Spinal Instability Neoplastic Score Research Articles

Impact of instrumentation material on local recurrence: a case-matched series using carbon fiber-PEEK vs. titanium.

Spine metastases are a major burden of oncologic care, contributing to substantial morbidity. A well-established treatment paradigm for patients with metastatic epidural spinal cord compression includes separation surgery followed by stereotactic body radiotherapy (SBRT). Innovations in implant technology have brought about the incorporation of Carbon fiber-reinforced polyetheretherketone (CFR-PEEK) instrumentation for spinal fixation. We present our experience of CFR-PEEK instrumentation, comparing outcomes and complication profiles with a matched cohort of titanium instrumented cases for spine metastatic disease. Oncology patients who underwent spinal fusion for metastatic spine disease from 2012 to 2023 were retrospectively reviewed. Ninety-nine cases with CFR-PEEK fusions were case-control matched with 50 titanium controls (2:1 ratio) based upon primary tumor type and spinal instability neoplastic score (SINS) location. Demographic, clinical, radiographic and progression free survival (PFS) were analyzed. In the study years, 263 patients underwent spinal decompression and fusion, for which 148 patients met predetermined inclusion criteria. Of these, 49 had titanium instrumentation, and 99 had CFR-PEEK. Complication profiles, including hardware failure and infection were similar between the groups. There was no significant difference in PFS between all CFR-PEEK and titanium patients (143 days versus 214 days; p = 0.41). When comparing patients in which recurrence was noted, CFR-PEEK patients had recurrence detected two times earlier than titanium patients (94 days versus 189 days; p = 0.013). In this case matched cohort, CFR-PEEK demonstrated decreased overall PFS suggestive of earlier local recurrence identification. Long-term studies are warranted for better evaluation of the impact on survival and systemic disease progression.

Safety and Efficacy of Balloon-Assisted Kyphoplasty Followed by Stereotactic Body Radiation Therapy for Pathological Fractures.

In patients experiencing pain secondary to pathological compression fractures, balloon-assisted kyphoplasty and subsequent stereotactic body radiation therapy (SBRT) may allow for restoration of vertebral height and irradiation of the underlying malignancy to control local disease progression. The aim of this study was to evaluate the safety and efficacy of kyphoplasty treatment before SBRT in patients with spinal metastases and benign tumors. An analysis of a prospectively collected database of 70 patients and 75 metastatic and benign spinal lesions that underwent kyphoplasty before SBRT at a single institution (2002-2023) was conducted. Patient characteristics were recorded, including treatment history, dosimetry and fractionation schedule, pain outcomes, local control (LC), and overall survival. The Bilsky score and Spinal Instability Neoplastic Score were calculated to assess epidural involvement and spinal stability, respectively. The median time from kyphoplasty to SBRT was 29 days (range: 2-159). Seventy-two lesions (96%) were managed with single-fraction SBRT and 3 lesions (4%) with a multifraction regimen. The median single-fraction prescription dose was 20 Gy (range: 12-25) delivered to a median tumor volume of 35.1 cc (range: 2.2-160). After a median follow-up period of 9 months (range: 1-201), 6 lesions (8%) locally progressed. Pain was reported to improve or remain stable for most patients (88%). The LC rate was 88% at 6 months, 1 year, and 2 years. No prognostic factors were significantly associated with LC. The median overall survival was 11 months (range: 1-201) after radiosurgery. There were no reports of cement extravasation or radiation-induced neurological deficit. Two acute pain flares (3%) were reported 1 and 3 months after radiosurgery. The combined kyphoplasty and SBRT treatment paradigm can be used to treat patients with painful pathological compression fractures. Long-term LC and patient-reported improvement in pain were observed without the morbidity associated with open surgery.

The Spinal Instability Neoplastic Score correlates with epidural spinal cord compression -a retrospective cohort of 256 surgically treated patients with spinal metastases

