Treatment of Retinoblastoma

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. 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. Close follow-up is needed for 2 years or more to check for signs of recurrence in the area around the eye.

Radiation Therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. 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 and stereotactic radiation therapy.
  • 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 them from dividing. The way the chemotherapy is given depends on the type and stage of the cancer being treated. Systemic chemotherapy— 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. Regional 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. Chemoreduction— Chemoreduction reduces the size of the tumor so it may be treated with local treatment (such as radiation therapy, cryotherapy, photocoagulation, or thermotherapy).

Clinical Trials

A 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. Because cancer in children is rare, taking part in a clinical trial should be considered. Some clinical trials are open only to patients who have not started treatment. New types of treatment are being tested in clinical trials.

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).

Ophthalmic arterial infusion therapy

Ophthalmic arterial infusion therapy is a type of regional chemotherapy used to deliver anticancer drugs directly to the eye. A catheter is put into an artery that leads to the eye and the anticancer drug is given through the catheter. During this treatment, a small balloon may be inserted into the artery to block it and keep most of the anticancer drug trapped near the tumor.

High-dose chemotherapy with stem cell transplant

High-dose chemotherapy with stem cell transplant is a way 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.

Biologic Therapy

Biologic therapy is a treatment that uses the patient’s immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body’s natural defenses against cancer. This type of cancer treatment is also called biotherapy or immunotherapy. Clinical trials for retinoblastoma are studying a biologic therapy called gene therapy. This is a treatment that changes a gene to improve the body’s ability to fight the disease.

Follow-up

Some of the tests that were done to diagnose the cancer or to find out the stage of the cancer may be repeated. Some tests will be repeated in order to see how well the treatment is working. Decisions about whether to continue change, or stop treatment may be based on the results of these tests. This is sometimes called re-staging. Some of the tests will continue to be done from time to time after treatment has ended. The results of these tests can show if your condition has changed or if the cancer has recurred (come back). These tests are sometimes called follow-up tests or check-ups.
 
Source
National Cancer Institute http://www.cancer.gov/cancertopics/types/retinoblastoma/