Treatment of retinoblastoma depends on the stage of the disease. Small tumours with a limited amount of disease get local therapies (laser or cryotherapy). More extensive tumours have IV chemotherapy as the first line treatment.
Current practice in the UK is to treat those children who relapse following IV chemotherapy with a course of chemotherapy infused directly into the main blood supply of the eye, the ophthalmic artery. This allows a high dose of chemotherapy to reach the tumour, but requires positioning a small catheter in the artery at the time of an angiogram.
The procedure is effective in saving vision in about 60% of the eyes, where the only alternative option would be enucleation.