Research of Water Phantom with Adjustable Length

Objective To develop a new water phantom specialized for absorbed dose measurement in total body irradiation(TBI) treatment.The width and height of water phantom have been fixed at 300 mm while the length can be adjust between 50 mm and 400 mm to meet the demands of different patients' physical sizes.Methods Cubical box was made by splicing 10 mm thick plexiglass sheet.A sleeve-like piston with suitable size and motion function was installed on one side wall of cubical box and then a tabular plexiglass piston was fixed inside the sleeve.Thus,the length of the water phantom could be controlled to meet our need by pulling and pushing the piston.Results In order to determine the accuracy of the water phantom,our water phantom was compared with the international standard water phantom.The absorbed doses at different water depths for these two water phantoms were detected by 6MV and 15MV X-ray,respectively.The results were used for comparison and statistical analysis which indicated that there were no statistical differences between two water phantoms.Conclusion The water phantom can fully meet the needs of clinical absorbed dose measurement in total body irradiation treatment.