When to repeat Dual-Energy X-ray Absorptiometry (DExa) scan with a T score indicating osteoporosis?

From the Guidelines

Repeat DEXA Scan Interval for Osteoporosis

Repeat the DEXA scan in 1-2 years for a T score indicating osteoporosis, as this allows for monitoring of bone mineral density (BMD) and assessment of treatment response 1.

Factors Influencing Scan Interval

• If the patient is on osteoporosis medication, such as alendronate (70mg weekly) or denosumab (60mg every 6 months), the scan can be repeated in 2 years 1.
• If the patient is not on medication, or if there are significant changes in clinical status, such as a new fracture, or significant changes in weight or height, the scan should be repeated in 1 year 1.
• Additionally, if the patient has a history of glucocorticoid use, such as prednisone (more than 5mg daily for more than 3 months), the scan should be repeated in 1 year 1.
• In patients with chronic liver disease, repeat DEXA scan after 2-3 years in patients with normal BMD, and within 1 year when rapid bone loss is expected 1.

Key Considerations

• The measurement of hip BMD continues to be the most reliable way of evaluating hip fracture risk, whereas imaging of the spine is optimal for monitoring treatment response 1.
• It is essential for patients to be scanned on the same DXA machine because differences in vendor technologies prohibit a direct comparison unless cross calibration has been performed 1.
• BMD measurements do not need to be repeated routinely in patients with osteopenia unless the baseline T-score is < 2.0 or risk factors develop 1.

From the Research

Repeating Dual-Energy X-ray Absorptiometry (DExa) Scan

• The decision to repeat a DExa scan depends on various factors, including the patient's risk factors, age, and previous scan results 2.
• For patients with osteoporosis, the scan should be repeated every 1 to 2 years to monitor the effectiveness of treatment and assess the risk of fractures 3.
• However, the frequency of repeating the scan may vary depending on the individual's condition and the presence of other risk factors, such as glucocorticoid-induced osteoporosis, which may require more frequent monitoring 2.
• In patients with thyrotoxicosis, a repeat DExa scan may be necessary after one year of treatment to assess the improvement in bone mineral density 4.
• The accuracy of DExa scan results can be affected by various factors, including degenerative changes, scoliosis, and the presence of foreign bodies, which should be taken into account when interpreting the results 5.

Factors Influencing Repeat Scans

• Age: Older patients may require more frequent monitoring due to the increased risk of osteoporosis and fractures 2, 3.
• Risk factors: Patients with multiple risk factors, such as female gender, increasing age, and long-term corticosteroid therapy, may require more frequent monitoring 2.
• Previous scan results: Patients with a T score indicating osteoporosis may require more frequent monitoring to assess the effectiveness of treatment and adjust the treatment plan as needed 2, 3.
• Treatment: Patients undergoing treatment for osteoporosis or other conditions that affect bone mineral density may require more frequent monitoring to assess the effectiveness of treatment 4, 3.