Interobserver agreement for the spine instability neoplastic score varies according to the experience of the evaluator

Incidence, epidemiology, radiology, and classification of metastatic spine tumors: WFNS Spine Committee recommendations

Spinal metastasis (SMs) are the most encountered tumors of the spine. Their occurrence is expected roughly around one to two years after primary tumor diagnosis. Since the advent of Magnetic Resonance Imaging (MRI), this technology has been considered the gold standard for SMs diagnosis and characterization due to its precise ability to comprehend the rate of soft tissue compression/invasion (dural sac/nervous tissue), which is one of the main drivers of management strategies. Computed Tomography (CT) remains unbeatable when a detailed bony anatomy and instability assessment is searched. Nuclear medicine technologies may have a role in diagnosis when standard MR or CT study findings are inconclusive or when the extent of the systemic metastatic disease is studied. The main objective of this study is to offer an update on the epidemiology and radiology of spinal metastasis (SMs), endorsed by the WFNS Spine Committee. A systematic review of the literature of the last ten years gave 1531 results with "spine/spinal metastatic tumors/metastasis AND radiology OR imaging OR classification" as search strings in all fields, of which 56 papers were fully analyzed. The results were discussed and voted on in two consensus meetings of the WFNS (World Federation of Neurosurgical Societies) Spine Committee, reaching a positive or negative consensus using the Delphi method. The committee stated nine recommendations on two main topics: (1) Incidence and epidemiology of SMs; (2) Radiology and classifications of SMs.

Surgical options for metastatic spine tumors: WFNS spine committee recommendations

Surgical treatments for metastatic spine tumors have evolved tremendously over the last decade. Improvements in immunotherapies and other medical treatments have led to longer life expectancy in cancer patients. This, in turn, has led to an increase in the incidence of metastatic spine tumors. Spine metastases remain the most common type of spine tumor. In this study, we systematically reviewed all available literature on metastatic spine tumors and spinal instability within the last decade. We also performed further systematic reviews on cervical metastatic tumors, thoracolumbar metastatic tumors, and minimally invasive surgery in metastatic spine tumors. Lastly, the results from the systematic reviews were presented to an expert panel at the World Federation of Neurosurgical Societies (WFNS) meeting, and their consensus was also presented.

En bloc vertebrectomy: A radical technique for spinal metastases but rarely used

INTRODUCTION AND IMPORTANCE

Total vertebrectomy En bloc by posterior approach is proposed for primary or secondary single-site malignant tumors of the spine to reduce local recurrence and increase patient survival. This type of surgery is gaining increasing recognition. However, it requires a high level of technical skill and knowledge of the anatomy, physiology and biomechanics of the spine.

CASE PRESENTATION

We present here a case of a patient with a single thoracic metastasis with neurological deficit treated by total vertebrectomy via the posterior approach, using a cage and pedicle screws in situ.

DISCUSSION

This surgery is technically demanding, and patient selection therefore requires careful preoperative evaluation.

CONCLUSION

The reproducibility of the En bloc vertebrectomy method documented in the literature is demonstrated and supported by our case.

Accuracy and precision of the spinal instability neoplastic score (SINS) for predicting vertebral compression fractures after radiotherapy in spinal metastases: a meta-analysis

Radiotherapy has played an important role in the treatment of spinal metastases. One of the major complications of radiotherapy is vertebral compression fracture (VCF). Although the spinal instability neoplastic score (SINS) was developed for evaluating spinal instability in patients with spinal metastases, it is also commonly used to predict VCF after radiotherapy in patients with spinal metastases. However, its accuracy for predicting radiotherapy-induced VCF and precision remain controversial. The aim of this study was to clarify the diagnostic value of the SINS to predict radiotherapy-induced VCF and to make recommendations for improving its diagnostic power. We searched core databases and identified 246 studies. Fourteen studies were analyzed, including 7 studies (with 1269 segments) for accuracy and 7 studies (with 280 patients) for precision. For accuracy, the area under the summary receiver operating characteristic curve was 0.776. When a SINS cut-off value of 7 was used, as was done in the included studies, the pooled sensitivity was 0.790 and the pooled specificity was 0.546. For precision, the summary estimate of interobserver agreement was the highest dividing 2 categories based on a cut-off value of 7, and the value was 0.788. The body collapse showed moderate relationship and precision with the VCF. The lytic tumor of bone lesion showed high accuracy and fair reliability, while location had excellent reliability, but low accuracy. The SINS system can be used to predict the occurrence of VCF after radiotherapy in spinal metastases with moderate accuracy and substantial reliability. Increasing the cut-off value and revising the domains may improve the diagnostic performance to predict the VCF of the SINS.

Readmission-Free Survival Analysis in Metastatic Spine Tumour Surgical Patients: A Novel Concept

BACKGROUND

Outcomes commonly used to ascertain success of metastatic spine tumour surgery (MSTS) are 30-day complications/mortality and overall/disease-free survival. We believe a new, effective outcome indicator after MSTS would be the absence of unplanned hospital readmission (UHR) after index discharge. We introduce the concept of readmission-free survival (ReAFS), defined as 'the time duration between hospital discharge after index operation and first UHR or death'. The aim of this study is to identify factors influencing ReAFS in MSTS patients.

PATIENTS AND METHODS

We retrospectively analysed 266 consecutive patients who underwent MSTS between 2005 and 2016. Demographics, oncological characteristics, procedural, preoperative and postoperative details were collected. ReAFS of patients within 2 years or until death was reviewed. Perioperative factors predictive of reduced ReAFS were evaluated using multivariate regression analysis.

RESULTS

Of 266 patients, 230 met criteria for analysis. A total of 201 had UHR, whilst 1 in 8 (29/230) had no UHR. Multivariate analysis revealed that haemoglobin ≥ 12 g/dL, ECOG score of ≤ 2, primary prostate, breast and haematological cancers, comorbidities ≤ 3, absence of preoperative radiotherapy and shorter postoperative length of stay significantly prolonged the time to first UHR.

