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.

scholarly journals Investigation of EBT3 Radiochromic Film Response in a High-Dose Range of 6 MV Photon and 6 MeV Electron Beams Using a Three-Color Flatbed Scanner

2020 ◽  
Keyword(s):  
Electron Beams ◽  
Beam Quality ◽  
Dose Range ◽  
Radiochromic Film ◽  
High Dose ◽  
Blue Color ◽  
Flatbed Scanner ◽  
Color Channel ◽  
Radiochromic Films ◽  
Red Color

Radiochromic film dosimetry has been commonly used for determination of dose measurement in radiotherapy for many years because of their high spatial resolution, low energy dependence and its approximate tissue equivalent. Additionally, it has other practical advantages, e.g.it is suitable for therapy range beam qualities, a water resistance material, a relatively insensitive to visible light, and does not need to make bathing process to obtain dose information. They are also independent to dose rate. Hence they are very useful and practical for clinical applications such as brachytherapy, electron therapy, skin dose measurements and stereotactic radiotherapy. Among them, the dynamic dose range of EBT3 radiochromic films are generally recommended for the dose range of 0.1 to 20 Gy. However, in this study, it is aimed to observe the behavior of EBT3 films in high dose range of up to 90 Gy under the irradiations. For this aim, the net optical densities were obtained with increasing dose values under photon and electron beams by employing three color scanning channel (red-green-blue). Thus, for making calibration curves, it was decided which color channel for EBT3 radiochromic film would be the most suitable one in different dose ranges. In experimental setup, the reference circumstances were first established and dose calibration procedure were carried out in RW3 phantom. Then the irradiated films were cut carefully into 2x2.5 cm2 pieces, and they were grouped into 2 as irradiation and control groups. The control group was waited for background, i.e. they are not irradiated. Before the irradiation, two groups of films have been scanned in flatbed scanner for three channels. After that, the irradiation group films was placed to align the exact place of effective point of ionization chamber under the reference condition. Later, they were irradiated one by one to up to 90 Gy with using 6 MV and 6 MeV beam qualities, respectively. Subsequently, both of film groups were again scanned in flatbed scanner for three –color channels. Optical densities and their standard deviations corresponding to the chosen dose values were obtained from the scanned films. Thus, calibration curves were plotted for all three colors channel according to two different beam conditions. The results obtained for 6 MV beam quality showed that if red color channel is selected for 0.9 Gy-7.3 Gy dose range, and green color channel is selected for 7.3 Gy-42.8 Gy dose range, and blue color channel is selected for 42.8 Gy-90.0 Gy dose range, the percentage uncertainty values in the obtained results are minimal. For the 6 MeV beam quality, if red color channel is selected for 0.9 Gy-7.7 Gy dose range, and green color channel is selected for 7.7 Gy-45.3 Gy dose range, and blue color channel is selected for 45.3 Gy-90.0 Gy dose range, the percentage uncertainty values in the obtained results are minimal. In conclusion, the percentage uncertainty values for the obtained results were evaluated for 6 MV photon and 6 MeV electron energies by using different scanning channels of EBT3 radiochromic film. It has been found that measurements having low percentage uncertainty values can be achieved by changing the scanning channel by deciding proper combinations with increasing doses for both energies (6MV photon and 6 MeV electron). The study also shows that EBT3 radiochromic films can be used at lower percentage uncertainty values ​​at doses higher than the recommended dose range values.

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.

Applications of a novel detector for pencil beam scanning proton therapy beam quality assurance

2021 ◽  
pp. 2140041
Author(s):  
Pei-Ying Yang ◽  
Yang-Wei Hsieh ◽  
Chen-Lin Kang ◽  
Chin-Dar Tseng ◽  
Chih-Hsueh Lin ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Proton Therapy ◽  
Beam Quality ◽  
Beam Width ◽  
Scanning Speed ◽  
Spot Size ◽  
Pencil Beam ◽  
Beam Position ◽  
The Cross ◽  
One Year

This study utilized a new type of detector, the CROSS II (Liverage Biomedical Inc., Taiwan), to perform a beam quality assurance (QA) procedure on a Sumitomo (Sumitomo Heavy Industries, Inc., Japan) pencil beam linear scanning proton therapy machine. The Cross II can monitor proton Pristine Bragg peak range, beam width, beam size, beam position, and scanning speed. All the data presented here were collected during a time span of over one year. The accuracy of the QA program could be verified if all the QA items were tested stably and within the programmed tolerances. Our results showed that the proton range remained within the [Formula: see text] mm tolerance, with the majority of measurements within [Formula: see text] mm, [Formula: see text] mm for spot size, 1.5 mm for spot position, and [Formula: see text]% for scanning speed. We found that the CROSS II detector is in high precise and steady state with highly efficient. Our proton therapy system was also proven to be in an accurate and reliable condition according to our QA results.

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.

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

EBT2 radiochromic film for quality assurance of complex IMRT treatments of the prostate: micro-collimated IMRT, RapidArc, and TomoTherapy

2011 ◽  
Vol 34 (3) ◽  
pp. 333-343 ◽  
Author(s):  
T. Kairn ◽  
N. Hardcastle ◽  
J. Kenny ◽  
R. Meldrum ◽  
W. A. Tomé ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Radiochromic Film

The origin of the flatbed scanner artifacts in radiochromic film dosimetry—key experiments and theoretical descriptions

2016 ◽  
Vol 61 (21) ◽  
pp. 7704-7724 ◽  
Author(s):  
Andreas A Schoenfeld ◽  
Soeren Wieker ◽  
Dietrich Harder ◽  
Bjoern Poppe
Keyword(s):  
Radiochromic Film ◽  
Film Dosimetry ◽  
Flatbed Scanner

SU-FF-T-208: Evaluation of a New Radiochromic Film/Flatbed Scanner System for Planar Clinical Dosimetry

2007 ◽  
Vol 34 (6Part10) ◽  
pp. 2449-2449
Author(s):  
M Goss ◽  
M Oldham
Keyword(s):  
Radiochromic Film ◽  
Flatbed Scanner
Sign in / Sign up

Export Citation Format

Share Document