Volume 36, Issue 6, June 2009
Index of content:
- Therapy Continuing Education Symposium: Ballroom B
- CE ‐ Therapy Symposium: Performance‐Based QA for Radiotherapy — In Memoriam of Arnold Feldman
36(2009); http://dx.doi.org/10.1118/1.3182411View Description Hide Description
The task group (TG) for quality assurance of medical accelerators was constituted by the American Association of Physicists in Medicine's Science Council, under the direction of the Radiation Therapy Committee and the Quality Assurance and Outcome Improvement Subcommittee. The task group (TG ♯142) had two main charges. First to update, as needed, recommendations of Table II of the AAPM TG‐40 Report on Quality Assurance, and second, to add recommendations for Asymmetric Jaws, Multileaf Collimation(MLC), and Dynamic/Virtual Wedges. The TG accomplished the update to TG‐40, specifying new test and tolerances, and has added recommendations for not only the new ancillary delivery technologies, but also for imaging devices that are part of the linear accelerator. The imaging devices include x‐ray imaging,photon portal imaging, and cone‐beam CT. The TG report was designed to account for the types of treatments delivered with the particular machine. For example, machines that are used for radiosurgery treatments, or intensity modulated radiotherapy(IMRT) require different tests and/or tolerances. There are specific recommendations for MLCquality assurance for machines performing IMRT. There are specific tables according to daily, monthly, and annual reviews, along with unique tables for wedge systems, MLC, and imaging checks. The report is geared to be flexible for the physicist to customize the QA program depending on clinical utility. This is consistent with the philosophy of TG‐100, “Method for Evaluating QA Needs in Radiation Therapy.” The report also gives recommendations as to action levels for the physicists to implement particular actions, whether they are inspection, scheduled action, or immediate and corrective action. The report also gives specific implementation recommendations regarding setup of a QA program by the physicist, such as; building a QA team, establishing procedures, training of personnel, documentation, and end‐to‐end system checks. The tabulated items of this report have been considerably expanded as compared with the original TG 40 report and the recommended tolerances accommodate differences of the intended functionality (i.e., non‐IMRT, IMRT, or Stereotactic Delivery).
1. To understand the updates to TG‐40 in the new TG‐142 report.
2. To understand the recommend QA tests for wedge, MLC, and imaging systems as they pertain to accelerator type and procedures performed (i.e. IMRT).
3. To understand the implementation plan and action level and response recommendations.
36(2009); http://dx.doi.org/10.1118/1.3182412View Description Hide Description
History: TG‐135 was approved by AAPM at the 2006 Annual Meeting. The intent of this TG was to fill the gap between TG‐40, which does not cover certain QA aspects of newer radiation delivery devices, and TG‐100, which will revise our current QA paradigm. General Outline of Report: The report consists of three major sections: (1) QA for individual system components, (2) QA for the integrated systems, (3) a summary with QA checklists. At the time of publication there is only one FDA‐approved roboticradiosurgery system (Cyberknife, Accuray Inc, Sunnyvale, CA) on the market, therefore the report is often vendor‐specific. Technologies which became available in the clinic after the report was submitted for review (e.g. IRIS collimator, XSight lung tracking) were not included. Major Highlights: Each individual Cyberknife component will be discussed, with reference to applicable AAPM reports and additional QA recommendations if necessary. We also highlight areas in which a good QA approach has not yet been developed. Those include the QA of the imager systems, but also periodic QA of individual beam pointing accuracy. The second section, QA for integrated systems, explains how the various subsystems interact, and how to design a QA program for the feedback loops. Similar to the individual component QA, there are areas in the integrated systems QA where more work needs to be done. This includes e.g. QA of the interaction between image quality and tracking algorithm accuracy, and individual beam pointing QA for non‐isocentric plans. The Task Group's recommendations on patient‐like and individual patient QA are also included. The report summarizes daily, monthly, annual and special considerations (software and hardware upgrades, earthquakes, etc). Report as it relates to TG‐100: This report is intended to give QA recommendations based on the philosophy of TG‐40. The QM approach to roboticradiosurgery will have to be adapted to the TG‐100 philosophy after its publication, which includes the data collection for a FMEA analysis for this relatively new technology. Implementation Plan: The recommendations of TG‐135 should be critically evaluated by the site physicist after the report is published. Changes to the existing QA program should be made at the next scheduled incidence (i.e. changes for the annual QA at the next annual QA). Roboticradiosurgery is a fast‐evolving field, therefore keeping informed through reading peer‐reviewed literature and attending CE programs on QA is essential. Timeline for Report Release: At the time of abstract submission, TG‐135 was undergoing the second revision within its subcommittee, with the goal of being submitted to the TPC for review and a publication in summer/fall of 2009.
