How is Proton Radiotherapy Given?
Tumor Localization: The tumor must first be localized using transillumination and/or indirect ophthalmoscopy during surgery. Four markers (tantalum rings) are sewn to the outside of the eyeball (sclera) at the edges of the tumor. The measurements of the tumor are measured on the sclera, and drawings are made to document the shape of the tumor and the location of the tantalum rings. This information is put into a treatment-planning computer program. For tumors involving the front part of the eye (ciliary body and peripheral choroid), transillumination can be used to define the tumor in relation to the iris and cornea without the need for surgery. Proton Radiation Planning: Simulation uses an interactive, three-dimensional treatment-planning program that helps determine all treatment parameters needed, including the position of the eye and all the settings for the proton radiation machine. These parameters are used to create a patient-specific treatment plan. During the simulation, x-ray
