Spinal Instability Neoplastic Score [Neurosurgery Wiki]

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====== Spinal Instability Neoplastic Score ======

{{rss>https://pubmed.ncbi.nlm.nih.gov/rss/search/123Q1E1Q18WAxqWBn5J2gH15jm3UScN449AbHz_fjbBgXMVs0A/?limit=15&utm_campaign=pubmed-2&fc=20230419185059}}

Assessment of [[spinal stability]] in [[spine metastases]] is challenging and is mostly done by relying on clinical experience, in the absence of validated [[guideline]]s or an established predetermined set of risk factors. The [[Spinal Instability]] Neoplastic [[Score]] (SINS) provides clinicians with a tool to assess tumor-related [[spine instability]].

{{::spinal_instability_neoplastic_score.jpg?600|}}
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===== 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 warrants surgical consultation to assess for instability prior to proceeding with any planned radiation treatment.
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Assessment of [[spinal stability]] in [[spine metastases]] is challenging and is mostly done by relying on clinical experience, in the absence of validated [[guideline]]s or an established predetermined set of risk factors. The [[Spinal Instability Neoplastic Score]] (SINS) provides clinicians with a tool to assess tumor-related [[spine instability]].

A total of 110 patients were included in this [[retrospective study]]. Time to event was calculated as the difference between start of radiotherapy and date of occurrence of an adverse event or last follow-up, with death being considered a competing event. A competing risk analysis was performed to estimate the effect of the SINS on the cumulative incidence of the occurrence of an adverse event.

Sixteen patients (15%) experienced an adverse event during follow-up. The cumulative incidence for the occurrence of an adverse event at 6 and 12 months was 11.8% (95% confidence interval 5.1%-24.0%) and 14.5% (95% confidence interval 6.9%-22.2%), respectively. Competing risk analysis showed that the final SINS classification was not significantly associated with the cumulative incidence of an adverse event within the studied population.

The clinical applicability of the SINS as a tool to assess spinal instability seems limited.

[[LEVEL OF EVIDENCE 3]].
((Bollen L, Groenen K, Pondaag W, van Rijswijk CSP, Fiocco M, Van der Linden YM,
Dijkstra SPD. Clinical Evaluation of the Spinal Instability Neoplastic Score in
Patients Treated With Radiotherapy for Symptomatic Spinal Bone Metastases. Spine 
(Phila Pa 1976). 2017 Aug 15;42(16):E956-E962. doi: 10.1097/BRS.0000000000002058.
PubMed PMID: 28800570.))
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Moore-Palhares et al. designed a 30 Gy in 4 fractions stereotactic body [[radiotherapy]] protocol, as an alternative option to our standard 2-fraction approach, for primarily large volume, multilevel, or previously radiated spinal metastases.

Objective: To report imaging-based outcomes of this novel fractionation scheme.

The [[institution]]al [[database]] was [[review]]ed to identify all patients who underwent 30 [[Gy]]/4 fractions from 2010 to 2021. [[Primary outcome]]s were magnetic resonance-based [[vertebral compression fracture]] (VCF) and local failure per treated vertebral segment.

They reviewed 245 treated segments in 116 patients. The median age was 64 years (range, 24-90). The median number of consecutive segments within the treatment volume was 2 (range, 1-6), and the clinical target volume (CTV) was 126.2 cc (range, 10.4-863.5). Fifty-four percent had received at least 1 previous course of radiotherapy, and 31% had previous spine surgery at the treated segment. The baseline [[Spinal Instability Neoplastic Score]] was stable, potentially unstable, and unstable for 41.6%, 51.8%, and 6.5% of segments, respectively. The cumulative incidence of local failure was 10.7% (95% CI 7.1-15.2) at 1 year and 16% (95% CI 11.5-21.2) at 2 years. The cumulative incidence of VCF was 7.3% (95% CI 4.4-11.2) at 1 year and 11.2% (95% CI 7.5-15.8) at 2 years. On multivariate analysis, age ≥68 years (P = .038), CTV volume ≥72 cc (P = .021), and no previous surgery (P = .021) predicted an increased risk of VCF. The risk of VCF for CTV volumes <72 cc/≥72 cc was 1.8%/14.6% at 2 years. No case of radiation-induced myelopathy was observed. Five percent of patients developed plexopathy.

30 Gy in 4 fractions was safe and efficacious despite the population being at increased risk of toxicity. The lower risk of VCF in previously stabilized segments highlights the potential for a multimodal treatment approach for complex metastases, especially for those with a CTV volume of ≥72 cc
((Moore-Palhares D, Sahgal A, Zeng KL, Myrehaug S, Tseng CL, Detsky J, Chen H, Ruschin M, Atenafu EG, Wilson J, Larouche J, da Costa L, Maralani PJ, Soliman H. 30 Gy in 4 Stereotactic Body Radiotherapy Fractions for Complex [[Spinal Metastases]]: Mature Outcomes Supporting This Novel Regimen. Neurosurgery. 2023 Apr 19. doi: 10.1227/neu.0000000000002498. Epub ahead of print. PMID: 37074052.)).