CONCLUSIONS

Readmission-free survival is a novel concept in MSTS, which relies on patients' general condition, appropriateness of interventional procedures and underlying disease burden. Additionally, it may indicate the successful combination of a multi-disciplinary treatment approach. This information will allow oncologists and surgeons to identify patients who may benefit from increased surveillance following discharge to increase ReAFS. We envisage that ReAFS is a concept that can be extended to other surgical oncological fields.

Is the Spinal Instability Neoplastic Score Accurate and Reliable in Predicting Vertebral Compression Fractures for Spinal Metastasis? A Systematic Review and Qualitative Analysis

Spinal metastases can present with varying degrees of mechanical instability. The Spinal Instability Neoplastic Score (SINS) was developed as a tool to assess spinal neoplastic-related instability while helping to guide referrals among oncology specialists. Some previous papers suggested that the SINS was accurate and reliable, while others disagreed with this opinion. We performed a systematic review regarding the SINS to evaluate its accuracy and precision in predicting vertebral compression fractures (VCFs). The 21 included studies investigated a total of 2118 patients. Thirteen studies dealt with the accuracy of SINS to predict post-radiotherapy VCFs, and eight dealt with the precision. Among 13 studies, 11 agreed that the SINS categories showed statistically significant accuracy in predicting VCF. Among eight studies, body collapse was effective for predicting VCFs in six studies, and alignment and bone lesion in two studies. Location has no statistical significance in predicting VCFs in any of the eight studies. The precision of SINS categories was substantial to excellent in six of eight studies. Among the six components of the SINS, the majority of the included studies reported that location showed near perfect agreement; body collapse, alignment, and posterolateral involvement showed moderate agreement; and bone lesion showed fair agreement. Bone lesion showed significant accuracy in predicting VCFs in half of eight studies, but displayed fair reliability in five of seven studies. Although location was indicated as having near perfect reliability, the component showed no accuracy for predicting VCFs in any of the studies and deleting or modifying the item needs to be considered. The SINS system may be accurate and reliable in predicting the occurrence of post-radiotherapy VCFs for spinal metastasis. Some components seem to be substantially weak and need to be revised.

THE SINS SCALE IN THE EVALUATION OF STABILITY IN PATIENTS WITH SPINAL METASTASIS

ABSTRACT Objective To evaluate the distribution of patients seen in the emergency care unit of the Instituto do Câncer do Estado de São Paulo in the categories “stable”, “indeterminate” and “unstable” as classified by the SINS scale. Methods The medical charts of patients treated between May and September 2013 were reviewed. Patients with a diagnosis of spinal metastasis were analyzed and data on age, sex, primary tumor location, neurological status, and the presence and intensity of pain at rest and in movement were obtained. The SINS criteria were used to evaluate the radiological involvement of the spine. Results We included 81 patients with a mean age of 59.57 years; 32 (39.51%) men and 49 (60.49%) women. Breast (19.75%), prostate (18.52%) and lung (17.28%) were the most common primary tumor sites. Only 18 patients (22.22%) had a single lesion and 51 (62.96%) had 3 or more metastatic lesions. Of the total, 56 (69.14%) were of undetermined stability, 19 were stable (23.46%) and 6 were unstable (7.41%). Twenty-two (27.2%) presented neurological deficit in the physical examination. None of the patients with severe deficit, Frankel A or B, were stable according to the SINS classification. All unstable lesions presented with kyphotic and/or scoliotic deviation (p <0.001). Most patients with undetermined lesions (78.6%) and all patients with unstable lesions had mechanical pain (p = 0.001). Conclusion In this case series, there was a high rate of patients classified by the SINS scale as of undetermined instability (69.14%). There was a high number of patients with multiple metastases (62.96%), which was not considered a modifier of the SINS instability criteria and which needs to be the focus of future studies. Level of evidence IV; Case Series.

Vertebral fractures following stereotactic body radiotherapy for spine metastases

Stereotactic body radiotherapy has emerged as one of the preferred treatments for patients with spine metastases, with the potential for long-term control from lesion irradiation. Post-treatment vertebral compression fractures are a known complication of this therapy, contributing to worsening pain and reduced quality of life, sometimes requiring surgical intervention. This review explores the current knowledge of post-radiotherapy fractures, in terms of the rates and associated predictive factors. A search of databases including Medline, Embase and the Cochrane Library was conducted using keywords such as 'vertebral compression fracture', 'stereotactic body radiotherapy' and 'spine metastases'. The search was limited to published studies up to March 2019, reporting clinical outcomes including both the post-treatment fracture rate and statistical identification of associated risk factors. Rates of post-treatment fractures ranged from 4 to 39%. A variety of factors were found to increase the risk, including the appearance of lytic vertebral disease, degree of pre-existing compression, spinal malalignment, increased dose per fraction and a Spinal Instability Neoplastic Score >6. This knowledge can enable clinicians to counsel patients when considering management options for spine metastases, maintaining the balance between local tumour control and the risk of subsequent fracture.

The clinical utility of the Spinal Instability Neoplastic Score (SINS) system in spinal epidural metastases: a retrospective study

STUDY DESIGN

A retrospective study.

OBJECTIVES

This study assessed the clinical utility of the Spinal Instability Neoplastic Score (SINS) in relation to the surgical treatment of spinal epidural metastasis and factors important for surgical decision-making. These factors include epidural spinal cord compression (ESCC), patient prognosis and neurologic status.

SETTING

Queen Elizabeth II Health Sciences Centre, Halifax, Canada.

METHODS

We identified 285 patients with spinal metastatic disease. Data were extracted through a retrospective review. SINS and ESCC were scored based on CT and MRI, respectively.

