Background
Retrospective multicenter study comparing short-course vs. long-course RT for spinal cord compression (SCC) in multiple myeloma. 172 patients with myeloma-related SCC treated with RT (no surgery). Short-course: 1×8 Gy or 5×4 Gy (n=61). Long-course: 10×3 Gy, 15×2.5 Gy, or 20×2 Gy (n=111). Assessed motor function improvement.
Interventions and follow up
Arm A: Long-course RT (10×3 Gy, 15×2.5 Gy, or 20×2 Gy)
Arm B: Short-course RT (1×8 Gy or 5×4 Gy)
Primary endpoint: Improvement of motor function at 6 and 12 month
mFollow up: 12 month
Arm B: Short-course RT (1×8 Gy or 5×4 Gy)
Primary endpoint: Improvement of motor function at 6 and 12 month
mFollow up: 12 month
Results
Motor Function Improvement at 6 months: Long-course 67% vs. short-course 43%, P=.043
Motor Function Improvement at 12 months: Long-course 76% vs. short-course 40%, P=.003
Ambulatory Recovery (non-ambulatory at baseline): 47% regained ability to walk overall
Overall Improvement: 52% across entire cohort
Motor Function Improvement at 12 months: Long-course 76% vs. short-course 40%, P=.003
Ambulatory Recovery (non-ambulatory at baseline): 47% regained ability to walk overall
Overall Improvement: 52% across entire cohort
Adverse events
Main adverse events: RT-related toxicities not systematically graded; short-course tolerated well in poor-prognosis patients. Myelosuppression potential with large spinal fields, particularly in heavily pre-treated myeloma patients.
Conclusions
Long-course RT significantly improves motor function compared to short-course at both 6 and 12 months in myeloma-related SCC. For patients with reasonable performance status and life expectancy, long-course RT (e.g., 10×3 Gy = 30 Gy) is preferred.
Key Limitations
Key Limitations: Retrospective, no randomization; fractionation schedule was physician choice introducing selection bias (short-course likely used for worse prognosis patients); no multivariate adjustment for performance status or pre-treatment ambulation status. Surgical decompression not studied.
Clinical Context
Myeloma is highly radiosensitive; RT is first-line for myeloma SCC (vs. surgical decompression which is preferred for solid tumors). 30 Gy in 10 fractions is the most common long-course regimen used. Short-course (e.g., 8 Gy × 1) reserved for very poor prognosis or frail patients. Consistent with ILROG 2018 recommendations.
References