Metastatic spine disease: epidemiology, pathophysiology, and evaluation of patients

Artificial intelligence in skeletal metastasis imaging

In the field of metastatic skeletal oncology imaging, the role of artificial intelligence (AI) is becoming more prominent. Bone metastasis typically indicates the terminal stage of various malignant neoplasms. Once identified, it necessitates a comprehensive revision of the initial treatment regime, and palliative care is often the only resort. Given the gravity of the condition, the diagnosis of bone metastasis should be approached with utmost caution. AI techniques are being evaluated for their efficacy in a range of tasks within medical imaging, including object detection, disease classification, region segmentation, and prognosis prediction in medical imaging. These methods offer a standardized solution to the frequently subjective challenge of image interpretation.This subjectivity is most desirable in bone metastasis imaging. This review describes the basic imaging modalities of bone metastasis imaging, along with the recent developments and current applications of AI in the respective imaging studies. These concrete examples emphasize the importance of using computer-aided systems in the clinical setting. The review culminates with an examination of the current limitations and prospects of AI in the realm of bone metastasis imaging. To establish the credibility of AI in this domain, further research efforts are required to enhance the reproducibility and attain robust level of empirical support.

Assessing visibility and bone changes of spinal metastases in CT scans: a comprehensive analysis across diverse cancer types

OBJECTIVES

To analyze the characteristics of spinal metastasis in CT scans across diverse cancers for effective diagnosis and treatment, using MRI as the gold standard.

METHODS

A retrospective study of 309 patients from four centers, who underwent concurrent CT and spinal MRI, revealing spinal metastasis, was conducted. Data on metastasis including total number, volume, visibility on CT (visible, indeterminate, or invisible), and type of bone change were collected. Through chi-square and Mann-Whitney U tests, we characterized the metastasis across diverse cancers and investigated the variation in the intra-individual ratio representing the percentage of lesions within each category for each patient.

RESULTS

Out of 3333 spinal metastases from 309 patients, 55% were visible, 21% indeterminate, and 24% invisible. Sclerotic and lytic lesions made up 47% and 43% of the visible and indeterminate categories, respectively. Renal cell carcinoma (RCC), prostate cancer, and hepatocellular carcinoma (HCC) had the highest visibility at 86%, 73%, and 67% (p < 0.0001, p < 0.0001, and p = 0.003), while pancreatic cancer was lowest at 29% (p < 0.0001). RCC and HCC had significantly high lytic metastasis ratios (interquartile range (IQR) 0.96-1.0 and 0.31-1.0, p < 0.001 and p = 0.005). Prostate cancer exhibited a high sclerotic lesion ratio (IQR 0.52-0.97, p < 0.001). About 39% of individuals had invisible or indeterminate lesions, even with a single visible lesion on CT. The intra-individual ratio for indeterminate and invisible metastases surpassed 18%, regardless of the maximal size of the visible metastasis.

CONCLUSIONS

This study highlights the variability in characteristics of spinal metastasis based on the primary cancer type through unique lesion-centric analysis.

Management of Metastatic Spinal Disease - A Practical Approach

STUDY DESIGN

Narrative review.

OBJECTIVE

This review presents a comprehensive approach to the management of spinal metastases.

METHODS

N/A.

RESULTS

The wide spectrum of clinical presentation in spinal metastases necessitates a personalized approach to treatment planning. This includes a comprehensive diagnostic workup, oncological management, palliation of symptoms, and surgical intervention if appropriate. A systematic and multidisciplinary approach allows optimal shared decision making to reach an evidence-informed and value-congruent treatment plan for the patient. We highlight how advances in stereotactic body radiotherapy (SBRT) and separation surgery may be incorporated into clinical management from a spine surgeon's perspective.

CONCLUSION

This review summarizes the approach and management of spinal metastases, its outcomes and complications.

Factors Affecting the Outcome of Spine Metastases: A Single-Center Evaluation in Surgically Treated Patients

BACKGROUND

The estimation of survival is extremely important for metastatic disease in the spine. The aim of this study was to determine the factors affecting the outcome of patients with spinal metastasis, primarily the character of neurologic deficit and the histopathology of the tumor.

METHOD

A retrospective examination was made of 158 patients with spinal metastasis who were followed up in our clinic between 2010 and 2020 and underwent surgical intervention. The patients were examined in respect of demographic characteristics, the primary tumor, comorbidities, preoperative-postoperative visual aAnalog scale scores, preoperative-postoperative neurologic examinations and neurologic deficit if present and ambulation status, postoperative survival duration, tumor localization, characteristics of the surgeries, complications, the Karnofsky Performance Scale, revised Tokuhashi, and Tomita scores.

RESULTS

Spinal metastasis was seen more frequently in males (72.8% male, 27.8% female). Male gender, multiple level involvement, intradural localization, and Karnofsky Performance Scale <70 were seen to cause a shorter survival time. Patients with a primary focus of hematologic malignancy, breast cancer, and lymphoma had a longer survival. The revised Tokuhashi and Tomita scores were observed to be successful in the prediction of survival. A decrease in postoperative visual analog scale score had a positive effect on functional survival. The absence of preoperative neurological deficit and the patient's ability for preoperative and postoperative ambulation affected survival positively. The overall survival period decreased in patients who were mobilized in the early postoperative period but became nonmobile in the late period, and in those who were nonmobile in both the early and late postoperative periods.

CONCLUSIONS

The neurologic and ambulatory status, the Tomita and Tokuhashi scores, intradural localization, and gender are the factors with a significant effect on prognosis.

Hematologic Malignancies Influence the Accuracy of Prediction of Survival in Patients With Solid Tumor Spinal Metastases Undergoing Surgery

PURPOSE

There is no consensus on how to identify patients with multiple-level spinal metastases who would benefit from surgery. Previous studies have revealed that patients with hematologic malignancies have a significantly longer median survival time than those with solid tumor spinal metastases. We aimed to compare predictors and survival data between patients with spinal metastases, including hematologic malignancies (all-malignancies group), with only those with nonhematologic malignancies (nonhematologic malignancies group).

MATERIALS AND METHODS

This single-center retrospective study included all patients age >18 years who underwent surgery to treat spinal metastases in our department from 2008 to 2018. The patients' baseline characteristics, treatment modalities, and laboratory results were analyzed. Survival was calculated from the date of surgery to the date of confirmed death. Cox regression analysis was used to identify independent predictors of survival.

RESULTS

The study cohort comprised 186 patients with a mean age of 57.1 ± 13.4 years, 101 of whom were male and 18 of whom had hematologic malignancies. The median survival time was 201 days in the all-malignancies group and 168 days in the nonhematologic malignancies group. Independent predictors of survival differed between the two groups. Eastern Cooperative Oncology Group status and response to preoperative chemotherapy were identified as independent factors in both groups. However, radiosensitivity and CNS metastases were identified only in the all-malignancies group, and tumor growth potential, albumin status, and number of vertebrae were identified only in the nonhematologic malignancies group. The receiver operating characteristics were comparable in the two groups: 0.75 in the all-malignancies group and 0.77 in the nonhematologic malignancies group.

CONCLUSION

Longer survival in patients with hematologic malignancies influences the overall prediction of survival. Tumor-specific prognostic factors may improve the prediction of survival in patients with spinal metastases.

Chronic Low Back Pain: History, Symptoms, Pain Mechanisms, and Treatment

Chronic low back pain (cLBP) is the most frequently reported cause of years lived with disability. Identifying the anatomical structures or dysfunction contributing to patients' symptoms is critical to guiding treatment. The etiology of back pain and differential diagnosis is often broad, ranging from non-degenerative cLBP (trauma, tumor, inflammation, infection, etc.) to degenerative (also described as nonspecific) cLBP. After eliminating suspicion for more insidious causes of cLBP, a thorough investigation can be conducted in an attempt to identify a source of degenerative cLBP. Degenerative cLBP can originate from many sources, and a detailed understanding of the structures potentially involved is invaluable for an accurate diagnosis. This review article aims to provide a broad overview of the utility of clinical history, physical exam findings, imaging findings, and diagnostic procedures in identifying the cause of patients' cLBP. We provide a framework to help guide clinicians by dividing the structures into groups as follows: anterior vertebral column, posterior vertebral column, and extra-vertebral pain. For each condition listed, we touch on the treatment options that can be considered.

