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CNS-Directed Systemic Chemotherapy
Source: Childhood Acute Lymphoblastic Leukemia Treatment (PDQ®)–Health Professional Version, National Cancer Institute.
Source updated: April 21, 2025 · Captured 2026-09-09.
Selected source text with whitespace normalised. This Triangle page is not an NCI PDQ summary.
Context: Central Nervous System (CNS)-Directed Therapy for Childhood ALL
In addition to therapy delivered directly to the brain and spinal fluid, systemically administered agents are also an important component of effective CNS prophylaxis. The following systemically administered drugs provide some degree of CNS prophylaxis:
Dexamethasone.
L-asparaginase (does not penetrate into CSF itself, but leads to CSF asparagine depletion).[7]
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High-dose methotrexate with leucovorin rescue.
Escalating dose intravenous (IV) methotrexate without leucovorin rescue.
Evidence (CNS-directed systemic chemotherapy):
In a randomized Children's Cancer Group (CCG) study of standard-risk patients who all received the same dose and schedule of intrathecal methotrexate without cranial irradiation, oral dexamethasone was associated with a 50% decrease in the rate of CNS relapse compared with oral prednisone.[8]
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In another standard-risk ALL trial (COG-1991), escalating dose IV methotrexate without leucovorin rescue significantly reduced the CNS relapse rate compared with standard, low-dose, oral methotrexate given during each of two interim maintenance phases.[9]
In a randomized clinical trial conducted by the former Pediatric Oncology Group, T-ALL patients who received high-dose methotrexate experienced a significantly lower CNS relapse rate than did patients who did not receive high-dose methotrexate.[10]
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Studies cited in this source section
Source citation is not a determination that a study applies to you.
Publication references
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Preserved source evidence · Not medical advice