CONVOLUTION MARGIN OPTIMIZATION BETWEEN CLINICAL TARGET VOLUME (CTV) AND PLANNING TARGET VOLUME (PTV) WITH ESTIMATE FRACTION USING SIMULATED ANNEALING METHOD

• Main Author: Nurhanivah, Devi
• Format: Theses
• Language: Indonesia
• Subjects: Fisika
• Online Access: https://digilib.itb.ac.id/gdl/view/34749
• Institution: Institut Teknologi Bandung

Radiotherapy Treatment Planning is a process to plan an appropriate therapy patient to get the radiotherapy treatment needed with cancer to determining the dose distribution, margins, duration of irradiation, fractionation and tissue homogeneity. The margin between Clinical Target Volume (CTV) and Planning Target Volume (PTV) is required to ensure that the planed dose delivered adequately, to allow for geometric uncertainty. If the margin is too small, it cause under dose, and if the margin is too large, it cause overdose. However at some hospitals, CTV-PTV margins are usually set at 1 cm without optimization. To determine the appropriate margin, it is necessary to do dose calculation. One of some popular margin determinations is convolution techniques. Some studies use this technique and also take into account the effects of irregularities by varying the number of fractions to minimize doses on healthy tissue around the target. Thus, the aim of this study is to optimize the convolution margin between CTV-PTV by taking into account the number of fractions using the simulated annealing optimization. The data came from three patients with different number of fractions. The results show the optimum margins are less than 1 cm. One parameter that affects this optimum margins is the number of fractions. It also can be seen that the number of beam angles affects the optimum margins obtained.