Prog Med Phys.  2017 Sep;28(3):129-133. 10.14316/pmp.2017.28.3.129.

A Pilot Study of the Scanning Beam Quality Assurance Using Machine Log Files in Proton Beam Therapy

• Chung K

• KMID: 2393374
• DOI: http://doi.org/10.14316/pmp.2017.28.3.129

Abstract

The machine log files recorded by a scanning control unit in proton beam therapy system have been studied to be used as a quality assurance method of scanning beam deliveries. The accuracy of the data in the log files have been evaluated with a standard calibration beam scan pattern. The proton beam scan pattern has been delivered on a gafchromic film located at the isocenter plane of the proton beam treatment nozzle and found to agree within ±1.0 mm. The machine data accumulated for the scanning beam proton therapy of five different cases have been analyzed using a statistical method to estimate any systematic error in the data. The high-precision scanning beam log files in line scanning proton therapy system have been validated to be used for off-line scanning beam monitoring and thus as a patient-specific quality assurance method. The use of the machine log files for patient-specific quality assurance would simplify the quality assurance procedure with accurate scanning beam data.

Keyword

Proton beam therapy; Scanning beam; Quality assurance; Machine log file

MeSH Terms

Calibration
Methods
Pilot Projects*
Proton Therapy*
Protons*
Protons

Figure

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  Fig. 1. A scanned EBT3 film irradiated with the standard scan pattern composed of 5x5 points (230 MeV).

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  Fig. 2. An example of scanning beam information recorded in the scanning control unit (Top left: x-position in time, top right: y-position in time, bottom left: monitor count in time, bottom right: x-position vs. y-position. Raw data without pedestal/noise reduction).

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  Fig. 3. A scanning beam information recorded in the scanning control unit (one sample layer of a patient beam delivery plan).

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