Spinal Instability Neoplastic Score: An Analysis of Reliability and Validity From the Spine Oncology Study Group

University of Saskatchewan, Royal University Hospital, 103 Hospital Dr, Saskatoon, Saskatchewan, Canada.
Journal of Clinical Oncology (Impact Factor: 18.43). 06/2011; 29(22):3072-7. DOI: 10.1200/JCO.2010.34.3897
Source: PubMed


Standardized indications for treatment of tumor-related spinal instability are hampered by the lack of a valid and reliable classification system. The objective of this study was to determine the interobserver reliability, intraobserver reliability, and predictive validity of the Spinal Instability Neoplastic Score (SINS).
Clinical and radiographic data from 30 patients with spinal tumors were classified as stable, potentially unstable, and unstable by members of the Spine Oncology Study Group. The median category for each patient case (consensus opinion) was used as the gold standard for predictive validity testing. On two occasions at least 6 weeks apart, each rater also scored each patient using SINS. Each total score was converted into a three-category data field, with 0 to 6 as stable, 7 to 12 as potentially unstable, and 13 to 18 as unstable.
The κ statistics for interobserver reliability were 0.790, 0.841, 0.244, 0.456, 0.462, and 0.492 for the fields of location, pain, bone quality, alignment, vertebral body collapse, and posterolateral involvement, respectively. The κ statistics for intraobserver reliability were 0.806, 0.859, 0.528, 0.614, 0.590, and 0.662 for the same respective fields. Intraclass correlation coefficients for inter- and intraobserver reliability of total SINS score were 0.846 (95% CI, 0.773 to 0.911) and 0.886 (95% CI, 0.868 to 0.902), respectively. The κ statistic for predictive validity was 0.712 (95% CI, 0.676 to 0.766).
SINS demonstrated near-perfect inter- and intraobserver reliability in determining three clinically relevant categories of stability. The sensitivity and specificity of SINS for potentially unstable or unstable lesions were 95.7% and 79.5%, respectively.

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Available from: Luiz Vialle, Jul 06, 2014
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    • "Where there is a suggestion of spinal instability, a CT scan with sagittal and coronal reconstructions can assess for vertebral body fracture and any involvement of the pars, facet joints and pedicles. The SINS classification (Fourney et al, 2011) is useful for evaluating the stability of the spine at the involved levels. This evidence-based classification helps to determine stability/instability in a spine affected by tumour by taking into account the location of the spine, pain, lytic nature, alignment, percentage vertebral body height loss and the presence of posterior bony elements: a score between 0–6 denotes stability, a score of 7–12 denotes "
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    ABSTRACT: Myeloma is one of the most common malignancies that results in osteolytic lesions of the spine. Complications, including pathological fractures of the vertebrae and spinal cord compression, may cause severe pain, deformity and neurological sequelae. They may also have significant consequences for quality of life and prognosis for patients. For patients with known or newly diagnosed myeloma presenting with persistent back or radicular pain/weakness, early diagnosis of spinal myeloma disease is therefore essential to treat and prevent further deterioration. Magnetic resonance imaging is the initial imaging modality of choice for the evaluation of spinal disease. Treatment of the underlying malignancy with systemic chemotherapy together with supportive bisphosphonate treatment reduces further vertebral damage. Additional interventions such as cement augmentation, radiotherapy, or surgery are often necessary to prevent, treat and control spinal complications. However, optimal management is dependent on the individual nature of the spinal involvement and requires careful assessment and appropriate intervention throughout. This article reviews the treatment and management options for spinal myeloma disease and highlights the value of defined pathways to enable the proper management of patients affected by it. © 2015 John Wiley & Sons Ltd.
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    • "This study revealed a sensitivity and specificity for potentially unstable or unstable lesions of 95.7% and 79.5%, respectively. It demonstrated near-perfect inter- and intra-observer reliability for differentiating the three clinical categories of stability [8]. Patients with spinal metastases receive the majority of their care from oncologists who often find evaluating stability difficult. "
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    ABSTRACT: The Spinal Instability Neoplastic Score (SINS) categorizes tumor related spinal instability. It has the potential to streamline the referral of patients with established or potential spinal instability to a spine surgeon. This study aims to define the inter- and intra-observer reliability and validity of SINS among radiation oncologists. Thirty-three radiation oncologists, across ten international sites, rated 30 neoplastic spinal disease cases. For each case, the total SINS (0-18 points), three clinical categories (stable: 0-6 points, potentially unstable: 7-12 points, and unstable: 13-18 points), and a binary scale ('stable': 0-6 points and 'current or possible instability'; surgical consultation recommended: 7-18 points) were recorded. Evaluation was repeated 6-8 weeks later. Inter-observer agreement and intra-observer reproducibility were calculated by means of the kappa statistic and translated into levels of agreement (slight, fair, moderate, substantial, and excellent). Validity was determined by comparing the ratings against a spinal surgeon's consensus standard. Radiation oncologists demonstrated substantial (kappa = 0.76) inter-observer and excellent (kappa = 0.80) intra-observer reliability when using the SINS binary scale ('stable' versus 'current or possible instability'). Validity of the binary scale was also excellent (kappa = 0.85) compared with the gold standard. None of the unstable cases was rated as stable by the radiation oncologists ensuring all were appropriately recommended for surgical consultation. Among radiation oncologists SINS is a highly reliable, reproducible, and valid assessment tool to address a key question in tumor related spinal disease: Is the spine 'stable' or is there 'current or possible instability' that warrants surgical assessment?
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    • "However, in some patients, the main complaint is axial pain caused by metastatic disease where there is a risk for tumor-related spinal instability. A recent study by Fourney et al. (12) verified good interobserver reliability in determining stability using SINS. However, the study participants only comprised experienced spinal surgeons, and agreement among less-experienced attending physicians was not evaluated. "
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