Table 4.
Zone 1 | The spinous process to the pars and inferior facet |
Zone 2 | The superior facet, transverse process and pedicle |
Zone 3 | Anterior three-fourth of the vertebral body |
Zone 4 | Posterior one-fourth of the vertebral body |
Level A | Intraosseous |
Level B | Extraosseous |
Level C | Distant tumour spread |