Göz İçi Tümör Radyocerrahisi İçin Göz Takip Sistemi ve Kalite Güvence Fantomunun Geliştirilmesi

Abstract

Uveal malignant melanoma is the most common type of intraocular cancer in adults. Stereotactic radiosurgery applications are often used in the treatment of such tumors. In these radiation treatments performed with external radiotherapy devices such as linear accelerators and proton therapy devices, the eye is immobilized with invasive methods during the treatment preparation phase in order to prevent wrong irradiation that may result from the movement of the target eye.

Within the scope of this thesis, it is aimed to develop an eye tracking system designed to manage the treatment autonomously by communicating with the treatment device, and an eye phantom that will enable quality assurance tests of the system. Instead of providing immobilization of the eye before the treatment, by following the eye position during the treatment using the developed system, it will be possible to irradiate the intraocular tumor autonomously only in the position where the treatment is planned. The eye tracking system is an image sensor-based system that tracks eyes with iris detection. The developed system can give output to continue the treatment if the traced iris is within the defined tolerance and to pause the treatment if it goes out of tolerance.

The iris detection success of the system has been tested with human eye images. The quality assurance tests needed to verify the angle values detected by the system were carried out with the eye phantom developed within the scope of this thesis to simulate eye movements. Detection of the movement of the eyeball on the phantom to the defined angle values was made by checking the video images recorded with the eye tracking system frame by frame and the amount of deviation was evaluated. It has been observed that the system successfully provides iris detection in human eye and the continuity of the obtained iris contour between the frames in the video images. Measurements were consistent in quality assurance tests with angle detection using the phantom. In addition, with the algorithms developed within the scope of the thesis, the simultaneous coordinates, angular motion and linear displacement information of the target, whose initial position in the moving eyeball is known, were calculated. In addition to providing guidance in defining the volume of the target to be treated and determining the amount of displacement to be allowed in the treatment, it is aimed to develop target tracking treatments by simultaneously determining the target location.

The system, which was developed for radiosurgery of intraocular tumors with external radiotherapy devices, is aimed to be used in different stages such as simulation imaging before treatment, determination of target organ volume and treatment. While ensuring the accuracy of the patient's treatment with the eye tracking system, a comprehensive treatment support system is designed to determine the motion tolerance, volume and simultaneous position of the target to be irradiated, and to perform the quality assurance tests of the system with the eye phantom.