THE EFFECTS OF USING SHIELDING DISC ON PERCENTAGE DEPTH DOSE (PDD) IN INTRA-OPERATIVE RADIATION THERAPY (IORT) FOR BREAST CANCER

• Main Author: AMALIA (NIM : 10212032), ANNISA
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/21134
• Institution: Institut Teknologi Bandung

The technique of radiation therapy for breast cancer that is commonly used in Indonesia is external beam radiation therapy which takes a long time. In some developed countries, a new technique known as Intra-Operative Radiation Therapy (IORT) has been introduced. This treatment delivers the radiation during the surgery. Since Indonesia does not have this new machine yet, the combination between IORT applicators and the conventional head linac can be an alternative. It will reduce the effect of radiation to normal tissue. It is equipped with a shielding disc that protects the organs at risk around the target. In this study, the effect of using shielding disc to percentage depth dose (PDD) from IORT applicator in conventional head linac in phantom breast cancer would be investigate. The shielding disc has 5 cm of diameters that consisting of polymethylmethacrylate (PMMA) and aluminium. The results showed that the difference between PDD from the phantom with and without shielding disc on normal tissue was 35.29% while on the organs at risk (lungs) was 3.63%. It is still under the recommended limit, i.e. 10%. The results are relevant to the goal of radiotherapy which is to maximize the dose in the target while minimize that in normal tissue.