Intrathecal chemotherapy is a method of administering chemotherapy drugs to treat cancer. With this method, the medications are injected directly into the cerebrospinal fluid that exists in the tissues that surround the spinal cord and brain. This type of chemotherapy is used for leptomeningeal spread, which is when the cancer has spread to the central nervous system. Intrathecal chemotherapy will only be effective before tumors have begun to grow in the spinal cord or brain.
Chemotherapy works by stopping the spread of cancer cells by preventing them from growing and dividing. The body cannot fight off cancer cells by itself because they multiply at an accelerated rate. A drawback to chemotherapy is that it also attacks the body’s healthy cells. Unlike most chemotherapy medicines, intrathecal chemotherapy drugs are able to penetrate through the blood-brain barrier, or the barrier between the central nervous system and the bloodstream. An example of an intrathecal chemotherapy drug is called Methotrexate.
This method of chemotherapy can be administered in two different ways: by intralumbar injection or via an Ommaya reservoir. An intralumbar injection, also called a lumbar injection, is administered with a needle into the spine. This type of injection may be painful. Caregivers may use local anesthesia to numb the area before administering this injection.
Using an Ommaya reservoir requires surgery. An area of the head will be shaved. Then, while the patient is under anesthesia, the reservoir will be inserted underneath the scalp. Patients may notice a raised area on the head following this procedure. Medication can then be administered via a small needle at the top of the Ommaya reservoir.
A patient’s chemotherapy may be administered in cycles. After receiving chemotherapy drugs for a period of time determined by the caregiver, the patient can then have a respite. The purpose of this respite is to let the body develop new, healthy cells.
Every patient’s chemotherapy needs are different. The doctor will determine whether the patient needs intrathecal chemotherapy on a daily, weekly, or monthly basis. Some patients may receive a combination of different chemotherapy drugs, which may shorten the length of treatment.
The administration of intrathecal chemotherapy poses several risks to the patient. Unlike oral chemotherapy, this method may result in the medications leaking into other parts of the body. This means that the chemotherapy may not target the cancer as effectively. The patient could also experience a dangerous build-up of drugs in the spinal fluid. If an Ommaya reservoir is used, it may become blocked or twisted, which requires surgery to correct.
Other risks of intrathecal chemotherapy include an infection in the spinal cord. It can also cause an increased sensitivity of the eyes to light. Patients should carefully discuss the possible risks and side effects of this course of treatment with their doctor.
Not all patients will experience the same side effects, however, some common side effects are extreme, long-lasting fatigue; sores in the mouth or throat; and severe headache pain. Patients may also lose their appetite, develop sexual problems, and experience abnormal moods or memory. Chemotherapy can also cause blurred vision and dizziness. Patients may reduce dizziness and balance problems by lying down for several hours after treatment. Despite the side effects of chemotherapy, living with untreated cancer can be far worse.