59 Set-up of a quality assurance program for 3T MRI images used in stereotactic radiotherapy (SRT) and radiosurgery (SRS)

2019 ◽  
Vol 68 ◽  
pp. 37
Author(s):  
J-B. Lacroix ◽  
V. Dedieu
Keyword(s):  
Quality Assurance ◽  
Stereotactic Radiotherapy ◽  
Quality Assurance Program ◽  
3T Mri ◽  
Set Up

Geometrical accuracy of the Novalis stereotactic radiosurgery system for trigeminal neuralgia

2004 ◽  
Vol 101 (Supplement3) ◽  
pp. 351-355 ◽  
Author(s):  
Javad Rahimian ◽  
Joseph C. Chen ◽  
Ajay A. Rao ◽  
Michael R. Girvigian ◽  
Michael J. Miller ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Trigeminal Neuralgia ◽  
Image Fusion ◽  
Stereotactic Radiosurgery ◽  
Ct Images ◽  
Radiochromic Film ◽  
Quality Assurance Program ◽  
Content Type ◽  
Geometrical Accuracy ◽  
Fine Print

Object. Stringent geometrical accuracy and precision are required in the stereotactic radiosurgical treatment of patients. Accurate targeting is especially important when treating a patient in a single fraction of a very high radiation dose (90 Gy) to a small target such as that used in the treatment of trigeminal neuralgia (3 to 4—mm diameter). The purpose of this study was to determine the inaccuracies in each step of the procedure including imaging, fusion, treatment planning, and finally the treatment. The authors implemented a detailed quality-assurance program. Methods. Overall geometrical accuracy of the Novalis stereotactic system was evaluated using a Radionics Geometric Phantom Chamber. The phantom has several magnetic resonance (MR) and computerized tomography (CT) imaging—friendly objects of various shapes and sizes. Axial 1-mm-thick MR and CT images of the phantom were acquired using a T1-weighted three-dimensional spoiled gradient recalled pulse sequence and the CT scanning protocols used clinically in patients. The absolute errors due to MR image distortion, CT scan resolution, and the image fusion inaccuracies were measured knowing the exact physical dimensions of the objects in the phantom. The isocentric accuracy of the Novalis gantry and the patient support system was measured using the Winston—Lutz test. Because inaccuracies are cumulative, to calculate the system's overall spatial accuracy, the root mean square (RMS) of all the errors was calculated. To validate the accuracy of the technique, a 1.5-mm-diameter spherical marker taped on top of a radiochromic film was fixed parallel to the x–z plane of the stereotactic coordinate system inside the phantom. The marker was defined as a target on the CT images, and seven noncoplanar circular arcs were used to treat the target on the film. The calculated system RMS value was then correlated with the position of the target and the highest density on the radiochromic film. The mean spatial errors due to image fusion and MR imaging were 0.41 ± 0.3 and 0.22 ± 0.1 mm, respectively. Gantry and couch isocentricities were 0.3 ± 0.1 and 0.6 ± 0.15 mm, respectively. The system overall RMS values were 0.9 and 0.6 mm with and without the couch errors included, respectively (isocenter variations due to couch rotation are microadjusted between couch positions). The positional verification of the marker was within 0.7 ± 0.1 mm of the highest optical density on the radiochromic film, correlating well with the system's overall RMS value. The overall mean system deviation was 0.32 ± 0.42 mm. Conclusions. The highest spatial errors were caused by image fusion and gantry rotation. A comprehensive quality-assurance program was developed for the authors' stereotactic radiosurgery program that includes medical imaging, linear accelerator mechanical isocentricity, and treatment delivery. For a successful treatment of trigeminal neuralgia with a 4-mm cone, the overall RMS value of equal to or less than 1 mm must be guaranteed.

Implementation and Assessment of a Telecytology Quality Assurance Program

2020 ◽  
Vol 9 (6) ◽  
pp. S63-S64
Author(s):  
Jonathan Marotti ◽  
Diane M. Green ◽  
Rebecca Proskovec ◽  
Linda Yaman ◽  
Danielle Dunn ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Quality Assurance Program

Benchmarking PRAISE-CANDU 1.0 With xLPR 1.0

2013 ◽  
Author(s):  
Min Wang ◽  
Xinjian Duan ◽  
Michael J. Kozluk
Keyword(s):  
Quality Assurance ◽  
Pilot Study ◽  
Fracture Mechanics ◽  
Software Quality ◽  
Verification And Validation ◽  
Quality Assurance Program ◽  
Software Quality Assurance ◽  
Full Compliance ◽  
Low Probability ◽  
State Of Art

A probabilistic fracture mechanics code, PRAISE-CANDU 1.0, has been developed under a software quality assurance program in full compliance with CSA N286.7-99, and was initially released in 2012 June. Extensive verification and validation has been performed on PRAISE-CANDU 1.0 for the purpose of software quality assurance. This paper presents the benchmarking performed between PRAISE-CANDU 1.0 and xLPR (eXtremely Low Probability of Rupture) version 1.0 using the cases from the xLPR pilot study. The xLPR code was developed in a configuration management and quality assured manner. Both codes adopted a state-of-art code architecture for the treatment of the uncertainties. Inputs to the PRAISE-CANDU were established as close as possible to those used in corresponding xLPR cases. Excellent agreement has been observed among the results obtained from the two PFM codes in spite of some differences between the codes. This benchmarking is considered to be an important element of the validation of PRAISE-CANDU.

Operational storm surge forecasting in the Netherlands: developments in the last decade

2005 ◽  
Vol 363 (1831) ◽  
pp. 1441-1453 ◽  
Author(s):  
Martin Verlaan ◽  
Annette Zijderveld ◽  
Hans de Vries ◽  
Jan Kroos
Keyword(s):  
Quality Assurance ◽  
The Netherlands ◽  
Kalman Filtering ◽  
Model Calibration ◽  
Storm Surges ◽  
Operational Environment ◽  
Hydrodynamic Models ◽  
Future Developments ◽  
Set Up ◽  
Storm Surge Forecasting

The accurate forecasting of storm surges is an important issue in the Netherlands. With the emergence of the first numerical hydrodynamic models for surge forecasting at the beginning of the 1980s, new demands and possibilities were raised. This article describes the main phases of the development and the present operational set-up of the Dutch continental shelf model, which is the main hydrodynamic model for storm surges in the Netherlands. It includes a brief discussion of applied data-assimilation techniques, such as Kalman filtering, the model calibration process and some thoughts on quality assurance in an operational environment. After further describing some select recent investigations, the paper concludes with some remarks on future developments in a European context.

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