Surgical Management of the Metastatic Spine Disease: A Review of the Literature and Proposed Algorithm

Measuring the paraspinal muscles as an important tool for predicting the overall survival period after spine surgery in lung cancer patients with spine metastasis

STUDY DESIGN

Retrospective cohort study BACKGROUND: Metastatic lung cancer in the spine is difficult to determine whether to perform an additional surgical intervention, as patients at the end stage of lung cancer often have low performance status with significant muscle atrophy. This study aimed to demonstrate whether sarcopenia affects the prognosis after spine surgery in lung cancer patients by measuring the paraspinal muscles.

METHODS

A total of 65 lung cancer patients who underwent spine surgery were reviewed. Patients were divided into two groups based on the survival period after surgery (≤ 6 months; n = 33 and > 6 months; n = 32). Based on magnetic resonance imaging, the quantity and quality of the paraspinal muscles (psoas major, quadratus lumborum, erector spinae, and multifidus) were analyzed by an Image J program. Patient- and surgery-related factors were compared between the two groups.

RESULTS

The quantity of the erector spinae muscle was higher in the > 6 months group (11.5 ± 2.8 cm2/m2) than in the ≤ 6 months group (10.0 ± 2.3 cm2/m2, p = 0.013). The logistic regression analysis showed that the muscle quantity of the erector spinae (p = 0.026, odds ratio 1.343) and the number of vertebrae involved in metastasis (p = 0.016, odds ratio 0.199) were the main prognostic factors for the survival period after spine surgery.

CONCLUSIONS

Lung cancer patients with a low quantity of the erector spinae muscles are at a high risk of poor prognosis after spine surgery. Therefore, measuring the erector spinae muscle could be an important tool for distinguishing patients appropriate for palliative treatments and surgical interventions.

Racial, Ethnic and Language-Related Disparities in Palliative Care Utilization in Spinal Metastatic Disease

Studies indicate racial and ethnic disparities in access to palliative care services. The relationship between race, ethnicity, and associated factors and inpatient palliative care utilization in spinal metastatic disease remains unclear. We conducted a retrospective review of electronic health records to identify adult patients diagnosed with spinal metastatic disease at a single institution between January 2004 and December 2024. The primary outcome was inpatient palliative care consultation (IPCC) use. Secondary outcomes included the total number of IPCCs and time to first IPCC since diagnosis. Bivariate analyses and multivariate regression assessed disparities in IPCC utilization. Overall, 851 patients were included, with 303 (35.6%) having at least one IPCC. Bivariate analyses showed significant differences in IPCC use across racial groups, with White, Asian, Native-American, and 'Other' individuals trending towards lower utilization. Multivariate regression indicated that Native-American race had reduced odds of IPCC encounters (vs White, odds ratio [OR] = 1.16, 95% confidence interval [CI] = [0.12-11.58]) and longer time to first IPCC (Hazard ratio [HR] = 0.58 [0.08-4.19]). Asian (B-coefficient = -0.63 [-3.69-2.43]) and 'Other' race (B-coefficient = -1.26 [-4.19-1.67]), Hispanic ethnicity (vs Non-Hispanic, B-coefficient = -2.24 [-5.17-0.70]), non-English language (vs English, B-coefficient = -0.99 [-4.12-2.14]) and requiring an interpreter (vs not, B-coefficient = -1.38 [-4.64-1.88]) were associated with fewer overall IPCCs. While results did not reach statistical significance post-adjustment, our bivariate analyses and the direction and magnitude of associations in regression analyses suggest racial, ethnic and language-based disparities in access to palliative care for spinal metastatic disease patients. Further research and policy changes are needed to address these disparities and improve outcomes.

