Quantitative computed tomography analysis of body composition changes in paediatric patients with acute lymphoblastic leukaemia

Abstract

Children with acute lymphoblastic leukaemia (ALL) are at risk for obesity and cardiometabolic diseases. To gain insight into body composition changes among children with ALL, we assessed quantitative computed tomography (QCT) data for specific body compartments (subcutaneous adipose tissue [SAT], visceral adipose tissue [VAT], total adipose tissue [TAT], lean tissue [LT], LT/TAT and VAT/SAT at lumbar vertebrae L1 and L2) at diagnosis and at off-therapy for 189 children with ALL and evaluated associations between body mass index (BMI) Z-score and clinical characteristics. BMI Z-score correlated positively with SAT, VAT and TAT and negatively with LT/TAT and VAT/SAT. At off-therapy, BMI Z-score, SAT, VAT and TAT values were higher than at diagnosis, but LT, LT/TAT and VAT/SAT were lower. Patients aged ≥10 years at diagnosis had higher SAT, VAT and TAT and lower LT and LT/TAT than patients aged 2.0-9.9 years. Female patients had lower LT and LT/TAT than male patients. Black patients had less VAT than White patients. QCT analysis showed increases in adipose tissue and decreases in LT during ALL therapy when BMI Z-scores increased. Early dietary and physical therapy interventions should be considered, particularly for patients at risk for obesity.

Keywords: acute lymphoblastic leukaemia; body composition; body mass index; children; quantitative computed tomography.

FIGURE 1.

Body composition analysis in quantitative computed tomography. The color coding for the image is based on the tissue class label: blue represents fat, yellow represents lean tissue, magenta represents trabecular bone, and green represents cortical bone. The actual calculations are performed with the consideration that a pixel/voxel represents a mixture of tissue types; however, for illustration purposes, the dominant tissue character of each pixel is shown. The green dots and line are used to define a contour around a muscle or a group of muscles in the abdomen, back, and/or spine. The estimates of tissue composition are determined for all tissues within an image and for those within a contour line. Adipose tissue within the contour is reported as visceral adipose tissue, whereas subcutaneous adipose tissue is reported as the difference between the total adipose tissue within the image and the visceral adipose tissue. Lean tissue measurements are based on assessments of tissue within the contour.