Using bone densitometry to monitor therapy in treating osteoporosis: pros and cons.

Measurement of bone density is crucial for evaluating fracture risk. Low bone mass is a powerful predictor of fracture and is necessary to assess the need for treatment. Dual energy x-ray absorptiometry is accurate and precise. Use of bone density for monitoring therapy is an important tool for evaluating response to therapy, but an understanding of the limitations of the procedure are important for the practicing physician. Precision error of the technology and what change in density is clinically significant (least significant change) are important concepts to interpret results and make appropriate treatment decisions. This article reviews the use of bone densitometry as a tool for monitoring treatment in patients with low bone mass.