Retinoblastoma is a cancer of the eye that occurs exclusively in children. The treatment for retinoblastoma may include surgery, chemotherapy, radiation and local treatments to the eye such as freezing (cryotherapy) and local radiation (brachytherapy). In some cases, a child with retinoblastoma will have active cancer in a single remaining eye with useful vision. In such cases, it is sometimes necessary to remove this eye. In such cases, the injection of chemotherapy directly into the artery that supplies the eye and the tumor may lead to regression of the tumor without the need to remove the eye.