2017 Volume 20 Issue 2 Pages 82-88
In radiotherapy, the severity of radiation induced skin toxicity depends mainly on the received dose, and when tumors are near the skin, it is essential to determine the skin dose. This study evaluates the accuracy of an optically stimulated luminescent detector（ OSLD） with different setup conditions by experimental measurement and Monte Carlo simulation in skin dosimetry. We calculated the dose in the buildup region by Monte Carlo simulation and compared the dose measured by OSLDs（ nanoDotTM, Nagase-Landauer, JP）. The setup conditions of OSLD are in the hole of a customized phantom and on the top of a solid water phantom. Since the recommended skin dose is 0.07 mm, to determine such dose at 0.07 mm, a dose at a shallower depth is calculated to obtain the ratio between the dose at the effective depth of OSLD and the calculated dose at 0.07 mm in water. The dose by OSLD setting in the hole of a customized phantom（ DOSLD_hole） shows good agreement with the dose by Monte Carlo simulation（ DMC） compared to the dose by OSLD setting on top of the phantom（ DOSLD_top）. In addition to the build-up region, the dose difference between DOSLD_hole and DOSLD_top is within ±2％. At a depth of 0 mm, the ratio of DMC to DOSLD_hole and the ratio of DMC to DOSLD_top is 1.14 and 1.16, respectively. Skin dose can be determined by OSLD with multiplication of the above-mentioned ratios. In conclusion, skin dose can be determined using OSLD with setup on top of a phantom considering an error within ±2％.
