A COMPARATIVE STUDY OF DOSE CORRECTION METHODS IN TISSUE INHOMOGENEITY

• Main Author: Khoirunnisaa, Larolina
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/55167
• Institution: Institut Teknologi Bandung

Radiotherapy is a cancer treatment using high doses of ionizing radiation to eradicate or slow the growth of cancer cells. The principle of radiotherapy is to maximize the dose to the target volume and on the other hand, to minimize the dose to the surrounding normal tissues. However, the presence of the tissue inhomogeneity can lead to over- or under-dosing. Inaccuracies in dosage calculations due to tissue inhomogeneity can be reduced by the application of a correction factor. This study aims to compare the value of the correction factor obtaining using the Tissue Air Ratio (TAR), Batho Power Law (BPL), and Modified Batho (MB) methods at different tissue densities of lung and bone tissue at 6 MV energy for a 10 cm × 10 cm field size. Lung tissue and bone were inserted in a simple geometric structure between the homogeneous tissue. The results of the calculation using those three methods were then compared with the result of the correction factor using Monte Carlo (MC) simulation method in the previous study. It can be seen that the MB method is the most accurate method because the value of the correction factor gives very good agreement with the correction factor measured by MC method with a difference of 0.8 – 4% in the lung region and only 0.05 – 1.5% in the bone region. The results of this study can be used as a consideration for the use of correction-based methods MB on 6 MV energy in Treatment Planning System.