title: Variability in dose intensity of high-dose methotrexate for nonmetastatic osteosarcoma.
abstract: The authors evaluated their ability to maintain planned dosing schedules for high-dose methotrexate (HD-MTX) in patients with nonmetastatic osteosarcoma. Twenty-seven patients who received therapy according to 2 POG protocols (8651 and 9351), both of which included HD-MTX (12 g/m(2)/week for 2 consecutive weeks), between 1988 and 1998 were studied. Significantly fewer HD-MTX infusions were given on the second week to patients treated on POG 9351 (33 vs. 93%; p < .0001). The hydration guidelines were identical and there was no difference in peak serum MTX levels either within or between protocols. Differences in the administration of combination chemotherapy in 9351 compared to 8651 may have contributed to the increased toxicity associated with HD-MTX on 9351, although this is speculative. The use of HD-MTX should be carefully planned so that it does not decrease its dose intensity or that of other effective agents.
authors.affiliation: Department of Pediatrics, Division of Hematology/Oncology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA. pleave@UTSouthwestern.edu
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Leavey
authors.forename: Elpis
authors.initials: E
authors.lastname: Mantadakis
authors.forename: Gerhard
authors.initials: G
authors.lastname: Maale
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage* / Q000097:blood / Q000633:toxicity; D002648:Child; D004305:Dose-Response Relationship, Drug; D006505:Hepatitis / Q000209:etiology; D006801:Humans; D008727:Methotrexate / Q000008:administration & dosage* / Q000097:blood / Q000633:toxicity; D012516:Osteosarcoma / Q000150:complications / Q000188:drug therapy* / Q000473:pathology; D012189:Retrospective Studies; D013280:Stomatitis / Q000139:chemically induced
chemical_list: D000964:Antimetabolites, Antineoplastic; D008727:Methotrexate