An automatic tracking system to facilitate gating of the eye during treatment of orbital cancer has been developed by the National Cancer Center of Korea (NCC).
Patients are seated for treatment with the affected eye propped open, head and neck immobilized, facing a proton beam nozzle. A computer screen shows the eyeball, with an x-axis and y-axis indicating the optimal time to inject the beam into the tumor.
“The eye can move at any time, but we cannot fix the eyeball. With our system, during patient treatment, a doctor can check eye movement”, says Se Byeong Lee, Ph.D, chief medical physicist, National Cancer Center of Korea. “During treatment of the eye for cancer, our camera detects eye movement, then our computer opens the beam gate when the eye is positioned properly to receive the proton beam.”
NCC is the only proton center that has this type of automatic eye tracking system, says Lee. A clinician has to manipulate the proton beam manually at other sites.