Retinoblastoma treatment options
There are a number of treatment options for children who have been diagnosed with retinoblastoma, which will depend on each child’s individual needs. Your consultant will discuss this with you in detail, but here is an overview of the different treatments that might be discussed with you:
Small tumours that are located at the front of the eye can be treated by a freezing treatment known as cryotherapy. An instrument called a cryoprobe is placed on the outer surface or sclera of the eye, at a position overlying the base of the tumour. The tumour cells are killed by being frozen.
This treatment is carried out under a general anaesthetic and more than one treatment may be needed. If this is the case they are usually at monthly intervals.
After cryotherapy the eyelids tend to look slightly puffy and the eye may be a bit sore for a day or two. The child will need to have eye drops or ointment for a few days following this treatment.
Some tumours are suitable for treatment by laser, either alone or in combination with chemotherapy. Small tumours tend to be suitable for laser alone, whereas larger tumours will often be treated with one or two cycles of chemotherapy first to shrink the tumour down to a size which can be treated with laser.
Laser uses heat to destroy tumour cells and is directed through the pupil whilst the child is under general anaesthetic. Laser requires a series of treatments at two to four-weekly intervals and may even continue after chemotherapy has finished.
Chemotherapy (drug treatment) is usually used in the first stage of treatment for patients with bilateral retinoblastoma and can be used for both small and large tumours.
It is also sometimes used for unilateral retinoblastoma, but only in situations where there is a good chance of preserving useful vision in the affected eye. Between four and six cycles of chemotherapy, at 3-4 weekly intervals, are usually given and local therapy (laser, cryotherapy or radioactive plaque) can be introduced once the tumour has shrunk.
Chemotherapy may also be required after an eye has been removed by surgery (enucleation), if there are signs that the tumour had involved the nerve, the deeper layers of the eye or the front chamber of the eye. In this situation usually only four cycles will be needed.
Children with a known family history of retinoblastoma receive regular screening at one of the Rb centres from birth and are therefore tend to be diagnosed at a younger age. If tumours are found, they are more likely to be relatively small. For such children, a combination of local therapy (cryotherapy or laser) with or without the addition of chemotherapy is the usual treatment.
When chemotherapy is recommended, the child will be under the care of a paediatric oncologist (children’s cancer doctor), who specialises in the drug treatment of cancer in children. Chemotherapy is given via an intravenous line (known as a central line), and this will stay in for the duration of the whole course of treatment. The nursing staff on the children’s cancer ward will teach the parents how to look after the central line.
Chemotherapy is usually given at the nearest children’s cancer centre and arrangements will be made for the child to be seen locally in between cycles of chemotherapy or if the child is unwell.
Possible side-effects of chemotherapy
• Nausea and vomiting – this can be treated with powerful anti-sickness drugs,
• Increased susceptibility to infection – this may require treatment in hospital with antibiotics,
• Tendency to bruise easily
• Thinning or loss of hair- this will regrow after completion of the treatment.
There is no evidence that shows fertility is impaired by the drugs used in the first line chemotherapy treatment of retinoblastoma.
If your child needs chemotherapy, you may find our advice leaflet from other parents of use.
This treatment can be used when a tumour recurs after initial intravenous chemotherapy.
This treatment is called intra–arterial chemotherapy or IAC and it is a method of delivering chemotherapy drugs directly to the eye rather than around the whole body as described above.
The child has a general anaesthetic for this treatment. The procedure involves passing a tiny catheter (plastic tube) through the femoral artery (the artery in the groin), all the way up until it is in the ophthalmic artery (the artery in the eye).
Once the catheter is in place the chemotherapy drug is administered via the tube and is able to work directly on the tumour/s in the eye. The treatment takes about two hours.
Once the chemotherapy is given the catheter is removed and the site compressed to stop any bleeding. Most children are given three courses of intra-arterial chemotherapy which can be repeated at a later stage if needed.
As the chemotherapy is administered directly to the eye and not to the whole body this method usually avoids the side effects of sickness, nausea, hair loss and suppression of the immune system which are normally associated with chemotherapy.
As with all treatments if the doctors feel this is a treatment option for your child they will discuss it with you in detail and answer any questions you may have.
Children who have developed seeds in the vitreous (the jelly part of the eye) may be offered injections of chemotherapy directly into the eye. This is likely to be a course of 4-6 injections at 1-2 weekly intervals.
