Experience on Commissioning the first Halcyon Linear Accelerator in China

Abstract Objective: This study is aimed to establish a proper clinical commissioning procedure for the Halcyon 1.0 linear accelerator (linac) with pre-configured reference beam data (RBD) set and to ensure the commissioning results meet the clinical treatment requirements. Methods: Four parts were carried out during the commissioning work on the first Halcyon linac in China, which were according to the characteristics of this linac, the experience of the acceptance tests and commissioning procedure of our existing linacs and treatment planning systems (TPS), reports of AAPM & IAEA and relevant publications with the choice of appropriate quality assurance (QA) tools and procedures. These four aspects were as follows: 1. Commissioning of the Halcyon linac; 2. commissioning of the Eclipse TPS; 3. QA and quality control (QA & QC) of the Halcyon linac; 4. QA & QC of the Eclipse TPS and developing the corresponding procedures. Results: The 3D radius of the isocenter of gantry and collimator rotation from Winston-Lutz test was 0.64mm, the coincidence of the virtual isocenter and the treatment isocenter was quite well, and the maximum travel position deviation was 0.7mm. Percentage Depth Doses (PDDs) was 63.3% at 10cm at the reference setup and the tolerance was within 1%. The Machine Performance Check (MPC) results were within the relevant tolerance, and the gantry isocenter size measured from MPC test was 0.67mm. The pre-configured beam model data was in agreement with the measured data. In the process of rotation, the speed of gantry rotation and multi-leaf collimator (MLC) movement and the control of dose rate were all accurate with all deviations were controlled below 2%. The CT values of Surface and Interior of the carbon fiber treatment couch were -750HU and -950HU, respectively. All MPPG 5.a recommended regular field gamma compare tests met the requirements. The task group 119 test was also performed on Halcyon, the point dose difference for intensity-modulated radiation therapy (IMRT) and RapidArc techniques were -0.003 ± 0.011 and - 0.012 ± 0.006, respectively, with confidence limits of 0.025 and 0.024. Conclusion: The measured data of the Halcyon linac are in good consistency with the pre-configured beam model data in Eclipse TPS. The commissioning results of the IMRT technique and the RapicArc technique are all within the tolerance ranges recommended by AAPM and relevant publications, which could meet the needs of clinical requirements. The pre-configured data can facilitate the commissioning work and the validation and replace fully collecting beam data, which will be the trend of the commissioning of linac in the future.

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Predictive quality assurance of a linear accelerator based on the machine performance check application using statistical process control and ARIMA forecast modeling

Journal of Applied Clinical Medical Physics ◽

10.1002/acm2.12917 ◽

2020 ◽

Vol 21 (8) ◽

pp. 73-82

Author(s):

Wayo Puyati ◽

Amnach Khawne ◽

Michael Barnes ◽

Benjamin Zwan ◽

Peter Greer ◽

...

Keyword(s):

Quality Assurance ◽

Process Control ◽

Statistical Process Control ◽

Linear Accelerator ◽

Statistical Process ◽

Machine Performance ◽

Predictive Quality ◽

Performance Check ◽

Forecast Modeling

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An Approach to Approximate the Full Strain Field of Turbofan Blades During Operation

Volume 7C: Structures and Dynamics ◽

10.1115/gt2018-77056 ◽

2018 ◽

Author(s):

Gen Fu ◽

Alexandrina Untaroiu ◽

Walter O’Brien

Keyword(s):

Numerical Model ◽

Cantilever Beam ◽

Strain Field ◽

Measured Data ◽

Mode Shapes ◽

Beam Model ◽

Reference Solution ◽

Full Field ◽

Field Response ◽

Critical Locations

The measurement of the aeromechanical response of the fan blades is important to quantifying their integrity. The accurate knowledge of the response at critical locations of the structure is crucial when assessing the structural condition. A reliable and low cost measuring technique is necessary. Currently, sensors can only provide the measured data at several discrete points. A significant number of sensors may be required to fully characterize the aeromechanical response of the blades. However, the amount of instrumentation that can be placed on the structure is limited due to data acquisition system limitations, instrumentation accessibility, and the effect of the instrumentation on the measured response. From a practical stand point, it is not possible to place sensors at all the critical locations for different excitations. Therefore, development of an approach that derives the full strain field response based on a limited set of measured data is required. In this study, the traditional model reduction method is used to expand the full strain field response of the structure by using a set of discrete measured data. Two computational models are developed and used to verify the expansion approach. The solution of the numerical model is chosen as the reference solution. In addition, the numerical model also provides the mode shapes of the structure. In the expansion approach, this information is used to develop the algorithm. First, a cantilever beam model is created. The influences of the sensor location, number of sensors and the number of modes included are analyzed using this cantilever beam model. The expanded full field response data is compared with the reference solution to evaluate the expansion procedure. The rotor 67 blade model is then used to test the expansion method. The results show that the expanded full field data is in good agreement with the calculated data. The expansion algorithm can be used for the full field strain by using the limited sets of strain data.