RESULTS

Patients were grouped into stable (35%), potentially unstable (52%), and unstable (13%) groups. The overall incidence of metastatic spinal deformity was 9%. Surgical interventions were performed in 21% of patients, including decompression and instrumented fusion (70%), decompression alone (17%), percutaneous vertebral augmentation (9%), and instrumented vertebral augmentation (5%). The use of spinal instrumentation was significantly associated with unstable SINS (p = 0.005). Grade 3 ESCC was also significantly associated with unstable SINS (p < 0.001). Kaplan-Meier analysis revealed that SINS was not a predictor of survival (p = 0.98). In the radiotherapy-alone group, a significant proportion of patients with potentially unstable SINS (30%) progressed into unstable SINS category at an average 364 ± 244 days (p < 0.001).

CONCLUSION

This study demonstrated that more severe categories of SINS were associated with higher degrees of ESCC, and surgical interventions were more often utilized in this group with more frequent placement of spinal instrumentation. Although SINS did not predict patient prognosis, it correlates with the progression of metastatic instability in patients treated with radiotherapy.

Intra- and interobserver reliability of the Spinal Instability Neoplastic Score system for instability in spine metastases: a systematic review and meta-analysis

Mechanical instability is one of the two main indications for surgical intervention in patients with metastatic spine disease. Since its publication in 2010, the Spinal Instability Neoplastic Score (SINS) has been the most commonly used means of assessing mechanical instability. To prove clinically valuable though, diagnostic tests must demonstrate consistency across measures and across observers. Here we report a systematic review and meta-analysis of all prior reports of intraobserver and interobserver reliability of the SINS score. To identify articles, we queried the PubMed, CINAHL, EMBASE, Cochrane, and Web of Science databases for all full-text English articles reporting interobserver or intraobserver reliability for the SINS score, category, or a domain of the SINS score. Articles reporting confidence intervals for these metrics were then subjected to meta-analysis to identify pooled estimates of reliability. Of 167 unique studies identified, seven met inclusion criteria and were subjected to qualitative review and meta-analysis. Intraobserver reliability for SINS score was found to be near perfect [estimate =0.815; 90% CI (0.661-0.969)] and interobserver reliability was substantial [0.673; (0.227-1.12)]. Intraobserver and interobserver reliability among spine surgeons was significantly better than reliability across all observers (both P<0.0001). Qualitative analysis suggested that increased surgeon experience may be associated with greater intraobserver and interobserver reliability among spine surgeons. On the whole, meta-analysis of the available literature suggests SINS to have good intraobserver and interobserver reliability, giving it the potential to be a valuable guide to the management of patients with spinal metastases. Further research is required to demonstrate that SINS score correlates with the clinical decision to stabilize.

Clinical management of spinal metastases-The Dutch national guideline

This article is a summary of the revised Dutch multidisciplinary evidence-based guideline 'Spinal metastases' (English translation available at: https://www.oncoline.nl/spinal-metastases) that was published at the end of 2015. This summary provides an easy-to-use overview for physicians to use in their daily practice.

Prognosis of Single Spinal Metastatic Tumors: Predictive Value of the Spinal Instability Neoplastic Score System for Spinal Adverse Events

STUDY DESIGN

This was a retrospective cohort study.

PURPOSE

We evaluated the predictive value of the Spinal Instability Neoplastic Score (SINS) system for spinal adverse events (SAEs) in patients with single spinal metastatic tumor.

OVERVIEW OF LITERATURE

The SINS system was developed to assess spinal instability in patients with single metastatic spinal tumor. However, the system's potential predictive value for SAEs has been partially studied.

METHODS

This system was applied to a retrospective cohort of 78 patients with single spinal metastatic tumors. The patients underwent surgical treatment and were postoperatively followed up for at least 2 years or until death. The attribution of each score and total SINS to SAE (vertebral compression fracture [VCF] and spinal cord compression [SCC]) occurrence was assessed using the Cox proportional hazards model.

RESULTS

SAEs occurred on average 7 months after diagnosis of spinal metastasis. The mean survival rate post diagnosis was 43 months. Multivariate analysis using the Cox proportional hazards model revealed that the pain (p =0.029) and spinal alignment (p =0.001) scores were significantly related to VCF occurrence, whereas the pain (p =0.008) and posterolateral involvement (p =0.009) scores were related to SCC occurrence.

CONCLUSIONS

Among the components of the SINS system, while pain and spinal alignment showed a significant association with VCF occurrence, pain and posterolateral involvement showed association with SCC occurrence.

The Role of Prognostic Scoring Systems in Assessing Surgical Candidacy for Patients With Vertebral Metastasis: A Narrative Review

STUDY DESIGN

Narrative review.

OBJECTIVES

To review the relevant literature regarding scoring systems for vertebral metastases and quantify their role in contemporary orthopedic practice.

METHODS

A literature search of PubMed, Google Scholar, and Embase was performed on February 7, 2017. Eight scoring systems were selected for detailed review-7 of which were scores focused solely on patient prognosis (Tokuhashi, Tomita, Bauer, Oswestry Spinal Risk Index, Van der Linden, Rades, and Katagiri). The eighth system reviewed was the Spinal Instability Neoplastic Score, which examines for impending spinal instability in patients with vertebral metastases and represents a novel approach compared with hitherto scoring systems.

RESULTS

The Bauer and Oswestry Spinal Risk Index have the most accurate prognostic predictive ability, with the newer Oswestry Spinal Risk Index being favored by the contemporary literature as it demands less investigation and is therefore more readily accessible. There was a growing trend in studies designed to customize scoring systems for individual cancer pathological subtypes. The Spinal Instability Neoplastic Score shows good reliability for predicting instability among surgeons and oncologists.

CONCLUSIONS

The increased understanding of cancer pathology and subsequent development of customized treatments has led to prolonged survival. For patients with vertebral metastases, this affects surgical candidacy not only on the basis of prognosis but also provides prolonged opportunity for the development of spinal instability. Scoring systems have a useful guidance role in these deciding for/against surgical intervention, but in order to remain contemporary ongoing review, development, and revalidation is mandatory.

