Verification imaging using a computed radiography system for high-energy electron beam therapy.
OBJECTIVE
The aim of this study was to examine a method to more conveniently acquire verification images. A computed radiography (CR) system was employed using a photostimulable phosphor plate and diagnostic cassette used for taking diagnostic X-ray photographs.


METHODS
Verification images were acquired using the diagnostic cassette and therapy cassette. Image processing parameters were adjusted to improve the image quality. Verification images were printed using optimum parameters, and 10 radiation technicians visually evaluated the images. The sign test was used, and image quality was evaluated using a two-sided test at a 5% level of significance. To assess its clinical value, a radiation oncologist evaluated patient verification images.


RESULTS
Verification image quality was improved by the adjustment of image processing parameters. As a result of the image quality evaluation, there were no significant differences between the two types of cassette (p>0.05). In most of the clinical cases (98%), the verification images were useful.


CONCLUSIONS
We found that good quality verification images were acquired by a CR system with a diagnostic cassette. This system is suitable for practical use to acquire daily verification images, and it is considered useful for maintaining quality assurance (QA) in high-energy electron beam therapy.
Department of Radiology, Osaka Prefectural Medical Center for Respiratory and Allergic Diseases, Habikino 583-8588, Japan.
Hideki
H
Fujita
Michihiro
M
Yamaguchi
Toshizo
T
Katsuda
Hisashi
H
Sakamoto
Tomio
T
Fujioka
Takuhito
T
Tada
Masami
M
Azuma
D006801:Humans; D007091:Image Processing, Computer-Assisted; D019047:Phantoms, Imaging; D010758:Phosphorus; D011881:Radiotherapy, Computer-Assisted / Q000379:methods*; D011882:Radiotherapy, High-Energy; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods
D010758:Phosphorus