Clinical Scorecard: Utilization of PET-CT for Diagnostic Assessment in Smoldering Multiple Myeloma: Identifying Patients Requiring Treatment

At a Glance

Key Highlights

• PET-CT positivity in SMM patients predicts a 75% probability of progression to active MM within 2 years.
• Presence of osteolytic lesions on PET-CT further increases progression risk to 87% at 2 years.
• PET-CT findings alone led to upstaging 24% of patients to active MM, guiding early treatment decisions.

Guideline-Based Recommendations

Diagnosis

• Use PET-CT imaging at diagnosis of SMM to identify patients at high risk of progression.
• Define positive PET-CT as abnormal increased uptake and/or lytic bone destruction on CT.
• Combine PET-CT findings with standard laboratory tests to confirm diagnosis of active MM.

Management

• Observe patients with negative PET-CT without therapy, given lower progression risk (30% at 2 years).
• Consider early treatment for patients with positive PET-CT, especially with osteolytic lesions, due to high progression risk.
• Use PET-CT results to guide decision-making on initiating therapy versus watchful waiting.

Monitoring & Follow-up

• Monitor patients with positive PET-CT closely for development of CRAB features or myeloma defining events.
• Repeat imaging and laboratory assessments as clinically indicated to detect progression.
• Track time to progression from PET-CT date to guide prognosis and treatment planning.

Risks

• Risk of progression to active MM is significantly higher in patients with positive PET-CT (75%) compared to negative PET-CT (30%) within 2 years.
• Osteolytic lesions on PET-CT indicate an even higher risk of progression (87% at 2 years).
• Delayed treatment in high-risk patients identified by PET-CT may worsen outcomes.

Patient & Prescribing Data

Patients with smoldering multiple myeloma undergoing PET-CT evaluation

Early treatment initiated in patients upstaged by PET-CT findings improves progression-free and overall survival compared to observation alone.

Clinical Best Practices

• Incorporate PET-CT imaging into initial diagnostic workup for SMM to stratify progression risk.
• Interpret PET-CT results in conjunction with clinical and laboratory data for accurate staging.
• Prioritize early intervention in patients with positive PET-CT and osteolytic lesions to improve outcomes.
• Maintain vigilant follow-up and monitoring for patients with negative PET-CT given lower but present risk of progression.

References

• International Myeloma Working Group Criteria for SMM
• Hillengass et al. MRI in SMM progression prediction
• Mayo Clinic Data Discovery and Query Database