Fabrication and calibration of a water phantom for dosimetry studies (original) (raw)

Water phantoms are being useJ for the dose calibration in radiotherapy treatment. In general phantoms are imported and the dimensions of such phantoms arc usually 30 em x 30 em x 30 em, But in few treatment cases such a, lung, total body irradiation (WI) and for routine eahhrations a large size phantom is required. For that reason a phantom of dimenslOns 45 em x 45 em x 33 em was fabricated in the present study. Dose measurements ofoneo beam were maJe at depths 2.5, 5.0, 7.5, 10.0, 12.5, 15.0, 17.5,20.0,22,5,25.0,27.5 and 30.0 em for field sizes 5 x 5, 10 x 10, 15 xIS, 20 x 20, 25 x 25 and 30 x 30 emz, Also in the case of linear accelerator doses were measured for the field sizes 5 x 5, 10 x 10, 15 x 15,20 x 20, 25 x 25, 30 x 30, 35 x 35, and 40 x 40 eml at the same depths. An ionization chamber (Model 23323) of volume 0.1 cm) in conjunction with a PTW UNIDOS electrometer was used for dose measurement. To get IAEA standard dose a conversion factor of 1.0343 is e:.tablished. The requ...