Retinoblastoma is a disease in which malignant (cancer) cells form in the tissues of the retina.

The retina is the nerve tissue that lines the inside of the back of the eye. The retina senses light and sends images to the brain by way of the optic nerve.

Although retinoblastoma may occur at any age, it usually occurs in children younger than 5 years of age. The tumor may be in one eye or in both eyes. Retinoblastoma rarely spreads from the eye to nearby tissue or other parts of the body. Retinoblastoma is usually found in only one eye and can usually be cured.

Retinoblastoma is sometimes caused by a gene mutation passed from the parent to the child.

Retinoblastoma is sometimes inherited (passed from the parent to the child). Retinoblastoma that is caused by an inherited gene mutation is called hereditary retinoblastoma. It usually occurs at a younger age than retinoblastoma that is not inherited. Retinoblastoma that occurs in only one eye is usually not inherited. Retinoblastoma that occurs in both eyes is always inherited. When hereditary retinoblastoma first occurs in only one eye, there is a chance it will develop later in the other eye. After diagnosis of retinoblastoma in one eye, regular follow-up exams of the healthy eye should be done every 2 to 4 months for at least 28 months. After treatment for retinoblastoma is finished, it is important that follow-up exams continue until the child is 7 years of age.

Treatment for both types of retinoblastoma should include genetic counseling (a discussion with a trained professional about inherited diseases). Brothers and sisters of a child who has retinoblastoma should also have regular check-ups and genetic counseling about the risk of developing the cancer.

Warning Signs

Possible signs of retinoblastoma include "white pupil" and eye pain or redness.

These and other symptoms may be caused by retinoblastoma. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur:

  • Pupil of the eye appears white instead of red when light shines into it. This may be seen in flash photographs of the child.
  • Eyes appear to be looking in different directions.
  • Pain or redness in the eye.

Tests that examine the retina are used to detect (find) and diagnose retinoblastoma.

The following tests and procedures may be used:

  • Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken. The doctor will ask if there is a family history of retinoblastoma.
  • Eye exam with dilated pupil: An exam of the eye in which the pupil is dilated (opened wider) with medicated eyedrops to allow the doctor to look through the lens and pupil to the retina. The inside of the eye, including the retina and the optic nerve, is examined with a light. Depending on the age of the child, this exam may be done under anesthesia.
  • Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram.
  • CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, such as the eye, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
  • MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body, such as the eye. This procedure is also called nuclear magnetic resonance imaging (NMRI).

Retinoblastoma is usually diagnosed without a biopsy (removal of cells or tissues so they can be viewed under a microscope to check for signs of cancer).

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) and treatment options depend on the following:

  • The stage of the cancer.
  • How likely it is that vision can be saved in one or both eyes.
  • The size and number of tumors.
  • Whether trilateral retinoblastoma occurs.

After retinoblastoma has been diagnosed, tests are done to find out if cancer cells have spread within the eye or to other parts of the body.

The process used to find out if cancer has spread within the eye or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment. The following tests and procedures may be used in the staging process:

  • Eye exam with dilated pupil: An exam of the eye in which the pupil is dilated (opened wider) with medicated eyedrops to allow the doctor to look through the lens and pupil to the retina. The inside of the eye, including the retina and the optic nerve, is examined using a light. Depending on the age of the child, this exam may be done under anesthesia.
  • Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram.
  • CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, such as the eye, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
  • MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body, such as the eye. This procedure is also called nuclear magnetic resonance imaging (NMRI).
  • Lumbar puncture: A procedure used to collect cerebrospinal fluid from the spinal column. This is done by placing a needle into the spinal column. This procedure is also called an LP or spinal tap. A lumbar puncture may be done if tests show that the cancer may have spread out of the eye.

There are several staging systems for retinoblastoma. For treatment, retinoblastoma is classified as intraocular (within the eye) or extraocular (outside the eye).

The following stages are used for retinoblastoma:

Intraocular retinoblastoma

Cancer is found in the eye but has not spread to tissues around the outside of the eye or to other parts of the body.

Extraocular retinoblastoma

The cancer has spread beyond the eye. It may be found in tissues around the eye or it may have spread to the central nervous system (brain and spinal cord) or to other parts of the body.

Treatment Option Overview

Different types of treatment are available for patients with retinoblastoma. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. Before starting treatment, patients may want to think about taking part in a clinical trial. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.

Some cancer treatments cause side effects months or years after treatment has ended.

Some cancer treatments cause side effects that continue or appear months or years after cancer treatment has ended. These are called late effects. Late effects of cancer treatment may include physical problems; changes in mood, feelings, thinking, learning or memory; and second cancers (new types of cancer.) Some late effects may be treated or controlled. It is important to talk with your child's doctors about the possible late effects caused by some treatments.

