QCT versus DXA in 320 survivors of childhood cancer: association of BMD with fracture history.

PURPOSE: To assess agreement on diagnosis of diminished bone mineral density (BMD) and correlation between BMD values obtained by dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT) in childhood cancer survivors. PATIENTS AND METHODS: We retrospectively reviewed lumbar spine QCT and DXA studies for BMD in patients who underwent both imaging studies within a 24-hr period. We determined correlation between BMD values and agreement on diagnosis of diminished BMD obtained by both modalities. Diminished BMD was defined as two or more SDs below mean for age- and gender-matched reference values. We evaluated the relationship of BMD values determined by each modality to self-reported fracture history in the 160 (50%) patients with available reports. RESULTS: Of 320 patients, 56% (178) were male; 87% (277) were white. Median age was 16.4 (range, 5.1-36.0) years. Median BMD Z-score was -1.43 (range, -5.96 to 3.20) by QCT and -1.30 (range, -5.50 to 2.80) by DXA. Correlation between QCT- and DXA-determined BMD values was significant but low, and agreement on diminished BMD was fair (kappa = 0.32). There was no association between BMD measured by either QCT or DXA and self-reported traumatic fracture history. Male gender was associated with doubling the traumatic fracture risk (P = 0.0499). CONCLUSIONS: Quantitative computed tomography and DXA may give discrepant results when used to assess bone health in childhood cancer survivors, especially in those of non-white race. This inconsistency in indicators of BMD deficiency may complicate clinical decision-making. Consecutive use of a single modality is recommended to provide reliable longitudinal information.

Abdominal compartment syndrome in a newly diagnosed patient with Burkitt lymphoma.

We present the radiological and clinical aspects of a patient with advanced-stage Burkitt lymphoma who presented with an acute abdomen complicated by abdominal compartment syndrome.