1. Be aware of the estimated publication date for the report, report structure, and implementation plan.
2. Understand the difference between individual component QA and integrated systems QA.
3. Know which areas of roboticradiosurgery QA are still under development.
4. Anticipate the future change of QA philosophy for roboticradiosurgery with TG‐100.
TU‐E‐BRB‐04: Performance‐Based QA for Radiotherapy: TG‐147 — QA for Non‐Radiographic Localization Systems36(2009); http://dx.doi.org/10.1118/1.3182413View Description Hide Description
History: Many devices for localizing and monitoring the patient have been developed over the past few years. These devices come as a result of better hardware and software to delivery highly conformal radiation. This task group was commissioned by the AAPM to make recommendations about the quality assurance and use of non‐radiographic localization and monitoring systems. These systems include camera based systems, RF guidance systems, and laser alignment systems. General Outline of Report: The report addresses systems that do not use radiographic localization and specifically describes several systems that are commercially available. Some commercially available systems that are described in this report are Calypso System, VisionRT AlignRT, LAP Galaxy, and C‐Rad Sentinel; however the report is written in such as a way as to be used for other systems as they may come available. The primary purpose of these devices is to align the patient to the correct location for treatment. QA recommendations of the report focus on installation recommendations as these systems are peripheral to the linear accelerator system, but must interface with all aspects of the radiotherapy workflow. Some specific issues in multi‐vendor installs are addressed. The major component of the report focuses on commissioning of these types of devices and on the routine QA of patient localization systems. Major Highlights: For non‐radiographic localization systems it is important that the system be installed properly relative to the machine isocenter. In order to do this, the linear accelerator mechanical QA should be performed and modifications performed as necessary. As part of the initial install of these peripheral types of localization equipment, a testing of the various communications between systems is important. The report also makes recommendations for testing the integrity of the radiation delivery system following the addition of equipment. The primary tool for QA of the localization system is the end to end test that can give the overall localization accuracy for the device in conjunction with traditional imaging and treatment planning. Recommendations about patient monitoring and tracking are also addressed. Report as it relates to TG‐100: This report makes recommendation on QA to insure that the localization system is working properly. These recommendations could be included in the institutions FEMA analysis in accordance with TG 100. Timeline for report Release: This report is to be submitted for review this summer and should be available for release sometime in 2010.
1. The audience should be able to identify the types of localization devices included in TG147
2. The audience should be able to describe the general practice of patient localization and how to implement a localization device
3. The audience should be able to describe how to setup and perform an end to end test with a localization device and record the devices overall localization accuracy.
36(2009); http://dx.doi.org/10.1118/1.3182414View Description Hide Description
History Helical tomotherapy is a relatively new modality with integrated treatment planning and delivery hardware for radiation therapytreatments. In view of the uniqueness of the hardware design of the helical tomotherapy unit and its implications in routine quality assurance, the Therapy Physics Committee (TPC) of the American Association of Physicists in Medicine (AAPM) commissioned Task Group 148 (TG148) to review this modality and make recommendations for quality assurance related methodologies. General Outline of Report The report is divided into three main chapters that cover treatmentimaging,treatment planning, and treatmentdelivery. Each chapter gives an overview of the unique accepts and proceeds to describe the recommended QA tests. A final chapter summarizes the QA recommendations and details daily, monthly, quarterly, and annual QA procedures. Major Highlights This report is designed with the intent to provide guidance to the physicist on the routine QA aspects of the tomotherapy unit. Since the imaging and treatment planning aspects are intimately connected with the physical machine hardware each aspect is covered in this review. Implementation Plan The summary chapter list daily, monthly, quarterly, and annual tests. This chapter is designed to facilitate the implementation of recommended QA procedures. Timeline for Report Release This TG report is currently under review by the Therapy Physics Council.