BackgroundBone metastases can compromise the integrity of the spinal canal and cause epidural spinal cord compression (ESCC). The Spinal Instability Neoplastic Score (SINS) was developed in order to evaluate spinal instability due to a neoplastic process. The SINS has reached wide acceptance among clinicans but its prognostic value is still controversial. The aim was to investigate the correlation between the SINS and ESCC and the association between SINS and ambulation before and survival after surgery.MethodsCorrelations were assessed between SINS and grades of ESCC in patients who underwent spine surgery for spinal metastases. CT and MRI were used to calculate SINS and the grades of ESCC respectively. Correlations were analyzed with the Spearman’s correlation test. Postoperative survival was estimated with Kaplan-Meier analysis and survival curves were compared with the log-rank test. The Cox proportional hazard model was used to assess the effect of prognostic variables including age, ambulation before surgery, SINS, and the Karnofsky Performance Status (KPS) as covariates.ResultsThe study included 256 patients (196 men and 60 women) with a median age of 70 (24–88) years. The mean SINS was 10. One hundred fifty-two patients (59%) had lost ambulation before surgery. One hundred and one patients had grades 0–2 and 155 patients had grade 3 according to the ESCC-scale. SINS correlated with the grades of ESCC (p = 0.001). The SINS score was not associated with ambulation before surgery (p = 0.63). The median postoperative survival was 10 months, and there was no difference in postoperative survival between the SINS categories (p = 0.25). The ability to walk before surgery and a high KPS were associated with longer postoperative survival.ConclusionSINS correlated with grades of ESCC, which implies that higher SINS may be considered as an indicator of risk for developing ESCC. The SINS was not associated with ambulation before or survival after surgery.

Feasibility and Safety of Lateral and Posterolateral Percutaneous Vertebroplasty of Osteolytic C1–C2 Lesions under Computed Tomography Guidance and Local Anesthesia

PurposeTo evaluate the safety and effectiveness of lateral or posterolateral percutaneous vertebroplasty (PVP) of osteolytic C1–C2 lesions performed under computed tomography (CT) guidance and local anesthesia. Materials and methodsA retrospective study of 16 consecutive patients (11 females and 5 males; aged from 24 to 86 years; median age, 65.5 years) who underwent 17 lateral or posterolateral PVP was performed. Pain status was assessed using a visual analog scale (VAS). Patients were evaluated preoperatively as baseline and at 24 hours and 1, 6, and 12 months postoperatively, until death, or until loss to follow-up. The Oswestry Disability Index was used to evaluate the patients’ functional disability preoperatively. The adverse events were recorded using the Society of Interventional Radiology (SIR) classification. ResultsThe technical success was 100% (17/17) for a median Spinal Instability Neoplastic Score of 13.5 (interquartile range [IQR], 6.75, 20.25). Mean clinical follow-up was 10.1 months (range, 6–36 months; median, 19.5 months, IQR, 4, 35 months). Mean VAS score decreased significantly from 7.5 (SD ± 2.1) preoperatively to 1.6 (SD ± 1.5) 24 hours postoperatively, and 1.0 (SD ± 1.1), 1.5 (SD ± 1), and 0.5 (SD ± 1.5) at 1, 6, and 12 months, respectively (all P < .001). No severe adverse events were observed, but 3 cases of asymptomatic cement leakage were noted (SIR Grade 1; 17.6% [3/17]). ConclusionsLateral and posterolateral PVP performed under CT guidance and local anesthesia is safe and effective to treat symptomatic osteolytic C1–C2 lesions.

Surgical Interventions Following Radiotherapy in Spinal Metastases with Intermediate Instability: A Risk Factor Analysis: The Korean Society of Spinal Tumor Multicenter Study (KSST 2022-02).

One important determinant in choosing a treatment modality is spinal instability. Clear management guidelines are suggested for stable and unstable spinal metastatic lesions, but lesions in the intermediate instability category (SINS [spinal instability neoplastic score] score of 7-12) remain a clinical dilemma. This study aims to analyze the risk factors necessitating surgical intervention after radiotherapy (RT) in patients with those lesions. A multicenter cohort of 469 patients with spinal metastases of intermediate instability who received radiotherapy (RT) as the initial treatment between 2019 and 2021 were retrospectively enrolled. All patients were neurologically intact at the time of RT. According to the performance of surgical intervention after RT, various clinical and radiographic risk factors for surgical intervention were compared between surgery and non-surgery groups using uni- and multivariate analyses. A recursive partitioning analysis (RPA) was performed using significant determinants identified in multivariate analysis. The mean age at the time of RT was 59.9 years and there were 198 females. The lung was the most common primary site. During the mean follow-up duration of 18.2 months, surgical treatment was required in 79 (17.9%) of patients. The most common surgical method was decompressive laminectomy with stabilization (62.0%), followed by vertebrectomy with stabilization (22.8%) and stabilization only (15.2%). The mean SINS for the total cohort was 9.0. Multivariate regression analyses revealed that the primary tumor site of the lung, liver, and kidney, higher Bilsky grades of ESCC, lytic bone lesions, and higher EQD210 were significant risk factors for surgical intervention after RT. Among them, Bilsky grade, primary tumor type of the lung, liver, and kidney, and EQD210 were the most important determinants for expecting the probability of surgical intervention on RPA. Surgical intervention was performed in 17.9% of patients with intermediate instability after RT as the initial treatment. The primary tumor site of the lung, liver, and kidney, higher Bilsky grade of ESCC, and EQD210 were the most important determinants for expecting the probability of surgical intervention. Therefore, the optimal treatment strategy needs to be devised by carefully evaluating the risk of surgical intervention.

