Table 1.
Patient characteristics
| Factor | Overall (N = 21) |
|---|---|
| Age | |
| Median [IQR] | 68 [56, 72] |
| Sex (%) | |
| Female | 7 (33.3) |
| Male | 14 (66.7) |
| ECOG performance status (%) | |
| 0 | 4 (19.0) |
| 1 | 15 (71.4) |
| 2 | 0 |
| 3 | 2 (9.5) |
| 4 | 0 |
| Primary lesion (%) | |
| Esophageal cancer | 6 (28.6) |
| Head and neck cancer | 7 (33.3) |
| Lung cancer | 6 (28.6) |
| Others (Hepatocellular carcinoma, Sarcoma) | 2 (9.5) |
| Initial RT prescription dose | |
| 50–60 Gy2 EQD2 | 6 (28.6) |
| 60–70 Gy2 EQD2 | 11 (52.4) |
| ≥ 70 Gy2 EQD2 | 4 (19.0) |
| Global maximum dose | |
| Maximum dose [IQR] | 90.6 [63.0, 72.3], Gy2 EQD2 |
| Spinal cord maximum dose | |
| Maximum dose [IQR] | 53.4 [31.8, 47.9], Gy2 EQD2 |
| < 40 Gy2 EQD2 | 12 (57.1) |
| 40–45 Gy2 EQD2 | 1 (4.8) |
| 45–50 Gy2 EQD2 | 5 (23.8) |
| ≥ 50 Gy2 EQD2 | 3 (14.3) |
| Esophageal maximum dose* | |
| Maximum dose [IQR] | 72.6 [51.7, 63.1], Gy2 EQD2 |
| < 50 Gy2 EQD2 | 3 (18.8) |
| 50–60 Gy2 EQD2 | 4 (25.0) |
| 60–70 Gy2 EQD2 | 8 (50.0) |
| ≥ 70 Gy2 EQD2 | 1 (6.2) |
| Symptom at diagnosis of recurrent MESCC | |
| Symptomatic | 17 (81.0) |
| Asymptomatic (Diagnosis by radiographic imaging) | 4 (19.0) |
| Surgery | |
| Surgery followed by SBRT | 10 (47.6) |
| SBRT alone | 11 (52.3) |
| Interval between initial RT and SBRT, months | |
| Median [IQR] | 13.7 [8.6, 30.8] |
| Target spinal levels (%) | |
| Cervical spine (C1–5) | 3 (14.3) |
| Cervical-thoracic junctional spine (C6–Th3) | 8 (38.1) |
| Thoracic spine (Th4–Th12) | 10 (47.6) |
| Number of target vertebrae (%) | |
| 1 | 10 (47.6) |
| 2–3 | 8 (38.1) |
| ≧ 4 | 3 (14.3) |
| Systemic disease | |
| Controlled | 6 (28.6) |
| Active | 15 (71.4) |
| SINS (%) | |
| 0–6 (stable) | 7 (33.3) |
| 7–12 (potentially unstable) | 7 (33.3) |
| 13–18 (unstable) | 7 (33.3) |
| Bilsky grade (%) | |
| 0 (Bone only disease) | 3 (14.3) |
| 1a (Epidural impingement, without thecal sac deformation) | 4 (19.0) |
| 1b (Thecal sac deformation, without spinal cord abutment) | 5 (23.8) |
| 1c (Spinal cord abutment, without compression) | 3 (14.3) |
| 2 (Spinal cord compression, CSF visible) | 3 (14.3) |
| 3 (Spinal cord compression, no CSF visible) | 3 (14.3) |
| Frankel classification (%) | |
| E (normal motor) | 18 (85.7) |
| D (preserved motor function) | 1 (4.8) |
| C (preserved motor non-functional) | 2 (9.6) |
IQR interquartile range, ECOG eastern cooperative oncology group, EQD2 equivalent dose at 2 Gy, MESCC metastatic epidural spinal cord compression, SBRT stereotactic body radiation therapy, SINS spinal instability neoplastic score, CSF cerebrospinal fluid
*The esophageal doses at initial RT for 16 patients are shown, excluding five patients who had primary head and neck cancer or underwent esophagectomy