Ionizing radiation damages DNA in the cancer cell so it can no longer divide and reproduce itself.
Two types of radiation therapy are used to treat retinoblastoma.
- A radioactive plaque can be surgically placed over the eye for several days to focus radiation directly on a tumour.
- External beam radiotherapy delivers high energy x-rays from outside the body in daily doses for up to six weeks.
If these treatments are recommended for your child, treatment should be done at a highly specialized hospital with solid experience in using radiation to treat retinoblastoma.
Radioactive Plaque (brachytherapy)
A radioactive plaque is stitched to the surface of eye for several days, delivering radiation directly to the tumour. The child is radioactive during treatment and will be nursed in a special isolation room. A parent can usually stay, with certain safety restrictions.
The isolation period during brachytherapy can be hard for a young child. Careful thought and planning beforehand can minimize stress for both you and your child.
High-energy x-rays beams are focused on the eye. Treatment is usually given daily for 2-5 weeks, and young children are usually sedated or anaesthetised as they must remain still during treatment. Children are not radioactive during these treatments.
Before radiotherapy begins, a mask is made to immobilise your child’s head during treatment. A simulation is also done to ensure the radiation is delivered accurately.
Each treatment takes only two or three minutes. However, set-up may take about half an hour for whole eye radiotherapy, and a little longer for lens sparing therapy
Healthy tissues may be irradiated during external beam radiotherapy, causing short, medium and long term side effects.
Questions to help you discuss the proposed treatment with your child’s doctors so you can make fully informed decisions about therapy and how to support your child.