The Truly Intermediate Subgroup Within the SINS “Potentially Unstable” Category: The Matryoshka Doll Phenomenon

A significant dilemma exists for the surgical plan of spinal metastases with a spinal instability neoplastic score (SINS) of 7-12. Our aim is to trim down this range of "potential instability" and find a virtual cut-off value for instrumentation. We performed a retrospective study on 60 patients who underwent surgical intervention for vertebral metastasis. They were segregated into 'instrumented' and "noninstrumented" groups. The primary endpoint of the study was to see whether surgical stabilization was done. Although univariate analysis showed the overall SINS score, involvement of posterior elements, and mechanical pain to be the factors that significantly affected our decision making in favor of stabilization, only the SINS score was found to be statistically significant on multivariate analysis. On plotting the proportion of patients undergoing stabilization at each SINS score we found the curves to crossover between SINS 8 and 9, ran almost parallel to each other at values 9 and 10 and then seemed to diverge from each other significantly at values above 10. Taking SINS 9 as the cut-off value above which instrumentation is advised, the receiver operating characteristic curve had a sensitivity of 67.57% (95% confidence interval 50.21% to 81.99%) and specificity of 73.91% (95% confidence interval 51.59% to 89.77%). The area under the curve was 0.79 (0.67-0.91). SINS 9-10 seems to be the actual ambiguous subset in the wider subgroup of the 'potentially unstable' category SINS 7-12, like a 'Matryoshka doll'. A SINS value of 9 can be seen as a cut-off value for instrumentation.

Remineralization of lytic spinal metastases after radiation therapy – A retrospective cohort study comparing conventional external beam radiation therapy with stereotactic ablative body radiation

IntroductionOsteolytic spinal metastases (SM) have a higher risk of fracture. In this study we aim to confirm the remineralization of lytic SM after radiation therapy. Secondary the influence of SBRT compared to cEBRT and tumor type will be analyzed. MethodsA retrospective cohort study was performed. Results87 patients, 100 SM were included. 29 received SBRT, 71 cEBRT. Most common primary tumors were breast (35 %), lung (26 %) and renal (11 %). Both cEBRT and SBRT resulted in a significant increase of bone mineral density (BMD) (83.76 HU ± 5.72 → 241.41 HU ± 22.58 (p < 0.001) and 82.45 ± 9.13 → 179.38 ± 47.83p = 0.026). There was a significant increase in absolute difference of BMD between the SM and reference vertebrae (p < 0.001). There was no significant difference between SBRT and cEBRT. There was no increase of BMD in renal lytic SM after radiation therapy (pre-treatment: 85.96 HU ± 19.07; 3 m 92.00 HU ± 21.86 (p = 0.882); 6 m 92.06 HU ± 23.94 (p = 0.902); 9 m 70.44 HU ± 7.45 (p = 0.213); 12 m 98.08 HU ± 11.24 (p = 0.740)). In all other primary tumors, a significant increase of BMD after radiation therapy was demonstrated (p < 0,05). ConclusionWe conclude that the BMD of lytic SM increases significantly after radiation therapy. Lytic SM of primary renal tumors are the exception; there is no significant remineralization of renal lytic SM after radiation therapy. There is no benefit of SBRT over cEBRT in this remineralization. These findings should be taken into account when deciding on surgery in the potentially unstable group defined by the spinal instability neoplastic score.

Vertebral body collapse after spine stereotactic body radiation therapy: a single-center institutional experience.

Spine stereotactic body radiation therapy (SBRT) for the treatment of metastatic disease is increasingly utilized owing to improved pain and local control over conventional regimens. Vertebral body collapse (VBC) is an important toxicity following spine SBRT. We investigated our institutional experience with spine SBRT as it relates to VBC and spinal instability neoplastic score (SINS). Records of 83 patients with 100 spinal lesions treated with SBRT between 2007 and 2022 were reviewed. Clinical information was abstracted from the medical record. The primary endpoint was post-treatment VBC. Logistic univariate analysis was performed to identify clinical factors associated with VBC. Median dose and number of fractions used was 24 Gy and 3 fractions, respectively. There were 10 spine segments that developed VBC (10%) after spine SBRT. Median time to VBC was 2.4 months. Of the 11 spine segments that underwent kyphoplasty prior to SBRT, none developed subsequent VBC. No factors were associated with VBC on univariate analysis. The rate of vertebral body collapse following spine SBRT is low. Prophylactic kyphoplasty may provide protection against VBC and should be considered for patients at high risk for fracture.

