Spinal instability neoplastic score (SINS)

The spinal instability neoplastic score (SINS) helps to assess tumor related instability of the vertebral column. It has been shown to useful in guiding the mobilization or operative management of patients with neoplastic spinal disease.

Studies have reported good inter-observer agreement among both radiologists and radiation oncologists in using the score .

Classification

Location
  • junctional: 3 points
    • occiput-C2, C7-T2, T11-L1, L5-S1
  • mobile spine: 2 points
    • C3-C6, L2-L4
  • semirigid:1 point
    • T3-T10
  • rigid: 0 points
    • S2-S5
Pain
  • mechanical pain: 3 points
    • improves with recumbency or pain with movement or spinal loading
  • occasional pain but not mechanical: 1 point
  • painless lesion: 0 points
Bone lesion
  • lytic: 2 points
  • mixed: 1 points
  • blastic: 0 points
Radiographic spinal alignment
  • subluxation/translation: 4 points
  • de novo deformity (kyphosis/scoliosis): 2 points
  • normal alignment: 0 points
Vertebral body collapse
  • >50% collapse: 3 points
  • <50% collapse: 2 points
  • no collapse with >50% vertebral body involved: 1 point
  • none of the above: 0 points
Posterior spinal element involvement
  • bilateral: 3 points
  • unilateral: 1 point
  • none of the above: 0 points

Treatment and prognosis

The total score is calculated from the parameters above and the following outcomes are inferred:

  • score 0-6: stable
  • score 7-12: potentially unstable
  • score 13-18: unstable

A SINS of 7-18 is meant to warrant surgical consultation to assess for instability prior to proceeding with any planned radiation treatment.

See also