Rethinking Strategies for Multi-Metastatic Patients: A Comprehensive Retrospective Analysis on Open Posterior Fusion Versus Percutaneous Osteosynthesis in the Treatment of Vertebral Metastases

Background: Managing vertebral metastases (VM) is still challenging in oncology, necessitating the use of effective surgical strategies to preserve patient quality of life (QoL). Traditional open posterior fusion (OPF) and percutaneous osteosynthesis (PO) are well-documented approaches, but their comparative efficacy remains debated. Methods: This retrospective study compared short-term outcomes (6-12 months) between OPF and PO in 78 cancer patients with spinal metastases. This comprehensive evaluation included functional, clinical, and radiographic parameters. Statistical analysis utilized PRISM software (version 10), with significance set at p < 0.05. Results: PO demonstrated advantages over OPF, including shorter surgical durations, reduced blood loss, and hospital stay, along with lower perioperative complication rates. Patient quality of life and functional outcomes favored PO, particularly at the 6-month mark. The mortality rates at one year were significantly lower in the PO group. Conclusions: Minimally invasive techniques offer promising benefits in VM management, optimizing patient outcomes and QoL. Despite limitations, this study advocates for the adoption of minimally invasive approaches to enhance the care of multi-metastatic patients with symptomatic VM.

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.

Clinical Efficacy of Percutaneous Osteoplasty Under Fluoroscopy and Cone-Beam CT Guidance for Painful Sternal Metastases: A Case Series

Background

Although percutaneous osteoplasty (POP) has been widely accepted and is now being performed for the treatment of painful bone metastases outside the spine. It is emerging as one of the most promising procedures for patients with painful bone metastasis who are unsuitable for surgery or who show resistance to radiotherapy and/or analgesic therapies. However, there are only scarce reports regarding osteoplasty in painful sternal metastases.

Subjects and Method

We report four patients with sternal metastases suffered with severe pain of anterior chest wall. The original tumors included lung cancer and thyroid cancer. For the initially pain medication failing, all the four patients received POP procedure under fluoroscopic and cone-beam CT (CBCT) guidance, and obtained satisfying resolution of painful symptoms at 6-month postop follow-up.

Conclusion

POP is a safe and effective treatment for pain caused by metastatic bone tumors in the sternum. In practice, however, percutaneous puncture of pathologic sternal fractures can be a challenge because of the long flat contour and the defacement by lytic tumor of bony landmarks. We find that the use of fluoroscopic and CBCT can facilitate POP for flat bone fractures with displacing the trajectory planning, needle advancement, and cement delivery in time.

Establishment and validation of an interactive artificial intelligence platform to predict postoperative ambulatory status for patients with metastatic spinal disease: a multicenter analysis

BACKGROUND

Identification of patients with high-risk of experiencing inability to walk after surgery is important for surgeons to make therapeutic strategies for patients with metastatic spinal disease. However, there is a lack of clinical tool to assess postoperative ambulatory status for those patients. The emergence of artificial intelligence (AI) brings a promising opportunity to develop accurate prediction models.

METHODS

This study collected 455 patients with metastatic spinal disease who underwent posterior decompressive surgery at three tertiary medical institutions. Of these, 220 patients were collected from one medical institution to form the model derivation cohort, while 89 and 146 patients were collected from two other medical institutions to form the external validation cohorts 1 and 2, respectively. Patients in the model derivation cohort were used to develop and internally validate models. To establish the interactive AI platform, machine learning techniques were used to develop prediction models, including logistic regression (LR), decision tree (DT), random forest (RF), extreme gradient boosting machine (eXGBM), support vector machine (SVM), and neural network (NN). Furthermore, to enhance the resilience of the study's model, an ensemble machine learning approach was employed using a soft-voting method by combining the results of the above six algorithms. A scoring system incorporating 10 evaluation metrics was used to comprehensively assess the prediction performance of the developed models. The scoring system had a total score of 0 to 60, with higher scores denoting better prediction performance. An interactive AI platform was further deployed via Streamlit. The prediction performance was compared between medical experts and the AI platform in assessing the risk of experiencing postoperative inability to walk among patients with metastatic spinal disease.

RESULTS

Among all developed models, the ensemble model outperformed the six other models with the highest score of 57, followed by the eXGBM model (54), SVM model (50), and NN model (50). The ensemble model had the best performance in accuracy and calibration slope, and the second-best performance in precise, recall, specificity, area under the curve (AUC), Brier score, and log loss. The scores of the LR model, RF model, and DT model were 39, 46, and 26, respectively. External validation demonstrated that the ensemble model had an AUC value of 0.873 (95% CI: 0.809-0.936) in the external validation cohort 1 and 0.924 (95% CI: 0.890-0.959) in the external validation cohort 2. In the new ensemble machine learning model excluding the feature of the number of comorbidities, the AUC value was still as high as 0.916 (95% CI: 0.863-0.969). In addition, the AUC values of the new model were 0.880 (95% CI: 0.819-0.940) in the external validation cohort 1 and 0.922 (95% CI: 0.887-0.958) in the external validation cohort 2, indicating favorable generalization of the model. The interactive AI platform was further deployed online based on the final machine learning model, and it was available at https://postoperativeambulatory-izpdr6gsxxwhitr8fubutd.streamlit.app/ . By using the AI platform, researchers were able to obtain the individual predicted risk of postoperative inability to walk, gain insights into the key factors influencing the outcome, and find the stratified therapeutic recommendations. The AUC value obtained from the AI platform was significantly higher than the average AUC value achieved by the medical experts ( P <0.001), denoting that the AI platform obviously outperformed the individual medical experts.

CONCLUSIONS

The study successfully develops and validates an interactive AI platform for evaluating the risk of postoperative loss of ambulatory ability in patients with metastatic spinal disease. This AI platform has the potential to serve as a valuable model for guiding healthcare professionals in implementing surgical plans and ultimately enhancing patient outcomes.

Is perioperative blood transfusion associated with postoperative thromboembolism or infection after metastatic spinal tumor surgery?

STUDY DESIGN

Retrospective cohort.

SUMMARY OF BACKGROUND DATA

Patients with metastatic spine disease who undergo surgical intervention have a high risk of requiring red blood cell (RBC) transfusion. Perioperative transfusion has been independently associated with increased risk of venous thromboembolic (VTE) and infectious complications following orthopedic procedures and degenerative spinal intervention; however, literature within spine oncology is limited.

OBJECTIVE

To determine the association between perioperative RBC transfusion and postoperative VTE or infection following spinal tumor surgery.

METHODS

A total of 153 patients who underwent surgery for spinal metastases between April 2012 and April 2022 were included. Medical records were reviewed to identify RBC transfusion administered either intraoperatively or within 96 h following surgery. The primary endpoints were: 1) development of any VTE or 2) development of any infection within 30 days following surgery. Any VTE was defined as deep vein thrombosis or pulmonary embolism, and any infection was defined as pneumonia, meningitis, Clostridium difficile infection, urinary tract infection, surgical site infection, or sepsis. Logistic regression analyses were performed.

RESULTS

Of the 153 patients included in the study, 43 % received a perioperative RBC transfusion. The overall incidence of postoperative VTE and infection was 15 % and 22 %, respectively. In univariate analysis, perioperative transfusion was not associated with postoperative VTE (odds ratio [OR] 2.41; 95 % confidence interval [CI] 0.97-6.00; p = 0.058) but was associated with infection (OR 3.02; 95 % CI 1.36-6.73; p = 0.007). After adjusting for confounders such as performance status, operative time, and surgical extent, transfusion was not associated with both VTE (OR 1.25; 95 % CI 0.36-4.32; p = 0.727) or infection (OR 1.86; 95 % CI 0.70-4.92; p = 0.210). While not statistically significant, sub-analyses demonstrated a trend towards increased VTE incidence in patients requiring transfusion earlier (within 24 h) as opposed to later postoperatively.

CONCLUSIONS

We found that perioperative transfusion was not an independent predictor of 30-day postoperative VTE or infection in patients undergoing metastatic spinal surgery. Further exploration of time-dependent transfusion outcomes is warranted.

Differentiation of benign and malignant vertebral fractures using a convolutional neural network to extract CT-based texture features

PURPOSE

To assess the diagnostic performance of three-dimensional (3D) CT-based texture features (TFs) using a convolutional neural network (CNN)-based framework to differentiate benign (osteoporotic) and malignant vertebral fractures (VFs).

METHODS

A total of 409 patients who underwent routine thoracolumbar spine CT at two institutions were included. VFs were categorized as benign or malignant using either biopsy or imaging follow-up of at least three months as standard of reference. Automated detection, labelling, and segmentation of the vertebrae were performed using a CNN-based framework ( https://anduin.bonescreen.de ). Eight TFs were extracted: Varianceglobal, Skewnessglobal, energy, entropy, short-run emphasis (SRE), long-run emphasis (LRE), run-length non-uniformity (RLN), and run percentage (RP). Multivariate regression models adjusted for age and sex were used to compare TFs between benign and malignant VFs.

RESULTS

Skewnessglobal showed a significant difference between the two groups when analyzing fractured vertebrae from T1 to L6 (benign fracture group: 0.70 [0.64-0.76]; malignant fracture group: 0.59 [0.56-0.63]; and p = 0.017), suggesting a higher skewness in benign VFs compared to malignant VFs.

