Is short-course radiotherapy with high doses per fraction the appropriate regimen for metastatic spinal cord compression in colorectal cancer patients?

Background and Purpose: Various radiotherapy (RT) schedules are used worldwide for metastatic spinal cord compression (MSCC). Every treatment session may cause discomfort to the mostly debilitated patients. A short overall treatment time appears beneficial, especially for MSCC patients with an extremely poor survival such as colorectal cancer patients. This study evaluates whether short-course RT (1 x 8 Gy given in 1 day, 5 x 4 Gy given in 1 week) is as effective as long-course RT (10 x 3 Gy given in 2 weeks, 15 x 2.5 Gy given in 3 weeks, 20 x 2 Gy given in 4 weeks) and whether higher doses per fraction (more cell kill) and shorter overall treatment time (less repopulation) can compensate for lower total doses. Patients and Methods: 81 colorectal cancer patients with MSCC were retrospectively investigated. The following potential prognostic factors for functional outcome were analyzed: age, sex, performance status, number of involved vertebrae, ambulatory status before RT, time of developing motor deficits before RT, radiation regimen (short-course, n = 31, vs. long-course RT, n = 50). Results: Improvement of motor function occurred in 14% of the patients, no change in 68%, and deterioration in 19%. There were no significant differences between short-course and long-course RT regarding improvement or deterioration of motor function (p = 0.50). Time of developing motor deficits before RT was the only significant prognostic parameter for functional outcome (> 7 days better than 1-7 days; p < 0.001). Conclusion: No significant difference was observed between short-course and long-course RT with respect to functional outcome. In the clinical situation, short-course RT may be considered preferable, as it means less patient discomfort.