Volume 35, Issue 6, June 2008
Index of content:
- Professional Session: Room 350
- Professional Proffered
TH‐D‐350‐01: Time and Manpower Requirements for Clinical Commissioning of the Passively Scattered Proton Beams at PTC‐H35(2008); http://dx.doi.org/10.1118/1.2962886View Description Hide Description
Purpose: To present major tasks and staffing for the clinical commissioning of the passively scattered proton beams at the Proton Therapy Center — Houston. Method and Materials: PTC‐H is designed to be a phased project with the large field passively scattered beams delivered in early phases. At the completion of acceptance testing, clinical physics began the commissioning. Each of the three beamlines has three snouts and eight energies. Major commissioning tasks included SOBP measurements to define the gating off tables, pristine Bragg Peak measurements and beam profile measurements as required for input to the planning system, validation of planning system output, and point dose measurements to define relative output factors for the different treatment delivery parameters. The PTW MP3 system was used for beam scanning, configured for four seconds per data point. Results: Approximately two years were required from the beginning of commissioning to the final initial measurements, taken on the small snout. After the first three months, patient treatments began. The majority of clinical commissioning occurred on Saturdays. Two to three clinical physicists made measurements, while another two physicists focused on the planning system. Approximately twelve hours of in room time were required for each of the 24 options with 2 hours to measure gating off SOBPs, 3 hours for planning system input data, 4 hours of planning system validation data, and 3 hours for point dose dosimetry factors. Additional time was devoted to spot checking other beamlines for confirmation that dosimetry characteristics are identical. Approximately fours were spent per option to prepare and enter data into the planning system. Conclusion: A limited number of clinical physicists can commission passively scattered proton beams in a phased manner, while patient treatments are also being delivered.
TH‐D‐350‐02: Implementation of An Electronic IMRT QA Process in a Network Comprised of Independent Treatment Planning, R&V, and Delivery Systems35(2008); http://dx.doi.org/10.1118/1.2962887View Description Hide Description
Purpose: The purpose of our study is to implement an electronic method to perform and analyzeIMRT QA using the ASi imager in a network comprised of independent treatment planning, R&V, and delivery systems. Method and Materials: A verification plan was generated in the treatment planning system using the actual treatment plan of a patient. After exporting the treatment fields to the R&V system, the fields were delivered in the QA mode with the ASi imager deployed. The resulting dosimetric images are automatically stored in a DicomRT format in the treatment console PC. The grey scale images are subsequently pushed to the R&V system. The measured images are then transferred electronically to the planning system and imported into the QA plan in the dosimetry work space for further analysis. The screen shots of the gamma evaluation and isodose comparison are imported into the R&V system as a word document to be reviewed prior to initiation of patient treatment. The calculated images can also be sent as a grey scale image to the R&V system to be compared with the measured dose represented as a gray scale image.Results/Discussion: Our department does not have an integrated planning, R&V, and delivery system. In spite of this, we are able to fully integrate a paperless and filmless IMRT QA mechanism. This process enables the QA process to be more efficient and the QA document can be directly attached electronically to its specific patient chart in the R&V system. The calculated and the measured grey scale images can be viewed electronically side by side to analyze the density differences and ensure proper dose delivery to patients. Conclusion: In the absence of an integrated planning, verifying, and delivery system, we have shown that it is nonetheless possible to develop a completely electronic IMRT QA process.
TH‐D‐350‐03: The Benefits of Integrating the Healthcare Enterprise (IHE) Efforts for the Radiation Oncology Physicist35(2008); http://dx.doi.org/10.1118/1.2962888View Description Hide Description
Purpose: An issue for the practicing clinical physicist is the integration of computer systems in support of radiation therapy. Standards such as DICOM and HL7 exist, however, applications in the process apply these standards differently, resulting in unreliable exchanges of data at points in the imaging, planning, and delivery of treatment. Solving this problem requires the support of users, vendors, and professional societies to achieve a global solution and allow ‘best‐of‐breed’ selection of applications. Method and Materials: IHE (Integrating the Healthcare Enterprise) is an effort started by RSNA and HIMSS. Its goal is improving the integration of information systems in support of clinical care. IHE‐RO (IHE Radiation Oncology) is an effort supported by ASTRO, AAPM, other societies, and vendors aimed at identifying issues of computer integration and developing solutions. Meetings were held to identify bottlenecks in the treatment process. Use cases were written and an “Integration Profile” was developed for the exchange of CT, Region‐of‐interest, treatment plan, and 3D dose calculation data among different vendors. Vendors then tested their product implementations using test tools developed in support of the effort, 2 rounds of testing (informal and formal), and a public demonstration. Results: In the first two rounds of testing a number of incompatible interpretations of DICOM protocols were identified. At the formal Connectathon, manufacturers were able to prove compliance with the Integration Profile for applications that included RT‐Archive, CT‐Simulation, Treatment Planning, and Dose Display. Conclusion: IHE‐RO is an effort that is beneficial to the practicing medical physicist. It provides a venue for controlled and demonstrable testing of multi‐application compatibility. It reduces the effort required in selection and integration of new systems into clinical practice by providing a reference of proven integration. The improved robustness of application‐to‐application information transfer results in reduced quality assurance requirements of such interfaces.
