DEXA Scan Repeat Interval for Normal Results
For patients with normal DEXA scan results (T-score ≥ -1), repeat screening should occur at a minimum of 2-year intervals, though extending to 3-5 years is reasonable for those without additional risk factors. 1
Standard Recommendations for Normal Bone Density
- Patients with normal BMD (T-score > -1) and no additional risk factors should have DEXA repeated every 2 years as the standard interval 1
- The American College of Clinical Oncology states that DEXA scans should not be performed more frequently than annually under any circumstances, as bone density changes occur slowly 1
- For low-risk individuals with normal baseline BMD and bone loss rates ≤1% per year, the change in BMD is unlikely to exceed the least significant change in less than 3 years, and unlikely to reach treatment thresholds for at least 16 years 2
Extended Intervals for Truly Low-Risk Patients
- If results are normal and the patient has no risk factors, testing can be repeated at 3-year intervals minimum, with consideration for even longer intervals based on individual risk assessment 3
- For childhood, adolescent, and young adult cancer survivors with normal BMD (Z-score > -1) at entry into long-term follow-up, repeat surveillance is recommended at age 25 when peak bone mass is achieved, rather than at fixed intervals 3
Clinical Context That Matters
The 2-year interval represents a balance between:
- The slow rate of bone loss in healthy individuals (typically <1% per year) 2
- The precision limitations of DEXA technology (least significant change ranges from 2.77% to 8% depending on machine precision) 2
- The practical need to detect clinically meaningful changes before fracture risk becomes substantial 1
Risk Factors That Shorten Intervals
Certain conditions warrant more frequent monitoring (annually or every 2 years):
- Initiation of glucocorticoid therapy or other medications affecting bone metabolism (aromatase inhibitors, androgen deprivation therapy, anticonvulsants, chronic heparin) 1, 4
- Development of medical conditions affecting bone health (chronic renal failure, rheumatoid arthritis, eating disorders, organ transplantation, prolonged immobilization, gastrointestinal malabsorption) 1
- Postmenopausal women on aromatase inhibitors, premenopausal women on tamoxifen with GnRH agonists, or women with chemotherapy-induced premature menopause require repeat DEXA every 2 years 3
Critical Pitfalls to Avoid
- Never scan more frequently than annually—this provides no clinically meaningful information and wastes resources 1, 4
- Always use the same DEXA machine for serial measurements, as different manufacturers' technologies cannot be directly compared without cross-calibration 4
- Compare absolute BMD values (g/cm²), not T-scores, between scans for accurate assessment of change 4
- Ensure identical patient positioning and scan the same anatomical side (hip/forearm) for all follow-up studies 4
Real-World Practice Patterns
Recent data shows that intensive DEXA testing (intervals <23 months) has decreased substantially in clinical practice, from 16.7% in 2006 to 6.7% in 2015, suggesting improved adherence to evidence-based guidelines 5