BONE METABOLISM AND MINERALIZATION AFTER CYTOTOXIC CHEMOTHERAPY INCLUDING IFOSFAMIDE

Lumbar spine bone mineral density and bone mineral metabolism were stu died in 13 children three months or more after completion of cytotoxic chemotherapy that included ifosfamide given for different malignancie s. Blood and urine were analysed for calcium, phosphorus, and magnesiu m and blood for alkaline phosphatase activity, parathyroid hormone, an d 1,25 (OH)(2) vitamin D-3. Bone mineral density (BMD) was measured at the lumbar spine (L1-L4) using a commercial dual x ray absorptiometer . Serum concentrations of calcium, phosphorus, and magnesium and alkal ine phosphatase activity, as well as plasma 1,25 (OH)(2) vitamin D-3 c oncentrations were normal in all children. Slightly raised parathyroid hormone concentrations were seen in two children. An increased urinar y excretion of calcium was found in five children. Mean (SD) BMD of th e children was -0.88 (1.44). Three children had osteopenia, as defined by a BMD lower than -2 SD for age and sex related standards. No signi ficant relation was found between the BMD and the biochemical paramete rs. In conclusion, a normal BMD was found in most patients who had rec eived ifosfamide, even in those with persisting hypercalciuria.