Confirmation of the Dose Distribution by Stereotactic Radiosurgery Technique with a Multi-purpose Phantom |
Hyung Jun Yoo, Il Han Kim, Sung Whan Ha, Charn Il Park, Sun Nyung Hur, Wee Saing Kang |
1Department of Therapeutic Radiology, Seoul National University College of Medicine, Seoul, Korea. ihkim@snu.ac.kr 2Department of Institute of Radiation Medicine, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea. |
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ABSTRACT |
PURPOSE: For the purpose of quality assurance of self-developed stereotactic radiosurgery system, a multi-purpose phantom was fabricated, and accuracy of radiation dose distribution during radiosurgery was measured using this phantom.
MATERIALS AND METHODS: A farmer chamber, a 0.125 cc ion chamber and a diode detector were used for the dosimetry.
Six MV x-ray from a linear accelerator (CL2100C, Varian) with stereotactic radiosurgery technique (Green Knife) was used, and multi-purpose phantom was attached to a stereotactic frame (Fisher type). Dosimetry was done by combinations of locations of the detectors in the phantom, fixed or arc beams, gantry angles (20 ~100 ), and size of the circular tertiary collimators (inner diameters of 10 degrees~40 degrees mm).
RESULTS: The measurement error was less than 0.5% by Farmer chamber, 0.5% for 0.125 cc ion chamber, and less than 2% for diode detector for the fixed beam, single arc beam, and 5-arc beam setup.
CONCLUSION: We confirmed the accuracy of dose distribution with the radiosurgery system developed in our institute and the data from this study would be able to be effectively used for the improvement of quality assurance of stereotactic radiosurgery or fractionated stereotactic radiotherapy system. |
Key Words:
Stereotactic radiosurgery, Phantom, Dose distribution, Quality assurance |
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