35(2008); http://dx.doi.org/10.1118/1.2962889View Description Hide Description
Purpose: This paper describes systematic choices and their rationale for structuring a curriculum for a RadiationOncologyPhysics Residency accreditable by the Commission on Accreditation of Medical PhysicsEducation Programs (CAMPEP). Method and Materials: The AAPM Report No. 90, “Essentials and Guidelines for Hospital‐based Medical Physics Residency Training Programs” lists ten rotation topics related to routine clinical treatment planning and delivery procedures and processes and the technical support and quality assurance that support them. The procedures implemented in a specific radiotherapy department depend upon the equipment and software purchased by the facility as well as the individual preferences of the radiationoncologists and staff of the department. Specific procedures and processes appropriate for the rotation categories were identified and listed. However, an approach to developing a Resident's competency performing the processes can be generalized into three phases. In Phase I the Resident observes a Mentor carry out the process and reads background material. In Phase II the Resident carries out the process under close supervision by the Mentor. In Phase III the Resident carries out the process independently. The Mentor documents satisfactory completion of each phase. The Assessment of the Resident's competency is completed by oral examinations by the Residency Program Faculty. Results: The approach was applied to writing a Self‐Study Document for CAMPEP. The document contained a detailed description of ten competency‐based rotations using the three phase format. The descriptions of the rotations composed the majority of the 233‐page study. Conclusion: A RadiationOncologyPhysics Residency Program can be systematically constructed by identifying processes and procedures associated with AAPM Report No. 90 competencies and then developing the Resident's competencies with these processes and procedures in three phases. Conflict of Interest : This work supported in part by a grant from the American Society of Therapeutic Radiology and Oncology.
35(2008); http://dx.doi.org/10.1118/1.2962890View Description Hide Description
Purpose: This is an update on the Remote Real‐time Teaching and Learning (RRTL) project. The purpose of the project is to conduct real‐time lectures to Medical Physics students over the Internet.Method and Materials: Since 2002 there has been ongoing collaboration between the University of Toronto and the University of Malaya, with lecturers in Toronto conducting lectures for Medical Physics students in Malaysia over the Internet. Another project has started this year between the University of Toronto and the University of Wuhan in China. Students at the University of Wuhan view Power Point slides as they are presented by the lecturer in Toronto. They could see a live video image of the lecturer, while listening to the live audio feed. Various typing and drawing tools allow the lecturer and the students to interact directly. The lectures could also be recorded and viewed at a later date. Guest lecturers as well as students can be included from multiple sites. The software platform Microsoft LiveMeeting is used as the main tool. Results: Some initial technical difficulties had to be addressed, but the system has attained a stable condition to allow the lectures to be carried out smoothly. The software platform is already a standard feature at our institution so the cost is minimal. The project is interesting enough to attract guest lecturers who have been generous to donate their time for a worthy course. Students find the experience very comparable to a traditional classroom environment, and the ability to interact directly with experts in the field highly valuable and rewarding. Conclusion: With the advent and ubiquity of the Internet, remote real‐time teaching/learning is an extremely cost‐effective way to deliver quality education, especially to locations where the profession is developing rapidly and there is high demand for training. It should be actively promoted.
35(2008); http://dx.doi.org/10.1118/1.2962891View Description Hide Description
Purpose: To describe a web‐based digital teaching file of imaging physics for Radiology residents. Method and Materials: The RSNA R&E Foundation supported the development of a web‐based physics teaching file for Radiology residents. This RSNA Physics Teaching File was completed at the end of 2007 and is freely available to any computer with internet access. Modalities that employ x‐rays in the image formation process are described, including radiography,mammography,fluoroscopy,angiography, and computed tomography. There are also sections on general characteristics of digital images and image processing, which has become ubiquitous in digital imaging.Results: The website is hosted at SUNY Upstate Medical University and may be viewed at http://www.upstate.edu/radiology/rsna. Each section contains digital images generated with appropriate phantoms on the various modalities, as well as a selection of clinical images. Illustrated are important technical issues related to image quality (i.e. contrast, resolution, and noise) and how these are affected by parameters associated with image acquisition. Effect of changing tube voltage, tube current, field of view, image matrix size, and scatter reduction techniques are illustrated. Special sections were included to explain dual‐energy imaging and other image processing techniques in radiography.Conclusion: The teaching file web site is a valuable resource for teaching the physics of x‐ray imaging to radiology residents.
35(2008); http://dx.doi.org/10.1118/1.2962892View Description Hide Description
Purpose: When the AAPM Report Number 36, “Guidelines for Residency Programs”, was published our institution created a program in Radiation Oncology. This report summarizes our 15 year history. Method and Materials: In 1993, our institution formalized our training approach and established Radiation Oncology Physics Residencies. In 1997, the program became the first accredited by CAMPEP. The program was re‐accredited in 2003. Over time we've tried to improve our program and modernize as technologies advance. We've tracked administrative aspects, particularly, the success of our graduates in terms of employment and board certification, and our applicant pool's background. Results: For the 27 individuals that have entered our program, 12 had been post‐doctoral fellows, 6 had graduated non‐CAMPEP programs, 4 graduated from CAMPEP accredited programs, and 4 had established careers. Twenty physicists have graduated (15 PhD, 15 MS), two failed to complete the program, and one departed due to medical issues. Of the graduates, 14 are at academic facilities and 6 are in non‐academic practice. Every graduate that has taken the ABR/ABMP exam, written and oral have passed at every stage on their1st attempt. Over the past 5 years, there have been 352 applicants for the position(s) that were available. Of these, 49% have been newly graduating physicists with only a small minority (9% of total applicants) graduating from CAMPEP‐accredited programs. Of the applicants 1/3 held post‐docs, 12% were established in a career, and 6% were from overseas. Some changes we've made over the years have been to establish more customized and advanced rotations (i.e. IMRT,IGRT) and to increase testing frequency. Conclusion: The majority of applicants have come from non‐CAMPEP accredited graduate programs, while we have primarily accepted and graduated applicants with post doctoral backgrounds. Our program is sufficiently dynamic to adapt to technological advancements and undergo continuous improvement.