scholarly journals Physical and Dosimetric Aspect of Euromechanics Add-on Multileaf Collimator on Varian Clinac 2100 C/D

2019 ◽  
Vol 9 (1Feb) ◽  
Author(s):  
S A Rohani ◽  
S R Mahdavi ◽  
A Mostaar ◽  
S Ueltzhöffer ◽  
R Mohammadi ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Full Width Half Maximum ◽  
Intensity Modulated Radiation Therapy ◽  
Multileaf Collimator ◽  
Dose Delivery ◽  
Positional Accuracy ◽  
Position Accuracy ◽  
Multi Leaf Collimator ◽  
Radiation Transmission ◽  
Study Application

Background: Before treatment planning and dose delivery, quality assurance of multi-leaf collimator (MLC) has an important role in intensity-modulated radiation therapy (IMRT) due to the creation of multiple segments from optimization process.Objective: The purpose of this study is to assess the quality control of MLC leaves using EBT3 Gafchromic films.Material and Methods: Leaf Position accuracy and leaf gap reproducibility were checked with Garden fence test. The garden fence test consists of 5 thin bands A) 0.2 Cm width spaced at 2 Cm intervals and B) 1 Cm width spaced at 1 Cm intervals. Each leaf accuracy was analyzed with measuring the full-width half-maximum (FWHM). Maximum and average leaf transmission were measured with gafchromic EBT3 films from Ashland for both 6 MV and 18 MV beams.Results: Leaf positions were found to be in a range between 1.78 – 2.53 mm, instead of nominal 2 mm for the test A and between 9.09 – 10.36 mm, instead of nominal 10 mm for the test B. The Average radiation transmission of the MLC was noted 1.79% and 1.98% of the open 10x10 Cm2 field at isocenter for 6 MV and 18 MV beams, respectively. Maximum radiation transmission was noted 4.1% and 4.4% for 6 MV and 18 MV beams, respectively.Conclusion: In this study, application of gafchromic EBT3 films for the quality assurance of Euromechanics multileaf collimator was studied. Our results showed that the average leaf leakage and positional accuracy of this type of MLC were in the acceptance level based on the Protocols.

scholarly journals Physical and Dosimetric Aspect of Euromechanics Add-on Multileaf Collimator on Varian Clinac 2100 C/D

2019 ◽  
Author(s):  
S A Rohani ◽  
S R Mahdavi ◽  
A Mostaar ◽  
S Ueltzhöffer ◽  
R Mohammadi ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Full Width Half Maximum ◽  
Intensity Modulated Radiation Therapy ◽  
Multileaf Collimator ◽  
Dose Delivery ◽  
Positional Accuracy ◽  
Position Accuracy ◽  
Multi Leaf Collimator ◽  
Radiation Transmission ◽  
Study Application

Background: Before treatment planning and dose delivery, quality assurance of multi-leaf collimator (MLC) has an important role in intensity-modulated radiation therapy (IMRT) due to the creation of multiple segments from optimization process.Objective: The purpose of this study is to assess the quality control of MLC leaves using EBT3 Gafchromic films.Material and Methods: Leaf Position accuracy and leaf gap reproducibility were checked with Garden fence test. The garden fence test consists of 5 thin bands A) 0.2 Cm width spaced at 2 Cm intervals and B) 1 Cm width spaced at 1 Cm intervals. Each leaf accuracy was analyzed with measuring the full-width half-maximum (FWHM). Maximum and average leaf transmission were measured with gafchromic EBT3 films from Ashland for both 6 MV and 18 MV beams.Results: Leaf positions were found to be in a range between 1.78 – 2.53 mm, instead of nominal 2 mm for the test A and between 9.09 – 10.36 mm, instead of nominal 10 mm for the test B. The Average radiation transmission of the MLC was noted 1.79% and 1.98% of the open 10x10 Cm2 field at isocenter for 6 MV and 18 MV beams, respectively. Maximum radiation transmission was noted 4.1% and 4.4% for 6 MV and 18 MV beams, respectively.Conclusion: In this study, application of gafchromic EBT3 films for the quality assurance of Euromechanics multileaf collimator was studied. Our results showed that the average leaf leakage and positional accuracy of this type of MLC were in the acceptance level based on the Protocols.