CONCLUSION

Three-dimensional CT-based global TF skewness assessed using a CNN-based framework showed significant difference between benign and malignant thoracolumbar VFs and may therefore contribute to the clinical diagnostic work-up of patients with VFs.

Quality of life and its selected determinants in the group of patients with surgically treated spinal tumors

Introduction

Spinal metastases are a common manifestation of advanced neoplastic disease. Destructive neoplastic lesions within the axial skeleton cause unrelieved pain and nervous system disorders involving spinal stenosis and other neural structures. The development of new systemic therapies, radiotherapy and minimally invasive spinal surgeries has increased patients' quality of life by minimising pain and neurological disorders due to vertebral neoplastic infiltration. The aim of the study was to assess the patients' quality of life before and after spine stabilisation surgery with spinal cord decompression to relieve the pressure associated with neoplastic destruction.

Materials and Methods

The study involved 115 subjects with spinal metastases in the preoperative period and 3-4 months after the surgery based on the inclusion criteria (metastatic spinal tumour, sensorimotor dysfunction). The data were collected using the following tools: the Rotterdam Symptom Checklist (RSCL-Rotterdam Symptom Checklist), Acceptance Illness Scale (AIS scale), Activities of Daily Living Scale (ADL scale) and Visual Analogue Scale (VAS). The correlation coefficient was calculated using Spearman's rho assuming the significance level at α = 0.05 (p<0.05).

Results

A higher quality of life was found after surgery (p<0.001) in terms of experiencing physical symptoms (30.7 ± 11.96 points before surgery vs. 20.91 ± 13.00 points after surgery) and psychological symptoms (43.98 ± 14.82 points before surgery vs. 31.35 ± 14.86 points after surgery). The activity level of the subjects also improved (p<0.001; 36.56 ± 22.43 points to 43.55 ± 20.40 points). The level of disease acceptance in the study group was higher after the surgery compared to the preoperative assessment. The subjects with a high level of disease acceptance presented a higher quality of life postoperatively. The independence of the subjects in performing everyday activities after the operation influenced the quality of life, in terms of somatic symptoms (p=0.006), mental symptoms (p=0.001) and activity (p<0.001). Along with the improvement in functional capacity, the quality of life in terms of symptoms and activity levels increased.

Conclusion

The study showed that spinal cord decompression surgery improves the quality of life of patients by reducing neurological dysfunction, increasing the acceptance of the disease and the ability to perform activities of daily living (ADL). Sociodemographic variables did not affect the quality of life of the respondents.

Frailty Indexes in Metastatic Spine Tumor Surgery: A Narrative Review

Quantification of preoperative frailty is an important prognostic tool in neurosurgical decision making. Metastatic spine tumor patients undergoing surgery are frail and have unfavorable outcomes that include an increased length of stay, unfavorable discharge disposition, and increased readmission rates. These undesirable outcomes result in higher treatment costs. A heterogeneous mixture of various frailty indexes is available with marked variance in their validation, leading to disparate clinical utility. The lack of a universally accepted definition for frailty, let alone in the method of creation or elements required in the formation of a frailty index, has resulted in a body of frailty literature lacking precision for predicting neurosurgical outcomes. In this review, we examine the role of reported frailty indexes in predicting postoperative outcomes after resection of metastatic spine tumors and aim to assist as a frailty guide for helping clinical decision making.

Prognostic Factors in Patients with Metastatic Spinal Cord Compression Secondary to Lung Cancer-A Retrospective UK Single-Centre Study

PURPOSE

Metastatic spinal cord compression (MSCC) is a severe complication of cancer that can lead to irreversible neurological impairment, necessitating prompt recognition and intervention. This retrospective, single-centre study aimed to determine the prognostic factors and survival rates among patients presenting with MSCC secondary to lung cancer.

METHODS AND MATERIALS

We identified 74 patients with epidural metastases-related spinal cord compression and a history of lung cancer through the electronic database of Medway Maritime Hospital in the United Kingdom (UK), spanning the period from April 2016 to September 2021. Among them, 39 were below 55 years old, while 35 were aged 55 years or older; 24 patients were diagnosed with small cell lung cancer (SCLC), and 50 patients had non-small cell lung cancer (NSCLC).

RESULTS

The median overall survival (OS) was 5.5 months, with 52 out of 74 patients dying within 6 months of diagnosis with MSCC. For the entire cohort, the statistically significant variables on multi-variate analysis were cancer type (NSCLC had improved OS), the number of involved vertebrae (one to two vertebrae involvement had improved OS), and the time taken to develop motor deficits (≤10 days to develop motor deficits had worsened OS). For the NSCLC cohort, the statistically significant variables on multivariate analysis were molecular alterations (patients with epidermal growth factor receptor (EGFR) mutation), pre-treatment ambulatory status, Eastern Cooperative Oncology Group (ECOG) performance status, and the time taken to develop motor deficits.

CONCLUSIONS

Within the entire cohort, patients diagnosed with NSCLC and spinal metastases affecting one to two vertebrae exhibited enhanced OS. Within the NSCLC subgroup, those with EGFR mutations who were ambulatory and possessed an ECOG performance status of 1-2 demonstrated improved OS. In both the entire cohort and the NSCLC subgroup, the development of motor deficits within a period of ≤10 days was associated with poor OS.

Spine Patient Optimal Radiosurgery Treatment for Symptomatic Metastatic Neoplasms (SPORTSMEN): a randomized phase II study protocol

Background

Approximately 40% of patients with metastatic cancer will have spinal metastatic disease. Historically treated with external beam radiation therapy (EBRT) with limited durability in pain control, the increased lifespan of this patient population has necessitated more durable treatment results via spine radiosurgery/stereotactic body radiation therapy (SBRT). The goal of this study is to assess three-month pain freedom rates via the Spine Patient Optimal Radiosurgery Treatment for Symptomatic Metastatic Neoplasms (SPORTSMEN) randomized trial.

Materials and methods

This study is a prospective randomized three-arm phase II trial which will recruit patients with symptomatic spine metastases. All patients will be randomized to standard-of care SBRT (24 Gy in 2 fractions), single-fraction SBRT (19 Gy in 1 fraction), or EBRT (8 Gy in 1 fraction), with the primary endpoint of three-month pain freedom (using the Brief Pain Inventory). We expect that SPORTSMEN will help definitively answer the efficacy of spine SBRT versus EBRT for achieving pain freedom, while defining the safety and efficacy of 19 Gy single-fraction spine SBRT. Local control will be defined according to Spine Response Assessment in Neuro-Oncology (SPINO) criteria.

Discussion

This is the first phase II trial to objectively assess optimal spine SBRT dosing in the treatment of symptomatic spine metastatic disease, while assessing spine SBRT versus EBRT. Findings should allow for better determination of the efficacy of two-fraction spine SBRT versus EBRT in the United States, as well as for the novel single-fraction 19 Gy spine SBRT regimen in patients with symptomatic spine metastases.

Trial Registration

Clinicaltrials.gov identifier: NCT05617716 (registration date: November 14, 2022).

Comparison of three techniques in the surgical management of metastatic vertebral fracture with posterior wall damage: a retrospective study

BACKGROUND

To retrospectively compare the safety and efficacy of percutaneous kyphoplasty (PKP), internal fixation (IF), and kyphoplasty combined with internal fixation (KP + IF) in treating metastatic vertebral fracture (MVF) with posterior wall damage.

METHODS

87 patients with MVF with posterior wall damage underwent surgery. In Group PKP, 36 patients underwent PKP; in Group IF, 20 patients underwent pedicle screw fixation; and in Group KP + IF, 31 patients underwent kyphoplasty combined with pedicle screw fixation. Operative time, intraoperative blood loss, clinical and radiological results, and complication rate in each group were evaluated and compared.

RESULTS

Significant improvement on the VAS, ODI scores, vertebral height and local kyphotic angle (LKA) was noted in each group (P < 0.001). Group PKP and Group KP + IF achieved better pain relief than Group IF (P < 0.05). At postoperative 3 days, Group PKP had better pain relief than Group KP + IF (P < 0.05). At other follow-up time points, there were no differences between Group PKP and KP + IF (P > 0.05). Group KP + IF and Group IF were more efficacious than Group PKP in terms of height restoration and LKA correction (P < 0.05). Group KP + IF had a higher incidence of postoperative complications than Group PKP and Group IF(P < 0.05).

CONCLUSIONS

PKP was safe and effective in treating MVF with posterior wall damage. It can achieve similar clinical outcomes compared to KP + IF, but associated with less operative time, less blood loss and fewer complications. IF alone should not be the first treatment option for its poorer analgesic effect.

