What Is Retinoblastoma?
Retinoblastoma is a rare childhood cancer of the eye. It starts in the retina, the nerve tissue in the back of the eye that is sensitive to light. When retinoblastoma stays in the eye, more than 95 percent of cases result in a cure.
- Doctors typically diagnose retinoblastoma before two years of age.
- More than 90 percent of cases are diagnosed by five years of age.
- It is equally common in boys and girls.
- The tumor may be present in one or both eyes and rarely spreads to other parts of the body.
- Retinoblastoma may be inherited within a family or may occur in a child without any family history of the disease.
- Retinoblastoma is rare. There are only about 250-300 cases in the United States each year.
Through our Retinoblastoma Program, children with retinoblastomas receive coordinated care from a team of oncologists, ophthalmologists, interventional radiologists, and other specialists with expertise in retinoblastoma. Dana-Farber/Boston Children's is an integrated pediatric oncology program that provides all the services of a leading cancer center and a world-renowned pediatric hospital.
We offer a full range of treatment options for retinoblastoma, including intra-arterial chemotherapy. This recently developed therapy can provide the most effective retinoblastoma treatment with the fewest side effects. Our neurointerventional radiology team carries out one of the highest volumes of pediatric brain and head and neck angiographic procedures, including intra-arterial chemotherapy, in the world.
Causes and Symptoms of Childhood Retinoblastoma
Retinoblastoma is genetic, which means that mutations in a gene cause it. These mutations prevent the body from making certain proteins that control how cells grow. When these proteins don’t develop correctly, too many cells can build up in one place and form a tumor.
While all retinoblastoma is genetic, only a proportion are hereditary. About 25 to 30 percent of retinoblastoma cases are hereditary. These children tend to develop tumors at a younger age and are more likely to have tumors in both eyes. Children with hereditary retinoblastoma are at higher risk of developing other tumors, including childhood tumors in the brain, osteosarcoma (a tumor of the bone), soft tissue sarcomas, and melanoma.
About 70 to 75 percent of retinoblastoma cases are nonhereditary, meaning that the child with the mutation doesn’t pass it on to future generations. This condition is known as “sporadic retinoblastoma.” It usually occurs in one eye. Children with nonhereditary retinoblastoma tend to develop tumors at a later age, and they do not have an increased risk of other tumors.
At Dana-Farber/Boston Children’s, we refer children with retinoblastoma to our Pediatric Cancer Genetic Risk Program. If genetic counselors identify hereditary retinoblastoma, they will provide further screening recommendations. We also test other family members through this program.
Retinoblastoma symptoms tend to develop before two years of age. The most common symptoms include:
- Leukocoria, causing the eye’s pupil to appear white instead of the expected red when light shines into it. This effect is also often seen in photos with a flash. Rather than the typical “red eye,” the pupil may appear white or distorted. It is the most common symptom of retinoblastoma. However, a doctor may make a diagnosis without it.
- Strabismus (also called “wandering eye” or “crossed eyes”) – one or both eyes don’t appear to be looking in the same direction.
- Nystagmus – involuntary movement of the eye(s).
- Poor vision or change in vision.
- (Rarely) pain or redness around the eye(s).
Other conditions can cause these symptoms. For example, a cataract can cause leukocoria and poor vision. It’s important always to see a specialist for a diagnosis.
How We Diagnose and Classify Childhood Retinoblastoma
The first step in treating your child is to obtain an accurate and complete diagnosis. In addition to a full medical history and physical examination, your child's doctor may order several tests to determine the cause of their symptoms. The tests are often performed under general anesthesia, so your child won't feel a thing.
Diagnostic tests may include:
- Complete eye (fundoscopic) examination performed while your child is under anesthesia. The doctor will dilate the pupils and look inside of the eye, including the retina and optic nerve.
- Magnetic resonance imaging (MRI) that will examine the orbits and brain.
- Ultrasound of the eye.
If your doctor suspects advanced disease, they may order additional specialized imaging such as a bone scan and studies such as a lumbar puncture and bone marrow evaluation. Patients don’t typically need a biopsy.
In addition to the physical exam and imaging procedures, our genetic counselors will discuss the possibility of taking a blood sample and running tests to look for an abnormal retinoblastoma gene. The results help us have an informed discussion with you about whether the condition in your child's case is hereditary.
During the diagnosis, your child's doctors will look to determine the size, number, location, and spread of the tumor or tumors. Your team will determine whether the retinoblastoma is intraocular (inside the eye) or extraocular (the cancer has also spread outside the eye). This is called staging. It is an important step in planning treatment.
After we complete all necessary tests, our experts meet to review and discuss what they have learned about your child's condition. Then we will meet with you and your family to discuss the results and to outline the best treatment options for your child.
