Estimation of Surface Skin Dose Using TPS and TLD of Breast Radiotherapy Using Co-60 Teletherapy Unit

Abstract

Estimation of surface skin dose is very important for patients who undergo breast radiotherapy to show that the skin dose is under the safe level and to avoid tumor recurrence. The aim of this study is utilizing the thermolumiscent dosimeters (TLDs) as quality control in conventional radiotherapy procedures. Twenty patients undergo breast remove were stimulated by treatment planning system (TPS) and six lithium florid TLD-LiF chips have applied at the irradiated breast area. All measurements were performed using a Co-60 teletherapy (open field). All TLD chips were measured using the Harshaw 6600 reader system. Results have been shown that the correlation coefficient and the Bland–Altman agreement plot of 20 patients at six points illustrated that no significant difference (p>0.05) between TPS calculations and TLD measurements except at beams centers, there is high significance difference (p<0.001), where the high dose was applied. Thus, the conclusion is that not all locations in the area of treatment absorbed the same dose either using TLD measurements or using TPS values