Changes in bone mineral density during therapy in childhood acute lymphoblastic leukemia.

Consecutive cases of ALL were enrolled from July to December 2004, and followed up for next 6 months. Children who had received ≥7 days of chemotherapy prior to referral, or those with relapsed disease were excluded. UKALL-X protocol was administered with following modifications: 3-drug induction with vincristine, prednisone and L-asparaginase; 6-weekly pulses of vincristine/dexamethasone instead of 4, and intensification delayed by 1-week to ensure count recovery. Quantitative computed tomography (QCT) for assessment of BMD was performed at diagnosis and following 6 months of therapy. The measurement was done on QCT-5000 bone densitometry system (General Electric, Columbia, KY-USA), which allows highly automated vertebral BMD measurements. Mineral content was determined in the midplane of three lumbar vertebrae (L1 to L3), in a single 10-mm slice, obtained at each level. BMD was expressed in units of population standard deviation; the T-score = ± number of SDs from young mean. Z-scores were estimated as well. The T and Z-scores(2) obtained at 6 months were compared with respective scores at diagnosis. X-ray lateral-view dorsolumbar spine and antero-posterior view of bilateral knee joints was performed at presentation and following 6 months of therapy.