How We Treat Childhood Retinoblastoma
We understand how difficult a diagnosis of retinoblastoma can be, both for your child and for your whole family. That's why our specialists are focused on family-centered care: from your first visit, you'll work with a team of professionals who are committed to supporting all of your family's physical and psychosocial needs. We'll work with you to create a care plan that's best for your child.
Treatments may include:
Intra-arterial chemotherapy is a relatively newer treatment for retinoblastoma in which the chemotherapy is injected directly into the main blood vessel of the eye (the ophthalmic artery). This treatment was designed to minimize the amount of contact the chemotherapy has with the rest of your child’s body so as to reduce side effects. Even though the total dose of chemotherapy injected is lower than in traditional IV treatment, the dose delivered directly into the eye is much higher, and so may eliminate more cancer cells in fewer treatments. The eye is uniquely suited to intra-arterial chemotherapy because the blood supply to the eye, in almost all cases, travels through just one feeding artery.
During this procedure, your child is put to sleep by an anesthesiologist. Then the surgeon inserts a thin catheter through a blood vessel in your child’s groin and feeds it up the arteries of the body to the ophthalmic artery. At this point, the chemotherapy is injected through the catheter directly into the eye. The average number of treatment sessions is three to four for each affected eye, delivered about every four weeks.
Because young children have smaller and more fragile arteries than adults, it is important that children who receive intra-arterial chemotherapy are treated at a pediatric-specific cancer center. At Dana-Farber/Boston Children’s, our interventional neuroradiologists have specialized expertise in working with children, including babies and toddlers, and our complication rates are the lowest published for comparable procedures performed at other centers, including both adult and pediatric centers.
Following the surgery, the eye is replaced with an orbital implant, and after the eye has healed, an artificial eye – made to match your child's healthy eye – can be worn. Some newer types of implants allow the artificial eye to move, but implants are not yet able to provide vision. Children who have an artificial eye can still participate in sports as long as they use proper protective eyewear.
While it is theoretically possible for the tumor to return even following this procedure, such cases would be extremely rare.
During cryotherapy, your child is first put to sleep by an anesthesiologist. Then the surgeon uses ultrasound to guide and place a small, extremely cold probe directly onto the tumor. The surgeon takes extreme care to ensure that the surrounding healthy tissue remains unharmed. Cryotherapy may be repeated on several occasions, if necessary.
An advantage of cryotherapy is that it may help prevent the need for enucleation or radiation therapy. The major disadvantages are that cryotherapy may leave a scar, which damages future vision, and that the procedure is not very effective in treating larger tumors.
- Intra-arterial chemotherapy: Traditional forms of treatment for retinoblastoma carry the risk of injuring the eye or causing ongoing symptoms. For these reasons, our retinoblastoma treatment team uses intra-arterial chemotherapy whenever it is the appropriate treatment.
- Chemoreduction: With chemoreduction, chemotherapy is given through an IV. It passes through your child's blood stream, and if successful, causes the tumors to shrink within a few weeks. Depending on which drugs your doctor prescribes, your child may or may not be hospitalized during treatment. Chemoreduction rarely, if ever, cures retinoblastoma when used alone, so additional treatments such as cryotherapy, thermotherapy, photocoagulation, or radiation also would be needed (see descriptions below).
- Surgery: We use surgery for children with advanced retinoblastoma that doesn't respond to other treatments. In these cases, the eye may need to be removed during a procedure called enucleation. Enucleation is a relatively simple operation that is performed while your child is under general anesthesia.
- Cryotherapy: Cryotherapy (sometimes called cryosurgery) applies extreme cold directly to the tumor and is used to treat small tumors or tumors that develop outside of the original tumor. Cryotherapy is often used together with chemotherapy, or it may be used after radiation therapy.
- Thermotherapy: Thermotherapy is a method of delivering heat to the eye using ultrasound, microwaves, or infrared radiation. Like cryotherapy, thermotherapy is only useful for very small tumors and can be combined with chemotherapy or radiation therapy. Thermotherapy leaves a relatively small scar and tends to preserve more vision than cryotherapy.
- Photocoagulation: Photocoagulation, also called light coagulation, is another method for treating small tumors. This technique uses focused light from a laser to destroy the tumor by destroying its blood supply. Photocoagulation is sometimes used in combination with chemotherapy.
- Radiation therapy: Radiation therapy is a cancer treatment that uses high-energy X-rays or other types of radiation to destroy cancer cells.
Dana-Farber/Boston Children’s also offers specialists who deliver integrative therapies. These treatments, which may help control pain and the side effects of therapy, include:
- Therapeutic touch
- Dietary recommendations
Talk to your child's team about whether integrative therapies might be a good option for your child.
Beyond treatment, we continue to care for your child through our pediatric survivorship programs. Services include annual visits to our clinic to manage disease complications and screen for recurrence, and counseling services ranging from psychological to nutritional support.