Surgical Management of Spinal Metastases

Trends in the surgical treatment for metastatic spinal tumor in Japanese administrative data between 2012 and 2020

BACKGROUND

Both cancer diagnosis/treatment modality and surgical technique for the spine have been developed recently. Nationwide trends in the surgical treatment for metastatic spinal tumors have not been reported in the last decades. This study aimed to examine recent trends in the surgical treatment for spinal metastasis and in-hospital patient outcomes using nationwide administrative hospital discharge data.

METHODS

The Diagnosis Procedure Combination database from 2012 to 2020 was used to extract data from patients who underwent surgical procedures for spinal metastasis with the number of non-metastatic spinal surgery at the institutions that have performed metastatic spine surgeries at least one case in the same year. Trends in the surgical treatment for spinal metastasis, patients' demographics, and in-hospital mortality/outcomes were investigated.

RESULTS

This study analyzed 10,321 eligible patients with spinal metastasis. The surgical treatment for spinal metastasis increased 1.68 times from 2012 to 2020, especially in fusion surgery, whereas the proportion of metastatic spinal surgery retained with a slight increase in the 2%s. Distributions of the primary site did not change, whereas age was getting older. In-hospital mortality and length of stay decreased over time (9.9-6.8%, p < 0.001; 37-30 days, p < 0.001). Postoperative complication and unfavorable ambulatory retained stable and slightly decreased, respectively.

CONCLUSION

During the last decade, surgical treatment for spinal metastasis, especially fusion surgery, has increased in Japan. In-hospital mortality and length of stay decreased. Recent advances in cancer treatment and surgical techniques might influence this trend.

Can Survival Scoring Systems for Spinal Metastases be Used to Predict Postoperative Neurologic Recovery? A Retrospective Study on 204 Patients With Thoracolumbar Metastases Treated at a Tertiary Center

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVE

Scoring systems for metastatic disease of the spine are used to select patients for surgical treatment based on survival estimation, but it is unknown whether they can be used to predict the outcome of surgery. This study aims to investigate the association between two widely used prognostic scores and the neurologic function after surgery.

METHODS

Retrospective analysis of 204 patients with thoracolumbar metastases treated with decompressive surgery at Karolinska University Hospital (2001-2020). Modified Bauer and Tokuhashi scores were categorized based on surgical indication, and post-operative neurological function was assessed using the Frankel scale at two different post-surgery intervals.

RESULTS

Modified Bauer scores ≥2 yielded higher late follow-up Frankel scores (3.9 ± 1.1) than scores <2 (3.5 ± 1.1), P = .03. Modified Tokuhashi scores ≥9 correlated with higher Frankel scores (4.5 ± .9) than scores <9 (3.5 ± 1.1), P < .0001. Both scoring systems positively predicted neurological outcomes at late follow-up, with odds ratios of 1.6 (P = .03) for Bauer and 9.2 (P < .0001) for Tokuhashi. However, only Tokuhashi predicted ambulatory function at late follow-up (P < .0001), demonstrating its utility in prognosticating post-surgical mobility.

CONCLUSION

Higher modified Bauer and Tokuhashi scores were associated with better neurologic function at last follow-up, as well as greater likelihood of being able to walk again. The Tokuhashi score was found to be more accurate than the modified Bauer score in predicting the neurological outcome after surgery.

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

BACKGROUND AND OBJECTIVES

The palliative impact of spine surgery for metastatic disease is evolving with improvements in surgical technique and multidisciplinary cancer care. The goal of this study was to prospectively evaluate long-term clinical outcomes including health-related quality-of-life (HRQOL) measures, using spine cancer-specific patient-reported-outcome (PRO) measures, in patients with symptomatic spinal metastases who underwent surgical management.

METHODS

The Epidemiology, Process, and Outcomes of Spine Oncology (EPOSO, ClinicalTrials.gov identifier: NCT01825161) trial is a prospective-observational cohort study that included 10 specialist centers in North America and Europe. Patients aged 18 to 75 years who underwent surgery for spinal metastases were included. Prospective assessments included both spine tumor-specific and generic PRO tools which were collected for a minimum of 2 years post-treatment or until death.