Patient-Reported and Clinical Outcomes of Surgically Treated Patients With Symptomatic Spinal Metastases: Results From Epidemiology, Process, and Outcomes of Spine Oncology (EPOSO), a Prospective, Multi-Institutional and International Study.

The palliative impact of spine surgery for metastatic disease is evolving with improvements in surgical technique and multidisciplinary cancer care. The goal of this study was to prospectively evaluate long-term clinical outcomes including health-related quality-of-life (HRQOL) measures, using spine cancer-specific patient-reported-outcome (PRO) measures, in patients with symptomatic spinal metastases who underwent surgical management. The Epidemiology, Process, and Outcomes of Spine Oncology (EPOSO, ClinicalTrials.gov identifier: NCT01825161) trial is a prospective-observational cohort study that included 10 specialist centers in North America and Europe. Patients aged 18 to 75 years who underwent surgery for spinal metastases were included. Prospective assessments included both spine tumor-specific and generic PRO tools which were collected for a minimum of 2 years post-treatment or until death. Two hundred and eighty patients (51.8% female, mean age 57.9 years) were included. At presentation, the mean Charlson Comorbidity Index was 6.0, 35.7% had neurological deficits as defined by the American Spinal Cord Injury Association scores, 47.2% had high-grade epidural spinal cord compression (2-3), and 89.6% had impending or frank instability as measured by a Spinal Instability Neoplastic Score of ≥7. The most common primary tumor sites were breast (20.2%), lung (18.8%), kidney (16.2%), and prostate (6.5%). The median overall survival postsurgery was 501 days, and the 2-year progression-free-survival rate was 38.4%. Compared with baseline, significant and durable improvements in HRQOL were observed at the 6-week, 12-week, 26-week, 1-year, and 2-year follow-up assessments from a battery of PRO questionnaires including the spine cancer-specific, validated, Spine Oncology Study Group Outcomes Questionnaire v2.0, the Short Form 36 version 2, EuroQol-5 Dimension (3L), and pain numerical rating scale score. Multi-institutional, prospective-outcomes data confirm that surgical decompression and/or stabilization provides meaningful and durable improvements in multiple HRQOL domains, including spine-specific outcomes based on the Spine Oncology Study Group Outcomes Questionnaire v2.0, for patients with metastatic spine disease.

The 5-Item Modified Frailty Index as a Predictor of Postoperative Outcomes in Thoracic Metastatic Epidural Spinal Cord Compression

BackgroundPatients with thoracic metastatic epidural spinal cord compression (MESCC) often undergo extensive surgical decompression to avoid functional decline. Though limited in scope, scales including the revised cardiac risk index (RCRI) are used to stratify surgical risk to predict perioperative morbidity. This study uses the 5-item modified frailty index (mFI-5) to predict outcomes following transpedicular decompression/fusion for high-grade MESCC. MethodsA retrospective chart review was conducted on patients who underwent transpedicular decompression and fusion for MESCC (baseline demographics, spinal instability neoplastic score, preoperative and postoperative Bilsky scores, primary cancer type, RCRI). Primary outcomes included length of stay (LOS), intraoperative estimated blood loss, readmission/reoperation within 90 days of index surgery, 90-day mortality, and post-hospitalization disposition. Results127 patients were included in our study. 90% of patients’ lesions were Bilsky 2 or greater. Increasing frailty, measured by mFI-5, was a significant predictor of increased LOS (p<0.01) and 90-day mortality (p<0.05). Multivariate analysis adjusting for sex, BMI, and age still showed statistical significance (p<0.05). MFI-5 was not a significant predictor of readmission/reoperation within 90 days or estimated blood loss. Age – not mFI-5 or RCRI – was a significant predictor for posthospitalization non-home disposition (p=0.001). ConclusionsThe mFI-5 can serve as a useful predictor of outcomes after transpedicular decompression and fusion for thoracic MESCC as it can account for the patient's frailty. Our study demonstrated the mFI-5 as a predictor of LOS and 90-day mortality. These results provide a background to both understanding and integrating frailty into decision-making in MESCC.

Ongoing decision-making dilemma for treatment of de novo spinal infections: a comparison of the Spinal Infection Treatment Evaluation Score with the Spinal Instability Spondylodiscitis Score and Spine Instability Neoplastic Score.

