gms | German Medical Science

Background: Life expectancy is markedly reduced in MSCC patients. A radiation schedule with a short overall treatment time is desired, as it is associated with less patient discomfort. However, a short schedule can only be recommended if it provides similar outcome as more protracted regimens. This study investigated 5 radiation schedules and potential prognostic factors for functional outcome in MSCC.

Materials and Methods: 1304 patients (irradiated 1/92-12/03) were included. The schedules 1x8Gy in 1 day (n=261), 5x4Gy in 1 week (n=279), 10x3Gy in 2 weeks (n=274), 15x2.5Gy in 3 weeks (n=233), and 20x2Gy in 4 weeks (n=257) were compared for post-treatment motor function, ambulatory status, and in-field recurrences. The following potential prognostic factors were investigated for functional outcome: age (<=63 vs. >=64 years), sex, ECOG performance status (1-2 vs. 3-4), histology (favorable: myeloma, lymphoma, seminoma vs. unfavorable: CUP, lung cancer, melanoma vs. other tumors), number of involved vertebrae (1-2 vs. 3-4 vs. >=5), pre-treatment ambulatory status, time of progression of motor deficits before RT (1-7 vs. 8-14 vs. >14 days).

Results: The 5 treatment groups were balanced for the potential prognostic factors. Motor function improved in 26% (1x8Gy), 28% (5x4Gy), 27% (10x3Gy), 31% (15x2.5Gy) and 28% (20x2Gy) (P=0.90). Post-treatment ambulatory rates were 69%, 68%, 63%, 66%, and 74% (P=0.58), respectively. On multivariate analysis, better performance status (P<0.001), favorable histology (P<0.001), involvement of only 1-2 vertebrae (P<0.001), and a slower progression of motor deficits before RT (>14 days, P<0.001) were associated with a better functional outcome. Pre-treatment ambulatory status achieved borderline significance (P=0.06). The radiation schedule had no significant impact (P=0.96). Acute toxicity was mild, late toxicity not observed. Follow up was 12 months for 467 patients. In-field recurrences at 2 years were 24% (1x8Gy), 26% (5x4Gy), 14% (10x3Gy), 9% (15x2.5Gy), and 7% (20x2Gy) (p<0.001). Neither the difference between 1x8Gy and 5x4Gy (P=0.44), nor between 10x3Gy, 15x2.5Gy and 20x2Gy (P=0.71) was significant.

Conclusions: The 5 radiation schedules provided similar functional outcome. The more fractionated schedules (10x3 Gy, 15x2.5 Gy, 20x2 Gy) were associated with fewer in-field recurrences. To minimize treatment time, two schedules are recommended, 1x8Gy for patients with a poor predicted survival and 10x3Gy for other patients.