Principles of Management of Spine Metastasis

[Spinal metastases and metastatic spinal cord compression: interpretation for National Institute for Health and Care Excellence (NICE) 2023 guideline]

Spine is a common site of metastasis in patients with malignant tumors, and tumor metastasis to the spine can lead to pain, pathological fractures, and nerve compression. In order to optimize the diagnosis and management of patients with spinal metastases and metastatic spinal cord compression (MSCC), the National Institute for Health and Care Excellence (NICE) in the UK proposed the first diagnostic and treatment guidelines for patients with MSCC (or at risk of MSCC) in 2008. In recent years, with the rapid advancement of spinal surgery and radiotherapy technology, the standardized process of MSCC diagnosis and treatment urgently needs to be updated. In 2023, NICE launched new guidelines for spinal metastases and MSCC. Based on a thorough study of the guidelines, this article discusses and interprets pain management, corticosteroid treatment, application of bisphosphonates and denosumab, tools for assessing spinal stability and prognosis, radiation therapy, surgical timing and approach, etc., providing reference for clinical diagnosis and treatment in China.

Transpedicular Corpectomy in Minimally Invasive Surgery for Metastatic Spinal Cord Compression: A Single-Center Series

Introduction The role of separation surgery in managing symptomatic spinal metastases has been increasing in recent years, and it represents a crucial part of the definitive management of this condition. Methods We report on a series of seven patients treated at the National Cancer Institute in Mexico using minimally invasive approaches to perform transpedicular corpectomy. The goal was to obtain a margin of tumor-free tissue, enabling the completion of oncological treatment with radiotherapy. Results We collected data from six cases. The mean age was 61.2 years. Surgical outcomes were good in 83.3% of patients. Ranging from minimally invasive instrumentations to total or partial corpectomies, these procedures achieved their intended function of generating healthy neural tissue free of tumor. This ensures that the radiation gradient does not affect this tissue. No surgical complications were reported. The objective of these surgeries was to establish a radiotherapy or radiosurgery regimen as soon as possible, thereby improving patients' quality of life (QoL). Conclusions Low-cost transpedicular corpectomy via minimally invasive surgery (MIS) is a safe and effective method that meets the goals of separation surgery. However, prospective studies are needed to directly compare open techniques with minimally invasive methods.

Stereotactic Radiosurgery in Metastatic Spine Disease-A Systemic Review of the Literature

BACKGROUND

This study investigated the efficacy of stereotactic radiosurgery (SRS) in managing spinal metastasis. Traditionally, surgery was the primary approach, but SRS has emerged as a promising alternative.

OBJECTIVE

The study aims to evaluate the efficacy of stereotactic radiosurgery in the management of spinal metastasis in terms of local tumor control, patient survival, and quality of life, identifying both advantages and limitations of SRS.

METHODS

Through an extensive literature search in PubMed with cross-referencing, relevant full-text-available papers published between 2012 and 2022 in English or German were included. The search string used was "metastatic spine diseases AND SRS OR stereotactic radiosurgery".

RESULTS

There is growing evidence of SRS as a precise and effective treatment. SRS delivers high radiation doses while minimizing exposure to critical neural structures, offering benefits like pain relief, limited tumor growth, and a low complication rate, even for tumors resistant to traditional radiation therapies. SRS can be a primary treatment for certain metastatic cases, particularly those without spinal cord compression.

CONCLUSIONS

SRS appears to be a preferable option for oligometastasis and radioresistant lesions, assuming there are no contraindications. Further research is necessary to refine treatment protocols, determine optimal radiation dose and fractionation schemes, and assess the long-term effects of SRS on neural structures.

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.

Short-term outcomes after spinal surgery for metastatic breast cancer: A single-center analysis

Background

Advances in detection and breast cancer treatment lead to higher survival rates, with more patients living with spine metastases. Those surgeries are palliative; however, they can improve the quality of life (QOL).

Objective

The aim of this study is to report pain and neurological function outcomes after surgery for spinal metastatic disease of breast cancer patients of a single institution. Complications were recorded.

Materials and Methods

A retrospective, single-center, single-arm study was performed. Consecutive patients who underwent spinal surgery were included. We analyzed demographic, surgical, histopathological, and clinical data.

