelines are based on review of requirements of the U.S. NRC, FDA, Department of Transportation, International Electrotechnical Commission Medical Electrical Equipment Standard 60601, European Commission for CE Marking, and institutional review boards and radiation safety committees. Learning Objectives: Understand the necessary dosimetric considerations for clinical implementation (including calibrations, dose calculations, and radiobiological aspects) to comply with existing societal dosimetric prerequisites for sources in routine clinical use. Evaluate risks and benefits from regulatory and safety perspectives. Identify necessary resources and create a plan for clinical introduction of innovative brachytherapy device or applications. Consultant for Theragenics Corp.; R. Nath, Consultant to Theragenics Corp.

60 APPLIED LIFE SCIENCES↗