Retinoblastoma.

Most eye tumors in children are retinoblastomas, a malignant tumor of early childhood. Proton therapy is an established alternative to conventional radiation and can lower the risk of injury to adjacent tissues such as the brain, optic nerve and growing bones of the face and orbit. In certain cases, proton therapy can be used in conjunction with chemotherapy to avoid enucleation (eye removal). The focused radiation dose delivered via proton therapy may be particularly important in retinoblastoma patients who have a genetic disposition to developing other, radiation-induced, second tumors.

Retinoblastoma
Proton therapy for a retinoblastoma