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Influence of multi-leaf collimator leaf transmission on head and neck intensity-modulated radiation therapy and volumetric-modulated arc therapy planning

Japanese Journal of Radiology ◽

10.1007/s11604-017-0661-8 ◽

2017 ◽

Vol 35 (9) ◽

pp. 511-525

Author(s):

Motoharu Sasaki ◽

Masahide Tominaga ◽

Takeshi Kamomae ◽

Hitoshi Ikushima ◽

Motonori Kitaoka ◽

...

Keyword(s):

Radiation Therapy ◽

Head And Neck ◽

Volumetric Modulated Arc Therapy ◽

Intensity Modulated Radiation Therapy ◽

Therapy Planning ◽

Intensity Modulated ◽

Multi Leaf Collimator ◽

Arc Therapy

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Interplay effect on a 6-MV flattening-filter-free linear accelerator with high dose rate and fast multi-leaf collimator motion treating breast and lung phantoms

Medical Physics ◽

10.1002/mp.12899 ◽

2018 ◽

Vol 45 (6) ◽

pp. 2369-2376 ◽

Cited By ~ 8

Author(s):

Tucker Netherton ◽

Yuting Li ◽

Paige Nitsch ◽

Simona Shaitelman ◽

Peter Balter ◽

...

Keyword(s):

Dose Rate ◽

Linear Accelerator ◽

High Dose Rate ◽

High Dose ◽

Flattening Filter Free ◽

Multi Leaf Collimator ◽

Flattening Filter ◽

Interplay Effect

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A Virtual Linear Accelerator for Verification of Treatment planning systems

The Use of Computers in Radiation Therapy ◽

10.1007/978-3-642-59758-9_168 ◽

2000 ◽

pp. 446-448

Author(s):

Elinore Wieslander ◽

Tommy Knöös

Keyword(s):

Treatment Planning ◽

Linear Accelerator ◽

Planning Systems ◽

Treatment Planning Systems

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Dose linearity and uniformity of a linear accelerator designed for implementation of multileaf collimation system-based intensity modulated radiation therapy

Medical Physics ◽

10.1118/1.1592640 ◽

2003 ◽

Vol 30 (8) ◽

pp. 2253-2256 ◽

Cited By ~ 12

Author(s):

Cheng B. Saw ◽

Sicong Li ◽

Komanduri M. Ayyangar ◽

Maung Yoe-Sein ◽

Susha Pillai ◽

...

Keyword(s):

Radiation Therapy ◽

Linear Accelerator ◽

Intensity Modulated Radiation Therapy ◽

Intensity Modulated ◽

Collimation System ◽

Dose Linearity ◽

Multileaf Collimation

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Comparison of Algorithms for Static Multi-Leaf Collimator Field Segmentation

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.80-81.1091 ◽

2011 ◽

Vol 80-81 ◽

pp. 1091-1095

Author(s):

Dong Dong Ni ◽

Xu Wu ◽

Jian Qi Chen ◽

Jia Jing ◽

Cai Xia Liu

Keyword(s):

Treatment Planning ◽

Treatment Time ◽

Beam Intensity ◽

Effective Strategy ◽

Monitor Unit ◽

Planning Systems ◽

Treatment Planning Systems ◽

Multi Leaf Collimator ◽

Leaf Sequencing ◽

Number Of Segments

Purpose: A multi-leaf collimator leaf sequencing comparison program in the sense that it translates beam intensity maps into the least number of MLC field segments was presented. Methods: The IMRT leaf sequencing calculation program based on Galvin, Bortfeld algorithms was constructed. The output of the leaf sequencing program were the number of segment and the total number of monitor unit. Results: Assuming 15 x 15 bixel fields with an average of 10 intensity levels, Bortfeld algorithm could yield better result on example 1 while Galvin algorithm yielded better results on example 2. Conclusions: This represented a useful tool for optimizing the leaf sequencing of static multi-leaf collimator that can yield shorter treatment time and higher utilization of photons by comparing with the total number of monitor units and number of segments of existed typical algorithms. It was an effective strategy and could be applied in commercial Treatment Planning Systems.

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