Monitoring treatment for osteoporosis by using bone densitometry

In recent years, the range of treatments available for patients with osteop orosis has greatly increased. A decade ago, the only proven therapy was est rogen, but today the choices include bisphosphonates, selective estrogen-re ceptor modulators, calcitonin, and parathyroid hormone. Clinical trials inv olving bone mineral density (BMD) scans of the spine and femur have had an important role in the evaluation of these new therapies. In particular, the efficacy of treatments has now been verified in large studies powered to s how reductions in fracture risk. In contrast with the use of BMD scans in r esearch studies, their value for monitoring response to treatment in indivi dual patients is lass certain. In many cases, the increases in BMD are too small to reliably distinguish between true changes and measurement error. H owever, experience with estrogen and bisphosphonates suggests that these tr eatments have a beneficial effect on bone in most patients. Follow-up scans for patients taking these agents are therefore of limited value, apart fro m offering reassurance to the patient and the doctor. However, when new the rapies are first introduced, follow-up scans have a useful role in building up the physician's experience and confidence. Copyright (C) 2001 by W.B. S aunders Company.