De novo spinal infections are an increasing medical problem. The decision-making for surgical or nonsurgical treatment for de novo spinal infections is often a non-evidence-based process and commonly a case-by-case decision by single physicians. A scoring system based on the latest evidence might help improve the decision-making process compared with other purely radiology-based scoring systems or the judgment of a single senior physician. Patients older than 18 years with an infection of the spine who underwent nonsurgical or surgical treatment between 2019 and 2021 were identified. Clinical data for neurological status, pain, and existing comorbidities were gathered and transferred to an anonymous spreadsheet. Patients without an MR image and a CT scan of the affected spine region were excluded from the investigation. A multidisciplinary expert panel used the Spine Instability Neoplastic Score (SINS), Spinal Instability Spondylodiscitis Score (SISS), and Spinal Infection Treatment Evaluation Score (SITE Score), previously developed by the authors' group, on every clinical case. Each physician of the expert panel gave an individual treatment recommendation for surgical or nonsurgical treatment for each patient. Treatment recommendations formed the expert panel opinion, which was used to calculate predictive validities for each score. A total of 263 patients with spinal infections were identified. After the exclusion of doubled patients, patients without de novo infections, or those without CT and MRI scans, 123 patients remained for the investigation. Overall, 70.70% of patients were treated surgically and 29.30% were treated nonoperatively. Intraclass correlation coefficients (ICCs) for the SITE Score, SINS, and SISS were 0.94 (95% CI 0.91-0.95, p < 0.01), 0.65 (95% CI 0.91-0.83, p < 0.01), and 0.80 (95% CI 0.91-0.89, p < 0.01). In comparison with the expert panel decision, the SITE Score reached a sensitivity of 96.97% and a specificity of 81.90% for all included patients. For potentially unstable and unstable lesions, the SISS and the SINS yielded sensitivities of 84.42% and 64.07%, respectively, and specificities of 31.16% and 56.52%, respectively. The SITE Score showed higher overall sensitivity with 97.53% and a higher specificity for patients with epidural abscesses (75.00%) compared with potentially unstable and unstable lesions for the SINS and the SISS. The SITE Score showed a significantly higher agreement for the definitive treatment decision regarding the expert panel decision, compared with the decision by a single physician for patients with spondylodiscitis, discitis, or spinal osteomyelitis. The SITE Score shows high sensitivity and specificity regarding the treatment recommendation by a multidisciplinary expert panel. The SITE Score shows higher predictive validity compared with radiology-based scoring systems or a single physician and demonstrates a high validity for patients with epidural abscesses.

Primary Stereotactic Body Radiotherapy for Spinal Bone Metastases From Lung Adenocarcinoma

ObjectiveThis study aimed to assess the results of primary stereotactic body radiotherapy (SBRT) for spinal bone metastases (SBM) originating from lung adenocarcinoma (ADC). We considered the revised Tokuhashi score (rTS), Spinal Instability Neoplastic Score (SINS), and genetic characteristics. MethodsWe examined adult patients with lung ADC who underwent primary SBRT (using the CyberKnife System) for SBM between March 2012 and January 2023. ResultsWe analyzed data from 99 patients, covering 152 SBM across 194 vertebrae. The overall local control (LC) rate was 77.6% for SBM from lung ADC, with a LC rate of 90.7% at 1 year. The median period for local progression (LP) occurrence was recorded at 10.0 (3-52) months. Additionally, Asian patients demonstrated higher LC rates than White patients. Utilizing the rTS and SINS as predictive tools, we revealed that a poor survival prognosis and an unstable spinal structure were associated with increased rates of LP. Furthermore, the presence of osteolytic bone destructions and pain complaints were significantly correlated with the occurrence of LP. In the cohort of this study, 108 SBM underwent analysis to determine the expression levels of programmed cell death ligand 1 (PD-L1). Additionally, within this group, 60 showed mutations in the epidermal growth factor receptor (EGFR) alongside PD-L1 expression. Nevertheless, these genetic differences did not result in statistically significant differences in the LC rate. ConclusionThe one-year LC rate for primary SBRT targeting SBM from lung ADC stood at 90.7%, particularly with the use of the CyberKnife System. Patients achieving LC exhibited significantly longer survival times compared to those with LP.

