DAMPED OSCILLATION MODEL FOR LUNG TUMOR MOTION MANAGEMENT WITH BREATH-HOLD METHOD ON RADIOTHERAPY

• Main Author: Triana, Hana
• Format: Final Project
• Language: Indonesia
• Subjects: Fisika
• Online Access: https://digilib.itb.ac.id/gdl/view/34795
• Institution: Institut Teknologi Bandung

Tumor motion is one of the major challenges of lung cancer radiation therapy. Tumor motion due to respiratory motion can reduce the accuracy of radiation dose delivery, which causes organ at risk (OAR) receiving higher dose radiotherapy. To reduce the negative effects of tumor motion, breath-hold method is usually used because of its ease of use. The breath-hold method that is carried out allows positioning of lung to be static within a certain period of time so that the tumor can receive a maximum radiation dose. Meanwhile motions that occur during the use of breath-hold method, can physically follow the concept of damped oscillation. This then encourages study on the concept to become a model of the breath-hold method so that its use has physical justification. The study of the damped oscillation models was conducted with a simple simulation utilizing variations of amplitude, frequency and damping factor to obtain a desired model. The model that has been built is then analyzed for the minimum time needed to reach the tolerance limit of tumor motion on radiotherapy for each variation. The results of the study of a damped oscillation model indicate that the model can be used as a justification for the use of the breath-hold method with radiation dose can be given at 0.9 – 1.5 seconds after starting to hold the breath so that it can be used in overcoming tumor motion on radiotherapy.