Is a whole body skeletal survey still ordered to investigate possible multiple myeloma?

Whole Body Skeletal Survey Is No Longer Recommended for Investigating Multiple Myeloma

Whole-body low-dose CT (WBLDCT) or FDG-PET/CT has replaced conventional skeletal survey as the standard imaging modality for investigating possible multiple myeloma. 1

Current Imaging Recommendations for Multiple Myeloma

First-Line Imaging Options

• Whole-body low-dose CT (WBLDCT) - Preferred primary method
• FDG-PET/CT - Equivalent alternative to WBLDCT

When to Use Conventional Skeletal Survey

• Only acceptable when advanced imaging is not available (e.g., in low-resource settings) 1
• Should not be used as first-line imaging when WBLDCT or PET/CT is accessible

Evidence Supporting Advanced Imaging Over Skeletal Survey

Superior Detection of Lesions

• WBLDCT detects significantly more osteolytic lesions than skeletal survey:
  • Identifies 25.5% more positive cases than skeletal survey 2
  • Detects an average of 8.2 lesions per patient vs. 3.6 with skeletal survey 3
  • Particularly superior for detecting lesions in spine, pelvis, skull, and ribs 1

Clinical Impact

• Advanced imaging leads to treatment changes in up to 20% of patients 1
• 22.2% of patients classified as having smoldering myeloma by skeletal survey are reclassified as active multiple myeloma when using WBLDCT 2
• Progressive bone disease is detected more frequently with WBLDCT (19 cases) compared to skeletal survey (8 cases) in prospective studies 3

Prognostic Significance

• Detection of lesions by advanced imaging has prognostic implications
• Patients with lytic bone lesions on WBLDCT have shorter time to progression (38 vs. 82 months) 2

Special Considerations

Role of MRI

• MRI is particularly useful for:
  • Discerning smoldering myeloma from active multiple myeloma 1
  • Detecting bone marrow involvement before cortical destruction 1
  • Cases where WBLDCT or skeletal survey is inconclusive 1

Follow-up Imaging

• Use the same imaging modality used during initial workup for follow-up assessments 1
• FDG-PET/CT is superior for follow-up as MRI normalizes over a prolonged period 1
• Residual focal lesions on follow-up imaging have adverse prognostic significance 1

Common Pitfalls to Avoid

1. Relying on skeletal survey alone - Underestimates disease burden and may miss critical lesions
2. Inadequate CT component in PET/CT - The CT portion should be equivalent to a whole-body low-dose CT, not just for attenuation correction 1
3. Overlooking skull and rib lesions - These may be better detected by focused X-rays if suspected 1
4. Neglecting to consider MRI for smoldering myeloma - MRI can detect early bone marrow involvement before osteolytic changes 1

In conclusion, conventional skeletal survey should no longer be used as the primary imaging modality for investigating multiple myeloma when advanced imaging options are available. The significantly higher sensitivity of WBLDCT and FDG-PET/CT for detecting bone lesions directly impacts patient diagnosis, staging, treatment decisions, and prognosis.