The ESCC grading system, developed by Bilsky et al., is based on axial T2-weighted MRI and describes the extent of tumor compression on the thecal sac and spinal cord.
| Grade | Description |
|---|---|
| 0 | Bone-only disease (no epidural involvement) |
| 1a | Tumor extends into the epidural space without displacing the dura |
| 1b | Dura displaced, no spinal cord contact |
| 1c | Spinal cord contact without deformation |
| 2 | Spinal cord compression with CSF visible around the cord |
| 3 | Spinal cord compression with no visible CSF around the cord |
Grades 2–3 = High-grade compression → Often require surgical decompression before SBRT to avoid radiation myelopathy and ensure local control.
* Grades 0–1c → Typically amenable to SBRT alone, depending on tumor histology and stability. * Grade 2 → Early deformation, CSF still visible → possible candidate for SBRT in radiosensitive tumors. * Grade 3 → Complete obliteration of CSF space → often mandates separation surgery.
* Based on T2-weighted axial MRI * Evaluate the relationship between tumor, dura, and spinal cord * Must be assessed at each involved level for accurate planning