RESULTS

Two hundred and eighty patients (51.8% female, mean age 57.9 years) were included. At presentation, the mean Charlson Comorbidity Index was 6.0, 35.7% had neurological deficits as defined by the American Spinal Cord Injury Association scores, 47.2% had high-grade epidural spinal cord compression (2-3), and 89.6% had impending or frank instability as measured by a Spinal Instability Neoplastic Score of ≥7. The most common primary tumor sites were breast (20.2%), lung (18.8%), kidney (16.2%), and prostate (6.5%). The median overall survival postsurgery was 501 days, and the 2-year progression-free-survival rate was 38.4%. Compared with baseline, significant and durable improvements in HRQOL were observed at the 6-week, 12-week, 26-week, 1-year, and 2-year follow-up assessments from a battery of PRO questionnaires including the spine cancer-specific, validated, Spine Oncology Study Group Outcomes Questionnaire v2.0, the Short Form 36 version 2, EuroQol-5 Dimension (3L), and pain numerical rating scale score.

CONCLUSION

Multi-institutional, prospective-outcomes data confirm that surgical decompression and/or stabilization provides meaningful and durable improvements in multiple HRQOL domains, including spine-specific outcomes based on the Spine Oncology Study Group Outcomes Questionnaire v2.0, for patients with metastatic spine disease.

The Influence of Preoperative Anticoagulant and Antiplatelet Therapy on Rebleeding Rates in Patients Suffering from Spinal Metastatic Cancer: A Retrospective Cohort Study

INTRODUCTION

The age of patients requiring surgery for spinal metastasis, primarily those over 65, has risen due to improved cancer treatments. Surgical intervention targets acute neurological deficits and instability. Anticoagulants are increasingly used, especially in the elderly, but pose challenges in managing bleeding complications. The study examines the correlation between preoperative anticoagulant/antiplatelet use and bleeding risks in spinal metastasis surgery, which is crucial for optimizing patient outcomes.

MATERIAL AND METHODS

In a retrospective study at our department from 2010 to 2023, spinal tumor surgery patients were analyzed. Data included demographics, neurological status, surgical procedure, preoperative anticoagulant/antiplatelet use, intra-/postoperative coagulation management, and the incidence of rebleeding. Coagulation management involved blood loss assessment, coagulation factor administration, and fluid balance monitoring post-surgery. Lab parameters were documented at admission, preop, postop, and discharge.

RESULTS

A cohort of 290 patients underwent surgical treatment for spinal metastases, predominantly males (63.8%, n = 185) with a median age of 65 years. Preoperatively, 24.1% (n = 70) were on oral anticoagulants or antiplatelet therapy. Within 30 days, a rebleeding rate of 4.5% (n = 9) occurred, unrelated to preoperative anticoagulation status (p > 0.05). A correlation was found between preoperative neurologic deficits (p = 0.004) and rebleeding risk and the number of levels treated surgically, with fewer levels associated with a higher incidence of postoperative bleeding (p < 0.01).

CONCLUSIONS

Surgical intervention for spinal metastatic cancer appears to be safe regardless of the patient's preoperative anticoagulation status. However, it remains imperative to customize preoperative planning and preparation for each patient, emphasizing meticulous risk-benefit analysis and optimizing perioperative care.

A new era in the management of spinal metastasis

Despite the recent advances in cancer treatment, the incidence of patients with spinal metastases continues to grow along with the total number of cancer patients. Spinal metastases can significantly impair activities of daily living (ADL) and quality of life (QOL), compared with other types of bone metastases, as they are characterized with severe pain and paralysis caused by skeletal-related events. Reduced ADL can also lead to treatment limitations as certain anticancer agents and radiation therapy are not compatible treatments; thus, leading to a shorter life expectancy. Consequently, maintaining ADLs in patients with spinal metastases is paramount, and spine surgeons have an integral role to play in this regard. However, neurosurgeon, orthopedic and spinal surgeons in Japan do not have a proactive treatment approach to spinal metastases, which may prevent them from providing appropriate treatment when needed (clinical inertia). To overcome such endemic inertia, it is essential for 1) spine surgeons to understand and be more actively involved with patients with musculoskeletal disorders (cancer locomo) and cancer patients; 2) the adoption of a multidisciplinary approach (coordination and meetings not only with the attending oncologist but also with spine surgeons, radiologists, rehabilitation specialists, and other professionals) to preemptive treatment such as medication, radiotherapy, and surgical treatment; and 3) the integration of the latest findings associated with minimally invasive spinal treatments that have expanded the indications for treatment of spinal metastases and improved treatment outcomes. This heralds a new era in the management of spinal metastases.

Clinical Characteristics, Surgical Outcomes, and Risk Factors for Emergency Surgery in Patients With Spinal Metastases: A Prospective Cohort Study

OBJECTIVE

To elucidate the patient characteristics and outcomes of emergency surgery for spinal metastases and identify risk factors for emergency surgery.