Results

Seventeen women were included. Three patients (17.6%) did not present pre- and postoperative pain (n = 3), 6 (35.3%) had pain in both situations, and 8 (47.1%) were pain-free postoperatively (P = 0.013). Ten (58.8%) patients had preoperative deficits: 3 (30%) did not improve and 7 (70%) improved after surgery. Six cases (35.2%) did not present preoperative deficits and did not get worse (n = 6). The Frankel classification after the following time showed that 11 patients (64.7%) remained stable after surgery and 5 patients (29.4%) got better. A single patient (5.6%) had deterioration of strength. Two patients (11.7%) had intraoperative complications.

Conclusions

Pain was significantly improved by surgery, with also a possibly positive effect on functionality. Considering the low complication rates, surgery is still a useful tool in the management of spinal metastases in breast cancer patients and may be related to better QOL.

Surgical management of spinal intradural metastatic pathologies: a case-based review

Intradural spinal metastases significantly impair neurological function and quality of life, necessitating multimodal, palliative management to preserve mobility and alleviate pain. The effectiveness of systemic chemotherapy and radiotherapy is limited due to the blood-spinal cord barrier and the tumours' radioresistance, respectively. This highlights the urgency for alternative treatments given the rapid neurological decline. Surgical intervention becomes crucial, focusing on maximum tumour debulking to enhance disease control, restore ambulation, and palliate symptoms without compromising neurological function. Achieving this involves meticulous preoperative planning and aggressive intraoperative neuromonitoring. Combining surgery with adjuvant therapies may improve local control and potentially delay recurrence. This case-based review emphasizes the surgical considerations and outcomes in two cases of intradural spinal metastases, underscoring the value of surgery in multimodal therapy.

Measurement properties of health-related quality of life measures for people living with metastatic disease of the spine: a systematic review

PURPOSE

Patients with spinal metastases (SM) suffer from a significant quality of life (QoL) deterioration. The measurement of QoL has garnered significant attention. In this study, the authors aimed to investigate the frequency of QoL measurement, systematically appraise the measurement properties of identified instruments, and facilitate the effective selection of an appropriate QoL instrument for patients with SM.

METHODS

This systematic review adhered to the newly revised Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement guidelines. The methodological quality of the studies was assessed using the Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) checklist. Measurement property results were assessed using the adapted criteria. Each measurement property was allocated a separate rating (excellent, good, fair, or poor). 'Best evidence synthesis' was performed using COSMIN outcomes and the quality of findings.

RESULT

Two hundred and nine publications were included, and 18 instruments were identified. ECOG, EuroQol-5D, SF-36, SOSGOQ, and EORTC-QLQ-C30 were the top five instruments used for patients with SM in published literature. The measurement properties evaluated included internal consistency (four instruments), reliability (three instruments), validity (five instruments), validity (nine measures), floor and ceiling effects (four instruments), responsiveness (four instruments), and interpretability (three measures). Based on the limited evidence, the Brief Pain Inventory (BPI) had the best methodological quality.

CONCLUSIONS

Owing to the limitations of BPI in assessment domains, we cannot fully support the use of BPI. For the lack of high-quality research, it is challenging to nominate a single appropriate measure. Additional studies are needed to explore the evidence before a confirmatory decision is made.

Identification of Origin for Spinal Metastases from MR Images: Comparison Between Radiomics and Deep Learning Methods

OBJECTIVE

To determine whether spinal metastatic lesions originated from lung cancer or from other cancers based on spinal contrast-enhanced T1 (CET1) magnetic resonance (MR) images analyzed using radiomics (RAD) and deep learning (DL) methods.

METHODS

We recruited and retrospectively reviewed 173 patients diagnosed with spinal metastases at two different centers between July 2018 and June 2021. Of these, 68 involved lung cancer and 105 were other types of cancer. They were assigned to an internal cohort of 149 patients, randomly divided into a training set and a validation set, and to an external cohort of 24 patients. All patients underwent CET1-MR imaging before surgery or biopsy. We developed two predictive algorithms: a DL model and a RAD model. We compared performance between models, and against human radiological assessment, via accuracy (ACC) and receiver operating characteristic (ROC) analyses. Furthermore, we analyzed the correlation between RAD and DL features.

