Patient population
During the study period, 196 HD-MTX doses were administered to 46 unique patients. Overall, patients included in the analysis were 39% non-Latino White, 33% Latino, and 24% non-Latino Black (Table 1). The mean age of the cohort was 10.5 years at diagnosis, and a majority patients were male (n=34; 74%). The most common oncologic diagnosis was anaplastic large cell lymphoma (ALCL; n=25, 54%), followed by 21 patients (46%) with mature B-NHL, and one patient with peripheral T-cell lymphoma, NOS. The median number of HD-MTX doses per patient was 4 (range: 1 to 6). All patients were treated on or according to one of the following protocols: ALCL99, ANHL12P1, ANHL01P1, and ANHL1131.[8, 10, 12, 13] All patients received protocol-defined supportive care as previously described,[8, 10, 12, 13] including intravenous hydration with alkalinized intravenous fluids, urine pH and output goals, scheduled leucovorin rescue, serum creatinine trending, and methotrexate serum level monitoring at hours 24, 48 and at least every 24 hours until methotrexate level <0.1 or 0.15 μM/L (per protocol). Supportive care interventions for methotrexate clearance were adjusted to achieve therapeutic goals per institutional practice or clinical trial protocol. Patients were counseled on good oral care and given a salt and soda mouthwash for mucositis prevention. Forty-one patients were alive at the time of data extraction (89%). No patient died due to methotrexate-related toxicity.