METHODS

We prospectively analyzed 216 patients with spinal metastases who underwent palliative surgery from 2015 to 2020. The Eastern Cooperative Oncology Group performance status, Barthel index, EuroQol-5 dimension (EQ5D), and neurological function were assessed at surgery and at 1, 3, and 6 months postoperatively. Multivariate analysis was performed to identify risk factors for emergency surgery.

RESULTS

In total, 146 patients underwent nonemergency surgery and 70 patients underwent emergency surgery within 48 hours of diagnosis of a surgical indication. After propensity score matching, we compared 61 patients each who underwent nonemergency and emergency surgery. Regardless of matching, the median performance status and the mean Barthel index and EQ5D score showed a tendency toward worse outcomes in the emergency than nonemergency group both preoperatively and 1 month postoperatively, although the surgery greatly improved these values in both groups. The median survival time tended to be shorter in the emergency than nonemergency group. The multivariate analysis showed that lesions located at T3-10 (p = 0.002; odds ratio [OR], 2.92; 95% confidence interval [CI], 1.48-5.75) and Frankel grades A-C (p < 0.001; OR, 4.91; 95% CI, 2.45-9.86) were independent risk factors for emergency surgery.

CONCLUSION

Among patients with spinal metastases, preoperative and postoperative subjective health values and postoperative survival are poorer in emergency than nonemergency surgery. Close attention to patients with T3-10 metastases is required to avoid poor outcomes after emergency surgery.

Survival in Patients With Spinal Metastatic Disease Treated Nonoperatively With Radiotherapy: Are the SORG-ML Algorithms Relevant?

SUMMARY OF BACKGROUND DATA

The SORG-ML algorithms for survival in spinal metastatic disease were developed in patients who underwent surgery and were externally validated for patients managed operatively.

OBJECTIVE

To externally validate the SORG-ML algorithms for survival in spinal metastatic disease in patients managed nonoperatively with radiation.

STUDY DESIGN

Retrospective cohort.

METHODS

The performance of the SORG-ML algorithms was assessed by discrimination [receiver operating curves and area under the receiver operating curve (AUC)], calibration (calibration plots), decision curve analysis, and overall performance (Brier score). The primary outcomes were 90-day and 1-year mortality.

RESULTS

Overall, 2074 adult patients underwent radiation for spinal metastatic disease and 29% (n=521) and 59% (n=917) had 90-day and 1-year mortality, respectively. On complete case analysis (n=415), the AUC was 0.76 (95% CI: 0.71-0.80) and 0.78 (95% CI: 0.73-0.83) for 90-day and 1-year mortality with fair calibration and positive net benefit confirmed by the decision curve analysis. With multiple imputation (n=2074), the AUC was 0.85 (95% CI: 0.83-0.87) and 0.87 (95% CI: 0.85-0.89) for 90-day and 1-year mortality with fair calibration and positive net benefit confirmed by the decision curve analysis.

CONCLUSION

The SORG-ML algorithms for survival in spinal metastatic disease generalize well to patients managed nonoperatively with radiation.

Automated planning of stereotactic spine re-irradiation using cumulative dose limits

Background and Purpose

The lack of dedicated tools in commercial planning systems currently restricts efficient review and planning for re-irradiation. The aim of this study was to develop an automated re-irradiation planning framework based on cumulative doses.

Materials and Methods

We performed a retrospective study of 14 patients who received spine SBRT re-irradiation near a previously irradiated treatment site. A fully-automated workflow, DART (Dose Accumulation-based Re-irradiation Tool), was implemented within Eclipse by leveraging a combination of a dose accumulation script and a proprietary automated optimization algorithm. First, we converted the prior treatment dose into equivalent dose in 2 Gy fractions (EQD2) and mapped it to the current anatomy, utilizing deformable image registration. Subsequently, the intersection of EQD2 isodose lines with relevant organs at risk defines a series of optimization structures. During plan optimization, the residual allowable dose at a specified tissue tolerance was treated as a hard constraint.

Results

All DART plans met institutional physical and cumulative constraints and passed plan checks by qualified medical physicists. DART demonstrated significant improvements in target coverage over clinical plans, with an average increase in PTV D99% and V100% of 2.3 Gy [range -0.3-7.7 Gy] and 3.4 % [range -0.4 %-7.6 %] (p < 0.01, paired t-test), respectively. Moreover, high-dose spillage (>105 %) outside the PTV was reduced by up to 7 cm3. The homogeneity index for DART plans was improved by 19 % (p < 0.001).

