Plaque radiotherapy is a form of internal radiotherapy. A radioactive piece of metal known as a plaque is attached to the sclera (white part of the eye) next to the tumour. This is around the size of a 5 pence coin (please see picture above). This is done in the operating theatre and is left in the eye between 3 and 7 days before being removed. Patients usually stay in ward 1C for this treatment. The tumour starts to shrink around 4-6 months after the plaque is removed. The effects can last for several years. Although being an effective treatment, the radiation can sometimes damage other parts of the eye. This may cause cataract, retinal detachment, nerve damage, or macular oedema (swelling of the back of the eye). New blood vessels may grow after treatment; these can sometimes block the drainage angle in the eye causing glaucoma. If we are unable to control this, we may have to consider removing the eye. Although there are risks of plaque radiotherapy, this treatment can stop growth of the tumour in around 80% of cases.
The picture above shows a choroidal melanoma after treatment with plaque radiotherapy.