RESULTS

The DL model outperformed RAD model across the board, with ACC/ area under the receiver operating characteristic curve (AUC) values of 0.93/0.94 (DL) versus 0.84/0.93 (RAD) when applied to the training set from the internal cohort, 0.74/0.76 versus 0.72/0.75 when applied to the validation set, and 0.72/0.76 versus 0.69/0.72 when applied to the external test cohort. For the validation set, it also outperformed expert radiological assessment (ACC: 0.65, AUC: 0.68). We only found weak correlations between DL and RAD features.

CONCLUSION

The DL algorithm successfully identified the origin of spinal metastases from pre-operative CET1-MR images, outperforming both RAD models and expert assessment by trained radiologists.

Use of Steroids in Spine Surgery

Steroids are commonly used in spine pathologies. A broad range of providers from different specialties such as primary care, emergency medicine, and spine surgeons use steroids. The indications and controversies of steroid use are discussed in this article. A literature review was conducted on the use of steroids in spine pathologies. Steroids have been successfully used in anterior cervical discectomy and fusion (ACDF) to prevent dysphagia, in spinal cord injuries to improve neurological function, in acute back and neck pain for pain control, and in spinal metastasis. Steroid injections have been used for axial as well as radicular pain. Techniques and complications are further discussed. Local and systemic steroids have been successful in preventing dysphagia after anterior cervical diskectomy and fusion. Steroids failed to improve the neurologic outcomes after spinal cord injuries, and they were associated with multiple complications. Systemic steroids have not been proven to provide better clinical outcomes for acute low back pain. Steroid injections are more effective in radicular pain rather than axial pain. There are not enough high-quality studies on the use of steroids for metastatic spinal cord compression.

2022 SPILF - Clinical Practice guidelines for the diagnosis and treatment of disco-vertebral infection in adults

These guidelines are an update of those made in 2007 at the request of the French Society of Infectious Diseases (SPILF, Société de Pathologie Infectieuse de Langue Française). They are intended for use by all healthcare professionals caring for patients with disco-vertebral infection (DVI) on spine, whether native or instrumented. They include evidence and opinion-based recommendations for the diagnosis and management of patients with DVI. ESR, PCT and scintigraphy, antibiotic therapy without microorganism identification (except for emergency situations), therapy longer than 6 weeks if the DVI is not complicated, contraindication for spinal osteosynthesis in a septic context, and prolonged dorsal decubitus are no longer to be done in DVI management. MRI study must include exploration of the entire spine with at least 2 orthogonal planes for the affected level(s). Several disco-vertebral samples must be performed if blood cultures are negative. Short, adapted treatment and directly oral antibiotherapy or early switch from intravenous to oral antibiotherapy are recommended. Consultation of a spine specialist should be requested to evaluate spinal stability. Early lifting of patients is recommended.

Radiomics of Spinal Metastases Originating From Primary Nonsmall Cell Lung Cancer or Breast Cancer and Ability to Predict Epidermal Growth Factor Receptor Mutation/Ki-67 Levels

OBJECTIVES

The aims of the study are to explore spinal magnetic resonance imaging (MRI)-based radiomics to differentiate spinal metastases from primary nonsmall cell lung cancer (NSCLC) or breast cancer (BC) and to further predict the epidermal growth factor receptor (EGFR) mutation and Ki-67 expression level.

METHODS

In total, 268 patients with spinal metastases from primary NSCLC (n = 148) and BC (n = 120) were enrolled between January 2016 and December 2021. All patients underwent spinal contrast-enhanced T1-weighted MRI before treatment. Two- and 3-dimensional radiomics features were extracted from the spinal MRI images of each patient. The least absolute shrinkage and selection operator regression were applied to identify the most important features related to the origin of the metastasis and the EGFR mutation and Ki-67 level. Radiomics signatures (RSs) were established using the selected features and evaluated using receiver operating characteristic curve analysis.

