- To identify whether prolonged (24 hour) intravenous infusions of HDMTX produce greater methotrexate polyglutamate (MTXPG) accumulation than short (4 hour) infusions 42 hours after 1 gm/m2 of HDMTX, stratified for lineage (T- vs B-lineage) and ploidy (hyperdiploid vs non-hyperdiploid B-lineage).