Treatment for retinoblastoma in children has two main goals: to prevent the return of the cancer and to preserve vision. Several types of therapies are used for retinoblastoma, and 99% of children can be cured.
Types of Retinoblastoma Treatment
This is chemotherapy given into a vein. Systemic chemotherapy helps to shrink tumors in the eye. The use of systemic chemotherapy often makes it possible to completely eliminate smaller tumors, in combination with other measures such as:
- Photocoagulation: using laser light to destroy blood vessels that supply nutrients to the tumor
- Thermotherapy: using heat to destroy cancer cells
- Cryotherapy: using extreme cold to destroy cancer cells
- Radioactive (iodine) plaque: placing a radioactive patch in the retina; the patch is removed after the tumor has received a specific dose of radiation
Systemic chemotherapy is also used after surgical removal of the eye (see below) when the tumor has advanced into the deep layers of the eye or into the optic nerve, and when the retinoblastoma has spread outside of the eye.
Chemotherapy may also be delivered locally to the eye. This can be done by an ophthalmologist who specializes in retinoblastoma. Sometimes the ophthalmologist can inject chemotherapy using a needle into structures of the eye. This is sometimes called subtenon or intravitreal chemotherapy. Sometimes a specialist called a neuroradiologist places a catheter into the artery of the eye for the opththalmologist to inject chemotherapy. In this case, the neuroradiologist introduces the catheter into an artery in the groin area and guides it under X-ray guidance all the way into an artery in the eye. This is called intra-arterial chemotherapy. Sometimes this is given in addition to systemic chemotherapy and sometimes it is used alone.
Doctors will use uses X-rays or other high-energy particles to destroy cancer cells and shrink tumors. Depending upon the dose, radiation can interfere with normal growth, including growth of the bones around the eye (orbit). The use of radiation can also increase the risk of tumors later in life for children with the genetic form of retinoblastoma. Sometimes retinoblastoma tumors are treated with radiation by placing a radioactive plaque outside the eye, immediately behind where the tumor is, for several hours so that a given dose of radiation can be administered locally.
In some cases, doctors will need to remove the eye in order to eliminate the cancer. This process is called enucleation. This is the treatment most often used when:
- The ocular oncologist determines that there is no hope of saving vision in the eye.
- The tumor does not respond to treatment.
- There is permanent damage to the retina.
Enucleation is a surgical procedure performed under general anesthesia. It generally takes about one hour and most children are discharged to home the same day. After the eyeball is removed, a device called an orbital implant is sometimes inserted into the socket. Then, a thin plastic plate called a temporary conformer is inserted. The conformer helps to maintain the shape of the eye and avoids a shrunken appearance. The eye is then covered with a special patch for 12 hours to help decrease swelling. The child may experience pain or discomfort for a short time following the enucleation, but this is usually controlled with pain medication.
For children who undergo enucleation, most will receive an artificial eye. About 6 weeks after surgery, the orbit will be healed and an artificial eye can be fitted. This eye, called an ocular prosthesis, is made of plastic and is molded to fit the inside of the eyelid. The color and appearance are made to match the other eye, so that it looks natural. The prosthesis is important because in addition to the cosmetic benefits, it allows the eyelid to open and close normally.
Often, the child will experience some tearing and mucous build-up with the prosthesis. The build-up is easily cleaned with water. It is recommended that the prosthesis be removed and cleaned thoroughly about every 3 months. A new prosthesis will be needed periodically until the child’s facial bones are fully grown.