What is the primary purpose of intrathecal chemotherapy in pediatric patients?

• A. CNS prophylaxis or treatment
• B. To treat systemic infections
• C. To promote blood formation
• D. To manage mucositis

Answer: (A)

Delivering chemotherapy directly into the cerebrospinal fluid is done to reach the central nervous system because the blood-brain barrier prevents many systemic drugs from reaching CSF in sufficient amounts. The main goal is CNS prophylaxis or treatment, preventing or addressing leukemia or cancer spread within the CNS, which is a common concern in pediatric patients with diseases like ALL. Intrathecal chemotherapy thus targets disease in the CNS rather than systemic infections, bone marrow formation, or mucosal toxicity. Systemic infections are treated with antibiotics, promoting blood formation isn’t achieved by this route, and mucositis is a side effect or consequence of chemotherapy rather than a purpose of intrathecal delivery.