Bone densitometry: patients receiving prolonged steroid therapy

Bone mass loss and osteoporosis are associated with various conditions, such as asymptomatic primary hyperparathyroidism, and treatments, such as prolonged steroid therapy. Bone densitometry is used to measure bone mass density to determine the degree of osteoporosis and to estimate fracture risk. Bone densitometers measure the radiation absorption by the skeleton to determine bone mass of the peripheral, axial, and total skeleton. Common techniques include single-photon absorptiometry (SPA) of the forearm and heel, dual-photon (DPA) and dual-energy x-ray absorptiometry (DXA) of the spine and hip, quantitative computed tomography (QCT) of the spine or forearm, and radiographic absorptiometry (RA) of the hand. Part I of this report addresses important technical considerations of bone densitometers, including radiation dose, site selection, and accuracy and precision, as well as cost and charges. Part II evaluates the clinical utility of bone densitometry in the management of patients receiving prolonged steroid therapy. Steroids have broad effects on both immune and inflammatory processes and have been used to treat a wide variety of immunologically mediated diseases. Osteoporosis and vertebral compression fractures have been considered major complications of prolonged steroid therapy. Bone loss is also a direct result of many of the diseases treated with steroids. Issues addressed are the type and extent of bone loss associated with steroid therapy, risk for fracture, whether steroid dose reduction or alternative therapy is an option, and whether osteoporosis associated with prolonged steroid use can be prevented or treated. The other assessments in this series address the clinical utility of bone densitometry for patients with: asymptomatic primary hyperparathyroidism, end-stage renal disease, vertebral abnormalities, and estrogen-deficient women.