Outpatient administration of high-dose methotrexate for osteosarcoma treatment in Brazil

10038 Background: We describe the experience with outpatient administration of high dose methotrexate (HDMTX) and leucovorin rescue for osteosarcoma treatment at Instituto de Oncologia Pediatrica. Methods: HDMTX (12g/m2) is administered as part of the Brazilian Osteosarcoma Treatment Group Protocol in an ambulatory basis. Daily MTX serum levels and fluid controls follows until the serum level is <0,2 μ/L. Families were oriented to measure urinary pH and volume, PO intake and to adjust leucovorin dose as needed. To achieve treatment adherence, a family education program was developed. Concomitantly to HD chemotherapy, low dose oral cyclophosphamide and MTX (metronomic treatment) were provided to metastatic (M) patients. This is a retrospective analysis of the HDMTX courses administered between 2006 and 2008. Results: Out of 341 HDMTX infusions, administered to 42 patients, 42.5% had abnormal serum levels at hour 24, 8.8% at hour 48 and 33.2% at hour 72. After required interventions, 2.9% (n = 8) had serum ...