What is Intrathecal Chemotherapy?

Intrathecal chemotherapy is the use of powerful medicines to treat cancer that has reached the central nervous system, such as brain tumors and some forms of leukemia and lymphoma. Medications given by mouth or through the vein typically cannot get past the blood-brain barrier, which protects the brain and spinal cord from certain foreign substances. Intrathecal chemotherapy bypasses this barrier by delivering drugs directly into the spinal fluid, targeting cancer cells found there. Currently, methotrexate and cytarabine are the only drugs approved for this type of chemotherapy.

Intrathecal chemotherapy can be given by inserting a needle between two bones in the lower spine (called vertebrae). This procedure is called lumbar puncture. When you go in for your treatment, your nurse will ask you to get in a position so that there is enough room between your vertebrae. She may ask you to sit with your arms, chest, and head resting on a table in front of you, or lie on your side, curled up with your knees bent. Then, she will determine the best place to insert the needle by feeling your back. You will not feel pain during the injection, as you will be given numbing medicine beforehand. The nurse will ask you to lay flat on your back for 30 minutes to an hour after your injection.

If you need frequent visits to receive intrathecal chemotherapy, your doctor may recommend using an Ommaya reservoir. This device has a small port that is surgically implanted under your scalp. One end of a thin, flexible tube is connected to the port, while the other end is placed into a ventricle, which is a space in your brain where spinal fluid is produced. When anti-cancer medication is injected into the port under your scalp, it will go directly into this fluid. Surgery to implant the Ommaya reservoir is done in an operating room, and you will be asleep throughout the one-hour procedure.

As with other anti-cancer medication delivery methods, you may experience one or more of the following side effects: fatigue, nausea, vomiting, headaches, and fever. Not everyone who receives intrathecal chemotherapy reacts to it in the same way. You may be asked to keep a daily log of any side effects you experience, along with details like how frequently they occur and how severe they are. Communicating with your doctor about the way your body is responding to the medication can help her better customize your chemotherapy regimen.