Table 2.
Treatment variables
| Variable | Category | N | % | Median | Mean | SD |
|---|---|---|---|---|---|---|
| Number of levels decompressed | — | 111 | 100 | 3 | 2.8 | 1 |
| 1 | 10 | 9 | ||||
| 2 | 26 | 23 | ||||
| 3 | 59 | 53 | ||||
| 4 | 11 | 10 | ||||
| 5 | 3 | 3 | ||||
| 6 | 2 | 2 | ||||
| Number of levels instrumented | — | 111 | 100 | 5 | 5.2 | 2.4 |
| 0 | 10 | 9 | ||||
| 3 | 4 | 4 | ||||
| 4 | 14 | 13 | ||||
| 5 | 43 | 39 | ||||
| 6 | 17 | 15 | ||||
| 7 | 8 | 7 | ||||
| >7 | 15 | 14 | ||||
| SRS dose (cGy) | — | 111 | 100 | 2700 | 2751.4 | 370.7 |
| 2700 | 68 | 61 | ||||
| 2400 | 15 | 14 | ||||
| 3000 | 14 | 13 | ||||
| Other | 14 | 13 | ||||
| SRS treatment fractions | — | 111 | 100 | 3 | 3.1 | 1.2 |
| 1 | 17 | 15 | ||||
| 3 | 70 | 63 | ||||
| 5 | 24 | 22 | ||||
| Concurrent radiation therapy to other level | Yes | 15 | 14 | |||
| No | 96 | 86 |
Abbreviation: SRS, stereotactic radiosurgery.