What is intra-arterial chemotherapy (IAC) for retinoblastoma?

Retinoblastoma is a rare childhood cancer that originates in the layer of nerve tissue that coats the back of the eye (the retina). Intra-arterial chemotherapy (IAC) is a method of delivering concentrated doses of cancer-killing medicine directly to the affected area of the eye.

In IAC, the chemotherapy dose is released into the ophthalmic artery, the primary blood supply at the back of the eye. While the patient is sedated, a very thin catheter (a long, flexible tube) is inserted into an artery in the hip and fed through the body’s network of arteries to the opening of the ophthalmic artery, behind the eye, where the chemotherapy dose is given.

In most cases, three IAC treatments are administered, spaced four weeks apart. The patient is then monitored to see that the cancerous cells have been eliminated and that they do not return.

What are the benefits of treatment with IAC for retinoblastoma?

There are several ways to treat retinoblastoma, and more than one treatment method may be used in an individual patient.

Until the 1990s, the standard treatment was radiation therapy or surgical removal of the affected eye. Advances in treatment have improved outcomes by expanding the range of options to include cryotherapy and thermotherapy (precise methods of destroying cancer cells with extreme cold and heat), plaque radiotherapy (carefully controlled and targeted doses of radiation using a surgically inserted radioactive plaque) and different means of chemotherapy.

Chemotherapy can be delivered to the entire body with intravenous injections. This is called systemic chemotherapy and is usually recommended by our team in cases of bilateral retinoblastoma. Treatment plans are developed together with our ophthalmology partners at Wills Eye Hospital. Systemic chemotherapy is also indicated when cancer is in many places in the body, as can be the case when retinoblastoma has spread beyond the eyes.

We believe that IAC is most effective in cases where the retinoblastoma is in one eye (unilateral), and there is no indication of cancer beyond that eye. It is used in newly diagnosed cases when the cancer is found in one eye, and as a second-line treatment, after other treatment methods have been used.

With IAC and other treatments, the survival rate for children in the United States with retinoblastoma is close to 100 percent, and the majority of those children retain both eyes with vision. The eye salvage rate varies with the amount of the cancer in the eye at the time of diagnosis.