Predicting the Need for Occipitocervical Fusion for Patients with Lower Clival Chordoma: A Single-Center Retrospective Study

To assess the impact of tumor extension into the occipital condyle (OC) in lower clival chordoma management and the need for occipito-cervical fusion (OCF). A retrospective analysis was conducted on 35 patients with lower clival chordoma. The preoperative area of the intact OCs, Hounsfield units, and the integrity of the apical ligament and the tectorial membrane were assessed using preoperative imaging. Seven (20%) patients were in the OCF group. The OCF group exhibited a higher prevalence of preoperative pain in the neck or head (p = 0.006), ligament absence (p = 0.022), and increased propensity for postoperative wound issues (p = 0.022) than the non-OCF group. The OCF group had less intact OCs (p < 0.001) and higher spinal instability neoplastic score (p = 0.002) than the non-OCF group. All patients with intact OCs<60% underwent OCF, and those with OCs≥70% were treated without OCF. Those with OCs between 60% and 69% underwent OCF if the ligaments were eroded, and did not undergo OCF if the ligaments were intact. Treatment strategies varied, with endoscopic endonasal approach (EEA) alone being common. Radiation therapy was administered to 89% of patients. All three patients treated with OCF after tumor resection had wound issues; none treated with OCF before resection had wound issues. None developed atlanto-occipital instability. Survival rates did not significantly differ between groups. In the absence of mobility-related neck pain, patients with lower clival chordoma and intact OC≥60%, intact apical ligament, and intact tectorial membrane, may not require OCF.

Clinical Outcome of Chemotherapy and Radiation Therapy Versus Chemotherapy, Radiation Therapy, and Multilevel Vertebroplasty or Kyphoplasty for Multiple Myeloma.

Vertebral augmentation including vertebroplasty and kyphoplasty may restore function without interfering with the therapeutic regimen of patients with multiple myeloma. We sought to evaluate the effects of adding multilevel vertebral augmentation to conventional therapy protocols for patients with multiple myeloma. Forty-four patients recently diagnosed with multiple myeloma were randomly assigned to two groups. One group received multilevel vertebral augmentation (kyphoplasty or vertebroplasty) in addition to conventional therapy (MVA), and the other group received conventional therapy alone (CTA). Patients were evaluated before treatment and at 3 months, 6 months, 1 year, 2 years, 3 years, 4 years, and 5 years after treatment by using the Oswestry Disability Index (ODI), the Stanford Score (SS), and the Spinal Instability Neoplastic Score (SINS). The mean ODI, SS, and SINS were nearly equal before treatment, being 34.19 (68.38%), 4.58, and 12.30, respectively, for the MVA group and 32.29 (64.58%), 4.63, and 13.88, respectively, for the CTA group. There were significant differences in the ODI, SS, and SINS between the two groups at all follow-up intervals. The ODI and SINS were statistically significantly different between the two groups (P=.020 and P<.001, respectively). There was an insignificant difference in SS between the two groups. This study found that performing kyphoplasty and vertebroplasty in addition to conventional therapy for patients with multiple myeloma resulted in enhanced morbidity and functional outcomes. [Orthopedics. 2024;47(4):225-231.].

Navigating the Indeterminate Zone: Surgeons' Decision-Making Factors in Treating Vertebral Metastases with Spinal Instability Scores of 7–12

BackgroundThe Spinal Instability Neoplastic Score (SINS) classification system, is a validated and the most widely accepted instrument for defining instability in vertebral metastasis (VM), in which lesions scoring between 7 – 12 are defined as indeterminate and the treatment is controversial. This study aimed to determine which variables more frequently are considered by spine surgeons for choosing between the conservative and the surgical treatment of VMs among patients with an indeterminate SINS. Material and MethodsA single-round online survey was conducted in ten spine surgeons with expertise in the management of VMs from our AO Spine Region. In this survey, each surgeon independently reviewed demographic and cancer-related variables of 36 real-life cases of patients with vertebral metastases scored between 7 – 12 in the SINS. Bivariate and multivariate analyses were performed to identify significant SINS and non-SINS variables influencing the decision-making on surgical treatment. ResultsThe most commonly variables considered important, were the SINS element ‘mechanical pain’, rated important for 44.4% of the cases, ‘lesion type’ for 36.1%, ‘degree of vertebral collapse’ and the non-SINS factor ‘tumor histology’ rated for 13.9% of cases. By far the factor most commonly rated unimportant was ‘posterior element compromise’ (in 72.2% of cases). ConclusionsSurgeons relied on mechanical pain and type of metastatic lesion for treatment choices. Vertebral collapse, spinal malalignment, and mobility were less influential. Spinal mobility was a predictor of surgical versus non-surgical treatment. The only variables not identified either by surgeons themselves or as a predictor of surgery selection was the presence/degree of posterolateral/posterior element involvement.

Predicting Skeletal-related Events Using SINS.

