AAPM Medical Physics Practice Guideline 3.a: Levels of supervision for medical physicists in clinical training

Autor: J. Anthony Seibert, Jessica B. Clements, Per H. Halvorsen, Michael G. Herman, Melissa C. Martin, Jatinder Palta, Douglas E. Pfeiffer, Robert J. Pizzutiello, Beth A. Schueler, S. Jeff Shepard, Lynne A. Fairobent
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Societies
Scientific
Educational measurement
medicine.medical_specialty
education
MEDLINE
Technical standard
Motion
Dogs
Imaging
Three-Dimensional
Medicine
Radiation Oncology Physics
Animals
Humans
Radiology
Nuclear Medicine and imaging
Medical physics
image guidance
Four-Dimensional Computed Tomography
Instrumentation
Radiation
business.industry
Phantoms
Imaging
Teaching
Radiotherapy Planning
Computer-Assisted
Mentors
Principal (computer security)
Guideline
AAPM Reports & Documents
automatic contouring
Magnetic Resonance Imaging
United States
Therapeutic Radiology
adaptive radiotherapy
Health physics
Models
Animal
Radiation Oncology
Professional association
Clinical Competence
Educational Measurement
motion tracking
Radiotherapy
Intensity-Modulated
business
Tomography
X-Ray Computed
Health Physics
Radiotherapy
Image-Guided
Zdroj: Journal of Applied Clinical Medical Physics
ISSN: 1526-9914
Popis: ViewRay is a novel MR‐guided radiotherapy system capable of imaging in near real‐time at four frames per second during treatment using 0.35T field strength. It allows for improved gating techniques and adaptive radiotherapy. Three cobalt‐60 sources (∼15,000 Curies) permit multiple‐beam, intensity‐modulated radiation therapy. The primary aim of this study is to assess the imaging stability, accuracy, and automatic segmentation algorithm capability to track motion in simulated and in vivo targets. Magnetic resonance imaging (MRI) characteristics of the system were assessed using the American College of Radiology (ACR)‐recommended phantom and accreditation protocol. Images of the ACR phantom were acquired using a head coil following the ACR scanning instructions. ACR recommended T1‐ and T2‐weighted sequences were evaluated. Nine measurements were performed over a period of seven months, on just over a monthly basis, to establish consistency. A silicon dielectric gel target was attached to the motor via a rod. 40 mm total amplitude was used with cycles of 3 to 9 s in length in a sinusoidal trajectory. Trajectories of six moving clinical targets in four canine patients were quantified and tracked. ACR phantom images were analyzed, and the results were compared with the ACR acceptance levels. Measured slice thickness accuracies were within the acceptance limits. In the 0.35 T system, the image intensity uniformity was also within the ACR acceptance limit. Over the range of cycle lengths, representing a wide range of breathing rates in patients imaged at four frames/s, excellent agreement was observed between the expected and measured target trajectories. In vivo canine targets, including the gross target volume (GTV), as well as other abdominal soft tissue structures, were visualized with inherent MR contrast, allowing for preliminary results of target tracking. PACS number: 87.61.Tg
Databáze: OpenAIRE
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