Management - spinal metastases

Due to a worldwide increase of cancer incidence and a longer life expectancy of patients with metastatic cancer, a rise in the incidence of symptomatic vertebral metastases has been observed. Metastatic spinal disease is one of the most dreaded complications of cancer as it is not only associated with severe pain, but also with paralysis, sensory loss, sexual dysfunction, urinary and fecal incontinency when the neurologic elements are compressed. Rapid diagnosis and treatment have been shown to improve both the quality and length of remaining life. This chapter on vertebral metastases with epidural disease and intramedullary spinal metastases will be discussed in terms of epidemiology, pathophysiology, demographics, clinical presentation, diagnosis, and management. With respect to treatment options, our review will summarize the evolution of conventional palliative radiation to modern stereotactic body radiotherapy for spinal metastases and the surgical evolution from traditional open procedures to minimally invasive spine surgery. Lastly, we will review the most common clinical prediction and decision rules, framework and algorithms, and guidelines that have been developed to guide treatment decision making.

En bloc vertebrectomy for the treatment of spinal lesions. Five years of experience in a single institution: a case series

OBJECTIVES

The objective of this study is to describe the experience of a Brazilian public university hospital regarding the treatment of metastatic or benign spine lesions with en bloc vertebrectomy of the thoracic and lumbar spines.

METHODS

This study was a retrospective case series and included all medical records of patients with benign aggressive, primary malignant, or metastatic spine lesions who underwent en bloc vertebrectomy from 2010 to 2015.

RESULTS

A total of 17 patients were included in the analysis. Most of them (71%) were indicated for surgery based on an oncologic resection for localized disease cure. Overall, 10 of the 17 patients (59%) underwent vertebrectomy via an isolated posterior approach using the technique described by Roy-Camille et al. and Tomita et al., while 7 patients (41%) underwent double approach surgeries. Of the 17 patients who underwent the en bloc resection, 8 are still alive and in the outpatient follow-up (47%), and almost all patients with metastatic lesions (8/9) died. The average survival time following the surgical procedure was 23.8 months. Considering the cases of metastatic lesions and the cases of localized disease (malignant or benign aggressive disease) separately, we observed an average survival time of 15 months and 47.6 months respectively.

CONCLUSION

This study demonstrates and reinforces the reproducibility of the en bloc vertebrectomy technique described by Tomita et al.

Spinal Instability Neoplastic Score (SINS): Reliability Among Spine Fellows and Resident Physicians in Orthopedic Surgery and Neurosurgery

STUDY DESIGN

Reliability analysis.

OBJECTIVES

The Spinal Instability Neoplastic Score (SINS) was developed for assessing patients with spinal neoplasia. It identifies patients who may benefit from surgical consultation or intervention. It also acts as a prognostic tool for surgical decision making. Reliability of SINS has been established for spine surgeons, radiologists, and radiation oncologists, but not yet among spine surgery trainees. The purpose of our study is to determine the reliability of SINS among spine residents and fellows, and its role as an educational tool.

METHODS

Twenty-three residents and 2 spine fellows independently scored 30 de-identified spine tumor cases on 2 occasions, at least 6 weeks apart. Intraclass correlation coefficient (ICC) measured interobserver and intraobserver agreement for total SINS scores. Fleiss's kappa and Cohen's kappa analysis evaluated interobserver and intraobserver agreement of 6 component subscores (location, pain, bone lesion quality, spinal alignment, vertebral body collapse, and posterolateral involvement of spinal elements).

RESULTS

Total SINS scores showed near perfect interobserver (0.990) and intraobserver (0.907) agreement. Fleiss's kappa statistics revealed near perfect agreement for location; substantial for pain; moderate for alignment, vertebral body collapse, and posterolateral involvement; and fair for bone quality (0.948, 0.739, 0.427, 0.550, 0.435, and 0.382). Cohen's kappa statistics revealed near perfect agreement for location and pain, substantial for alignment and vertebral body collapse, and moderate for bone quality and posterolateral involvement (0.954, 0.814, 0.610, 0.671, 0.576, and 0.561, respectively).

CONCLUSIONS

The SINS is a reliable and valuable educational tool for spine fellows and residents learning to judge spinal instability.

Diagnostic algorithm, prognostic factors and surgical treatment of metastatic cancer diseases of the long bones and spine

Oncological management of skeletal metastases has changed dramatically in the last few decades. A significant number of patients survive for many years with their metastases.

Surgeons are more active and the technical repertoire is broader, from plates to intramedullary devices to (tumour) endoprostheses.

The philosophy of treatment should be different in the case of a trauma-related fracture and a pathological fracture. A proper algorithm for establishing a diagnosis and evaluation of prognostic factors helps in planning the surgical intervention.

The aim of palliative surgery is usually to eliminate pain and to allow the patient to regain his/her mobility as well as to improve the quality of life through minimally invasive techniques using life-long durable devices.

In a selected group of patients with an oncologically controlled primary tumour site and a solitary bone metastasis with positive prognostic factors, which meet the criteria for radical excision (approximately 10% to 15% of the cases), a promising three to five years of survival may be achieved, especially in cases of metastases from breast and kidney cancer.

Spinal metastases require meticulous evaluation because decisions on treatment mostly depend on the tumour type, segmental stability, the patient’s symptoms and general state of health.

Advanced radiotherapy combined with minimally invasive surgical techniques (minimally invasive stabilisation and separation surgery) provides durable local control with a low complication rate in a number of patients.

Cite this article: EFORT Open Rev 2017;2:372-381.

Clinical Evaluation of the Spinal Instability Neoplastic Score in Patients Treated With Radiotherapy for Symptomatic Spinal Bone Metastases

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine the predictive value of the Spinal Instability Neoplastic Score (SINS) in a cohort of patients treated with radiotherapy for spinal bone metastases.

