Is yearly MRI necessary to assess lytic lesion status in patients with good laboratory results, including normal calcium levels (hypercalcemia) and renal function (Impaired renal function)?

Yearly MRI for Lytic Lesion Assessment in Multiple Myeloma with Normal Labs

In patients with multiple myeloma who have good laboratory results (normal calcium and renal function), yearly MRI is not routinely necessary for monitoring lytic lesion status, but annual skeletal imaging with low-dose CT or plain radiography is recommended to detect early radiological progression even in asymptomatic patients. 1

Risk-Stratified Surveillance Approach

The need for imaging surveillance depends on your patient's disease status and risk category:

For Smoldering (Asymptomatic) Myeloma

• Skeletal imaging should be performed yearly even in the absence of symptoms to detect evidence of early radiological progression 1
• Low-dose skeletal CT is the preferred surveillance modality over traditional skeletal surveys 1
• MRI may be particularly useful in patients with:
  • Monoclonal protein >30 g/L 1
  • IgA monoclonal protein 1
  • Bence Jones proteins >50 mg/day 1
• MRI can detect focal lesions that may reclassify patients from smoldering to active myeloma even before CRAB features develop 1

For Active Myeloma in Remission with Good Labs

• Annual skeletal imaging is recommended to monitor for progression 1
• Skeletal evaluations can be performed once yearly in patients with stable disease 1
• More frequent imaging (every 3-6 months) should be reserved for patients with:
  • Rising tumor markers (M-protein, free light chains) 1
  • New symptoms 1
  • High-risk cytogenetics 1

Imaging Modality Selection

The choice between MRI, CT, and plain radiography should be guided by clinical context:

• Low-dose whole-body CT is increasingly preferred over traditional skeletal surveys as it is more sensitive for detecting lytic lesions 1
• MRI is superior to plain radiography for detecting early bone marrow involvement and focal lesions, particularly in the spine 1
• MRI should be used selectively when:
  • Symptomatic areas show no abnormality on routine radiographs 1
  • Spinal cord compression is suspected 1
  • Evaluating high-risk smoldering myeloma patients 1
• PET/CT may be considered but should not be used systematically for routine surveillance 1

Critical Caveats

Normal laboratory values do not exclude disease progression. Imaging can detect radiological progression before biochemical changes occur 1, 2. The presence of focal lesions on MRI is now considered a myeloma-defining event, even in the absence of CRAB features 1.

Avoid the pitfall of relying solely on skeletal surveys, as they significantly underestimate the extent of bone lesions, especially in early disease phases 2, 3. Traditional radiographs may miss up to 30-50% of lesions detected by more sensitive imaging 2.

For patients on maintenance therapy or in remission, continue monitoring with serum/urine monoclonal protein studies and complete blood counts every 3 months, with annual skeletal imaging 1. If tumor markers begin rising or new symptoms develop, increase imaging frequency accordingly 1.