Adsorbered Dose Radiotherapy Stations

Question: Discuss about theAdsorbered Dosefor Radiotherapy Stations. Answer: Discussion and Conclusion Radiotherapy stations many at times uses lucite phantom sheets to analyze the ratio of penetration with a ratio of 20/10 cm depth-ionization. Since there is differences in density and effective the measurement will not give the TPR of 20/10 ratios(Mayles 2007, p. 122). Since there is some loss (attenuation) and losses due to scattering nature of Perspex are not the same from water. This makes it difficult to a convincing reason for measured ionization ratio at given depths for photons. In photon, we always select 5, and 15 cm depth Perspex phantom instead of 20/10cm which is used because the 5 cm depth gives data on how photon beam output become stable since this value is above the measurement of dose highest value for 15MV and 6 MV photons. And there is a need to calculate the ratio of ionization which is got for 15cm and 5 cm and 17.75cm and 5.95cm, but in this our experiment we used 20/10 cm. That shows that the excess Perspex attenuation is reduced when these photon beams in Perspex are scattered. For this electron beams, we have to select different combinations of depth to help check the quality of the beam. In the calculation of dose, we calculated ionizing radiation dose at different depth in mGy for both depths at 10cm and 20cm. We can easily note that the ionizing radiation dose is higher when the depth is small (5 cm) and it is relatively more when the depth increases (at 20cm). This is because at less distance the attenuation/losses are few as opposed to relatively deeper ones. And because of this attenuation, we need to calculate the correction form which will reduce the effect of this loss(Mayles 2007, p. 245). This is calculated from; Of which in our experiment we got it to = 1.0027 The value of TPR can be directly calculated from the averages of mGy readings from both depths. In our average experiment depth at 10cm was 79,416 while that at 20 cm was 532,166. So we say TPR = . At a set-up of 5cm deep, we got readings of 100 Mus at a ratio of 10/10, for the readings 1,2 and 3 and we got the average to be 16.35 so this value in conjunction with other values and variables we got previously we can easily calculate the absolute dose as below(purdy 2012, p. 204), After the experiment, we got ourselves familiarized with absolute reference dose measurement in-phantom technique with MV photon beams since we were able to calculate the value of the dose and understand most ratios and why some ratios are better than others. The attenuation can be reduced by the use of correction. Bibliography Mayles, P 2007, Handbook of radiography physics :Theory and practise, 3rd edn, CRC press , Washington DC. purdy, JA 2012, Technoical basics of radiation : Practical clinical application, 5th edn, Springer science and Business Media, New york.