SUMMARY OF BACKGROUND DATA

Assessment of spinal stability in metastatic disease is challenging and is mostly done by relying on clinical experience, in the absence of validated guidelines or an established predetermined set of risk factors. The SINS provides clinicians with a tool to assess tumor-related spinal instability.

METHODS

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.

RESULTS

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.

CONCLUSION

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

LEVEL OF EVIDENCE

3.

Is there a correlation between the spinal instability neoplastic score and mechanical pain in patients with metastatic spinal cord compression? A prospective cohort study

INTRODUCTION

The decision for selecting patients for surgical treatment of metastatic spinal cord compression (MSCC) is challenging even for experienced surgeons. Recently, the spinal instability neoplastic score (SINS) has been proposed to help surgeons in the evaluation of spinal stability in the setting of spinal metastases. This study aimed to evaluate the correlation between SINS and preoperative visual analog scale (VAS), as well as the pre- and post-operative association of the VAS and neurological function.

METHODS

A prospective cohort study was conducted in a tertiary referral cancer center. Seventy-nine patients with MSCC were surgically treated from June 2012 to March 2015. Pain status before and after surgery was assessed using VAS score, and neurological status was evaluated using the American Spine Injury Association Impairment Scale (AIS) before and after surgery. Pain was classified as VAS (0-4) none or mild pain; VAS (5-8) moderate pain; and VAS (9-10) as severe pain. Neurological function was scored as AIS A: Complete deficits, AIS B-D: Incomplete deficits, AIS E: Neurologically intact. SINS degrees were classified as 0-6-stable; 7-12 potentially unstable, and 13-18-unstable. Spearman's correlation coefficient test was utilized for correlation between pain and SINS; Chi-square association test was utilized for evaluating pre- and post-operative pain and AIS, as well as the association between SINS and tumor types.

RESULTS

A higher SINS correlates with severe mechanical pain preoperatively (ρ = 0.38, P = 0.001); surgical procedure improved neurological function (P = 0.0001), and decrease pain (P = 0.84). Finally, a higher SINS was also associated with osteolytic tumors (P = 0.03).

CONCLUSIONS

The SINS correlates with mechanical pain. Surgery provides a significant improvement in pain and neurological status, especially in patients who presented higher SINS scores and some degree of preoperative neurological function.

The spine instability neoplastic score (SINS) in the assessment of response to radiotherapy for bone metastases

BACKGROUND

Vertebral metastases are often causing pain and spine instability. Radiotherapy is of significant benefit for painful spine metastases but the response can be very variable. The spine instability neoplastic score (SINS) is a recent classification system for diagnosis of spinal instability caused by vertebral metastases. We analysed the degree of pain relief, the need of drug therapy and the imaging features and the SINS before and after radiotherapy. In particular, we investigated the possible correlation of spine instability defined by pre-treatment SINS with pretreatment pain and with response to radiotherapy.

MATERIAL/METHODS

This study included 121 patients with spine metastases treated with palliative 3D conformal radiotherapy. Pain "at rest" and "breakthrough pain", need for drug therapy in terms of "anti-inflammatory", "weak opioid", "strong opioid", imaging studies and SINS were assessed before and after radiotherapy. Statistical analysis was performed by the correlation coefficient of Spearman and Kruskal-Wallis test.

RESULTS

Pain relief after radiotherapy was observed in 50.4 and 57.8% of patients in terms of pain at rest and breakthrough pain, respectively. The correlation between pain before radiotherapy and SINS was not statistically significant for both pain at rest (p = 0.4) and breakthrough pain (p = 0.49). The correlation between pain response after radiotherapy and SINS was statistically significant for both pain at rest (p = 0.007) and breakthrough pain (p = 0.047).

DISCUSSION/CONCLUSION

The degree of instability, classified according to SINS, resulted to be predictive factor for pain response after radiotherapy. SINS might become a valid tool to identify those patients who can benefit the most from radiotherapy.

The Spinal Instability Neoplastic Score: Impact on Oncologic Decision-Making

STUDY DESIGN

Systematic literature review.

OBJECTIVE

To address the following questions in a systematic literature review: 1. How is spinal neoplastic instability defined or classified in the literature before and after the introduction of the Spinal Instability Neoplastic Score (SINS)? 2. How has SINS affected daily clinical practice? 3. Can SINS be used as a prognostic tool?

SUMMARY OF BACKGROUND DATA

Spinal neoplastic-related instability was defined in 2010 and simultaneously SINS was introduced as a novel tool with criteria agreed upon by expert consensus to assess the degree of spinal stability.

METHODS

PubMed, Embase, and clinical trial databases were searched with the key words "spinal neoplasm," "spinal instability," "spinal instability neoplastic score," and synonyms. Studies describing spinal neoplastic-related instability were eligible for inclusion. Primary outcomes included studies describing and/or defining neoplastic-related instability, SINS, and studies using SINS as a prognostic factor.

RESULTS

The search identified 1414 articles, of which 51 met the inclusion criteria. No precise definition or validated assessment tool was used specific to spinal neoplastic-related instability prior to the introduction of SINS. Since the publication of SINS in 2010, the vast majority of the literature regarding spinal instability has used SINS to assess or describe instability. Twelve studies specifically investigated the prognostic value of SINS in patients who underwent radiotherapy or surgery.

CONCLUSION

No consensus could be determined regarding the definition, assessment, or reporting of neoplastic-related instability before introduction of SINS. Defining spinal neoplastic-related instability and the introduction of SINS have led to improved uniform reporting within the spinal neoplastic literature. Currently, the prognostic value of SINS is controversial.

LEVEL OF EVIDENCE

N/A.

Interobserver reproducibility of radiographic evaluation of lumbar spine instability

OBJECTIVE:

To measure the interobserver reproducibility of the radiographic evaluation of lumbar spine instability.

METHODS:

Measurements of the dynamic radiographs of the lumbar spine in lateral view were performed, evaluating the anterior translation and the angulation among the vertebral bodies. The tests were evaluated at workstations of the organization, through the Carestream Health Vue RIS (PACS), version 11.0.12.14 Inc. 2009© system.