RESULTS

We identified 6, 5, and 4 features from spinal MRI to develop Ori-RS, EGFR-RS, and Ki-67-RS for predicting the metastatic origin, EGFR mutation, and Ki-67 level, respectively. The 3 RSs performed well in the training (area under the receiver operating characteristic curves: Ori-RS vs EGFR-RS vs Ki-67-RS, 0.890 vs 0.793 vs 0.798) and validation (area under the receiver operating characteristic curves: Ori-RS vs EGFR-RS vs Ki-67-RS, 0.881 vs 0.744 vs 0.738) cohorts.

CONCLUSIONS

Our study demonstrated the value of spinal MRI-based radiomics for identifying the metastatic origin and evaluating the EGFR mutation status and Ki-67 level in patients with NSCLC and BC, respectively, which may have the potential to guide subsequent individual treatment planning.

The Role of Cytokines in the Metastasis of Solid Tumors to the Spine: Systematic Review

Although many studies have investigated the role of cytokines in bone metastases, our knowledge of their function in spine metastasis is limited. Therefore, we performed a systematic review to map the available evidence on the involvement of cytokines in spine metastasis in solid tumors. A PubMed search identified 211 articles demonstrating a functional link between cytokines/cytokine receptors and bone metastases, including six articles confirming the role of cytokines/cytokine receptors in spine metastases. A total of 68 cytokines/cytokine receptors were identified to mediate bone metastases; 9 (mostly chemokines) played a role in spine metastases: CXC motif chemokine ligand (CXCL) 5, CXCL12, CXC motif chemokine receptor (CXCR) 4, CXCR6, interleukin (IL) 10 in prostate cancer, CX3C motif chemokine ligand (CX3CL) 1 and CX3C motif chemokine receptor (CX3CR) 1 in liver cancer, CC motif chemokine ligand (CCL) 2 in breast cancer, and transforming growth factor (TGF) β in skin cancer. Except for CXCR6, all cytokines/cytokine receptors were shown to operate in the spine, with CX3CL1, CX3CR1, IL10, CCL2, CXCL12, and CXCR4 mediating bone marrow colonization, CXCL5 and TGFβ promoting tumor cell proliferation, and TGFβ additionally driving bone remodeling. The number of cytokines/cytokine receptors confirmed to mediate spinal metastasis is low compared with the vast spectrum of cytokines/cytokine receptors participating in other parts of the skeleton. Therefore, further research is needed, including validation of the role of cytokines mediating metastases to other bones, to precisely address the unmet clinical need associated with spine metastases.

Survival and Functional Outcomes after Surgical Treatment for Spinal Metastasis in Patients with a Short Life Expectancy

This study aimed to analyze the survival and functional outcome after surgery in spinal metastasis patients with a short life expectancy and to compare the baseline characteristics based on 3-month survival. A total of 492 surgical treatment cases with a preoperative revised Tokuhashi score ≤ 8were reviewed. Median survival was calculated and Kaplan−Meier analysis was used to analyze the survival rates at 6 months, 1 year, and 2 years postoperatively. The surgical period was divided into three time frames to examine the time trends. For the functional outcome, Eastern Cooperative Oncology Group Performance Status (ECOG-PS) was analyzed. This study categorized subjects based on 3-month survival and compared the baseline characteristics. The median overall survival was 10.6 months. The 2013−2020 period showed a significantly better median survival than the other two periods (p < 0.001). Lung and kidney cancers showed a significant survival improvement in 2013−2020 (p < 0.001). Patients with ECOG-PS ≤ 2 increased from 37.4% preoperatively to 63.7% postoperatively (p < 0.001). There were significantly more cases of preoperative favorable performance status, slow and moderate growth cancers, and chemotherapy after surgery in the survival ≥3 months group. Depending on the type of primary cancer, surgery can be considered even in spinal metastasis patients with a short life expectancy, particularly those with a good performance status.

