Karakterisasi Bolus Berbahan Campuran Beeswax dan Petroleum Jelly Menggunakan Berkas Elektron Pada Energi 6 MeV dan 9 MeV

In radiotherapy cases of cancer on the surface of the skin generally use electron beams. The electron beam has not been able to provide the optimum surface radiation dose. Therefore, a material that is able to increase the dose of surface radiation is needed, which is called a bolus. This study tested a bolus made from a mixture of beeswax and petroleum jelly. The bolus test includes the determination of density, the value of Relative Electron Density (RED) and the determination of the absorbed dose. The absorbed dose value was obtained by irradiating using a Linear Accelerator (LINAC) at 6 MeV and 9 MeV energies. The RED value was obtained from the bolus tomography image using a CT-simulator by determining the Region of Interest (ROI). The bolus density values obtained from physical measurements using the TPS program have almost the same average density values. The RED bolus value obtained at a thickness of 0.2 cm to 0.8 cm has a lower RED value than the RED value of the breast, which is 0.976. However, at 1.0 cm thickness, the RED value is equivalent to breast tissue. The value of the absorbed dose in a bolus made from a mixture of beeswax and petroleum jelly, the thicker the bolus used, the smaller the increase in the absorbed dose. The results of this study indicate that a bolus made from a mixture of beeswax and petroleum jelly can be the choice of bolus material during radiotherapy.