A dosimetric evaluation of water equivalent phantoms for kilovoltage x-ray beams
- 19 October 2005
- journal article
- Published by IOP Publishing in Physics in Medicine & Biology
- Vol. 50 (21), N331-N344
- https://doi.org/10.1088/0031-9155/50/21/n06
Abstract
Solid phantoms are widely used in radiation therapy for both relative and reference dosimetry. Two water equivalent phantoms, RMI-457 Solid Water and Plastic Water, were evaluated for use in kilovoltage x-ray dosimetry in the energy range from 75 to 300 kVp. Relative and reference dosimetry measurements were performed in the solid phantoms and compared with water. The results indicate that RMI-457 Solid Water could be used for output factor determination for all energies tested and the measurement of percentage depth doses for the 300 kVp x-ray beam, with data agreeing to within 1%, compared to the same measurements in water. For the same criteria, Plastic Water could only be used for output factor determination of the 300 kVp x-ray beam. The superior agreement of the calculated mass-energy absorption coefficients for Solid Water and water, as compared to Plastic Water and water was consistent with the experimental results. Reference dosimetry is not recommended with the solid phantoms for the energies studied due to the lack of published correction factors. It is recommended that any solid phantom be tested by comparison with water in the same manner before being used for the dosimetry of kilovoltage x-ray beams.Keywords
This publication has 22 references indexed in Scilit:
- Output factor measurements for a kilovoltage x-ray therapy unitAustralasian Physics & Engineering Sciences in Medicine, 2005
- Addendum to the IPEMB code of practice for the determination of absorbed dose for x-rays below 300 kV generating potential (0.035 mm Al–4 mm Cu HVL)Physics in Medicine & Biology, 2005
- Dosimetry of a low-kV intra-operative X-ray source using basic analytical beam modelsAustralasian Physics & Engineering Sciences in Medicine, 2002
- On the accuracy of monomer/polymer gel dosimetry in the proximity of a high-dose-rate192Ir sourcePhysics in Medicine & Biology, 2001
- An analytical model of a kilovoltage beam phase spaceMedical Physics, 1999
- Dosimetric evaluation of a widely used kilovoltage x‐ray unit for endocavitary radiotherapyMedical Physics, 1998
- Measurement of percentage depth dose and lateral beam profile for kilovoltage x-ray therapy beamsPhysics in Medicine & Biology, 1997
- Performance characteristics of the Pantak DXT-300 kilovoltage X-ray treatment machineThe British Journal of Radiology, 1996
- A new miniature x‐ray source for interstitial radiosurgery: Device descriptionMedical Physics, 1996
- Beam characteristics of the Therapax DXT300 orthovoltage therapy unitPhysics in Medicine & Biology, 1994