Prognostic significance of the time of developing motor deficits before radiation therapy in metastatic spinal cord compression: one-year results of a prospective trial.

Abstract

To investigate prospectively the prognostic value of the time of developing motor deficits before radiation therapy (RT) for post-treatment functional outcome in metastatic spinal cord compression. From November 1998 until October 1999, 57 patients were included. Two subgroups were formed according to the time of developing motor deficits before RT: 1-14 days (n = 29) and > 14 days (n = 28). Therapeutic effect on motor function was evaluated by an 8-point scale directly, 6, 12, and 24 weeks after RT. Patients with rapid deterioration of motor function within 48 h before RT (n = 14) were evaluated separately. Directly after RT, 26/28 patients (93%) of the group developing motor deficits > 14 days showed improvement of motor function, in comparison to 3/29 patients (10%) of the group 1-14 days (p < 0.001). Deterioration rates were 0% (> 14 days) and 45% (1-14 days). In patients with rapid deterioration of motor function within 48 h before RT, prognosis was poor (improvement 0%, no change 43%, deterioration 57%). Results were comparable 6, 12, and 24 weeks after RT. A slower development of motor deficits before RT predicts a better post-treatment functional outcome. In patients with rapid deterioration of motor function within 48 h before RT, prognosis was extraordinarily poor. These results support the findings of our preceding retrospective analysis.