Clinical evaluation of vertebral body replacement of carbon fiber-reinforced polyetheretherketone in patients with tumor manifestation of the thoracic and lumbar spine

PURPOSE

Radiolucent anterior and posterior implants by carbon fiber-reinforced polyetheretherketone (CFR PEEK) aim to improve treatment of primary and secondary tumors of the spine during the last years. The aim of this study was to evaluate clinical and radiological outcomes after dorsoventral instrumentation using a CFR PEEK implant in a cohort of patients representing clinical reality.

METHODS

A total of 25 patients with tumor manifestation of the thoracic and lumbar spine underwent vertebral body replacement (VBR) using an expandable CFR PEEK implant between January 2021 and January 2022. Patient outcome, complications, and radiographic follow-up were analyzed.

RESULTS

A consecutive series aged 65.8 ± 14.7 (27.6-91.2) years were treated at 37 vertebrae of tumor manifestation, including two cases (8.0%) of primary tumor as well as 23 cases (92.0%) of spinal metastases. Overall, 26 cages covering a median of 1 level (1-4) were implanted. Duration of surgery was 134 ± 104 (65-576) min, with a blood loss of 792 ± 785 (100-4000) ml. No intraoperative cage revision was required. Surgical complications were reported in three (12.0%) cases including hemothorax in two cases (one intraoperative, one postoperative) and atrophic wound healing disorder in one case. In two cases (8.0%), revision surgery was performed (fracture of the adjacent tumorous vertebrae, progressive construct failure regarding cage subsidence). No implant failure was observed.

CONCLUSION

VBR using CFR PEEK cages represents a legitimate surgical strategy which opens a variety of improvements-especially in patients in need of postoperative radiotherapy of the spine and MRI-based follow-up examinations.

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.

Spinal Metastases and the Evolving Role of Molecular Targeted Therapy, Chemotherapy, and Immunotherapy

Metastatic involvement of the spine is a common complication of systemic cancer progression. Surgery and external beam radiotherapy are palliative treatment modalities aiming to preserve neurological function, control pain and maintain functional status. More recently, with development of image guidance and stereotactic delivery of high doses of conformal radiation, local tumor control has improved; however recurrent or radiation refractory disease remains a significant clinical problem with limited treatment options. This manuscript represents a narrative overview of novel targeted molecular therapies, chemotherapies, and immunotherapy treatments for patients with breast, lung, melanoma, renal cell, prostate, and thyroid cancers, which resulted in improved responses compared to standard chemotherapy. We present clinical examples of excellent responses in spinal metastatic disease which have not been specifically documented in the literature, as most clinical trials evaluate treatment response based on visceral disease. This review is useful for the spine surgeons treating patients with metastatic disease as knowledge of these responses could help with timing and planning of surgical interventions, as well as promote multidisciplinary discussions, allowing development of an individualized treatment strategy to patients presenting with widespread multifocal progressive disease, where surgery could lead to suboptimal results.

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.

Percutaneous Sacroplasty with or without Radiofrequency Ablation for Treatment of Painful Sacral Metastases

BACKGROUND AND PURPOSE

Percutaneous sacroplasty is a variation of percutaneous vertebroplasty that has gained attention as a therapeutic option for patients with painful sacral insufficiency fractures due to osteoporosis or metastases. Additionally, percutaneous sacroplasty can also be used to treat painful sacral metastases without a pathologic fracture. The purpose of this retrospective study was to compare the efficacy and safety of fluoroscopy-guided percutaneous sacroplasty alone versus percutaneous sacroplasty plus radiofrequency ablation for the treatment of painful sacral metastases.

MATERIALS AND METHODS

For this retrospective study, 126 patients (with a total of 162 painful sacral metastases) were enrolled from October 2012 to February 2021 and assigned to receive either percutaneous sacroplasty plus radiofrequency ablation (n = 51, group A) or percutaneous sacroplasty alone (n = 75, group B). Four different approaches were used for percutaneous sacroplasty: transiliac, interpedicular, anterior-oblique, and posterior. The Visual Analog Scale, Oswestry Disability Index, and Karnofsky Performance Scale were used to evaluate outcomes.

RESULTS

The Visual Analog Scale, Oswestry Disability Index, and Karnofsky Performance Scale scores showed significant improvement in both groups after treatment (P < .05). The overall pain relief rate was significantly better in group A than in group B (90% versus 76%, P = .032). There were no significant differences in the incidence of polymethylmethacrylate leakage between the 2 groups or among the 4 different approaches (P > .05).

CONCLUSIONS

Both percutaneous sacroplasty alone and the combination of percutaneous sacroplasty and radiofrequency ablation are safe and effective for treatment of painful sacral metastases. The combination of percutaneous sacroplasty and radiofrequency ablation appears to be more effective than percutaneous sacroplasty alone.

Multidisciplinary Approach to Patients With Metastatic Spinal Cord Compression: A Diagnostic Therapeutic Algorithm to Improve the Neurological Outcome

Introduction

The morbidity associated with metastatic spinal disease is significant because of spinal cord and/or nerve root compression. The purpose of this paper is to define a diagnostic-therapeutic path for patients with vertebral metastases and from this path to build an algorithm to reduce the devastating consequences of spinal cord compression.

Materials and Methods

The algorithm is born from the experience of a primary care center. A spine surgeon, an emergency room (ER) physician, a neuroradiologist, a radiation oncologist, and an oncologist form the multidisciplinary team. The ER physician or the oncologist intercept the patient with symptoms and signs of a metastatic spinal cord compression. Once the suspicion is confirmed, the following steps of the flow-chart must be triggered. The spine surgeon takes charge of the patient and, on the base of the anamnestic data and neurological examination, defines the appropriate timing for magnetic resonance imaging (MRI) in collaboration with the neuroradiologist. From the MRI outcome, the spine surgeon and the radiation oncologist consult each other to define further therapeutic alternatives. If indicated, surgical treatment should precede radiation therapy. The oncologist gets involved after surgery for systemic therapy.

Results

In 2021, the Spine and Spinal Cord Surgery department evaluated 257 patients with vertebral metastasis. Fifty-three patients presented with actual or incipient spinal cord compression. Among these, 27 were admitted due to rapid progression of symptoms, neurological deficits and/or spine instability signs. The level was thoracic in 21 cases, lumbar in 4 cases, cervical in 1 case, sacral in 1 case. Fifteen were operated on, 10 of these programmed and 5 in emergency.

Discussion

Patients with a history of malignancy can present to the ER or to the oncology department with symptoms that must be correctly framed in the context of a metastatic involvement. Even when there is no previous cancer history, the patient's pain characteristics and clinical signs must be interpreted to yield the correct diagnosis of vertebral metastasis with incipient or current spinal cord compression. The awareness of the alert symptoms and the application of an integrated paradigm consent to frame the patients with spinal cord compression, obtaining the benefits of a homogeneous step-by-step diagnostic and therapeutic path. Early surgical or radiation therapy treatment gives the best hope for preventing the worsening, or even improving, the deficits.

Conclusions

Metastatic spinal cord compression can cause neurological deficits compromising quality of life. Treatment strategies should be planned comprehensively. A multidisciplinary approach and the application of the proposed algorithm is of paramount importance to optimize the outcomes of these patients.

Spinal metastases of bronchopulmonary cancer: Role of spinal surgery and value of prognostic scores (Modified Tokuhashi and Tomita)

INTRODUCTION

Bone metastasis is frequent in bronchopulmonary cancer. We report a series of 52 patients, and analyze indications and the efficacy of surgery.

MATERIALS AND METHODS

We retrospectively studied the records of 52 patients operated on for spinal metastases of bronchopulmonary cancer over a 6-year period from January 2009 to December 2014 in the neurosurgery department of the North Hospital of Marseille, France.

RESULTS

Mean age was 63.6 years; with a sex ratio of 3:1 (M:F). Spinal pain associated with vertebral fracture and spinal cord compression was the most frequent clinical presentation (59.6%). SINS score was ≥7 in 78.9% of cases. Karnofski Performance Status was average in 67.4% of cases. Predicted survival beyond 12 months was zero according to the modified Tokuhashi score. The surgical indication was essentially palliative. Evolution showed regression of pain in 84.6% of cases, and stabilization and improvement in motor deficit in 80.6%. Median postoperative survival was 16 months.

CONCLUSION

Our results highlight the interest of surgery for pain relief, spinal stabilization and improvement in neurological function in patients with spinal metastases of bronchopulmonary cancer, and the unreliability of predictive survival scores.

