Quality control of source positioning and timer accuracy for high - dose rate afterloading machine / 中华放射肿瘤学杂志

ABSTRACT

Objective To explore and establish accurate detection quality control method of source positioning and timer precision for afterloading equipment. Methods The source positioning detection device was made of hd camera,EBT3 disposable film and steel rule,collecting source in each resident point for video images and film. Accurate measurement of radioactive source positioning and timer accuracy, including the timing absolute error and linear error through analysis of image sampling rate. After the film grayscale distribution analysis,comparison between film gray peak position and the measurement of resident point geometry,got the stay point source physics and radiation center deviation. Results Radioactive source physics and radiation center deviation was (-0.33± 0. 10) mm;For all default dwell time,timer average absolute deviation was (0.22±0. 02) s,linear fitting result was y=x-0. 226,R2=1,timing linear error was-0. 01％ Conclusions established detection means through the video images and film exposure quantitative analysis for accurately determination of source positioning,dwell time and source radiation center precision. After experimental testing the machine precision satisfied the requirement of clinical use.