A validated scoring system to identify long-term survivors after radiotherapy for metastatic spinal cord compression

Purpose: This study aimed to develop and validate a scoring system to identify long-term survivors after conventional radiotherapy (RT) for metastatic spinal cord compression (MSCC). Patients and methods: Data from 1,125 patients who had received long-course RT for MSCC were included in this study. Of these patients, 344 survived for over 12 months and 781 died within a year following RT. Based on differences between the distributions of patient characteristics in the two groups, a scoring system was developed. Scores ranged from 0 to 18 points and 15 points was selected as the cutoff for identifying long-term survivors. Data from the 1,125 long-course RT patients (test group) were compared to data from 773 patients receiving short-course RT (validation group). Results: A score of ≥ 15 points was associated with a 94 % proportion of long-term survivors. The 15-point cutoff resulted in a specificity of 98 % and a positive predictive value of 94 % for identification of long-term surviving patients. The proportions of long-term survivors for each scoring point in the validation group were very similar to those in the test group. Conclusion: This new scoring system enabled identification of long-term survivors after RT for MSCC with very high specificity and positive predictive value. The score proved to be valid and reproducible.