Spinal metastasis: narrative reviews of the current evidence and treatment modalities

The treatment for spinal metastasis has evolved significantly during the past decade. An advancement in systemic therapy has led to a prolonged overall survival in cancer patients, thus increasing the incidence of spinal metastasis. In addition, with the improved treatment armamentarium, the prediction of patient survival using traditional prognostic models may have limitations and these require the incorporation of some novel parameters to improve their prognostic accuracy. The development of minimally-invasive spinal procedures and minimal access surgical techniques have facilitated a quicker patient recovery and return to systemic treatment. These modern interventions help to alleviate pain and improve quality of life, even in candidates with a relatively short life expectancy. Radiotherapy may be considered in non-surgical candidates or as adjuvant therapy for improving local tumour control. Stereotactic radiosurgery has facilitated this even in radioresistant tumours and may even replace surgery in radiosensitive malignancies. This narrative review summarizes the current evidence leading to the paradigm shifts in the modern treatment of spinal metastasis.

Automated Differentiation Between Osteoporotic Vertebral Fracture and Malignant Vertebral Fracture on MRI Using a Deep Convolutional Neural Network

STUDY DESIGN

Retrospective study of magnetic resonance imaging (MRI).

OBJECTIVES

To assess the ability of a convolutional neural network (CNN) model to differentiate osteoporotic vertebral fractures (OVFs) and malignant vertebral compression fractures (MVFs) using short-TI inversion recovery (STIR) and T1-weighted images (T1WI) and to compare it to the performance of three spine surgeons.

SUMMARY OF BACKGROUND DATA

Differentiating between OVFs and MVFs is crucial for appropriate clinical staging and treatment planning. However, an accurate diagnosis is sometimes difficult. Recently, CNN modeling-an artificial intelligence technique-has gained popularity in the radiology field.

METHODS

We enrolled 50 patients with OVFs and 47 patients with MVFs who underwent thoracolumbar MRI. Sagittal STIR images and sagittal T1WI were used to train and validate the CNN models. To assess the performance of the CNN, the receiver operating characteristic curve was plotted and the area under the curve was calculated. We also compared the accuracy, sensitivity, and specificity of the diagnosis made by the CNN and three spine surgeons.

RESULTS

The area under the curve of receiver operating characteristic curves of the CNN based on STIR images and T1WI were 0.967 and 0.984, respectively. The CNN model based on STIR images showed a performance of 93.8% accuracy, 92.5% sensitivity, and 94.9% specificity. On the other hand, the CNN model based on T1WI showed a performance of 96.4% accuracy, 98.1% sensitivity, and 94.9% specificity. The accuracy and specificity of the CNN using both STIR and T1WI were statistically equal to or better than that of three spine surgeons. There were no significant differences in sensitivity based on both STIR images and T1WI between the CNN and spine surgeons.

CONCLUSION

We successfully differentiated OVFs and MVFs based on MRI with high accuracy using the CNN model, which was statistically equal or superior to that of the spine surgeons.Level of Evidence: 4.

Posterior Percutaneous Pedicle Screws Fixation Versus Open Surgical Instrumented Fusion for Thoraco-Lumbar Spinal Metastases Palliative Management: A Systematic Review and Meta-analysis

Background

Surgical palliative treatment of spinal metastases (SM) could influence the quality of life (QoL) in cancer patients, since the spine represents the most common site of secondary bony localization. Traditional open posterior instrumented fusion (OPIF) and Percutaneous pedicle screw fixation (PPSF) became the main surgical treatment alternatives for SM, but in Literature there is no evidence that describes the absolute superiority of one treatment over the other.

Materials and Methods

This is a systematic review and meta-analysis of comparative studies on PPSF versus OPIF in patients with SM, conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The outcomes of interest were: complications, blood loss, infections, mortality, pain and also the Quality of Life (QoL).

Results

There were a total of 8 studies with 448 patients included in the meta-analyses. Postoperative complications were more frequent in OPIF (odds ratio of 0.48. 95% CI, 0.27 to 0.83; p= 0.01), PPFS was associated with blood loss (odds ratio -585.70. 95% IC, -848.28 to -323.13.69; p< 0.0001) and a mean hospital stay (odds ratio -3.77. 95% IC, -5.92 to -1.61; p= 0.0006) decrease. The rate of infections was minor in PPFS (odds ratio of 0.31. 95% CI, 0.12 to 0.81; p= 0.02) whereas the occurrence of reinterventions (0.76. 95% CI, 0.25 to 2.27; p= 0.62) and the mortality rate was similar in both groups (odds ratio of 0.79. 95% CI, 0.40 to 1.58; p= 0.51). Finally, we also evaluated pre and post-operative VAS and the meta-analysis suggested that both techniques have a similar effect on pain.

Discussion and Conclusion

The PPSF treatment is related with less complications, a lower rate of infections, a reduction in intraoperative blood loss and a shorter hospital stay compared to the OPIF treatment. However, further randomized clinical trials could confirm the results of this meta-analysis and provide a superior quality of scientific evidence.

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.

Outcomes and survival of spinal metastasis with epidural compression

Objective:

The goal of the study was to retrospectively evaluate the demographics, clinical manifestation, outcomes, treatment result, and survival of patients with spinal metastasis with epidural metastasis who underwent surgical treatment.

Materials and Methods:

A retrospective evaluation of 103 patients with spinal metastasis and epidural compression who underwent surgical treatment between 2009 and 2015 was performed. The recorded parameters selected for the study were general demographic data (gender, age, and educational level) and clinical data (primary tumor, performance status according to Karnofsky score, neurological status according to Frankel scale, pain, surgical treatment outcomes, and patient survival).

Results:

The mean age of the patients was 55.28 ± 15.79 years, and spinal metastasis was more frequent in males (61.7%). The two most frequent tumors were malignant breast cancer (26.21%) and prostate cancer (22.33%). Preoperative pain was presented in 96 (94.12%) patients and improvement was observed in 44 (47.31%) patients. Symptoms of spinal cord compression were the initial clinical manifestation of the primary tumor in 35 (33.98%) patients. Neurological deficit was observed in 66 (64.07%) patients, and improvement was observed in 43 (41.74%) patients. Improvement of functional outcome and pain was observed in 34 (37.38%) patients. The mean survival was 12.26 months. Longer survival (mean 19.13 months) was observed in patients who showed improvement in their ability to walk or kept it preserved (Frankel D or E).

Conclusions:

Surgical treatment of spinal metastasis can improve pain and functional activities. Longer survival was observed in patients that keep or recovery the walking ability.

Central Nervous System Metastases

The proportion of patients developing central nervous system (CNS) metastasis is increasing. Most are identified once symptomatic. Surgical resection is indicated for solitary or symptomatic brain metastases, separation surgery for compressive radioresistant spinal metastases, and instrumentation for unstable spinal lesions. Surgical biopsies are performed when histological diagnoses are required. Stereotactic radiosurgery is an option for limited small brain metastases and radioresistant spinal metastases. Whole-brain radiotherapy is reserved for extensive brain metastases and leptomeningeal disease with approaches to reduce cognitive side effects. Radiosensitive and inoperable spinal metastases typically receive external beam radiotherapy. Systemic therapy is increasingly being utilized for CNS metastases.

Subregional radiomics analysis for the detection of the EGFR mutation on thoracic spinal metastases from lung cancer

The present study intended to use radiomic analysis of spinal metastasis subregions to detect epidermal growth factor receptor (EGFR) mutation. In total, 94 patients with thoracic spinal metastasis originated from primary lung adenocarcinoma (2017-2020) were studied. All patients underwent T1-weighted (T1W) and T2 fat-suppressed (T2FS) MRI scans. The spinal metastases (tumor region) were subdivided into phenotypically consistent subregions based on patient- and population-level clustering: Three subregions, S1, S2 and S3, and the total tumor region. Radiomics features were extracted from each subregion and from the whole tumor region as well. Least shrinkage and selection operator (LASSO) regression were used for feature selection and radiomics signature definition. Detection performance of S3 was better than all other regions using T1W (AUCs, S1 versus S2 versus S3 versus whole tumor, 0.720 versus 0.764 versus 0.786 versus 0.758) and T2FS (AUCs, S1 versus S2 versus S3 versus whole tumor, 0.791 versus 0.708 versus 0.838 versus 0.797) MRI. The multi-regional radiomics signature derived from the joint of inner subregion S3 from T1W and T2FS MRI achieved the best detection capabilities with AUCs of 0.879 (ACC = 0.774, SEN = 0.838, SPE = 0.840) and 0.777 (ACC = 0.688, SEN = 0.947, SPE = 0.615) in the training and test sets, respectively. Our study revealed that MRI-based radiomic analysis of spinal metastasis subregions has the potential to detect the EGFR mutation in patients with primary lung adenocarcinoma.