RESULTS:

Agreement in detecting cases of radiographic instability among the observers varied from 88.1 to 94.4%, and the agreement coefficients AC1 were all above 0.8, indicating excellent agreement.

CONCLUSION:

The interobserver analysis performed among orthopedic surgeons with different levels of training in dynamic radiographs of the spine obtained high reproducibility and agreement. However, some factors, such as the manual method of measurement and the presence of vertebral osteophytes, might have generated a few less accurate results in this comparative evaluation of measurements.

OBJETIVO:

Mensurar a reprodutibilidade interobservadores da avaliação radiográfica da instabilidade da coluna lombar.

MÉTODOS:

Foram realizadas mensurações das radiografias dinâmicas de coluna lombar na incidência em perfil, avaliando-se a translação anterior e a angulação entre os corpos vertebrais. Os exames foram avaliados em workstations da própria instituição, por meio do sistema Vue RIS (PACS) da Carestream Health, versão 11.0.12.14 Inc. 2009©.

RESULTADOS:

A proporção de concordância em detecção de casos de instabilidade radiográfica entre os observadores variou de 88,1 a 94,4%, e os coeficientes de concordância AC1 estiveram todos acima de 0,8, indicando concordância excelente.

CONCLUSÃO:

A análise interobservadores realizada entre médicos ortopedistas com diferentes níveis de treinamento em radiografias dinâmicas da coluna vertebral obteve elevada reprodutibilidade e concordância. No entanto, alguns fatores, como método manual de aferição e a presença de osteófitos vertebrais, podem ter gerado alguns resultados menos consistentes nessa avaliação comparativa de medidas.

Spine Instability Neoplastic Score: agreement across different medical and surgical specialties

BACKGROUND CONTEXT

Spinal instability is an acknowledged complication of spinal metastases; in spite of recent suggested criteria, it is not clearly defined in the literature.

PURPOSE

This study aimed to assess intra and interobserver agreement when using the Spine Instability Neoplastic Score (SINS) by all physicians involved in its management.

STUDY DESIGN

Independent multicenter reliability study for the recently created SINS, undertaken with a panel of medical oncologists, neurosurgeons, radiologists, orthopedic surgeons, and radiation oncologists, was carried out.

PATIENT SAMPLE

Ninety patients with biopsy-proven spinal metastases and magnetic resonance imaging, reviewed at the multidisciplinary tumor board of our institution, were included.

OUTCOME MEASURES

Intraclass correlation coefficient (ICC) was used for SINS score agreement. Fleiss kappa statistic was used to assess agreement on the location of the most affected vertebral level; agreement on the SINS category ("stable," "potentially stable," or "unstable"); and overall agreement with the classification established by tumor board.

METHODS

Clinical data and imaging were provided to 83 specialists in 44 hospitals across 14 Spanish regions. No assessment criteria were pre-established. Each clinician assessed the SINS score twice, with a minimum 6-week interval. Clinicians were blinded to assessments made by other specialists and to their own previous assessment. Subgroup analyses were performed by clinicians' specialty, experience (≤7, 8-13, ≥14 years), and hospital category (four levels according to size and complexity). This study was supported by Kovacs Foundation.

RESULTS

Intra and interobserver agreement on the location of the most affected levels was "almost perfect" (κ>0.94). Intra-observer agreement on the SINS score was "excellent" (ICC=0.77), whereas interobserver agreement was "moderate" (ICC=0.55). Intra-observer agreement in SINS category was "substantial" (k=0.61), whereas interobserver agreement was "moderate" (k=0.42). Overall agreement with the tumor board classification was "substantial" (κ=0.61). Results were similar across specialties, years of experience, and hospital category.

CONCLUSIONS

Agreement on the assessment of metastatic spine instability is moderate. The SINS can help improve communication among clinicians in oncology care.

Consensus building in metastatic spine disease

Arana E, Kovacs FM, Royuela A, Asenjo B, Pérez-Ramírez Ú, Zamora J, the Spanish Back Pain Research Network Task Force for the Improvement of Inter-Disciplinary Management of Spinal Metastasis. Spine Instability Neoplastic Score: agreement across different medical and surgical specialties. Spine J 2016;16:591-9 (in this issue).

Prediction of skeletal-related events in patients with non-small cell lung cancer

PURPOSE

Advanced lung cancer frequently causes bone metastasis which can be associated with skeletal-related events (SREs) that may cause significant deterioration of the patient's quality of life (QoL). The Spinal Instability Neoplastic Score (SINS) can be used to assist in standardizing evaluations of neoplastic spinal instability between spinal and non-spine surgeons. This research investigated the association between SREs and SINS for patients with non-small cell lung cancer (NSCLC).

METHODS

Between 2009 and 2013, 47 patients with NSCLC who were diagnosed with bone metastasis were classified using SINS into either a stable group (SINS, 0-6 points) or unstable group (SINS, 7-18 points). The primary endpoint was time from diagnosis of metastasis to SREs. Secondary endpoints included tumor type and epidermal growth factor receptor (EGFR) mutational status. SREs were defined as spinal compression, pathologic fracture, spinal surgery, and hypercalcemia.

RESULTS

Patients included 37 cases of adenocarcinoma and 10 cases of squamous cell carcinoma. Mean follow-up time was 10.2 ± 13.7 months. SRE incidence was 15.0 % (3/20) in the stable group versus 44.4 % (12/27) in the unstable group (p = 0.048). A Cox regression model revealed that an EGFR-positive mutational status (hazard ratio [HR] = 0.15, 95 % CI, 0.030.71; p = 0.017) or good spinal stability (HR = 0.49; 0.08-0.99; p = 0.049) were favorable prognostic factors.

CONCLUSION

The incidence of SREs was significantly lower in NSCLC patients with better spinal stability as determined by SINS, which was a good prediction tool for SREs from bone metastasis. The lower incidence of SREs in EGFR-positive patients suggests tumor biology should be considered when predicting SREs.