Hybrid Therapy with SBRT Target-Tailored Tumor Resection for High-Grade Metastatic Epidural Spinal Cord Compression (MESCC): Illustrative Case

Background: Spinal metastases affect approximately 40% of patients with systemic cancers; metastatic epidural spinal cord compression (MESCC) occurs in up to 20% of cases and leads to potential significant morbidity. Recent advancements in high-dose conformal radiation techniques, such as Stereotactic Body Radiation Therapy (SBRT) and Stereotactic Radiosurgery (SRS), enable histology-independent ablative treatments, yet optimal dose fractionation remains undetermined. Methods and Results: This case of vertebral metastases with high-grade ESCC exemplifies the model of a comprehensive treatment workflow that emphasizes interdisciplinary collaboration, within the framework of a personalized medicine. The "Hybrid Therapy" combines Separation Surgery, aimed at achieving circumferential spinal cord decompression, with SBRT/SRS. The oncologic resection has been performed in a navigation-assisted technique that is tailored to the SBRT target, pre-operatively defined on the neuronavigation station. Conclusions: This seamless integration during initial planning of surgery with the ideal radio-oncological target is aimed at avoiding delays in referral and limitations in subsequent treatment options. This integrative holistic strategy not only prioritizes functional preservation, minimizing surgical invasiveness, but also promotes tumor control, thus offering potential promising new avenues for patient-centered oncologic care. Future high-quality studies are warranted to validate the widespread potential utility and safety of this approach.

"White Cord Syndrome" as clinical manifestation of the spinal cord reperfusion syndrome: a systematic review of risk factors, treatments, and outcome

OBJECTIVE

Paralysis subsequent to spinal cord decompression in the cervical or thoracic region is infrequent, with White Cord Syndrome (WCS) being among its several causes. Due to WCS's infrequency, there exists a paucity of high-level evidence concerning its manifestations. Our primary objective is to systematically collate all documented WCS cases, discern prevalent risk and prognostic factors, appraise available treatment modalities, and evaluate patient outcomes.

METHODS

A systematic review was conducted following PRISMA guidelines. The search included PubMed, Scopus, Embase, and Web of Science databases. Inclusion criteria required studies to be written in English, be case reports, and contain data on clinical features, management, and treatment outcomes. Exclusion criteria excluded meta-analyses, reviews, editorials, letters, books, studies with insufficient clinical data, and studies not in English or with unavailable full texts. Grey literature was not actively pursued due to identification challenges, potentially introducing selection bias. Two authors independently evaluated papers based on criteria. Disagreements were resolved with a third author. Additionally, the included articles' references were screened for additional relevant articles.

RESULTS

We found a total of 580 articles through our electronic search. After removing duplicates, 399 articles were screened. Out of the remaining 51 studies, 27 were included in the final quantitative analysis. The average age was 54 (3-79 years) with a male-to-female ratio of 2:1, 33% had OPLL, and Common medical histories were hypertension (30%), diabetes mellitus (20%), and previous ACDF surgery (8%). Of all Surgeries, 70% were done with a posterior approach and 30% with the anterior approach. 48% of cases used Intraoperative NeuroMonitoring(IONM), and Loss of Motor Evoked Potentials (MEP) occurred in 37% of cases. Patients received high-dose intravenous steroids. In 26% of cases, additional posterior cervical decompression was performed, and efforts were made to maintain mean arterial pressure above 85 mmHg in 37% of cases. Other medications were administered in 30% of cases. Over an average 26-week follow-up, 37% of patients had good recovery, 40% had partial recovery, and 23% showed no recovery. The average final Nurick grade was 3.2.

CONCLUSIONS

WCS is a rare cause of postoperative neurological deficit following spinal cord decompression surgery. Risk factors for WCS include advanced age, extensive surgery, posterior approach for decompression, and the presence of OPLL. Treatment includes high-dose steroids, posterior cervical decompression, maintaining MAP over 85mmHg, rehabilitation, and sometimes neurotrophic drugs. Most patients can walk with or without assistance during follow-up, but around a quarter never regain neurological function. The only preoperative factor impacting outcomes is the preoperative neurological status (Nurick Grade).

ChatGPT's Performance in Spinal Metastasis Cases-Can We Discuss Our Complex Cases with ChatGPT?

