What is the treatment ?
Various modalities are available for the treatment of retinoblastoma. The treatment depends upon various factors such as size of the tumor, type and whether the tumor involves one eye or both.
There are two staging systems used for treating retinoblastoma. They are intraocular retinoblastoma and extraocular retinoblastoma. In intraocular retinoblastoma the cancer is still only in the eye, whether in the retina or in other parts of the eye, but it hasn’t spread to the tissues around the outside of the eye or other parts of the body.
Extraocular retinoblastoma can spread beyond the eye to tissues around the eye or brain, or to other parts of the body such as bone marrow or lymph nodes.
Small tumors can be treated without surgery. Vision is usually saved when tumors are small, hence the importance of early diagnosis.
Various treatments in retinoblastoma are:
- Laser photocoagulation, which uses laser beams to heat and destroy the tumor cells. Argon or diode lasers are used for this purpose. Lasers are effective only in small tumors. It may require three treatments to completely shrink the tumor.
- Cryotherapy with the help of a probe kills the tumor cells by freezing them. The probe is cooled to a very low temperature with the help nitrous oxide or carbon dioxide gas. The probe is applied on the surface of the eye corresponding to the site of the tumor.
- Chemotherapy involves use of anticancer drugs that are given orally or intravenously to kill the cells. Chemotherapy alone is tried initially for tumors present at macula, the central part of retina, which is critical for vision. This treatment is used to shrink larger tumors and to facilitate other treatments. It’s also used if the tumor has spread beyond the eye.
- Radiotherapy involves destroying the tumor cells with radiation. Brachytherapy (internal radiation) uses implantation of radioactive plaques into the eye to destroy the tumor. Radioactive plaques are removed after some days. Brachytherapy is used in small and medium-sized tumors.
- External radiation uses radioactive beams from a radiation machine to destroy the tumor. External radiation has lots of adverse effects such as retarded growth of bones surrounding the eye, deficiency of growth hormone and other effects on the brain, and cataracts, etc. Newer technologies have reduced the incidence of these adverse effects. External radiation is indicated in progressive diseases despite adequate chemotherapy and if the tumor spreads beyond the optic nerve.
- Enucleation, surgical removal of the eye, is the treatment of choice when the tumor has already destroyed the eye’s visual potential. Enucleation is appropriate when the other eye is not involved. An artificial implant is put in the bony cavity (orbit) after removal.
- Exenteration, an extensive surgery in which the eye and the contents of the orbit are removed if the tumor has spread in the orbit.
During the treatment for retinoblastoma, a child will need periodic examinations of the eyes to ensure the effectiveness of the treatment.
Recurrent retinoblastoma is a cancer that can return or continues to grow after the treatment is completed. This can affect the eye, tissues surrounding it or any other part of the body. Children with hereditary cases of retinoblastoma are more likely to develop new tumors years after the treatment. Therefore, follow-ups are important, and you shouldn’t skip them.
What is the prognosis of retinoblastoma ?
Usually, 90 percent of children affected with retinoblastoma survive the disease and lead a perfectly normal life. There’s a risk of death only when the tumor spreads beyond the eyes.