Treatment of retinoblastoma depends on the number, size and location of tumour(s), whether one or both eyes is affected, whether the cancer has spread or is likely to spread, and the child’s general health.
Treatments include laser, cryotherapy (freezing), chemotherapy, brachytherapy (radioactive plaque), radiotherapy and enucleation (surgical removal of the eye). In many developing countries, surgical removal of the eye is the only available life-saving treatment. Delaying surgery while pursuing other options can kill the child.
Laser, cryotherapy, periocular and intravitreal chemotherapy injections are given during an Exam Under Anaesthesia (EUA). They may be used separately or in combination with other therapies. As primary treatment, they are effective only for small tumours that do not threaten vision.
Focal therapies are most often given to “finish off” tumours that have first been shrunk by other treatments such as systemic or intra-arterial chemotherapy. Repeated treatments are usually needed at monthly intervals for some time after chemotherapy ends.
Drugs that target cancer cells are given in repeated cycles, usually for between 5-8 months. Several courses may be needed. A central venous catheter is often surgically implanted to deliver treatment without the child having repeated needle sticks.
Systemic chemotherapy can have strong side effects. During treatment, children are especially vulnerable to infection, fatigue and bruising due to low blood counts. Medications and transfusions may be given to boost blood counts.
IAC delivers potent chemotherapy directly into the eye during an EUA, via the ophthalmic artery. It is reached by a catheter inserted into the femoral artery. IAC is used to treat medium to large sized intra-ocular retinoblastoma, and should only be used when there is no risk that tumour can spread outside the eye.
The plaque is stitched to the surface of the eye while the child is under general anaesthetic. A continuous low dose of radiation is focused directly to the tumour for several days before the plaque is removed during a second surgery.
Close contact with other people is limited while the plaque is in place, but a parent is usually permitted to stay with the child in the isolation room.
Radiotherapy used to be a standard retinoblastoma treatment, but it has significant long term side effects. In developed countries, it is now primarily a last resort treatment to save a single remaining eye.
Radiotherapy usually lasts 4-5 weeks. A Perspex mask is worn during treatment to protect areas outside the radiation field. Many children receive a short acting general anaesthetic for each daily treatment, but with good child life support, children as young as 2 years can complete radiotherapy awake.
Surgical removal of the eye is the best treatment to protect the child when retinoblastoma affects only one eye. Surgery is also needed if treatments fail to kill bilateral tumours, or when there is a high risk that the cancer will spread outside the eye.
During enucleation surgery, an implant should be placed to replace the eye and maintain the shape of the socket. After surgery, the child wears a conformer for about six weeks, while the socket heals. The conformer is usually a clear plastic shell with one or two small holes, through which antibiotic drops are administered to prevent infection. Some conformers are painted to look like a real eye.
Once the eye socket has healed, the child should be fitted for an artificial eye. The eye does not enable the child to see. Ocular Prosthetics are a work of art – can you tell which eye is artificial in these pictures?
The artificial eye maintains the structure of the eye socket, and helps prevent infection. Artificial eyes are also hugely important for the psychological well-being of the child and family.
In developing countries, these intensive treatments are rarely available, or are too expensive, and most hospitals lack the expertise to provide effective care, As a result, most children with extraocular and trilateral retinoblastoma can only receive palliative care. Prompt diagnosis and eye removal is essential to save the child’s life.