Transmission, Penumbra and Leaf Positional Accuracy in Commissioning and Quality Assurance Program of a Multileaf Collimator for Step-and-Shoot IMRT Treatments

2006 ◽  
Vol 92 (6) ◽  
pp. 511-516 ◽  
Author(s):  
Massimo Pasquino ◽  
Valeria Casanova Borca ◽  
Paola Catuzzo ◽  
Franca Ozzello ◽  
Santi Tofani
Keyword(s):  
Quality Assurance ◽  
Laser Scanning ◽  
Intensity Modulated Radiation Therapy ◽  
High Energy ◽  
Quality Assurance Program ◽  
Transmission Measurement ◽  
Multileaf Collimator ◽  
Positional Accuracy ◽  
Average Value ◽  
The Cross

Aims and background The performance characteristics of a commercial multileaf collimator (MLC) for intensity modulated radiation therapy (IMRT) and a comprehensive quality assurance program (QA) to be performed during the commissioning of the MLC were investigated. Materials and methods The midleaf transmission and interleaf leakage, the in-plane penumbra and its in-plane/cross-plane variation, the cross-plane penumbra and its in-plane/cross-plane variation, and the leaf positional accuracy of a high-energy photon (6 MV) Sli Precise Elekta linear accelerator were measured. Kodak EDR2 Ready Pack film was used for MLC transmission measurement; for the other characterization measurements we used Kodak X-Omat XV2 Ready Pack film placed at 5 cm depth in a solid RW3 phantom. Each film was digitized with a laser scanning photodensitometer VXR-12 Plus using the Omni Pro-Accept 6.0A film dosimetry system and converted to dose by means of H&D curves. The dose calibration measurements were performed with a Farmer ionization chamber according to the guidelines of the IAEA Technical Report No. 277. Results The average midleaf transmission and interleaf leakage were 1.8% ± 0.1% and 2.1% ± 0.2%, respectively. The average value of the cross-plane penumbra was 5.4 mm ± 0.3 mm with maximum variation less than 0.4 mm and 1.0 mm in the in-plane and cross-plane direction, respectively. The average value of the in-plane penumbra was 3.2 mm ± 0.2 mm and 3.5 mm ± 0.2 mm for the step side and groove side of the leaves, respectively. A dose profile perpendicular to the direction of the leaf travel passing through the central axis shows a tongue-and-groove effect of about 33%. The positional accuracy of the leaves was investigated according to AAPM Report No. 72 TG50; the deviation of the net optical density along all the match lines was less than ± 20%. Moreover, the results obtained with a step field technique showed a positional accuracy of less than 1 mm. Conclusions The results suggest the necessity of extensive knowledge of the MLC dosimetric characteristics for IMRT applications in order to allow physicists to study their influence on treatment delivery and to perform a comprehensive routine QA program of the investigated parameters.

Extra-target doses in children receiving multileaf collimator (MLC) based intensity modulated radiation therapy (IMRT)

2004 ◽  
Vol 42 (7) ◽  
pp. 626-630 ◽  
Author(s):  
Mary Koshy ◽  
Arnold C. Paulino ◽  
Robert B. Marcus ◽  
Joseph Y. Ting ◽  
Daisy Whitaker ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Intensity Modulated Radiation Therapy ◽  
Multileaf Collimator ◽  
Intensity Modulated

scholarly journals Positional Accuracy and Quality Assurance of Backup JAWs Required for Volumetric Modulated Arc Therapy

2012 ◽  
Vol 68 (11) ◽  
pp. 1486-1491
Author(s):  
Daisaku Tatsumi ◽  
Ryosei Nakada ◽  
Akinori Ienaga ◽  
Akane Yomoda ◽  
Makoto Inoue ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Volumetric Modulated Arc Therapy ◽  
Positional Accuracy ◽  
Arc Therapy

scholarly journals A survey on the current clinical application and practice of helical tomotherapy in mainland China

2019 ◽  
Vol 18 (4) ◽  
pp. 375-382 ◽  
Author(s):  
Zhiqiang Liu ◽  
Jianrong Dai ◽  
Tinglin Qiu ◽  
Ye Zhang ◽  
Jufang Shi ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Clinical Application ◽  
Helical Tomotherapy ◽  
Mainland China ◽  
Staffing Levels ◽  
Multi Leaf Collimator ◽  
Full Capacity ◽  
Efficacy Research ◽  
Utilisation Efficiency ◽  
Clinical Utilisation

AbstractAim:To assess helical tomotherapy (TOMO) current clinical application and practice in mainland China.Materials and methods:Data were collected for all TOMO units clinically operational in mainland China by 30 April 2016, including (a) the distribution of installation and staffing levels; (b) types of cancers treated; (c) utilisation efficiency; (d) quality assurance; (e) maintenance; (f) optional features; and (g) satisfaction levels. The data were collected as a census and analysed qualitatively and quantitatively.Results:As of 30 April 2016, 23 TOMO units were used clinically by 22 hospitals in mainland China. In the same period, 22,558 cancer patients were treated. For TOMO units with more than a year of clinical utilisation, a median of 378 cases were treated annually per machine. The median daily operation was 10·5 hours, and treatment headcount was 38·3 patients. The median service outage rate was 2·6%, and the most common cause was malfunction of the multi-leaf collimator. In terms of overall satisfaction levels, 3 hospitals were very satisfied, 16 were satisfied and 3 considered their satisfaction level as average.Findings:The overall operation of TOMO is good, but there are some problems due to running at full capacity, lack of clinical efficacy research and insufficient quality assurance regulations.

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