Metastatic spinal cord compression - Influence of time between onset of motoric deficits and start of irradiation on therapeutic effect

Background: In a retrospective analysis we investigated the prognostic sign ificance of the interval between first appearance of motoric deficits and t he beginning of radiation therapy (RT) with regard to posttreatment motoric function. Material and Methods: Data of more than 400 consecutive patients being irra diated at our department between 1994 and 1997 because of vertebral metasta ses were reviewed. Ninety six patients fulfilled selection criteria includi ng motoric deficits, no preceding surgical or radiotherapeutic treatment of the spinel minimum total dose of 24 Gy referred to spinal cord, and additi onal treatment with dexamethasone. Two subgroups with a similar number of p atients for better comparability were formed according to the time of devel oping motoric deficits: 1 to 13 days (49 patients) and greater than or equa l to 14 days (47 patients). Effect of irradiation on motoric function was e valuated 2 weeks and about 3 months after radiotherapy. Patients with sever e deterioration of motoric function within 48 hours before radiation therap y (31 patients) were looked at separately. Results: Two weeks after radiotherapy 42/47 patients (89%) developing motor ic deficits greater than or equal to 14 days showed improvement of motoric function in comparison to 6/49 patients (12%) of the other group. Deteriora tion occurred in 1/47 patients (2%) of the first and in 24/49 patients (49% ) of the latter group. In case of severe deterioration of motoric function within 48 hours before radiation therapy only 2/31 patients (6%) showed imp rovement, but 20/31 (65%) deterioration. About 3 months after radiotherapy comparable results were observed. Median survival time was 4 months. Conclusion: A slower development of motoric deficits before beginning of ra diotherapy means a better therapeutic effect and a more favorable functiona l outcome after treatment. The prognosis is extraordinarily poor if severe deterioration of motoric function occurs within 48 hours before radiotherap y.