Purpose: To compare the results of short-course vs. long-course radiotherapy (RT) for metastatic spinal cord compression.
Methods and materials: A total of 231 patients who underwent RT between January 2006 and August 2007 were included in this two-arm prospective nonrandomized study. Patients received short-course (n = 114) or long-course (n = 117) RT. The primary endpoint was progression-free survival (PFS). The secondary endpoints were local control (LC), functional outcome, and overall survival (OS). An additional 10 potential prognostic factors were investigated for outcomes. PFS and LC were judged according to motor function, not pain control.
Results: The PFS rate at 12 months was 72% after long-course and 55% after short-course RT (p = 0.034). These results were confirmed in a multivariate analysis (relative risk, 1.33; 95% confidence interval, 1.01-1.79; p = 0.046). The 12-month LC rate was 77% and 61% after long-course and short-course RT, respectively (p = 0.032). These results were also confirmed in a multivariate analysis (relative risk, 1.49; 95% confidence interval, 1.03-2.24; p = 0.035). The corresponding 12-month OS rates were 32% and 25% (p = 0.37). Improvement in motor function was observed in 30% and 28% of patients undergoing long-course vs. short-course RT, respectively (p = 0.61). In addition to radiation schedule, PFS was associated with the interval to developing motor deficits before RT (relative risk, 1.99; 95% confidence interval, 1.10-3.55; p = 0.024). LC was associated only with the radiation schedule. Post-RT motor function was associated with performance status (p = 0.031), tumor type (p = 0.013), interval to developing motor deficits (p = 0.001), and bisphosphonate administration (p = 0.006). OS was associated with performance status (p < 0.001), number of involved vertebrae (p = 0.007), visceral metastases (p < 0.001), ambulatory status (p < 0.001), and bisphosphonate administration (p < 0.001).
Conclusion: Short-course and long-course RT resulted in similar functional outcome and OS. Long-course RT was significant for improved PFS and improved LC.