Dosimetric evaluation of total skin electron irradiation in-vivo dose measurements using diode and thermoluminescence dosimeters on human phantom

In total skin electron irradiation (TSEI), the accuracy of the applied dose should be determined using in vivo dosimetry systems due to wide treatment surface, long skin surface distance (SSD), long fractionation schemas. The aim of this study is to compare TLD and semiconductor diode detector in-vivo doses in total skin electron irradiations performed using Stanford Technique and determine the dosimetric system suitable to clinic for routine use. The gantry angles 90±19o has been checked in total skin electron irradiation that is implemented using the Stanford technique and profile measurements performed with TLD and diode detector. The cGy value per MU has been calculated from the dose readings of parallel plate ionization chamber obtained for the diode calibration. Having used Stanford Technique, 55 MU dose has been given to each field and full treatment has been applied with a total of 12 areas. TLD and diode detector dose measurements were performed imposing full treatment to 17 different skin point on human phantom. Average skin dose for TLD and diode was found to be 119 and 118 cGy respectively. TLD and diode in-vivo dose results was compared and their proximity to the treatment dose (120 cGy) was evaluated. There was no statistically significant difference between the dose of the points measured with both dosimetry systems. In line with these results, it is understood that the use of both techniques in all skin electron irradiation treatment performed in a clinic is convenient.