Introduction
Acquisition of peak bone mineral mass, essential to bone health in
adults, occurs during late childhood, adolescence and early adult life.
This process can be disturbed by numerous factors including diet,
disease, treatment and lifestyle.¹ Such perturbation is well described
in children and adolescents with acute lymphoblastic leukemia (ALL)
before, during and after therapy.² Important contributors to the
outcome, osteopenia, are corticosteroids and
methotrexate²׳3 which are part of all treatment
regimens for this disease. The most common method for determining bone
mineral density (BMD) is dual energy X-ray absorptiometry (DXA) focused
on the lumbar spine (LS). A limitation of DXA is the provision of
two-dimensional measurement, so providing areal (a) BMD. Peripheral
quantitative computed tomography (pQCT) allows the determination of
volumetric (v) BMD, separate assessment of cortical and trabecular bone
(not possible with DXA), and portability. In the overall study of bone
health and body composition of long term survivors of ALL in early
life,⁴ pQCT was undertaken in addition to DXA to enable a comprehensive
evaluation of bone geometry, density and strength.⁵ The purpose was to
improve understanding of the mechanisms resulting in enhanced risk of
fracture and an element of the frailty syndrome which are well
recognized in these survivors.⁶ This report describes the pQCT component
of the study. Such insights relating to bone structure should also
inform strategies for amelioration and even prevention of osteopenia and
its attendant morbidity.