Predictive study utilized retrospectively collected data. The primary objective was to evaluate the predictive association between the Spine Instability Neoplastic Score (SINS) and Skeletal-related events (SREs). Secondary objectives included examining characteristics of cases with SINS < 6 among those who developed SRE, and evaluating the impact of additional predictors on prediction accuracy. Advances in cancer treatment have prolonged the lives of cancer patients, emphasizing the importance of maintaining quality of life. Skeletal-related events from metastatic spinal tumors significantly impact quality of life. However, currently, there is no scientifically established method to predict the occurrence of SRE. SINS, developed by the Spine Oncology Study Group, assesses spinal instability using six categories. Therefore, the predictive performance of SINS for SRE occurrence is of considerable interest to clinicians. This predictive study utilized retrospectively collected data from a single-center registry comprising over 1,000 patients with metastatic spinal tumors. SINS and clinical data were collected. Logistic regression was used to create a prediction equation for SRE using SINS. Additional analyses explored factors associated with SRE in patients with SINS < 6. The study included 1,041 patients with metastatic spinal tumors. SRE occurred in 121 cases (12%). The prediction model for SRE using SINS demonstrated an area under the curve (AUC) of 0.832. Characteristics associated with SRE included lower female prevalence, surgeries to primary sites, bone metastases to non-spinal sites, and metastases to other organs. A post hoc analysis incorporating additional predictors improved the AUC to 0.865. The SINS demonstrated reasonable predictive performance for SRE within one month of the initial visit. Incorporating additional factors improved prediction accuracy. The study emphasizes the need for a comprehensive clinical prediction model for SRE in metastatic spinal tumors.

Stereotactic Radiosurgery for Patients with Spinal Metastases from Thyroid Cancer: A 20-Year Experience

Primary thyroid cancer metastasizing to the spine portends poor survival and low quality of life. Current management strategies continue to evolve. This single-institution retrospective study analyzes outcomes after spinal stereotactic radiosurgery (SRS) for patients with spinal metastases from thyroid cancer. Nineteen patients (median age: 64.5 years) were treated with SRS for spinal primary thyroid metastases (40 metastases, 47 vertebral levels) between 2003-2023. Nineteen (47.5%) lesions had epidural involvement, and 20 (50%) lesions were classified as potentially unstable or unstable via the Spinal Instability Neoplastic Score. The median tumor volume per lesion was 33 cc (range: 1.5-153). The median single-fraction prescription dose was 20 Gy (range: 12-23.5). The median follow-up period was 15 months (range: 2-40). Five (12.8%) lesions locally progressed at a median of 9 months (range: 4-26) after SRS. The 1-, 2-, and 3-year local tumor control rates per lesion were 90.4%, 83.5%, and 75.9%, respectively. On univariate analysis, age at SRS > 70 years (p=0.05, HR: 6.86, 95% CI: 1.01-46.7) was significantly correlated with lower rates of local tumor control. The median overall survival was 35 months (range: 2-141). The 1-, 2-, and 3-year overall survival rates were 73.7%, 50.4%, and 43.2%, respectively. For 33 lesions initially associated with pain, patients reported pain improvement (22 lesions, 66.7%), stability (10 lesions, 30.3%), and worsening (1 lesion, 3.0%) after SRS. One patient developed dysphagia 4 months after SRS treatment. SRS can be utilized as an effective and safe primary and adjuvant treatment option for primary thyroid metastases to the spine.

Magnetic Resonance Imaging Frequency After Stereotactic Body Radiation Therapy for Spine Metastases

BackgroundStereotactic body radiation therapy (SBRT) is increasingly used to treat spine metastases. Current post-SBRT imaging surveillance strategies in this patient population may benefit from a more data-drive and personalized approach. The objective of this study was to develop risk stratified post-SBRT magnetic resonance imaging (MRI) surveillance strategies using quantitative methods. MethodsAdult patients with bony spine metastases treated with SBRT between 2008 and 2021 and who had at least two follow-up spine MRIs were retrospectively reviewed. A recursive partitioning analysis (RPA) model was developed to separate patients into different risk categories for post-SBRT progression anywhere within the spine. Imaging intervals were derived for each risk category using parametric survival regression based on multiple expected spine progression rates per scan. ResultsA total of 446 patients and 1,039 vertebral segments were included. Cumulative incidence of spine progression was 19.2% at 1 year, 26.7% at 2 years, and 35.3% at 4 years. The internally validated risk stratification model was able to divide patients into three risk categories based on epidural disease, paraspinal disease, and Spinal Instability Neoplastic Score category. The 4-year risk of spine progression was 23.4%, 39.0%, and 51.8%, respectively, for the low, intermediate, and high-risk groups. Using an expected per-scan spine progression rate of 3.75%, the low-risk group would require follow-up scans every 6.0 (95% confidence interval: 4.9-7.6) months and the intermediate-risk group would require surveillance every 3.1 (2.6-3.7) months. At an expected spine progression rate of 5%, the high-risk group would require surveillance every 1.3 (1.1-1.6) months during the first 13.2 months after SBRT, and every 5.9 (2.8-12.3) months thereafter. ConclusionData-driven follow-up MR surveillance intervals at a range of expected spine progression rates have been determined for patients at different risks of spine progression based on an internally validated, single-institution risk stratification model.

