Motor function and survival following radiotherapy alone for metastatic epidural spinal cord compression in melanoma patients

The major goal of this study was the identification of predictors for motor function and survival after irradiation alone for metastatic epidural spinal cord compression (MESCC) from melanoma. Ten variables (age, gender, performance status, number of involved vertebrae, pre-radiotherapy ambulatory status, further bone metastases, visceral metastases, interval from melanoma diagnosis to MESCC, time developing motor deficits before radiotherapy, fractionation regimen) were investigated for post-radiotherapy motor function, ambulatory status and survival in 27 patients. On multivariate analysis, motor function was significantly associated with time developing motor deficits (P = 0.006). On univariate analysis, post-radiotherapy ambulatory rates were associated with pre-radiotherapy ambulatory status (P < 0.001) and performance status (P = 0.046). Variables having a significant impact on survival in the univariate analysis were performance status (P < 0.001), number of involved vertebrae ( P = 0.007), pre-radiotherapy ambulatory status (P = 0.020), further bone metastases (P = 0.023), visceral metastases (P < 0.001), and time developing motor deficits (P = 0.038). On multivariate analysis of survival, the Eastern Cooperative Oncology Group (ECOG) performance status (risk ratio [RR] = 4.35; 95% confidence interval [CI] = 1.04-16.67; P = 0.044) and visceral metastases (RR = 3.70; 95% CI = 1.10-12.50; P = 0.034) remained significant and were included in a survival score. Scoring points were obtained from 6-month survival rates divided by 10. Total scores represented the sum scores of both variables and were 3, 9 or 15 points. Six-month survival rates were 7%, 29% and 100% (P = 0.004). Thus, three predictors for functional outcomes were identified. The newly developed survival score included three prognostic groups. Patients with 3 points may receive 1 x 8 Gy, patients with 9 points 5 x 4 Gy and patients achieving 15 points longer-course radiotherapy. In the latter two groups, upfront decompressive surgery may be considered.