SU-E-T-162: Dosimetric Comparison of Radiochromic Film and Diode Array Measurements for Quality Assurance of Small IMRT Fields

2011 ◽  
Vol 38 (6Part12) ◽  
pp. 3523-3523
Author(s):  
T Ivanova ◽  
A Kassaee
Keyword(s):  
Quality Assurance ◽  
Radiochromic Film ◽  
Diode Array ◽  
Dosimetric Comparison ◽  
Array Measurements

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 of an in vivo radiochromic film QA procedure

2016 ◽  
Author(s):  
◽  
Jason Stanford
Keyword(s):  
Quality Assurance ◽  
Radiation Treatment ◽  
Radiochromic Film ◽  
In Vivo Dosimetry ◽  
Patient Specific ◽  
Attractive Alternative ◽  
Quality Assurance Procedure ◽  
Imaging Device ◽  
Treatment Techniques

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Advance treatment techniques, such as IMRT and dynamic conformal arc delivery, are novel radiation treatment procedures at the forefront of accurate and precise radiotherapy. However, the risk of suboptimal treatment resulting in injury is far greater with these techniques due to their complexity. An in vivo quality assurance system is the most appropriate validation of the delivered dose to the patient from these techniques. The intent of this research is to propose an in vivo dosimetry quality assurance procedure using radiochromic film. This research proved that radiochromic in vivo dosimetry is a viable method of detecting spatial patient specific errors in radiotherapy; however, the process is time consuming and not sensitive enough for dosimetric errors associated with weight change. Although time consuming, in vivo radiochromic dosimetry is an attractive alternative for small cancer centers and developing countries without the large startup capital to acquire the electronic portal imaging device necessary for EPID in vivo dosimetry.

scholarly journals [P134] Validation of the sunnuclear arccheck diode array for the patient specific quality assurance (PSQA) in stereotactic body radiotherapy treatment (SBRT) delivered with VMAT

2018 ◽  
Vol 52 ◽  
pp. 137-138
Author(s):  
Luca Leandro Vigna ◽  
Ashenafi Kumela Rikitu ◽  
Eleonora Monès ◽  
Federica Puricelli ◽  
Chiara Secco ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Stereotactic Body Radiotherapy ◽  
Patient Specific ◽  
Diode Array ◽  
Radiotherapy Treatment

Quality assurance of asymmetric jaw alignment using 2D diode array

2013 ◽  
Vol 40 (12) ◽  
pp. 122101 ◽  
Author(s):  
Sun Mo Kim ◽  
Renata Chmielewski ◽  
Ahmar Abbas ◽  
Ivan W. T. Yeung ◽  
Douglas J. Moseley
Keyword(s):  
Quality Assurance ◽  
Diode Array

1486 poster QUALITY ASSURANCE ON RECEPTION OF NEW RADIOCHROMIC FILM BOXES

2011 ◽  
Vol 99 ◽  
pp. S553
Author(s):  
J. Lopez-Tarjuelo ◽  
N. de Marco-Blancas ◽  
J.D. Quirós-Higueras ◽  
X.J. Juan-Senabre ◽  
A. Santos Serra ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Radiochromic Film

Strategies for accurate response assessment of radiochromic film using flatbed scanner for beam quality assurance

2019 ◽  
Vol 30 (11) ◽  
Author(s):  
Xu-Dong Zhang ◽  
Yuan-Hao Liu ◽  
Xiao-Bin Tang ◽  
Ming-Chen Hsiao ◽  
Wei-Lin Chen ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Beam Quality ◽  
Response Assessment ◽  
Radiochromic Film ◽  
Flatbed Scanner

scholarly journals Quality assurance procedures based on dosimetric, gamma analysis as a fast reliable tool for commissioning brachytherapy treatment planning systems

2017 ◽  
Vol 51 (4) ◽  
pp. 469-474 ◽  
Author(s):  
Grzegorz Zwierzchowski ◽  
Grzegorz Bieleda ◽  
Janusz Skowronek
Keyword(s):  
Quality Assurance ◽  
Treatment Planning ◽  
Dose Distribution ◽  
Beam Quality ◽  
Calculated Data ◽  
Radiochromic Film ◽  
Film Dosimetry ◽  
Planning Systems ◽  
Treatment Planning Systems ◽  
Gamma Analysis

Abstract Background Fast and easily repeatable methods for commissioning procedures for brachytherapy (BT) treatment planning systems (TPS) are needed. Radiochromic film dosimetry with gamma analysis is widely used in external beam quality assurance (QA) procedures and planar film dosimetry is also increasingly used for verification of the dose distribution in BT applications. Using the gamma analysis method for comparing calculated and measured dose data could be used for commissioning procedures of the newly developed TG-186 and MBDCA calculation algorithms. The aim of this study was dosimetric verification of the calculation algorithm used in TPS when the CT/MRI ring applicator is used. Materials and methods Ring applicators with 26 and 30 mm diameters and a 60 mm intra-uterine tube with 60° angle were used for verification. Gafchromic® EBT films were used as dosimetric media. Dose grids, corresponding to each plane (dosimetric film location), were exported from the TPS as a raw data. Gafchromic® films were digitized after irradiation. gamma analysis of the data were performed using the OMNI Pro I’mRT® system, as recommended by the AAPM TG-119 rapport criterion for gamma analysis of 3%, 3 mm and a level of 95%. Results For the 26 mm and 30 mm rings, the average gamma ranged, respectively, from 0.1 to 0.44 and from 0.1 to 0.27. In both cases, 99% of the measured points corresponded with the calculated data. Conclusions This analysis showed excellent agreement between the dose distribution calculated with the TPS and the doses measured by Gafchromic films. This finding confirms the viability of using film dosimetry in BT.

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