International external validation of the SORG machine learning algorithms for predicting 90-day and one-year survival of patients with spine metastases using a Taiwanese cohort

BACKGROUND CONTEXT

Accurately predicting the survival of patients with spinal metastases is important for guiding surgical intervention. The SORG machine-learning (ML) algorithm for the 90-day and one-year mortality of patients with metastatic cancer to the spine has been multiply validated, with a high degree of accuracy in both internal and external validation studies. However, prior external validations were conducted using patient groups located on the east coast of the United States, representing a generally homogeneous population. The aim of this study was to externally validate the SORG algorithms with a Taiwanese population.

STUDY DESIGN/SETTING

Retrospective study at a single tertiary care center in Taiwan PATIENT SAMPLE: Four hundred and twenty-seven patients who underwent surgery for metastatic spine disease from November 1, 2010 to December 31, 2018 OUTCOME MEASURES: 90-day and one-year mortality METHODS: The baseline characteristics of our validation cohort were compared with those of the previously published developmental and external validation cohorts. Discrimination (c-statistic and receiver operating curve), calibration (calibration plot, intercept, and slope), overall performance (Brier score), and decision curve analysis were used to assess the performance of the SORG ML algorithms in this cohort.

RESULTS

Ninety-day and one-year mortality rates were 110 of 427 (26%) and 256 of 427 (60%), respectively. The external validation cohort and the developmental cohort differed in body mass index (BMI), preoperative performance status, American Spinal Injury Association impairment scale, primary tumor histology and in several laboratory measurements. The SORG ML algorithm for 90-day and 1-year mortality demonstrated a high level of discriminative ability (c-statistics of 0.73 [95% confidence interval [CI], 0.67-0.78] and 0.74 [95% CI, 0.69-0.79]), overall performance, and had a positive net benefit throughout the range of threshold probabilities in decision curve analysis. The algorithm for 1-year mortality had a calibration intercept of 0.08, representing a good calibration. However, the 90-day mortality algorithm underestimated mortality for the lowest predicted probabilities, with an overall intercept of 0.81.

CONCLUSIONS

The SORG algorithms for predicting 90-day and 1-year mortality in patients with spinal metastatic disease generally performed well on international external validation in a predominately Taiwanese population. However, 90-day mortality was underestimated in this group. Whether this inconsistency was due to different primary tumor characteristics, body mass index, selection bias or other factors remains unclear, and may be better understood with further validative works that utilize international and/or diverse populations.

Are spine metastasis survival scoring systems outdated and do they underestimate life expectancy? Caution in surgical recommendation guidance

OBJECTIVE

Survival scoring systems for spine metastasis (SPM) were designed to help surgical practice. The authors sought to validate the prognostic accuracy of the main preoperative scoring systems for SPM.

METHODS

It was hypothesized that true patient survival in SPM was better than that predicted using prognosis scores. To investigate this hypothesis, the authors designed a French national retrospective study of a prospectively collected multicenter database involving 739 patients treated for SPM between 2014 and 2017.

RESULTS

In this series, the median survival time for all patients from an SPM diagnosis was 17.03 ± 1.5 months. Sensitivity and specificity were estimated using the area under the curve (AUC). The AUC of Tomita's prognosis score was the lowest and poorest (0.4 ± 0.023, range 0.35-0.44), whereas the AUC of the Tokuhashi score was the highest (0.825). The Lei score presented an AUC of 0.686 ± 0.022 (range 0.64-0.7), and the Rades score showed a weaker AUC (0.583 ± 0.020, range 0.54-0.63). Differences among AUCs were all statistically significant (p < 0.001). The modified Bauer score and the Rades score had the highest rate of agreement in predicting survival, with a weighted Cohen's kappa of 0.54 and 0.41, respectively, indicating a moderate agreement. The revised Tokuhashi and Lei scores had a fair rate of agreement (weighted Cohen's kappa = 0.24 and 0.22, respectively). The van der Linden and Tomita scores demonstrated the worst performance, with only a "slight" rate of agreement (weighted Cohen's kappa = 0.19 and 0.16, respectively) between what was predicted and the actual survival.

CONCLUSIONS

The use of prognostic scoring systems in the estimation of survival in patients with SPM has become obsolete and therefore underestimates survival. Surgical treatment decisions should no longer be based on survival estimations alone but must also take into account patient symptoms, spinal instability, and quality of life.

Current Overview of Treatment for Metastatic Bone Disease

The number of patients with bone metastasis increases as medical management and surgery improve the overall survival of patients with cancer. Bone metastasis can cause skeletal complications, including bone pain, pathological fractures, spinal cord or nerve root compression, and hypercalcemia. Before initiation of treatment for bone metastasis, it is important to exclude primary bone malignancy, which would require a completely different therapeutic approach. It is essential to select surgical methods considering the patient’s prognosis, quality of life, postoperative function, and risk of postoperative complications. Therefore, bone metastasis treatment requires a multidisciplinary team approach, including radiologists, oncologists, and orthopedic surgeons. Recently, many novel palliative treatment options have emerged for bone metastases, such as stereotactic body radiation therapy, radiopharmaceuticals, vertebroplasty, minimally invasive spine stabilization with percutaneous pedicle screws, acetabuloplasty, embolization, thermal ablation techniques, electrochemotherapy, and high-intensity focused ultrasound. These techniques are beneficial for patients who may not benefit from surgery or radiotherapy.

The role of percutaneous transarterial embolization in the management of spinal bone tumors: a literature review

PURPOSE

Spinal bone tumors include a heterogeneous broad of primary or metastatic lesions that may present as incidental findings or manifest with painful symptoms and pathological fractures. Optimal management of spine bone lesions is often difficult and treatment algorithms are usually solidly based on surgery. We aimed to evaluate the contribution of trans-arterial embolization in this field, with particular attention to the procedure efficacy, technical difficulties and complications.

METHODS

We present a literature review on the role of trans-arterial embolization in the management of spinal bone tumors, both primary and metastatic, evaluating its contribution as preoperative treatment, palliative procedure and standalone curative strategy.

RESULTS

Trans-arterial embolization provides an important contribution to reducing surgery hemorrhagic risks, offering a better visualization of the operating field, and possibly increasing tumor susceptibility to chemotherapy or radiation therapy. Nonetheless, it plays an important part in pain palliation, with the unquestionable advantage of being easily repeatable in case of necessity. Its curative role as a standalone therapy is still subject of debate, and at the present time, satisfactory results have been recorded only in the treatment of aneurysmal bone cysts.

CONCLUSION

Percutaneous trans-arterial embolization has established as a highly useful minimally invasive procedure in the management of spinal bone lesions, particularly as adjuvant preoperative therapy and palliative treatment.

Plastic surgery wound closure following resection of spinal metastases

OBJECTIVE

Surgical site infection and dehiscence are devastating complications of surgery for spinal metastases. Wound closure involving plastic surgeons has been proposed as a strategy to lower post-operative complications. Here we investigated whether plastic surgery closure is associated with lower rates of wound complications, wound infection, and wound reoperation compared to simple closure by spine surgeons.

METHODS

Patients surgically treated for metastatic tumors at a single comprehensive cancer center between April 2013-2020 were retrospectively identified. Primary pathology, demographic information, clinical characteristics, pre-operative laboratory values, tumor location, operative characteristics, and post-operative outcomes were collected. Univariable analyses used student t-tests for continuous variables and χ² tests for categorical variables. Multivariable regressions were performed to control for confounders.

RESULTS

We included 317 patients, of which 56 underwent closure by plastic surgeons and 291 by neurosurgeons. Patients in the plastic surgery cohort were more likely to have received prior radiation to the surgical site, more often on long-term corticosteroid therapy, and more likely to have sacrococcygeal tumors. Operations involving plastic surgeons were more likely to be revision surgeries, corpectomies, and to involve a staged approach. Additionally, patients in the plastic surgery cohort had longer incision lengths, longer surgeries, greater intraoperative blood loss (IOBL), were more likely to receive transfusions, and had longer hospitalizations. Local paraspinous advancement flaps were the most common complex wound closure technique. Plastic surgery closure was not significantly associated with a difference in rates of post-operative wound complications, wound infection, or wound-related reoperations compared to simple wound closure.

CONCLUSION

We identified that patients undergoing plastic surgery wound closure had worse baseline risk, longer surgeries, greater IOBL, and longer hospitalizations compared to patients receiving simple closure. Despite their increased risk, complex wound closure did not significantly alter the rates of post-operative wound complications, wound infection, or wound-related reoperations. Consideration may be given to plastic surgery closure in patients at high risk of wound complications or with extensive wound defects.

Metastatic L1 root compression presenting as an inguinal pain: A case report

As the spine is the third most common place for metastatic involvement, spinal examination is essential in patients with a known history of cancer, even in those with no related complains (ie. Backpain).

