الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Acute lymphoblastic leukemia (ALL) is the most common malignancy in children and adolescents, accounting for the majority of cancer-related fatalities in this age range. The current focus is on maintaining high ALL survival rates while reducing treatment-related long-term toxicity.
Methotrexate (MTX) courses, given either by short IV infusion or at high dosages over 24 hours, followed by folinic acid administration to ”rescue” normal tissues from toxic effects, are a fundamental component of modern ALL regimens. High-dose methotrexate therapy (HDMTX) was first used to improve penetration into sanctuary sites such as the CNS and testicular tissue as well as to overcome cellular resistance to the drug.
Despite its effectiveness, HDMTX therapy has the potential to induce significant toxicity, resulting in not only morbidity and mortality, but also the interruption of cancer treatment, potentially resulting in poor anticancer results. Plasma MTX concentrations after an HDMTX infusion with a fixed dose and duration can vary significantly across patients and within a patient on various cycles. It is still debatable whether testing plasma MTX concentrations after HDMTX can predict different toxicities.
Moreover, resource-limited settings face practical difficulties in MTX monitoring as the non-availability of the test and the long turnaround time when samples were transferred to another laboratory.
The aim of the present study was to investigate the relationship between plasma methotrexate levels (at 6 hours, 24 hours, and 42 hours after the start of HDMTX infusion) in children with ALL during the first cycle of consolidation of TOTAL XV protocol and the occurrence of toxicity. In addition, the toxicity of different doses of HDMTX were compared according to risk stratification (Low-risk: 2.5 g/m2 vs. standard/high-risk: 5 g/m2) in the four cycles of consolidation.