This treatment is usually well tolerated with no nausea or vomiting. The eye may be a little sore because of the freezing treatment given as part of the procedure. Children are encouraged to wear a shield for 24 hours afterwards.
If the tumour is very large and has damaged the sight in the eye beyond repair, then the ophthalmologist will recommend that the eye be removed. This operation is called an enucleation. Enucleation is only recommended when it is felt other treatments would not be effective, and/or would put the child’s life at risk.
Approximately 70% of children with unilateral Rb will require enucleation.
Children recover very rapidly following this surgery. There are no stitches to be removed after surgery and your child will be kept comfortable with regular paracetamol. Other painkillers can be given if necessary.
Usually the child will be able to come home one or two days after the operation and parents/carers will be taught how to put antibiotic drops into the socket. These drops are necessary until they receive their artificial eye. A temporary artificial eye (conformer) will be put in during the operation. It is worn to protect the socket whilst it is healing. Conformers can be clear or may be coloured like an eye.
More information about artificial eyes can be found here.
Pathology following enucleation surgery
When an eye has to be removed, it is sent to a pathologist who will examine it under the microscope. The pathologist looks for evidence of retinoblastoma cells in the optic nerve, the deeper layers of the eye and in the front chamber of the eye. If any of these features are found, chemotherapy will then be considered
About 1 in 4 children who have an eye removed will require additional treatment with chemotherapy based on the pathology results. Your doctor will discuss this with you.
When chemotherapy is necessary after enucleation, a number of tests will be done to check that the tumour has not spread outside the eye. The investigations may include blood tests, a lumbar puncture to examine the cerebrospinal fluid (CSF) which surrounds the brain and spinal cord, and a bone marrow test. In some cases, an MRI scan of the head may be done. The paediatric oncologist will advise which tests are necessary and more information about these tests will be given to the parents.
Sometimes, when tumour cells are seen in the optic nerve, it is necessary to give both chemotherapy directly into the spinal fluid and radiotherapy to the socket, to help prevent retinoblastoma developing in the membranes covering the brain. Fortunately this is very rare.
If your child needs enucleation, you may find our advice leaflet from other parents of use.
Depending on the location of the tumour, solitary tumours can sometimes be treated with a radioactive plaque. This is a tiny piece of radioactive material which is attached to the outside lining of the eye to kill targeted cancerous cells inside.
If the child has treatment with a plaque, s/he will have to be nursed in a hospital side room for a few days, and close contact with other people will be limited because of the radioactive material used. Usually one parent is able to stay in the room with the child. Pregnant women and children are not allowed to visit during this period.
The child will need to remain in this room between 1-3 days; the exact time depends on the strength of the plaque and the amount of radiation that is required for the particular tumour being treated. The child will need to have a general anaesthetic so the plaque can be inserted and another one to remove the plaque.
If your child needs a radioactive plaque, you may find our advice leaflet from other parents of use.
External beam radiotherapy
Very occasionally it is necessary to consider external beam radiotherapy if other treatments have failed. This is given by a specialist known as a radiotherapist, or by a clinical oncologist who works in a radiotherapy centre. The treatment will be given on a daily basis over a period of 4 – 5 weeks, giving a total of about 20 treatments. The treatment is usually done on a daily out-patient basis, Monday to Friday.
The child will be given a general anaesthetic for the radiotherapy as it is essential that s/he remains perfectly still during the treatment. The actual treatment only lasts about 2 or 3 minutes each day, but there is a lot of preparation to make sure that the beam is directed accurately on the tumours in the retina.
In some children, it is possible to protect the lens of the eye during radiotherapy: this is known as lens-sparing radiotherapy.
Whole eye radiotherapy
Occasionally children may need to have the whole eye irradiated. This can lead to damage to the lens of the eye and the chance of developing a cataract during childhood.
Other side effects can include dry eye(s), and it may be necessary for the child to use lubricating eye drops and cream on a regular basis.
If your child needs radiotherapy, you may find our advice leaflet from other parents of use.
Proton beam therapy uses a high energy beam of protons rather than X-rays to deliver a dose of radiotherapy. The beams stop once they hit the target, rather than carrying on through the body. It can be a more effective form of radiotherapy as it causes minimal damage to surrounding tissue and a reduced risk of late side-effects.
Very occasionally, proton therapy may be considered the most appropriate treatment for a child with Rb. This treatment is currently available in the USA for children from the UK and patients must travel there for several weeks to receive treatment. However, this treatment will be available in the UK within the next few years. More information on proton therapy is available to download here.