Characterization and Treatment of Spinal Tumors

The prevalence of spinal tumors is rare in comparison to brain tumors which encompass most central nervous system tumors. Tumors of the spine can be divided into primary and metastatic tumors with the latter being the most common presentation. Primary tumors are subdivided based on their location on the spinal column and in the spinal cord into intramedullary, intradural extramedullary, and primary bone tumors. Back pain is a common presentation in spine cancer patients; however, other radicular pain may be present. Magnetic resonance imaging (MRI) is the imaging modality of choice for intradural extramedullary and intramedullary tumors. Plain radiographs are used in the initial diagnosis of primary bone tumors while Computed tomography (CT) and MRI may often be necessary for further characterization. Complete surgical resection is the treatment of choice for spinal tumors and may be curative for well circumscribed lesions. However, intralesional resection along with adjuvant radiation and chemotherapy can be indicated for patients that would experience increased morbidity from damage to nearby neurological structures caused by resection with wide margins. Even with the current treatment options, the prognosis for aggressive spinal cancer remains poor. Advances in novel treatments including molecular targeting, immunotherapy and stem cell therapy provide the potential for greater control of malignant and metastatic tumors of the spine.

Complications and Risk Factors in En Bloc Resection of Spinal Tumors: A Retrospective Analysis on 298 Patients Treated in a Single Institution

En bloc resection consists in the surgical removal of a vertebral tumor in a single piece with a sufficient margin, to improve survival and reduce recurrence rate. This procedure is technically demanding and correlates with a high complication rate. The purpose of this study is to investigate the risk factors for complications in en bloc resection and evaluate if benefits overcome the risks in term of overall survival. We retrospectively analyzed prospectively collected data of patients treated with en bloc resection between 1980 and 2021. Complications were classified according to SAVES-V2. Overall Survival was estimated using Kaplan-Meier method. A total of 149 patients out of 298 (50%) suffered from at least one complication. Moreover, 220 adverse events were collected (67 intraoperative, 82 early post-operative, 71 late post-operative), 54% of these were classified as grade 3 (in a severity scale from 1 to 6). Ten years overall survival was 67% (95% CI 59-74). The occurrence of relapses was associated to an increased risk of mortality with OR 3.4 (95% CI 2.1-5.5), while complications did not affect the overall survival. Despite a high complication rate, en bloc resection allows for a better control of disease and should be performed in selected patients by specialized surgeons.

Biological and Clinical Aspects of Metastatic Spinal Tumors

Simple Summary

Spine metastases are a common life-threatening complication of advanced-stage malignancies and often result in poor prognosis. Symptomatic spine metastases develop in the course of about 10% of malignant neoplasms. Therefore, it is essential for contemporary medicine to understand metastatic processes in order to find appropriate, targeted therapeutic options. Our literature review aimed to describe the up-to-date knowledge about the molecular pathways and biomarkers engaged in the spine’s metastatic processes. Moreover, we described current data regarding bone-targeted treatment, the emerging targeted therapies, radiotherapy, and immunotherapy used for the treatment of spine metastases. We hope that knowledge comprehensively presented in our review will contribute to the development of novel drugs targeting specific biomarkers and pathways. The more we learn about the molecular aspects of cancer metastasis, the easier it will be to look for treatment methods that will allow us to precisely kill tumor cells.

Abstract

Spine metastases are a common life-threatening complication of advanced-stage malignancies and often result in poor prognosis. Symptomatic spine metastases develop in the course of about 10% of malignant neoplasms. Therefore, it is essential for contemporary medicine to understand metastatic processes in order to find appropriate, targeted therapeutic options. Thanks to continuous research, there appears more and more detailed knowledge about cancer and metastasis, but these transformations are extremely complicated, e.g., due to the complexity of reactions, the variety of places where they occur, or the participation of both tumor cells and host cells in these transitions. The right target points in tumor metastasis mechanisms are still being researched; that will help us in the proper diagnosis as well as in finding the right treatment. In this literature review, we described the current knowledge about the molecular pathways and biomarkers engaged in metastatic processes involving the spine. We also presented a current bone-targeted treatment for spine metastases and the emerging therapies targeting the discussed molecular mechanisms.

Hybrid Therapy Versus Total En Bloc Spondyectomy in the Treatment of Solitary Radioresistant Spinal Metastases: A Single-center, Retrospective Study

STUDY DESIGN

This was a retrospective study.

OBJECTIVE

To compare the treatment efficacy of hybrid therapy (HT) with that of total en bloc spondylectomy (TES) in patients with solitary radioresistant high-grade epidural spinal cord compression (ESCC) spinal metastases.

