THE EFFECT OF MATERIAL AND SEED MARKER POSITION ON INTERSEED ATTENUATION IN LUNG CANCER BRACHYTHERAPY

• Main Author: Rahmadini, Afina
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/81160
• Institution: Institut Teknologi Bandung

Lung cancer is the most frequently diagnosed cancer and is a common cause of cancer death worldwide. There are several ways to treat lung cancer, one way is radiotherapy. Brachytherapy is a radiotherapy method that places or brings the source closer to the cancer area. Before carrying out therapy, you are required to carry out a Treatment Planning System (TPS). Task Group 43 (TG-43) is one of the most widely used methods for calculating TPS in brachytherapy. The TG-43 protocol calculates the distribution of dose distributions by superposition of single seed distributions. However, the TG-43 calculation ignores the influence of the presence of other seeds or Interseed Attenuation (ISA). ISA is defined as attenuation or disruption of the dose absorbed by the tissue, which is caused by the presence of other seeds that block the photon path, so that the total absorbed dose received by the tissue is reduced due to the dose absorbed by the surrounding seeds. Photon attenuation in a medium depends greatly on the photon energy, the thickness of the medium, and the atomic number of the medium through which it passes. Therefore, ISA is influenced by several factors such as the radioactive source used and the seed core material. There has been some research on ISA. In this research, simulations were carried out with variations in materials and distance between seeds. Simulations were carried out using the Monte Carlo method using DOSXYZnrc software. From the simulation results obtained, it shows that the higher the density of marker seeds, the smaller the DVH. From the research results, it was found that the silver marker material is the best to use. From the research results, it was found that a variation in the distance between seeds of 0.25 cm was the best to use.