How often should a patient get a Dual-Energy X-ray Absorptiometry (DEXA) scan screening?

DEXA Scan Screening Frequency

For most patients, DEXA scans should be repeated every 2 years, with annual screening reserved for high-risk populations including those on glucocorticoids, aromatase inhibitors, androgen deprivation therapy, or with chemotherapy-induced premature menopause. 1, 2

Standard Screening Intervals by Risk Category

Low-Risk Patients (Normal BMD or Mild Osteopenia)

• Repeat DEXA every 2 years for patients with normal bone mineral density or mild osteopenia without additional risk factors 1, 2
• For truly low-risk patients with normal baseline DEXA and no risk factors, testing intervals can extend to 3 years or longer based on individual assessment 1
• BMD measurements should never be performed more frequently than annually, as bone density changes occur slowly and shorter intervals rarely provide clinically meaningful information 1, 3

Postmenopausal Women

• All women ≥65 years should undergo baseline DEXA scanning 2
• Postmenopausal women <65 years with risk factors should be screened 2
• Baseline DEXA scan is recommended for all postmenopausal breast cancer survivors 4
• Repeat scans every 2 years for those with moderate to severe osteopenia 2

High-Risk Populations Requiring Annual Monitoring

Cancer Treatment-Related

• Women taking aromatase inhibitors: Repeat DEXA every 2 years due to accelerated bone loss in the first 12-24 months 4, 1
• Premenopausal women on tamoxifen plus GnRH agonists: Repeat DEXA every 2 years 4
• Women with chemotherapy-induced premature menopause: Repeat DEXA every 2 years 4
• Men on androgen deprivation therapy: Consider baseline DEXA after 6 months of therapy, then annually 4, 2, 3

Medication-Induced Bone Loss

• Glucocorticoid therapy >3 months: Repeat DEXA every 1-2 years (annually for highest risk) 4, 1, 2, 3
• Anticonvulsants, chronic heparin, or other bone-depleting medications: Consider annual to every 2 years based on risk 4, 3

Medical Conditions

• Organ transplant patients: Due to rapid bone loss in first 6-12 months post-transplant, follow same guidelines as glucocorticoid therapy (every 2-3 years) 4
• Chronic inflammatory diseases, malabsorption, eating disorders: Shorter intervals of 1-2 years 4, 3
• Hypogonadal men >18 years or surgically/chemotherapeutically induced castration: More frequent monitoring warranted 4, 3

Special Populations

Premenopausal Women

• Screening BMD should NOT be performed in premenopausal women except for two specific scenarios 4:
  • History of fractures from minor trauma
  • Known causes of bone loss (chronic disease, low BMI, systemic lupus erythematosus)
• For those requiring monitoring: every 2-3 years 4
• Women <40 years with premature menopause (especially chemotherapy-induced): Consider baseline DEXA 4

Men

• Men <50 years: Diagnosis of osteoporosis cannot be made on BMD alone; use Z-scores (not T-scores) 4
• Men ≥50 years with HIV: Initial DEXA, then repeat every 2-5 years depending on proximity to treatment thresholds 1

Female Athletes

• Athletes with Female Athlete Triad risk factors (eating disorders, amenorrhea, prior stress fractures): DXA testing every 1-2 years 1

Situations Requiring Immediate Repeat Testing

• New fragility fracture occurs 2
• New risk factors develop (hyperparathyroidism, malabsorption, initiation of bone-depleting medications) 2, 3
• Major risk factors change in patients already on monitoring 4
• Prior to temporary cessation of bisphosphonate therapy 3

Critical Technical Considerations

Ensuring Accurate Comparisons

• Always use the same DXA machine for follow-up scans to ensure accurate comparison 1, 2, 3
• Compare BMD values, NOT T-scores, between serial scans for more accurate assessment of changes 1, 2, 3
• Recognize that degenerative changes can falsely elevate BMD values, particularly in the spine, potentially masking true bone loss 1, 3

Timing Considerations

• Avoid scanning intervals <1 year as they typically don't show clinically meaningful changes due to the slow nature of bone density alterations 1, 3
• For patients with established osteoporosis on stable treatment: every 2 years 2

Common Clinical Pitfalls to Avoid

• Failing to recognize accelerating factors: New conditions like hyperparathyroidism, malabsorption, or initiation of bone-depleting medications warrant earlier follow-up regardless of previous schedule 3
• Ignoring lumbar spine artifacts: Degenerative changes, osteoarthritis, and other artifacts commonly cause spurious increases in BMD values at the spine 3
• Over-scanning low-risk patients: Transition to osteoporosis occurs over approximately 17 years for those with normal BMD, making frequent scanning unnecessary 2
• Using T-scores instead of BMD values for serial comparison 1, 2