Background: The integration of artificial intelligence (AI), particularly large language models (LLMs) like ChatGPT-4, is transforming healthcare. ChatGPT's potential to assist in decision-making for complex cases, such as spinal metastasis treatment, is promising but widely untested. Especially in cancer patients who develop spinal metastases, precise and personalized treatment is essential. This study examines ChatGPT-4's performance in treatment planning for spinal metastasis cases compared to experienced spine surgeons. Materials and Methods: Five spine metastasis cases were randomly selected from recent literature. Consequently, five spine surgeons and ChatGPT-4 were tasked with providing treatment recommendations for each case in a standardized manner. Responses were analyzed for frequency distribution, agreement, and subjective rater opinions. Results: ChatGPT's treatment recommendations aligned with the majority of human raters in 73% of treatment choices, with moderate to substantial agreement on systemic therapy, pain management, and supportive care. However, ChatGPT's recommendations tended towards generalized statements, with raters noting its generalized answers. Agreement among raters improved in sensitivity analyses excluding ChatGPT, particularly for controversial areas like surgical intervention and palliative care. Conclusions: ChatGPT shows potential in aligning with experienced surgeons on certain treatment aspects of spinal metastasis. However, its generalized approach highlights limitations, suggesting that training with specific clinical guidelines could potentially enhance its utility in complex case management. Further studies are necessary to refine AI applications in personalized healthcare decision-making.

Temporary halo fixation and radiotherapy as alternative to long-construct spondylodesis in patients with multiple unstable cervical metastases

Background and purpose

Currently no minimally invasive surgical treatment exists to provide immediate stability for unstable cervical/cervicothoracic metastases. Long-construct spondylodesis carries a high complication risk and has severe impact on residual range of motion. This study explores temporary halo fixation and radiotherapy as an alternative to long-construct cervical spondylodesis.

Materials and methods

This retrospective cohort study included twenty patients with multiple unstable cervical metastases treated between 2013-2023. All patients underwent halo fixation for an intended duration of three months to allow for safe reossification of lytic lesions following radiotherapy, with a dose fractionation scheme best suited to the histological origin of the tumor.

Results

Immobilization with halo fixation lasted a median 83 days (range, 41-132 days). Radiotherapy started on average 7 days after halo fixation (range, -35-118 days). The median pain score at baseline was 8, and was 0 at halo removal and at last follow-up. All patients had no or minor neurological deficits at baseline and did not develop new neurological deficits. At halo removal, 17/18 patients showed radiographic evidence of reossification. The majority of patients experienced minor limitations or had full range of motion of the neck at last follow-up.

Conclusion

Patients with multiple unstable cervical metastases treated with halo fixation and radiotherapy showed complete pain response or substantial pain reduction, reossification of the vertebrae and a, mostly, preserved range of motion. In selected neurologically intact patients, this treatment might be a patient-friendly alternative to fixation. Prospective evaluation of this treatment combination is needed.

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.

Development of a core outcome set of clinical research on the integration of traditional Chinese and Western medicine for spinal metastases:

BACKGROUND

In recent years, the incidence of spinal metastasis (SM) has been increasing steadily. In response to this serious public health problem, researchers have made progress by using the integration of traditional Chinese and Western medicine. However, considerable heterogeneity in the definition and measurement of outcomes across clinical research studies, along with the lack of uniform measurement standards for study data, makes it difficult for researchers to compare different treatments. Therefore, it is crucial to accurately evaluate clinical research on the integration of traditional Chinese and Western medicine for SM.

METHODS

This study protocol outlines a comprehensive research programme based on the Core Outcome Set Standards Protocol Items. The study consists of four phases: a literature review, semistructured interviews, a two-round modified Delphi survey, a consensus meeting. Phase 1 involves a comprehensive literature review to extract outcomes used in current clinical studies of integrated traditional Chinese and Western medicine or Western medicine for the treatment of SM. A semistructured interview format will be used to survey patients and caregivers in phase 2 to collect suggestions from the patient perspective. Phase 3 involves a two-round modified Delphi survey to complete a prioritisation evaluation of outcomes to generate a candidate list for core outcome set (COS). Finally, phase 4 involves a face-to-face consensus meeting to review and establish the COS.

