Background
Consensus guidelines from the International Lymphoma Radiation Oncology Group (ILROG) on radiation therapy in multiple myeloma: symptomatic bone disease, solitary plasmacytoma of bone (SPB), extramedullary plasmacytoma (EMP), and spinal cord compression. Based on systematic review and expert consensus.
Interventions and follow up
Scope: RT for symptomatic bone disease, SPB, EMP, spinal cord compression
Primary endpoint: Consensus guideline development (not a clinical trial)
mFollow up: Not applicable (expert consensus process)
Primary endpoint: Consensus guideline development (not a clinical trial)
mFollow up: Not applicable (expert consensus process)
Results
Dose, SPB/EMP: 40-50 Gy (standard); 45 Gy in 25 fractions most common practice
Dose, pain palliation: 8 Gy x1 or 20 Gy x5
Dose, spinal cord compression: 20-30 Gy; long-course preferred over short-course for ambulatory patients with good prognosis
Local control, SPB/EMP: 80-90% with 40-50 Gy
Dose, pain palliation: 8 Gy x1 or 20 Gy x5
Dose, spinal cord compression: 20-30 Gy; long-course preferred over short-course for ambulatory patients with good prognosis
Local control, SPB/EMP: 80-90% with 40-50 Gy
Adverse events
Constitutional: fatigue common with multi-fraction courses
Hematologic: myelosuppression with large-field or spine RT
Site-specific: mucositis for head/neck EMP; radiation pneumonitis risk with rib/thoracic lesions
Overall: RT for bone myeloma generally well tolerated
Hematologic: myelosuppression with large-field or spine RT
Site-specific: mucositis for head/neck EMP; radiation pneumonitis risk with rib/thoracic lesions
Overall: RT for bone myeloma generally well tolerated
Conclusions
ILROG guidelines provide consensus dose recommendations across the spectrum of myeloma presentations. RT remains highly effective for local control in SPB and EMP, with 40-50 Gy achieving local control of 80-90%. Single-fraction 8 Gy is standard for uncomplicated painful bone lesions.
Key Limitations
Consensus-based, not derived from prospective RCTs; SPB dose recommendations lack randomized dose-comparison data; evidence base largely retrospective; optimal integration with modern systemic therapy (daratumumab, CAR-T) remains undefined.
Clinical Context
RT is indispensable in myeloma for pain palliation, impending fracture, spinal cord compression, and definitive treatment of plasmacytoma. These ILROG guidelines are the standard reference for radiation oncologists. SPB treated with 40-50 Gy achieves local control in ~90%, though progression to MM occurs in ~50% of bone SP at 5 years; symptomatic bone disease is treated with 8 Gy x1 for pain palliation or 20-30 Gy for more durable control/impending fracture.