1x8 Gy versus 5x4 Gy for metastatic epidural spinal cord compression: A matched-pair study of three prognostic patient subgroups

Background: This study provides separate comparisons of 1×8Gy to 5×4Gy for metastatic epidural spinal cord compression (MESCC) in patients with poor, intermediate and favorable survival prognoses. Methods: Patients receiving 1×8Gy were matched to patients receiving 5×4Gy for age, gender, performance status, tumor type, involved vertebrae, other bone metastases, visceral metastases, interval between tumor diagnosis and MESCC, ambulatory status and time developing motor deficits. From a study including patients with poor (N=156) or intermediate (N=86) survival prognoses, subgroup analyses were performed. Furthermore, 232 new patients with favorable prognoses matched the same way were included. Results: In poor prognoses patients, 6-month survival rates were 10% after 1×8Gy and 6% after 5×4Gy (p=0.38); in-field reRT rates in few patients alive at 6months were 15 and 2% (p=0.16). In intermediate prognoses patients, 6-month survival rates were 49% after 1×8Gy and 58% after 5×4Gy (p=0.30). ReRT rates at 6months were 23 and 13% (p=0.25). In favorable prognoses patients, 6-month survival rates were 89% after 1×8Gy and 91% after 5×4 Gy. ReRT rates at 6months were 14 and 3% (p=0.007). In no subgroup, RT regimen had a significant impact on motor function. Conclusions: Since in patients with poor prognoses, outcomes after 1×8Gy and 5×4Gy were not significantly different, 1×8Gy may be an option. In patients with intermediate prognoses, a trend was found in favor of 5×4 Gy. In patients with favorable prognoses, need for in-field reRT was greater after 1×8 Gy.