Ambulatory high-dose methotrexate administration among pediatric osteosarcoma patients in an urban, underserved setting is feasible, safe, and cost-effective

Background: We describe the safety, feasibility, and provide a cost-estimate of outpatient high-dose methotrexate administration (HDMTX) among an urban, underserved population. Procedure: A retrospective analysis of ambulatory HDMTX administration among osteosarcoma patients, at Montefiore Medical Center's Children's Hospital (Bronx, NY) was performed. HDMTX (12g/m ²) was given intravenously (IV) over 4hr after urine alkalinization. Patients were discharged home to continue IV hydration and alkalinization delivered via a home infusion pump. Families were instructed to monitor urine pH overnight and management was adjusted according to our institution's treatment algorithm until MTX level ≤0.1μmol/L. A cost estimate was performed to assess the difference in costs for outpatient versus hypothetical inpatient administrations. Results: Of the 97 ambulatory HDMTX administrations, 99% were successfully completed. One patient failed outpatient administration secondary to home infusion pump malfunction. This patient successfully completed subsequent courses as an outpatient. Most patients (72%) had a MTX level of <10μmol/L at 24hr post-HDMTX. No patients were found to have a MTX level of >50μmol/L at 24hr. About 26% of courses were associated with grade III or IV neutropenia, 4% were associated with grade III or IV thrombocytopenia and 1% were associated with grade III/IV leukopenia. Compared to a hypothetical hospital inpatient stay, the hospital costs for ambulatory HDMTX were an average of $1400 less per cycle. Conclusion: Ambulatory HDMTX administration among an underserved, urban population is safe, feasible, and cost-effective.