Is there a relationship between spinal instability in neoplastic disease and Tokuhashi scoring system?

Spinal instability neoplastic score (SINS) classification evaluates spinal stability by adding together six radiographic and clinical components. The objective of this study was to verify the association between SINS and Tokuhashi scoring system (TSS) score. Fifty-eight patients with vertebral metastases were admitted from 2010 to 2014 at Hospital do Servidor Público Estadual de São Paulo. They were evaluated according to their SINS and Tokuhashi SS score. Fourteen patients (24.13 %) scored from 0 to 6 points (stable spine), 37 (63.79 %) scored from 7 to 12 (potentially unstable), and 7 (12.06 %) scored from 13 to 18 (unstable). In stable spine patients according to SINS, the mean TSS score was 9.2. In potentially unstable spine patients, the mean TSS score was 8.24. In unstable spine patients, mean TSS score was 6.28. There was a statistically significant difference of the TSS score between stable and unstable patients. After evaluating TSS score in each patient, the worse the SINS, the worse was also the TSS score.

The Effect of Introducing the Spinal Instability Neoplastic Score in Routine Clinical Practice for Patients With Spinal Metastases

BACKGROUND

Stable spinal metastases are effectively treated with radiotherapy, whereas unstable spinal metastases often need surgical fixation followed by radiotherapy for local control. The Spinal Instability Neoplastic Score (SINS) was developed as a tool to assess spinal neoplastic related instability with the goal of helping to guide referrals among oncology specialists. We compare the average degree of spinal instability between patients with spinal metastases referred for surgery or for radiotherapy and evaluate whether this difference changed after introduction of the SINS in clinical practice.

METHODS

All patients with spinal metastases treated with palliative surgery or radiotherapy in the period 2009-2013 were identified in two spine centers. For all patients, the SINS was scored on pretreatment imaging. The SINS before and after introduction of the SINS in 2011 were compared within the surgical and radiotherapy group. Furthermore, the overall SINS was compared between the two groups.

RESULTS

The overall SINS was significantly higher in the surgical group, with a mean SINS of 10.7 (median 11) versus 7.2 (median 8) for the radiotherapy group. The mean SINS decreased significantly for both groups after introduction of the SINS in clinical practice from 11.2 to 10.3 in the surgical group and from 8.4 to 7.2 in the radiotherapy group.

CONCLUSION

The SINS differed significantly between patients treated with surgery or radiotherapy. The introduction of SINS led to a decrease in SINS score for both groups, suggesting that using SINS in metastatic spinal disease increases awareness for instability and may subsequently result in earlier referrals for surgical intervention.

IMPLICATIONS FOR PRACTICE

Spinal metastases can present with varying degrees of mechanical instability. Because unstable spinal metastases may respond insufficiently to palliative radiotherapy and can lead to loss of ambulation, timely detection and appropriate referral are important. The Spinal Instability Neoplastic Score (SINS) may help physicians caring for patients with metastasized disease to identify spinal instability before the onset of neurological deficits. In this study, it was shown that the introduction of SINS in routine practice led to a decrease in spinal instability in radiotherapy and surgical cohorts. The use of SINS may increase awareness of instability and subsequently result in earlier referrals.

ASSESSMENT OF SCORES IN DECISION MAKING IN METASTASES OF THE SPINE

Objective : The aim of this study is to assess the intra- and interobserver concordance of SINS, Harrington, Tokuhashi and Tomita scores among general orthopedic surgeons and spine surgeons with experience above 5 and 10 years in the evaluation of patients with spinal metastasis. Methods : Twenty cases of patients with metastatic lesion of the spine were presented to 10 examiners and the scores aforementioned have been applied. After six weeks, the cases were reintroduced in a different order and data were analyzed. Results : The intraobserver reliability showed better agreement in SINS score among examiners with less experience and Harrington and Tomita scores among those who had more than 10-year experience. The interobserver reliability of the examiners of the group with over 10-year experience showed higher precision when using these scores, especially Harrington and Tomita. The SINS score was the choice for daily practice and was able to modify the management more often. Conclusions : This study demonstrated that the use of predictive scores of instability, Harrington, and prognosis, Tomita, had a higher intra- and interobserver reliability particularly among spine surgeons with experience above 10 years.

Late failure of posterior fixation without bone fusion for vertebral metastases

OBJECTIVE

: To verify the frequency of late radiological com-plications in spinal fixation surgeries performed without fu-sion in oncological patients

METHODS

: This is a retrospective analysis analysing failure in cases of non-fused vertebral fixation in an oncology reference hospital between 2009 and 2014. Failure was defined as implant loosening or bre-akage, as well as new angular or translation deformities

RESULTS

: One hundred and five cases were analyzed. The most common site of primary tumor was the breast and the most common place of metastasis was the thoracic spine. The average follow-up was 22.7 months. Nine cases (8%) of failure were reported, with an average time until failure of 9.5 months. The most common failure was implant loosening. No case required further surgery

CONCLUSION

: The occurrence of failure was not different than that reported for fused cases. The time interval until failure was higher than the median of survival of the majority (88%) of cases. Level of Evidence IV, Therapeutic Study.

Spinal instability as defined by the spinal instability neoplastic score is associated with radiotherapy failure in metastatic spinal disease

BACKGROUND CONTEXT

Although radiotherapy is effective in achieving pain relief in most patients, it is not completely understood why some patients respond well to radiotherapy and others do not. Our hypothesis was that metastatic bone pain, if predominantly caused by mechanical instability of the spine, responds less well to radiotherapy than metastatic bone pain caused by local tumor activity. Recently, the spinal instability neoplastic score (SINS) was proposed as a standardized referral tool for nonspine specialists to facilitate early diagnosis of spinal instability.

PURPOSE

To investigate the association between spinal instability as defined by the SINS and response to radiotherapy in patients with spinal metastases.