ETHICS AND DISSEMINATION

Conducted in response to the current dilemma of SM, the study was endorsed by the Spine Oncology Group of the Orthopaedic Surgeons Branch of the Chinese Physicians' Association. It will be developed and reported through a rigorous process, with the results of the study to be published in a peer-reviewed journal.Registration: COMET Registry: COMET 2938; https://www.comet-initiative.org/Studies/Details/2938.

Clinical performance of implanted devices used in surgical treatment of patients with spinal tumors: a systematic review

PURPOSE

Implanted devices used in metastatic spine tumor surgery (MSTS) include pedicle screws, fixation plates, fixation rods, and interbody devices. A material to be used to fabricate any of these devices should possess an array of properties, which include biocompatibility, no toxicity, bioactivity, low wear rate, low to moderate incidence of artifacts during imaging, tensile strength and modulus that are comparable to those of cortical bone, high fatigue strength/long fatigue life, minimal or no negative impact on radiotherapy (RT) planning and delivery, and high capability for fusion to the contiguous bone. The shortcomings of Ti6Al4V alloy for these applications with respect to these desirable properties are well recognized, opening the field for an investigation about novel biomaterials that could replace the current gold standard. Previously published reviews on this topic have exhibited significant shortcomings in the studies they included, such as a small, heterogenous sample size and the lack of a cost-benefit analysis, extremely useful to understand the practical possibility of applying a novel material on a large scale. Therefore, this review aims to collect information about the clinical performance of these biomaterials from the most recent literature, with the objective of deliberating which could potentially be better than titanium in the future, with particular attention to safety, artifact production and radiotherapy planning interference. The significant promise showed by analyzing the clinical performance of these devices warrants further research through prospective studies with a larger sample size also taking into account each aspect of the production and use of such materials.

METHODS

The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were used to improve the reporting of the review. The search was performed from March 2022 to September 2023.

RESULTS

At the end of the screening process, 20 articles were considered eligible for this study. Polyetheretherketone (PEEK), Carbon-fibre reinforced polyetheretherketone (CFR-PEEK), long carbon fiber reinforced polymer (LCFRP), Polymethylmethacrylate (PMMA), and carbon screw and rods were used in the included studies.

CONCLUSION

CFR-PEEK displays a noninferior safety and efficacy profile to titanium implanted devices. However, it also has other advantages. By decreasing artifact production, it is able to increase detection of local tumor recurrence and decrease radiotherapy dose perturbation, ultimately bettering prognosis for patients necessitating adjuvant treatment. Nonetheless, its drawbacks have not been explored fully and still require further investigation in future studies. This does not exclude the fact that CFR-PEEK could be a valid alternative to titanium in the near future.

A Multidisciplinary Update on Treatment Modalities for Metastatic Spinal Tumors with a Surgical Emphasis: A Literature Review and Evaluation of the Role of Artificial Intelligence

Spinal metastases occur in up to 40% of patients with cancer. Of these cases, 10% become symptomatic. The reported incidence of spinal metastases has increased in recent years due to innovations in imaging modalities and oncological treatments. As the incidence of spinal metastases rises, so does the demand for improved treatments and treatment algorithms, which now emphasize greater multidisciplinary collaboration and are increasingly customized per patient. Uniquely, we discuss the potential clinical applications of AI and NGS in the treatment of spinal metastases. Material and Methods: A PubMed search for articles published from 2000 to 2023 regarding spinal metastases and artificial intelligence in healthcare was completed. After screening for relevance, the key findings from each study were summarized in this update. Results: This review summarizes the evidence from studies reporting on treatment modalities for spinal metastases, including minimally invasive surgery (MIS), external beam radiation therapy (EBRT), stereotactic radiosurgery (SRS), CFR-PEEK instrumentation, radiofrequency ablation (RFA), next-generation sequencing (NGS), artificial intelligence, and predictive models.

Area Socioeconomic Status is Associated with Refusal of Recommended Surgery in Patients with Metastatic Bone and Joint Disease

BACKGROUND

This study sought to identify associations between the Yost Index, a geocoded area neighborhood socioeconomic status (nSES) score, and race/ethnicity with patient refusal of recommended surgery for metastatic bone disease.

