Chemotherapy may be injected directly into cerebrospinal fluid bathing the brain and spine.
The blood‑brain barrier reduces chances of medication reaching the central nervous system (brain and spine), so intrathecal chemotherapy may be more effective than delivering the same drugs into a vein.
Intrathecal chemotherapy is given by means of a lumbar puncture or through an ommaya reservoir.
Lumbar Puncture
A hollow needle is inserted between two vertebrae in the lower spine into the subarachnoid space where cerebrospinal fluid is found. After a CSF sample has been collected, a syringe will be attached to the needle, containing chemotherapy. As the drugs are slowly injected, your child will have a sensation of cold or pressure down one leg, but this does not hurt.
For a full explanation of a lumbar puncture, click here.
Ommaya Reservoir
An ommaya reservoir is surgically placed by a neurosurgeon, under general anaesthetic. A catheter is inserted in a ventricle of the brain, and attached to a reservoir implanted under the scalp. Chemotherapy can then be delivered painlessly, and CSF samples taken for analysis.
Awake or Under Anaesthetic
A lumbar puncture to administer chemotherapy may be done during a routine EUA. When it is not done during EUA, your child may still be given a short acting anaesthetic or sedation during the procedure. With good child life support, even young children can complete this procedure awake.
If your child is awake during the procedure, a topical anaesthetic like EMLA will be used to numb the lumbar puncture site. Different topical anaesthetics require application at different times to ensure they take effect before the procedure. Make sure you understand the timing instructions.
Chemotherapy can be delivered through an ommaya reservoir while awake as it does not hurt. However, good child life support is still important to keep your child calm during the procedure.
After the Procedure
Some children experience severe headaches after a lumbar puncture or Ommaya chemotherapy. These may occur whether your child’s procedure was done awake or under sedation or general anaesthetic.
Pain is made worse by leaning forward, but are usually relieved or prevented completely by laying still for 30-60 minutes after the procedure.
