High-dose methotrexate in childhood all

Area of Science:

• Pediatric Oncology
• Hematology
• Neuro-oncology

Background:

• Acute lymphocytic leukemia (ALL) survival rates are high, but long-term therapy side effects remain a challenge.
• Cranial irradiation, once standard for CNS prophylaxis in ALL, is linked to secondary malignancies and neurotoxicities.
• Methotrexate-based chemotherapy is now preferred for CNS prophylaxis in ALL.

Purpose of the Study:

• To evaluate the efficacy and safety of high-dose methotrexate for central nervous system (CNS) prophylaxis in acute lymphocytic leukemia (ALL).
• To compare methotrexate-based CNS prophylaxis with cranial irradiation in pediatric ALL patients.

Main Methods:

• Review of historical and recent ALL treatment protocols focusing on CNS prophylaxis strategies.
• Analysis of data from studies utilizing intermediate and high-dose methotrexate (intrathecal and intravenous) for CNS prophylaxis.
• Comparison of CNS relapse rates and neurotoxicity profiles between methotrexate and cranial irradiation groups.

Main Results:

• High-dose methotrexate (5-8 g/m2) combined with intrathecal administration significantly reduces CNS relapse rates in ALL.
• Studies show CNS relapse rates as low as 2.2% with high-dose methotrexate, compared to historical rates with irradiation.
• High-dose methotrexate, when irradiation is avoided, is associated with manageable adverse effects like mucositis and myelosuppression, unlike the neurotoxicities of cranial irradiation.

Conclusions:

• High-dose methotrexate is a safe and effective alternative to cranial irradiation for CNS prophylaxis in pediatric ALL.
• Methotrexate-based regimens minimize long-term neurotoxicities and secondary malignancies associated with cranial irradiation.
• Careful monitoring and supportive care, including folinic acid rescue, are crucial for managing methotrexate therapy.