STUDY DESIGN

A retrospectively matched case-control study in an academic tertiary referral center, conducted according to the Strengthening the Reporting of Observational Studies in Epidemiology guidelines.

PATIENT SAMPLE

Thirty-eight patients with spinal metastases who were retreated after initial palliative radiotherapy from January 2009 to December 2010 were matched to 76 control patients who were not retreated.

OUTCOME MEASURES

Radiotherapy failure as defined by retreatment (radiotherapy, surgery, and conservative) after palliative radiotherapy for spinal metastases.

METHODS

Radiotherapy planning computed tomography scans were scored by a blinded spine surgeon according to the SINS criteria. The association between SINS and radiotherapy failure was estimated by univariate and multivariate conditional logistic regression analysis.

RESULTS

Median SINS was 10 (range 4-16) for cases and 7 (range 1-16) for controls. The SINS was significantly and independently associated with radiotherapy failure (adjusted odds ratio, 1.3; 95% confidence interval, 1.1-1.5; p=.01).

CONCLUSIONS

This study shows that a higher spinal instability score increases the risk of radiotherapy failure in patients with spinal metastases, independent of performance status, primary tumor, and symptoms. These results may support the hypothesis that metastatic spinal bone pain, predominantly caused by mechanical instability, responds less well to radiotherapy than pain mainly resulting from local tumor activity.

Management of neoplastic spinal tumors in a spine surgery care unit

BACKGROUND CONTEXT

Spinal cord compression and fracture are possible complications of spine metastasis and multiple myeloma. Prompt diagnosis and treatment of threatening lesions are likely to reduce the frequency of these dreaded complications.

PURPOSE

To evaluate the proportion of neoplastic spine lesions operated on emergency.

STUDY DESIGN

Retrospective study.

PATIENT SAMPLE

All patients who underwent palliative surgery for the treatment of a neoplastic spine lesion in our institution between 2005 and 2012.

OUTCOME MEASURES

Percentage of patients who underwent surgery as an emergency for acute fracture or rapid neurological decline.

METHODS

We retrospectively reviewed the data of all patients who underwent palliative surgery for the treatment of a neoplastic spine lesion from solid cancer or multiple myeloma, in our institution between January 2005 and December 2012. The study was supported by grant from our institution.

RESULTS

A total of 317 patients were included in the study. There were 166 men and 151 women and the mean age was 57.97 years (range 26-88; SD 12.45). The cancer was known for 224 patients, while the lesion revealed the disease for the other 93 patients. The percentage of patients with known cancer operated as an emergency in our institution decreased significantly between 2005 and 2012 (p = 0.0006).

CONCLUSION

Due to the variability of clinical and radiological presentations, best care requires a truly multidisciplinary approach, to offer each patient a prompt and individualized treatment option, which is likely to reduce the incidence of emergency surgeries.

Laminectomy without instrumentation for surgical treatment of metastatic spinal cord compression

OBJECTIVE: To analyze the development of mechanical complications as a result of spinal decompression or cauda equina in patients with metastatic tumors of the spine via laminectomy or laminoartrectomy without fixation. METHODS: We studied the medical records of all patients submitted to spine decompression with laminectomy without fixation. The decompression was indicated to treat cord compression or cauda equina caused by metastatic tumors. Patients were evaluated for the development of postoperative mechanical instability by comparing the preoperative radiological examinations with the latest one available in the medical record review.. In these images, we evaluated the emergence of new deformity in the sagittal or coronal planes and translational deformity. We consider new deformity, signs of deformity greater or equal to 5° in the coronal or sagittal planes and signs of increased vertebral translation greater than or equal to 3 mm. RESULTS: No patient developed radiological instability in the period evaluated with an average follow-up of 163.24 days (3-663). The complication rate in our sample was not higher than the previously reported in the literature. CONCLUSION: Isolated laminectomy at one or more levels is a safe procedure for the treatment of metastatic spinal cord compression where the spine is judged stable before surgery.

Current paradigms for metastatic spinal disease: an evidence-based review

INTRODUCTION

Management of metastatic spine disease is quite complex. Advances in research have allowed surgeons and physicians to better provide chemotherapeutic agents that have proven more efficacious. Additionally, the advancement of surgical techniques and radiosurgical implementation has altered drastically the treatment paradigm for metastatic spinal disease. Nevertheless, the physician-patient relationship, including extensive discussion with the neurosurgeon, medicine team, oncologists, radiation oncologists, and psychologists, are all critical in the evaluation process and in delivering the best possible care to our patients. The future remains bright for continued improvement in the surgical and nonsurgical management of our patients with metastatic spine disease.

METHODS

We include an evidence-based review of decision making strategies when attempting to determine most efficacious treatment options. Surgical treatments discussed include conventional debulking versus en bloc resection, conventional RT, and radiosurgical techniques, and minimally invasive approaches toward treating metastatic spinal disease.

CONCLUSIONS

Surgical oncology is a diverse field in medicine and has undergone a significant paradigm shift over the past few decades. This shift in both medical and surgical management of patients with primarily metastatic tumors has largely been due to the more complete understanding of tumor biology as well as due to advances in surgical approaches and instrumentation. Furthermore, radiation oncology has seen significant advances with stereotactic radiosurgery and intensity-modulated radiation therapy contributing to a decline in surgical treatment of metastatic spinal disease. We analyze the entire spectrum of treating patients with metastatic spinal disease, from methods of diagnosis to the variety of treatment options available in the published literature.

[Prognosis scores for spinal metastases]

Advances in early detection and therapy of spinal metastasis have improved life expectancy of patients with various tumor entities. However, this and the demographic development have led to an increased risk for developing spinal metastases. Numerous prognostic factors have been determined to allow an assessment of outcome and survival time of patients with metastatic spinal tumors. The implementation of these factors into different scoring systems has been encouraging in the decision making process of spinal surgery. This overview highlights some of the most important prognostic factors and scores which may facilitate surgical considerations.