The role of spine stereotactic radiosurgery for patients with breast cancer metastases.

Breast cancer that metastasizes to the spine is associated with low quality of life and poor survival. Radiosurgery has an increasing role in this patient population. This single-institution (2003-2023) study analyzes clinical outcomes and prognostic factors for patients who underwent spinal stereotactic radiosurgery (SSRS) for metastatic breast cancer. Ninety patients (155 unique breast cancer spinal metastases) were treated with SSRS. The median age was 57years (range: 35-88), and the median KPS was 80 (range: 40-100). Forty-two (27%) lesions were managed surgically prior to radiosurgery. At SSRS, 75 (48%) lesions impinged or compressed the spinal cord per the epidural spinal cord scale (ESCC). Seventy-nine (51%) lesions were categorized as potentially unstable or unstable by the Spinal Instability Neoplastic Score (SINS). The median follow-up was 15months (range: 1-183). The median single-session tumor volume was 25.4cc (range: 2-197), and the median single-fraction prescription dose was 17Gy (range: 12-25). Seven (5%) lesions locally progressed. The 1-, 2-, and 5-year local control rates were 98%, 97%, and 92%, respectively. The median overall survival (OS) for the cohort was 32months (range: 2-183). The 1-, 2-, and 5-year OS rates were 72%, 53%, and 30%, respectively. On univariate analysis, KPS ≥ 80 (p = 0.009, HR: 0.51, 95% CI: 0.31-0.84) was associated with improved OS. Patient-reported pain improved (68%), remained stable (29%), or worsened (3%) following radiosurgery. Fifteen (10%) radiation-induced toxicities were reported. Spinal radiosurgery is a safe and highly effective long-term treatment modality for metastases to the spine that originate from breast cancer.

Excellent long-term pain response and local control following postoperative radiotherapy in patients with multiple myeloma.

Multiple myeloma is associated with osteolytic bone lesions, often requiring surgery of the spine and postoperative radiotherapy (RT). Although common, data for clinical and informed decision-making are sparse. In this monocentric retrospective study, we aim to report the outcome of patients who underwent spinal surgery and postoperative RT due to multiple myeloma. Atotal of 54patients with multiple myeloma who underwent prior spinal surgery and postoperative RT at our institution between 2009 and 2020 were analyzed. Spinal instability neoplastic score (SINS) and Bilsky score, posttherapeutic adverse events, clinical data, and outcomes were collected and analyzed. The primary endpoint of this study was overall survival (OS), secondary endpoints were progression-free survival (PFS), pain response, local control, and skeletal-related events (SRE). The 3‑ and 5‑year overall survival (OS) was 74.9% (95% confidence interval [CI]: 63.5-88.4%) and 58% (95% CI: 44.5-75.6%), respectively. Median survival was not reached and 75% survival was 34.3months (95% CI: 28.7-95.4 months). Median follow-up was 63months (95% CI: 49-94months). The number of patients with good to adequate performance status (Karnofsky performance score [KPS] ≥ 70) significantly increased after surgery (p < 0.01). We observed no grade3/4 toxicity and only 13 (24%) grade1/2 adverse events. Two patients (4%) experienced SRE. Overall, 92% of patients reported reduced pain after radiotherapy, with 66% reporting complete pain response. There was no difference in pain response between patients with different Bilsky scores. Bisphosphonate therapy and lower Bilsky score at the start of RT were associated with improved OS in univariate analysis (all p < 0.05). Multivariate Cox regression confirmed aBilsky score of2 or3 as an independent negative prognostic factor (HR 3.89; 95CI 1.4-10.7; p < 0.01). We observed no in-field recurrences. In this study, we were able to show that the current standard of RT after spinal surgery of osteolytic lesions is safe. In addition, we observed avery low rate of SRE (4%) and no in-field recurrences, demonstrating the local efficacy of RT in multiple myeloma patients. Higher Bilsky scores were associated with worse OS in multivariate analysis, but had no effect on pain response.