SUMMARY OF BACKGROUND DATA

Both HT and TES can yield good results for solitary radioresistant metastatic spinal tumors with high-grade ESCC. However, there is still a lack of comparative studies on the treatment efficacy of these 2 methods.

MATERIALS AND METHODS

We retrospectively reviewed patients with the above-mentioned tumors between January 2012 and May 2019. A total of 157 patients underwent surgery, 64 of whom received HT and 93 were treated with TES. Propensity score matching (1:1 ratio) allowed the generation of best-matched pairs for the 2 categories. Local control rates and survival rates were estimated using the Kaplan-Meier method.

RESULTS

All patients had a minimum 2-year follow-up. The longest follow-up period was 88 months. The survival rates and local progression-free survival rates after HT were comparable with those after TES at 1 year (84.6% vs. 83.1% and 90.2% vs. 90%, respectively), 2 years (60.8% vs. 64.3% and 64.1% vs. 62.1%, respectively), and 5 years (18.8% vs. 24.1% and 24.4% vs. 28.4%, respectively). There were no significant differences in pain control, improvement in neurological status, spine stabilization restoration, incidence of perioperative complications, and improvement in quality of life between the groups. However, HT showed more advantages than TES in that it had a shorter operative time and lower intraoperative blood loss.

CONCLUSIONS

HT can obtain satisfactory results comparable to TES for solitary radioresistant metastatic spinal tumors with high-grade ESCC. In addition, HT has a shorter operative time and fewer perioperative complications than TES. HT may be a promising treatment for solitary radioresistant metastatic spinal tumors with high-grade ESCC.

Percutaneous CT-Guided Microwave Ablation Combined with Vertebral Augmentation for Treatment of Painful Spinal Metastases

BACKGROUND AND PURPOSE

Percutaneous thermal ablation followed by vertebral augmentation is an emerging minimally invasive therapeutic alternative for the management of spinal metastases. This study aimed to retrospectively evaluate the effectiveness and safety of microwave ablation combined with vertebral augmentation for the treatment of painful vertebral metastases.

MATERIALS AND METHODS

Overall, 91 patients with 140 metastatic vertebrae who experienced refractory moderate-to-severe pain were treated with CT-guided microwave ablation and vertebral augmentation. Procedural effectiveness was determined using the visual analog scale, daily morphine consumption, and the Oswestry Disability Index preprocedurally and during follow-up. Local tumor control was assessed at follow-up imaging.

RESULTS

The procedure was technically successful in all patients. The median visual analog scale score and mean morphine dose were 6 (range, 4-10) and 77.8 (SD, 31.5) mg (range, 15-143 mg), preprocedurally; 5 (range 3-8) and 34.5 (SD, 23.8) mg (range, 0-88 mg) at 3 days; 4 (range, 2-7) and 28.7 (SD, 16.4) mg (range, 0-73 mg) at 1 week; 3 (range, 1-6) and 24.6 (SD, 13.2) mg (range, 0-70 mg) at 1 month; 3 (range, 1-6) and 21.70 (SD, 10.0) mg (range, 0-42 mg) at 3 months; and 3 (range, 1-8) and 21.0 (SD, 9.9) mg (range, 0-46 mg) at 6 months postprocedurally (all P < .05). A decrease in the Oswestry Disability Index score was also observed (P < .01). Local control was achieved in 94.8% of the treated metastatic vertebrae during the 6-month follow-up period. Asymptomatic cement leakage occurred in 42 (30%) treated vertebrae. A grade 3 neural injury was observed in 1 patient (1.1%). The patient's neurologic function returned to normal following treatment with mannitol, glucocorticoids, and radiation therapy.

CONCLUSIONS

This study demonstrates that percutaneous CT-guided microwave ablation combined with vertebral augmentation is a safe and effective minimally invasive intervention for the treatment of painful spinal metastases.

Three-Dimensional Endoscopy-Assisted Excision and Reconstruction for Metastatic Disease of the Dorsal and Lumbar Spine: Early Results

Background

The aim of this study was to explore the role of three-dimensional (3D) endoscopy in surgical management of metastatic disease of the dorsal and lumbar spine.

