Table 1.
Patient characteristics according to Bilsky grade in spinal metastasis
| Characteristic | No. of regions | Grade 0 (n=80) | Grade 1 (n=39) | Grade 2 (n=21) | Grade 3 (n=9) | p-valuea) |
|---|---|---|---|---|---|---|
| Age (yr) | ||||||
| ≤ 55 | 50 | 35 (43.8) | 11 (28.2) | 2 (9.5) | 2 (22.2) | 0.017 |
| > 55 | 99 | 45 (56.3) | 28 (71.8) | 19 (90.5) | 7 (77.8) | |
| Sex | ||||||
| Male | 90 | 49 (61.3) | 22 (56.4) | 12 (57.1) | 7 (77.8) | 0.679 |
| Female | 59 | 31 (38.8) | 17 (43.6) | 9 (42.9) | 2 (22.2) | |
| ECOG performance status | ||||||
| 0-1 | 137 | 77 (96.3) | 34 (87.2) | 19 (90.5) | 7 (77.8) | 0.127 |
| 2-4 | 12 | 3 (3.8) | 5 (12.8) | 2 (9.5) | 2 (22.2) | |
| Primary tumor | ||||||
| Lung | 32 | 17 (21.3) | 10 (25.6) | 3 (14.3) | 2 (22.2) | 0.810 |
| Breast | 25 | 14 (17.5) | 7 (17.9) | 4 (19.0) | 0 | |
| HCC | 33 | 17 (21.3) | 8 (20.5) | 5 (23.8) | 3 (33.3) | |
| RCC | 10 | 4 (5.0) | 3 (7.7) | 1 (4.8) | 2 (22.2) | |
| Others | 49 | 28 (35.0) | 11 (28.2) | 8 (38.1) | 2 (22.2) | |
| Solitary metastasis | ||||||
| No | 129 | 68 (85.0) | 34 (87.2) | 19 (90.5) | 8 (88.9) | 0.919 |
| Yes | 20 | 12 (15.0) | 5 (12.8) | 2 (9.5) | 1 (11.1) | |
| SINS criteria | ||||||
| Tumor location | ||||||
| Junctional (occiput-C2, C7-T2, T11-L1, L5-S1) | 58 | 36 (45.0) | 14 (35.9) | 4 (19.0) | 4 (44.4) | 0.194 |
| Mobile spine (C3-C6, L2-L4) | 44 | 25 (31.3) | 10 (25.6) | 6 (28.6) | 3 (33.3) | |
| Semi-rigid (T3-T10) | 47 | 19 (23.8) | 15 (38.5) | 11 (52.4) | 2 (22.2) | |
| Pain | ||||||
| Pain-free lesion | 38 | 24 (30.0) | 7 (17.9) | 6 (28.6) | 1 (11.1) | 0.012 |
| Occasional pain but not mechanical | 78 | 41 (51.3) | 27 (69.2) | 5 (23.8) | 5 (55.6) | |
| Mechanical | 33 | 15 (18.8) | 5 (12.8) | 10 (47.6) | 3 (33.3) | |
| Bone lesion quality | ||||||
| Lytic | 102 | 59 (73.8) | 26 (66.7) | 11 (52.4) | 6 (66.7) | 0.008 |
| Mixed (lytic/blastic) | 30 | 9 (11.3) | 8 (20.5) | 10 (47.6) | 3 (33.3) | |
| Blastic | 17 | 12 (15.0) | 5 (12.8) | 0 | 0 | |
| Radiographic spinal alignment | ||||||
| Normal alignment | 143 | 78 (97.5) | 37 (94.9) | 19 (90.5) | 9 (100) | 0.306 |
| Kyphosis/Scoliosis | 5 | 2 (2.5) | 2 (5.1) | 1 (4.8) | 0 | |
| Subluxation/Translation | 1 | 0 | 0 | 1 (4.8) | 0 | |
| Vertebral body fracture | ||||||
| None of the below | 85 | 52 (65.0) | 17 (43.6) | 12 (57.1) | 4 (44.4) | 0.213 |
| No collapse with > 50% body involved | 28 | 15 (18.8) | 9 (23.1) | 3 (14.3) | 1 (11.1) | |
| < 50% collapse | 28 | 11 (13.8) | 9 (23.1) | 4 (19.0) | 4 (44.4) | |
| > 50% collapse | 8 | 2 (2.5) | 4 (10.3) | 2 (9.5) | 0 | |
| Posterolateral involvement of spinal elements | ||||||
| None of the above | 83 | 56 (70.0) | 20 (51.3) | 5 (23.8) | 2 (22.2) | < 0.001 |
| Unilateral | 44 | 18 (22.5) | 11 (28.2) | 12 (57.1) | 3 (33.3) | |
| Bilateral | 22 | 6 (7.5) | 8 (20.5) | 4 (19.0) | 4 (44.4) | |
| SINS classification | ||||||
| Stability | 83 | 49 (61.3) | 22 (56.4) | 9 (42.9) | 3 (33.3) | 0.104 |
| Intermediate stability | 62 | 30 (37.5) | 17 (43.6) | 10 (47.6) | 5 (55.6) | |
| Instability | 4 | 1 (1.3) | 0 | 2 (9.5) | 1 (11.1) | |
| SRS dose (Gy) | ||||||
| ≤ 20 | 135 | 66 (82.5) | 39 (100) | 21 (100) | 9 (100) | 0.004 |
| > 20 | 14 | 14 (17.5) | 0 | 0 | 0 | |
| SRS dose (Gy) | ||||||
| Median (range) | 149 | 18 (12-24) | 18 (14-20) | 18 (13-20) | 18 (16-20) | 0.009b) |
| ISRC sites number of treatment field | ||||||
| 1-3 | 62 | 45 (56.3) | 7 (17.9) | 8 (38.1) | 2 (22.2) | 0.001 |
| 4-6 | 87 | 35 (43.8) | 32 (82.1) | 13 (61.9) | 7 (77.8) |
Values are presented as number (%) unless otherwise indicated. ECOG, Eastern Cooperative Oncology Group; HCC, hepatocellular carcinoma; RCC, renal cell carcinoma; SINS, Spinal Instability Neoplastic Score; SRS, stereotactic radiosurgery; ISRC, International Spine Radiosurgery Consortium.
a)
Pearson’s chi-squared test,
b)
ANOVA test.