Diagnostic Accuracy of Quantitative Imaging Biomarkers in the Differentiation of Benign and Malignant Vertebral Lesions : Combination of Diffusion-Weighted and Proton Density Fat Fraction Spine MRI

Purpose

To compare and combine the diagnostic performance of the apparent diffusion coefficient (ADC) derived from diffusion-weighted imaging (DWI) and proton density fat fraction (PDFF) derived from chemical-shift encoding (CSE)-based water-fat magnetic resonance imaging (MRI) for distinguishing benign and malignant vertebral bone marrow lesions (VBML).

Methods

A total of 55 consecutive patients with 53 benign (traumatic, inflammatory and primary) and 36 malignant (metastatic and hematologic) previously untreated VBMLs were prospectively enrolled in this IRB-approved study and underwent sagittal DWI (single-shot spin-echo echo-planar with multi-slice short TI inversion recovery fat suppression) and CSE-based MRI (gradient-echo 6‑point modified Dixon) in addition to routine clinical spine MRI at 1.5 T or 3.0 T. Diagnostic reference standard was established according to histopathology or imaging follow-up. The ADC = ADC (0, 800) and PDFF = fat / (water + fat) were calculated voxel-wise and examined for differences between benign and malignant lesions.

Results

The ADC and PDFF values of malignant lesions were significantly lower compared to benign lesions (mean ADC 861 × 10⁻⁶ mm²/s vs. 1323 × 10⁻⁶ mm²/s, p < 0.001; mean PDFF 3.1% vs. 28.2%, p < 0.001). The areas under the curve (AUC) and diagnostic accuracies were 0.847 (p < 0.001) and 85.4% (cut-off at 1084.4 × 10⁻⁶ mm²/s) for ADC and 0.940 (p < 0.001) and 89.9% for PDFF (cut-off at 7.8%), respectively. The combined use of ADC and PDFF improved the diagnostic accuracy to 96.6% (malignancy if ADC ≤ 1118.2 × 10⁻⁶ mm²/s and PDFF ≤ 20.0%, otherwise benign).

Conclusion

Quantitative evaluation of both ADC and PDFF was useful in differentiating benign VBMLs from malignancy. The combination of ADC and PDFF improved the diagnostic performance and yielded high diagnostic accuracy for the differentiation of benign and malignant VBMLs.

Comparison of prognostic scales for patients with metastatic spine disease

This is one-centre retrospective study with the aim to identify the scale, which provides the most accurate prediction of life expectancy in patients with metastatic lesions in spine. A retrospective analysis of clinical data of 138 patients with metastatic spinal tumors. Patients underwent spinal cord decompression and instrumented stabilization of affected area. We evaluated the general condition according to the Karnofsky and ECOG scales, the presence of metastases in the visceral organs, spine and other bones, the neurological status and conduction of the medical therapy before spinal surgery. Observed clinical parameters were converted to Tokuhashi, Tomita, and Katagiri scales. For statistical analysis, software environment R 3.4.1 was used. Assessment of prognostic accuracy was performed using ROC analysis. The Tokuhashi scale showed AUC 0.605 (95% CI 0.586-0.616), Tomita scale showed AUC 0.708 (95% CI 0.573-0.842), Katagiri scale showed AUC 0.650 (95% CI 0.508-0.792). The best results for survival rate predicting after surgical treatment for metastatic spinal lesions were shown the Tomita scale.

Low Implant Failure Rate of Percutaneous Fixation for Spinal Metastases: A Multicenter Retrospective Study

OBJECTIVE

To evaluate incidence and types of implant failure observed in a series of patients with spinal metastases (SM) treated with minimally invasive stabilization surgery without fusion.

METHODS

In this multicenter, retrospective, observational study, we reviewed the files of patients >18 years old who underwent surgery for SM using percutaneous spinal stabilization without fusion with a minimum 3-month follow-up. The following variables were included: demographics, clinical findings, prior radiation history, SM location, epidural spinal cord compression scale, Spinal Instability Neoplastic Scale, neurological examination, and surgery-related data. Primary outcome measure was implant failure rate, as observed in patients' last computed tomography scan. Multivariable analysis was performed to identify baseline factors and factors associated with implant failure.

RESULTS

Analysis included 72 patients. Mean age of patients was 62 years, 39 patients were men, and 75% of patients had an intermediate Spinal Instability Neoplastic Scale score. Tumor separation surgery was performed in 48.6% of patients. Short instrumentation was indicated in 54.2% of patients. Three patients (4.2%) experienced implant failure (2 screw loosening, 1 screw cut-out); none of them required revision surgery. In 73.6% of cases, survival was >6 months. No significant predictors of failure were identified in the multivariate analysis.

CONCLUSIONS

A low implant failure rate was observed over the short and medium term, even when short instrumentations without fusion were performed. These findings suggest that minimally invasive stabilization surgery without fusion may be an effective and safe way to treat complicated SM.

Long-term outcome after combined kyphoplasty and intraoperative radiotherapy (Kypho-IORT) for vertebral tumors

INTRODUCTION

The spine represents the site which is most frequently affected by bone metastases in patients with systemic cancer. Of all local treatment options, combined kyphoplasty and intraoperative radiotherapy (Kypho-IORT) provides both, instantaneous stabilization and immediate pain relief. We here report on the long-term outcomes of the largest cohort treated with Kypho-IORT to date.

METHODS

Between 2009 and 2019 a total of 104 patients underwent Kypho-IORT to vertebral tumors in the thoracic, lumbar, or sacral spine with transpedicular kyphoplasty and intraoperative irradiation with a needle-shaped electronic brachytherapy source at our center. Patients were treated either on trial, within the prospective Kypho-IORT studies (NCT01280032 and NCT02773966), or, after completion of the study, off trial but compliant with the study protocol. Follow-up and imaging with computed tomography (CT) or magnetic resonance imaging was scheduled after 3 and 6 months and then bi-annually.

RESULTS

A total of 143 vertebrae (89 thoracic spine, 53 lumbar spine, and 1 sacral spine) were treated in 104 patients. The median follow-up was 14.5 months (range 0.4-109). Local progression occurred in 10 patients (10 vertebrae) after a median time of 22.3 months (range 1.5-73) resulting in local control rates of 97.1, 95.9, and 94.2% at 6, 12, and 24 months, respectively. Overall survival was 74.6, 61.7, and 50.3% at 6, 12, and 24 months, respectively. A single serious adverse event was reported.

CONCLUSION

In addition to immediate pain reduction and stabilization, Kypho-IORT shows excellent long-term local control with minimal side effects.

Multidisciplinary management of metastatic spine disease: initial symptom-directed management

In the past 2 decades, a deeper understanding of the cancer molecular signature has resulted in longer longevity of cancer patients, hence a greater population, who potentially can develop metastatic disease. Spine metastases (SM) occur in up to 70% of cancer patients. Familiarizing ourselves with the key aspects of initial symptom-directed management is important to provide SM patients with the best patient-specific options. We will review key components of initial symptoms assessment such as pain, neurological symptoms, and spine stability. Radiographic evaluation of SM and its role in management will be reviewed. Nonsurgical treatment options are also presented and discussed, including percutaneous procedures, radiation, radiosurgery, and spine stereotactic body radiotherapy. The efforts of a multidisciplinary team will continue to ensure the best patient care as the landscape of cancer is constantly changing.

Minimally Invasive Pedicle Screw Fixation With Indirect Decompression by Ligamentotaxis in Pathological Fractures

BACKGROUND

The spine is the most common site of bony metastases. Associated pathological fractures can result in pain, neurological deficit, biomechanical instability, and deformity.

OBJECTIVE

To present a minimally invasive technique for indirect decompression by ligamentotaxis in pathological fractures.

METHODS

A minimally invasive approach was utilized to perform percutaneous pedicle screw fixation in patients who required stabilization for pathological fractures. Preoperative and postoperative computed tomography and magnetic resonance imaging were used to compare spinal canal area and midsagittal canal diameter.

RESULTS

Two patients with newly diagnosed pathological fractures underwent minimally invasive treatment. Each presented with minimal epidural disease and a chief complaint of intractable back pain without neurological deficit. They underwent minimally invasive pedicle screw fixation with indirect decompression by ligamentotaxis. In each case, postoperative imaging demonstrated an increase in spinal canal area and midsagittal canal diameter by an independent neuroradiologist. There were no perioperative complications, and each patient was neurologically stable without evidence of hardware failure at their 5- and 6-mo follow-up visits.

CONCLUSION

Minimally invasive percutaneous fixation can be used to stabilize pathological fractures and provide indirect decompression by ligamentotaxis. This procedure is associated with minimal blood loss, low morbidity, and rapid initiation of radiation therapy. Only patients with minimal epidural disease, stenosis caused primarily by bony retropulsion, and mild-to-moderate deformity should be considered candidates for this approach.

