Multi-institutional dosimetric and geometric commissioning of image-guided small animal irradiators

Autor: Lindsay, P. E., Granton, P. V., Gasparini, Alessia, Jelveh, S., Clarkson, R., van Hoof, S., Hermans, J., Kaas, J., Wittkamper, F., Sonke, J. -J., Verhaegen, F., Jaffray, D. A.
Přispěvatelé: Promovendi ODB, Promovendi PHPC, Huisartsgeneeskunde, Radiotherapie, RS: GROW - Oncology, RS: GROW - R3 - Innovative Cancer Diagnostics & Therapy
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Zdroj: Medical Physics, 41(3):031714. Wiley
Medical physics
ISSN: 0094-2405
Popis: Purpose: To compare the dosimetric and geometric properties of a commercial x-ray based image-guided small animal irradiation system, installed at three institutions and to establish a complete and broadly accessible commissioning procedure. Methods: The system consists of a 225 kVp x-ray tube with fixed field size collimators ranging from 1 to 44 mm equivalent diameter. The x-ray tube is mounted opposite a flat-panel imaging detector, on a C-arm gantry with 360. coplanar rotation. Each institution performed a full commissioning of their system, including half-value layer, absolute dosimetry, relative dosimetry (profiles, percent depth dose, and relative output factors), and characterization of the system geometry and mechanical flex of the x-ray tube and detector. Dosimetric measurements were made using Farmer-type ionization chambers, small volume air and liquid ionization chambers, and radiochromic film. The results between the three institutions were compared. Results: At 225 kVp, with 0.3 mm Cu added filtration, the first half value layer ranged from 0.9 to 1.0 mm Cu. The dose-rate in-air for a 40 x 40 mm(2) field size, at a source-to-axis distance of 30 cm, ranged from 3.5 to 3.9 Gy/min between the three institutions. For field sizes between 2.5 mm diameter and 40 x 40 mm2, the differences between percent depth dose curves up to depths of 3.5 cm were between 1% and 4% on average, with the maximum difference being 7%. The profiles agreed very well for fields >5 mm diameter. The relative output factors differed by up to 6% for fields larger than 10 mm diameter, but differed by up to 49% for fields
Databáze: OpenAIRE
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