Six types of standard treatment are used:

Enucleation

Enucleation is surgery to remove the eye and part of the optic nerve. The eye will be checked with a microscope to see if there are any signs that the cancer is likely to spread to other parts of the body. This is done if the tumor is large and there is little or no chance that vision can be saved. The patient will be fitted for an artificial eye after this surgery.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, plaques, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated. Methods of radiation therapy used to treat retinoblastoma include the following:

  • Intensity-modulated radiation therapy (IMRT): A type of 3-dimensional (3-D) radiation therapy that uses a computer to make pictures of the size and shape of the tumor. Thin beams of radiation of different intensities (strengths) are aimed at the tumor from many angles. This type of radiation therapy causes less damage to healthy tissue near the tumor.
  • Stereotactic radiation therapy: Radiation therapy that uses a rigid head frame attached to the skull to aim high-dose radiation beams directly at the tumors, causing less damage to nearby healthy tissue. It is also called stereotactic external-beam radiation, stereotactic radiosurgery, and stereotaxic radiosurgery. This procedure does not involve surgery.
  • Proton beam radiation therapy: Radiation therapy that uses protons made by a special machine. A proton is a type of high-energy radiation that is different from an x-ray.
  • Plaque radiotherapy: Radioactive seeds are attached to one side of a disk, called a plaque, and placed directly on the outside wall of the eye near the tumor. The side of the plaque with the seeds on it faces the eyeball, aiming radiation at the tumor. The plaque helps protect other nearby tissue from the radiation.

Cryotherapy

Cryotherapy is a treatment that uses an instrument to freeze and destroy abnormal tissue, such as carcinoma in situ. This type of treatment is also called cryosurgery.

Photocoagulation

Photocoagulation is a procedure that uses laser light to destroy blood vessels to the tumor, causing the tumor cells to die. Photocoagulation may be used to treat small tumors. This is also called light coagulation.

Thermotherapy

Thermotherapy is the use of heat to destroy cancer cells. Thermotherapy may be given using a laser beam aimed through the dilated pupil or onto the outside of the eyeball, or using ultrasound, microwaves, or infrared radiation (light that cannot be seen but can be felt as heat).

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ (such as the eye), or a body cavity (such as the abdomen), the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.

A form of chemotherapy called chemoreduction is used to treat retinoblastoma. Chemoreduction reduces the size of the tumor so it may be treated with local treatment (such as radiation therapy, cryotherapy, photocoagulation, or thermotherapy).

New types of treatment are being tested in clinical trials. These include the following:

Subtenon chemotherapy

Subtenon chemotherapy is the use of drugs injected through the membrane covering the muscles and nerves at the back of the eyeball. This is a type of regional chemotherapy. It is usually combined with systemic chemotherapy and local treatment (such as radiation therapy, cryotherapy, photocoagulation, or thermotherapy).

High-dose chemotherapy with stem cell transplant

High-dose chemotherapy with stem cell transplant is a method of giving high doses of chemotherapy and replacing blood-forming cells destroyed by the cancer treatment. Stem cells (immature blood cells) are removed from the blood or bone marrow of the patient or a donor and are frozen and stored. After the chemotherapy is completed, the stored stem cells are thawed and given back to the patient through an infusion. These reinfused stem cells grow into (and restore) the body's blood cells.

Treatment Options for Retinoblastoma

Intraocular Retinoblastoma
Extraocular Retinoblastoma
Recurrent Retinoblastoma



Intraocular Retinoblastoma

If the cancer is in one eye and the tumor is large, treatment is usually enucleation.

If the cancer is in one eye and it is expected that vision can be saved, treatment may include the following:

  • Radiation therapy.
  • Photocoagulation.
  • Cryotherapy.
  • Thermotherapy.
  • Chemotherapy (chemoreduction).

If the cancer is in both eyes, treatment may include the following:

  • Enucleation of the eye with the most cancer, and radiation therapy to the other eye.
  • Radiation therapy to both eyes or chemotherapy (chemoreduction) followed by local treatment. This may be done if there is a chance to save vision in both eyes.
  • Surgery only, when vision cannot be saved.
  • A clinical trial of subtenon chemotherapy combined with systemic chemotherapy and local treatment.

Extraocular Retinoblastoma

There is no standard treatment for extraocular retinoblastoma. Radiation therapy and chemotherapy have been used. Treatment may be a clinical trial of high-dose chemotherapy with stem cell transplant.

Recurrent Retinoblastoma

Recurrent retinoblastoma is cancer that has recurred (come back) after it has been treated. The cancer may recur in the eye, in tissues around the eye, or in other places in the body. Tumors that were not treated with radiation therapy or surgery commonly recur, usually within 6 months.

If the cancer is small and in the eye only, treatment is usually local therapy (enucleation, radiation therapy, cryotherapy, photocoagulation, or thermotherapy).

 

Source:  National Cancer Institute