Methods

This is a prospective study on 33 patients (15 men and 18 women, mean age of 61.6 ± 8.9 years) with biopsy-proven metastatic disease of the spine managed by sequential/staged posterior decompression-stabilization, followed by 3D endoscopy-assisted anterior corpectomy and stabilization with a mesh cage. All patients had significant extradural compression or spinal instability or both. Sixteen patients had neurological deficits. Visual analog scale (VAS), Frenkel grade (neurological deficits), Karnofsky performance status scale, and the 36-item short-form health survey (SF-36) were used for assessment preoperatively and at 3, 6, and 12 months from surgery.

Results

At a mean follow-up of 1.7 ± 0.7 years from surgery, 18 patients were alive. VAS showed significant improvement at the latest follow-up compared to preoperative levels (4.39 vs. 6.61, p = 0.001). Karnofsky status did not show any significant improvement. Frenkel grade improved in 5 patients, deteriorated in 4 patients, and remained unchanged in 24 patients. Regarding SF-36 parameters, general health showed deterioration, but role functioning—physical, role functioning—emotional, social functioning, and body pain showed statistically significant improvement. There was no change in physical health, viability, and mental health. Subjectively the surgeons felt better depth perception and smoother surgical experience with the 3D optics technology. The only complication was delayed wound healing in three patients who had a previous history of radiotherapy to the surgical site.

Conclusions

3D endoscopy is a valuable tool in the management of metastatic spinal disease requiring excision and reconstruction using the combined posterior and anterior approaches. These early results warrant confirmation with more data and longer follow-ups.

How to Target Spinal Metastasis in Experimental Research: An Overview of Currently Used Experimental Mouse Models and Future Prospects

The spine is one of the organs that is most affected by metastasis in cancer patients. Since the control of primary tumor is continuously improving, treatment of metastases is becoming one of the major challenges to prevent cancer-related death. Due to the anatomical proximity to the spinal cord, local spread of metastasis can directly cause neurological deficits, severely limiting the patient’s quality of life. To investigate the underlying mechanisms and to develop new therapies, preclinical models are required which represent the complexity of the multistep cascade of metastasis. Current research of metastasis focuses on the formation of the premetastatic niche, tumor cell dormancy and the influence and regulating function of the immune system. To unveil whether these influence the organotropism to the spine, spinal models are irreplaceable. Mouse models are one of the most suitable models in oncologic research. Therefore, this review provides an overview of currently used mouse models of spinal metastasis. Furthermore, it discusses technical aspects clarifying to what extend these models can picture key steps of the metastatic process. Finally, it addresses proposals to develop better mouse models in the future and could serve as both basis and stimulus for researchers and clinicians working in this field.

Factors Related to Instrumentation Failure in Titanium Mesh Reconstruction for Thoracic and Lumbar Tumors: Retrospective Analysis of 178 Patients

Purpose

To investigate risk factors for instrumentation failure (IF) in titanium (Ti) mesh reconstruction for thoracic and lumbar tumors.

Patients and Methods

The clinical data of patients with thoracic or lumbar tumors who received Ti mesh reconstruction via the posterior approach in our hospital from 2013 to 2018 were analyzed retrospectively. The observation indexes included sex, age, BMI, the vertebra resection mode, the number of resected vertebral segments, application of bone cement, radiotherapy, chemotherapy, revision or primary surgery, and primary tumor metastasis. Correlations between these factors and IF were analyzed by Kaplan–Meier survival and logistics regression analyses.

Results

The 178 patients included 108 males and 70 females with a mean age of 48.09±16.21 (6–78) years and a mean follow-up period of 51.18 (24–90) months. The data showed that 17 patients (9.55%) were inflicted with IF, involving the thoracic vertebra in 11 cases, thoracolumbar vertebrae (T12–L1) in 2 cases, and lumbar vertebrae in 4 cases. The mean interval between surgery to IF was 35.18±14.17 (14–59) months. Univariate analysis showed that total vertebral body resection, the number of resected vertebral segments, radiotherapy and multiple tumor resection were potential factors for IF, while multivariate analysis showed that only total vertebral body resection, the number of resected vertebral segments and radiotherapy were independent factors.

Conclusion

Total vertebra resection, the number of resected vertebral segments (≥2) and radiotherapy before and after operation were significant risk factors related to IF.