Output factor measurements for a kilovoltage x-ray therapy unit

被引：25

作者：

Healy B.J. ^{[1
]}

Gibbs A. ^{[1
]}

Murry R.L. ^{[1
]}

Prunster J.E. ^{[1
]}

Nitschke K.N. ^{[1
]}

机构：

[1] Southern Zone Radiation Oncology Service - Mater Centre, Princess Alexandra Hospital, South Brisbane, QLD 4101, Raymond Tce.

来源：

Australasian Physics & Engineering Sciences in Medicine | 2005年 / 28卷 / 2期

关键词：

Ionisation chambers; Kilovoltage x-rays; Output factors; Water substitutes;

D O I：

10.1007/BF03178702

中图分类号：

学科分类号：

摘要：

Output factors at the surface for treatment cones and lead cut-outs have been measured for a Pantak Therapax SXT 150 superficial therapy unit with x-ray beam qualities from 1 to 13 min A1 HVL. A variety of phantom materials and two ionisation chambers were tested for their suitability in output factor and percentage depth dose measurement. Solid water proved a useful water-equivalent phantom material with discrepancies between measurements in water and solid water less than 2.3% for percentage depth dose and less than 0.6% for output factors. Larger measurement discrepancies were found for Plastic Water and Perspex. A PTW Markus chamber was found to compare well with a NE 2532/3 low energy chamber in percentage depth dose measurement, but discrepancies arose between the chambers in output factor measurements, up to 5% for small field sizes. Measurements indicated that the Markus chamber had an energy dependent response in the kilovoltage range, which could account for the discrepancy in output factor measurement. Copyright © 2005 ACPSEM/EA.

引用

页码：115 / 121

页数：6

共 20 条

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