Intravitreal Chemotherapy Injection (IViC)
Intravitreal chemotherapy describes injection of anti-cancer drugs directly into the eye’s fluid-filled core.
When Intravitreal chemotherapy Injection Is Used
Primary treatments for retinoblastoma usually fail due to unresponsive vitreous seeds – fragments of cancerous cells that break off the main tumour and float into the fluid-filled centre of the eye.
Intravitreal chemotherapy is used to treat seeds of tumour that have survived other therapies. Used in combination with other treatments, injections only begin after the main tumour producing the seeds is controlled.
Intravitreal chemotherapy is best used in the context of a clinical trial that will carefully document the potential benefits and complications.
How Intravitreal chemotherapy Injection Is Given
The child receives a general anaesthetic.
A detailed ultrasound may be used to check that the injection site is tumour-free before delivery of intravitreal chemotherapy.
Pressure inside the eye is lowered by removing a small amount of fluid from the front of the eye, or by massaging the eye with the finger.
Chemotherapy (melphalan alone or combined with topotecan) is injected into the vitreous with a small needle.
On withdrawing the needle, the injection site is sealed and sterilized with cryotherapy and the eye is gently manipulated to distribute the chemotherapy.
Anti-cancer drugs can be delivered directly into the vitreous humour of the eye to treat resistant seeds, without the side effects associated with systemic chemotherapy.
There is a theoretical risk of the tumour spreading along the needle track and outside the eye. This is the reason retinoblastoma is never biopsied to confirm diagnosis.
Toxicity is potential damage to retina exposed to too high a dose of drug. Toxicity is minimal when the dose of drugs and techniques for delivery follow published guidelines.
Complications may include failure to recognize, and therefore inadequately treat, the source of the seeds, which can then continue to seed and even extend outside the eye.
Questions To Ask the Doctors
- Is this treatment part of a clinical trial?
- Can I have a copy of the clinical trial protocol?
- How many times have you done this procedure?
- What side effects have you observed?
- What side effects have been reported?
- How many of your patients relapsed with cancer outside their eye after IViC?
- How do you know there is no risk to my child’s life in doing IViC?
- What chemotherapy drugs will you use?
- Will my child need more than one IViC treatment?
- How often will you treat the eye/s?
- Will my child receive other treatments in combination with IAC?
- How will you combine these treatments?
- How might this treatment impact my child’s vision?
- What follow-up care will my child receive?
- Will my child be followed by a paediatric oncologist?