METHODS

Patients with metastatic bone disease were extracted from the Surveillance, Epidemiology, and End Results database. The Yost Index was geocoded using factor analysis and categorized into quintiles using census tract-level American Community Service (ACS) 5-year estimates and seven nSES measures. Multivariable logistic regression models calculated odds ratios (ORs) of refusal of recommended surgery and 95% confidence intervals (CIs), adjusting for clinical covariates.

RESULTS

A total of 138,257 patients were included, of which 14,943 (10.8%) were recommended for surgical resection. Patients in the lowest nSES quintile had 57% higher odds of refusing surgical treatment than those in the highest quintile (aOR = 1.57, 95% CI 1.30-1.91, p < 0.001). Patients in the lowest nSES quintile also had a 31.2% higher age-adjusted incidence rate of not being recommended for surgery compared with those in the highest quintile (186.4 vs. 142.1 per 1 million, p < 0.001). Black patients had 34% higher odds of refusing treatment compared with White patients (aOR = 1.34, 95% CI 1.14-1.58, p = 0.003). Advanced age, unmarried status, and patients with aggressive cancer subtypes were associated with higher odds of refusing surgery (p < 0.001).

CONCLUSIONS

nSES and race/ethnicity are independent predictors of a patient refusing surgery for metastatic cancer to bone, even after adjusting for various clinical covariates. Effective strategies for addressing these inequalities and improving the access and quality of care of patients with a lower nSES and minority backgrounds are needed.

A critical appraisal of clinical practice guidelines on surgical treatments for spinal metastasis

PURPOSE

As an important treatment for spinal metastasis, surgery has strict applicable conditions. Although various organizations have formulated different guidelines on surgical treatment for spinal metastasis (SM), there are certain differences in the content, standardization and quality of the guidelines and it is necessary to make a critical appraisal of them. We aim to systematically review and appraise the current guidelines on surgical treatments of SM and summarize the related recommendations with the quality evaluation of supporting evidence, as to provide a reference for the standardization of surgical treatment plans, and help clinical front-line medical workers can make safe and effective clinical decisions faster.

METHODS

We searched Pubmed, Web of Science, and Embase for three major databases and online guideline databases. According to certain inclusion and exclusion criteria, the latest guidelines on the surgical treatment of SM were sorted out. AGREE II was used to evaluated the guideline's quality, and we extracted and compared the recommended treatment content of each guideline with evaluating by the evidence-grading scale.

RESULTS

Eight guidelines from 2013 to 2019 were included. Seven guidelines are comprehensive guidelines and one related to the reconstructive surgery of SM. Five guidelines were evaluated as "recommended," and three guidelines were evaluated as "recommended with modifications." Regarding the indications of surgery with SM, four guidelines, seven guidelines, seven guidelines, three guidelines and three guidelines recommended surgical treatment for patients with SM with intractable pain, mechanical instability, metastatic epidural spinal cord compression (MESCC), recurrent spinal metastasis (RSM), and survival predication, respectively. Regarding the surgical strategies, three guidelines recommended minimally invasive therapy but had strict indications. Six guidelines and five guidelines recommend palliative surgery and with receiving radiation therapy, respectively. For the aggressive surgery, only one guideline recommended to apply to patients in good general conditions who has isolated symptomatic SM. Regarding the surgical reconstructions, one guideline didn't recommend iliac bone graft and three guidelines recommended PMMA bone cement.

CONCLUSION

Most of the guidelines do not provide clear criteria for surgical application and provide more of a basic framework. The level of evidence for these surgical recommendations ranges from LOE B to D, and almost all guidelines recommend vertebroplasty and kyphoplasty, but for palliative and more aggressive surgery, which recommended to personalize specific surgical strategies with multidisciplinary collaboration.

Perioperative Management for Complex Spine Fusion Surgery

Complex spine surgeries performed worldwide continue to increase in number, as do the age and comorbidity of patients undergoing these operations. Perioperative care protocols related to blood management, postoperative pain control, and intraoperative measures to mitigate morbidity may improve clinical workflows and patient outcomes.