Uncorrect diagnosis of tubercolar spondylodiscitis in aggressive and bone destructive metastasis of melanoma: A case report and literature review

Differential diagnosis of destructive osteolytic spinal lesions can be a diagnostic challenge. In this study, we described a rare case of spinal metastases from primary desmoplastic melanoma which had incorrectly been diagnosed and treated as tuberculous spondylodiscitis. An 82-year-old male patient with ongoing low back pain and a history of lumbar localized Pott's performed a lumbar spine MRI that showed osteolytic lesion with first hypothesis of spondylodiscitis L2-L3. The patient was hospitalized and cause of worsening of the lumbar pain underwent a following series of non-diagnostic CT-guided and open lumbar biopsy at L2-L3 with unsuccessful antibiotic-antitubercular therapy. A new MRI revealed a worsening of previous lesions, extension of the osteolytic lesion at the level of L1-L2 and L3-L4 with neurological impairment. The diagnosis of metastatic melanoma was obtained with surgical decompression and open posterior biopsy procedure. The case described is pathognomonic of the difficulty in detecting the correct diagnosis in front of similar clinical and radiological manifestations. The presence of a previous Pott's disease in the same involved vertebral site was of crucial importance in deflecting the correct diagnostic classification of the pathology, which was possible to ascertain only following an extensive biopsy sampling in the last surgery performed.

Diagnostic accuracy of MR, CT, and ECT in the differentiation of neoplastic from nonneoplastic spine lesions

AIM

To provide guidance for appropriate imaging examinations for diagnosing spinal tumors or tumor-like lesions.

METHODS

A total of 121 patients with suspected spinal tumors were included this retrospective study. Each patient underwent ≥2 imaging examinations, including computerized tomography (CT), magnetic resonance (MR), and/or emission computed tomography (ECT). All patients were diagnosed by pathology after core needle or surgical biopsies. The results were compared with those of pathological examinations using paired chi-squared tests, and compared with each other. Statistical indicators that tested the consistency of the results included McNemar's and kappa coefficients, as well as receiver operating characteristic curves.

RESULTS

The differences among MR, CT, ECT, and pathology were not significant. The kappa coefficient of MR, CT, and ECT was 46.1%, 36.0%, and 55.9%, respectively. The area under the curve of ECT, MR, and CT scans was 0.809, 0.705, and 0.704, respectively; and the differences among them were significant (P < .05). Post hoc multiple comparisons showed no significant differences among imaging examinations in terms of sensitivity, specificity, misdiagnosis rate, and coincidence rate (P > .05). However, significant differences were noted in the kappa coefficient and missed diagnosis rate (P < .05).

CONCLUSIONS

Although ECT was the most accurate imaging method, its high cost and large radiation dosage limit its widespread application. Furthermore, MR verified spinal tumors more effectively; however, CT excluded them more efficiently. In summary, when all factors are considered, MR is still the optimal modality for the diagnosis of spinal tumors, especially during the initial screening.

Distribution and predictive value of initial presenting symptoms in spinal metastases from primary cancer patients

PURPOSE

Primary cancer patients may have some symptoms and develop spinal metastases in their disease progression. This study was to report the distribution and predictive value of specific initial presenting symptoms in patients with spine metastatic disease.

METHODS

The clinical information about patients with primary cancers was retrospectively collected and analyzed at their initial diagnosis from January 2008 to December 2017. The distribution and specific value of initial presenting symptoms were analyzed in predicting spinal metastases.

RESULTS

A total of 14,603 cancer patients were finally included, of whom 1665 (11.4%) cases were confirmed with spinal metastases. 41.55% (6067/14,603) patients had initial presenting symptoms, while 92.19% (1535/1665) patients with spinal metastases presented at least one initial presenting symptoms. Among 6269 patients with symptoms, 1535 (24.49%) were diagnosed with spinal metastases. Factors including primary tumor type, local pain, night-aggravating pain, limb numbness, limb weakness, unstable gait, claudication, loss of sphincter control, and weight loss are associated with the distribution of spinal metastases. The pooled sensitivity, specificity, positive predictive value, and negative predictive value were 90.9% (89.4-92.2%), 64.9% (64.0-65.7%), 24.99% (23.91-26.11%), and 98.23% (97.92-98.50%), respectively. Positive likelihood ratio of "night-aggravating pain" was 33.25 (12.65-87.36) and 17.26 (12.25-24.32) in patients < 45 and 45-64 years old, respectively.

CONCLUSIONS

The distribution of spinal metastases is associated with primary tumor type and initial presenting symptoms. The predictive value of initial presenting symptoms differs in age groups, but resembles in cancer types. The presence of night-aggravating pain had relative high value in predicting metastases in cancer patients under 65 years old.

MRI-guided cryoablation for metastatic spine disease: intermediate-term clinical outcomes in 14 consecutive patients

OBJECTIVE

Minimal access ablative techniques have emerged as a less invasive option for spinal metastatic disease reduction and separation from neural tissue. Compared with heat-based ablation modalities, percutaneous image-guided cryoablation allows for more distinct visualization of treatment margins. The authors report on a series of patients undergoing MRI-guided cryoablation as a feasible method for treating spinal metastatic disease.

METHODS

A total of 14 patients with metastatic spine disease undergoing MR-monitored cryoablation were prospectively enrolled. Procedures were performed in an advanced imaging operating suite with the use of both CT and MRI to gain access to the spinal canal and monitor real-time cryoablation.

RESULTS

The average age was 54.5 years (range 35-81 years). The mean preoperative Karnofsky Performance Status score was 79.3 (range 35-90). The average radiographic follow-up was 7.1 months (range 25-772 days), and the average clinical follow-up was 9.8 months (range 7-943 days). In 10 patients with epidural disease, 7 patients underwent postprocedural imaging, and of these 71% (5/7) had stable or reduced radiographic disease burden. Bone regrowth was observed in 63% (5/8) of patients with bone ablation during the treatment who had postoperative imaging. Pre- and postoperative visual analog scale scores were obtained, and a significant reduction in these scores was found following ablation. There were no complications.

CONCLUSIONS

MR-guided cryoablation is a minimally invasive treatment option for metastatic spine disease. In patients with epidural disease, the majority experienced tumor reduction or arrest at follow-up. In addition, pain was significantly improved following ablation. The average hospital stay was short, and the procedure was safe in a range of patients who are otherwise not ideal candidates for standard treatment.

Evaluation of Elements Spine SRS Plan Quality for SRS and SBRT Treatment of Spine Metastases

Purpose: The Elements Spine Stereotactic Radiosurgery treatment planning system uses automated volumetric modulated arc radiotherapy that can provide a highly conformal dose distribution to targets, which can provide superior sparing of the spinal cord. This study compares the dosimetric quality of Elements plans with the clinical plans of 20 spine stereotactic radiosurgery/stereotactic body radiation therapy (SRS/SBRT) patients treated at our institution.

Methods: Twenty spine SRS/SBRT patients who were clinically treated at our institution were replanned using the automated Elements planning workflow with prespecified templates. Elements automatically evaluates the size and shape of the target to determine if splitting the PTV into simplistic subvolumes, each treated by their own arc(s), would increase conformity and spinal cord sparing. The conformity index, gradient index, PTV D_5%, and maximum and mean cord dose were evaluated for the Elements and clinical plans. Treatment delivery efficiency was also analyzed by comparing the total number of monitor units and the modulation factor. Wilcoxon rank-sum tests were performed on the statistics.

Results: Elements split the PTV for 50% of cases, requiring four or six arcs. Overall, Elements plans were found to be superior to clinical plans in conformity index, gradient index, and maximum cord dose. The PTV D_5% and cord mean dose for the Elements plans trended higher and lower, respectively. The numbers of monitor units and modulation factor were also higher for Elements plans, although the differences were not significant.

Conclusion: Automated Elements plans achieved superior conformity and cord dose sparing compared to clinical plans and PTV splitting successfully improved spinal cord sparing.

Principles of Management of Spine Metastasis

BACKGROUND

With evolution of medicine, radiation therapy and surgical methods, cancer care has improved the quality of life for patients with improved survival and functional status in patients with skeletal metastasis. The most common site of skeletal metastases from other primary malignant neoplasms is the spine, hence, understanding the epidemiology of metastatic spine disease and its presentation is essential for developing a diagnostic and treatment strategy which eventually results in optimum care to reduce disease-related morbidity.

PURPOSE

With this review article we intend to describe an evidence-based review on the presentation, diagnosis and treatment of metastatic spinal disease.

METHODS

We reviewed the current available literature on management of spinal metastasis and have described a step wise evaluation and management strategy of metastatic spine disease.

CONCLUSION

The present review article addresses various aspects and related controversies related to evaluation, staging and treatment options in the management of spinal metastasis.