Conclusions

DART provides a powerful framework to achieve more tailored re-irradiation plans by accounting for dose distributions from the previous treatments. The superior plan quality could improve the therapeutic ratio for re-irradiation patients.

Enhanced Precision and Safety in Thermal Ablation: O-Arm Cone Beam Computed Tomography with Magnetic Resonance Imaging Fusion for Spinal Column Tumor Targeting

Spinal metastatic tumors are common and often cause debilitating symptoms. Image-guided percutaneous thermal ablation (IPTA) has gained significant recognition in managing spinal column tumors due to its exceptional precision and effectiveness. Conventional guidance modalities, including computed tomography, fluoroscopy, and ultrasound, have been important in targeting spinal column tumors while minimizing harm to adjacent critical structures. This study presents a novel approach utilizing a fusion of cone beam computed tomography with magnetic resonance imaging to guide percutaneous thermal ablation for four patients with secondary spinal column tumors. The visual analog scale (VAS) evaluated the procedure effectiveness during an 18-month follow-up. Percutaneous vertebroplasty was performed in two cases, and a thermostat was used during all procedures. Imaging was performed using the Stealth Station navigation system Spine 8 (SSS8) and a 1.5T MRI machine. The fusion of CBCT with MRI allowed for precise tumor localization and guidance for thermal ablation. Initial results indicate successful tumor ablation and symptom reduction, emphasizing the potential of CBCT-MRI fusion in spinal column tumor management. This innovative approach is promising in optimizing therapy for secondary spinal column tumors. Further studies are necessary to validate its efficacy and applicability.

Development of Machine-Learning Models to Predict Ambulation Outcomes Following Spinal Metastasis Surgery

STUDY DESIGN

Retrospective cohort study.

PURPOSE

This study aimed to develop machine-learning algorithms to predict ambulation outcomes following surgery for spinal metastasis.

OVERVIEW OF LITERATURE

Postoperative ambulation status following spinal metastasis surgery is currently difficult to predict. The improved ability to predict this important postoperative outcome would facilitate management decision-making and help in determining realistic treatment goals.

METHODS

This retrospective study included patients who underwent spinal metastasis at a university-based medical center in Thailand between January 2009 and November 2021. Collected data included preoperative parameters and ambulatory status 90 and 180 days following surgery. Thirteen machine-learning algorithms, namely, artificial neural network, logistic regression, CatBoost classifier, linear discriminant analysis, extreme gradient boosting, extra trees classifier, random forest classifier, gradient boosting classifier, light gradient boosting machine, naïve Bayes, K-neighbor classifier, Ada boost classifier, and decision tree classifier were developed to predict ambulatory status 90 and 180 days following surgery. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC) and F1-score.

RESULTS

In total, 167 patients were enrolled. The number of patients classified as ambulatory 90 and 180 days following surgery was 140 (81.9%) and 137 (82.0%), respectively. The extreme gradient boosting algorithm was found to most accurately predict 180-day ambulatory outcome (AUC, 0.85; F1-score, 0.90), and the decision tree algorithm most accurately predicted 90-day ambulatory outcome (AUC, 0.94; F1-score, 0.88).

CONCLUSIONS

Machine-learning algorithms were effective in predicting ambulatory status following surgery for spinal metastasis. Based on our data, the extreme gradient boosting and decision tree best predicted postoperative ambulatory status 180 and 90 days after spinal metastasis surgery, respectively.

The NOMS approach to metastatic tumors: Integrating new technologies to improve outcomes

Treatment paradigms for patients with spine metastases have evolved significantly over the past two decades. The most transformative change to these paradigms has been the integration of spinal stereotactic radiosurgery (sSRS). sSRS allows for the delivery of tumoricidal radiation doses with sparing of nearby organs at risk, particularly the spinal cord. Evidence supports the safety and efficacy of radiosurgery as it currently offers durable local tumor control with low complication rates even for tumors previously considered radioresistant to conventional external beam radiation therapy. The role for surgical intervention remains consistent, but a trend has been observed toward less aggressive, often minimally invasive techniques. Using modern technologies and improved instrumentation, surgical outcomes continue to improve with reduced morbidity. Additionally, targeted agents such as biologics and checkpoint inhibitors have revolutionized cancer care by improving both local control and patient survival. These advances have brought forth a need for new prognostication tools and a more critical review of long-term outcomes. The complex nature of current treatment schemes necessitates a multidisciplinary approach including surgeons, medical oncologists, radiation oncologists, interventionalists and pain specialists. This review recapitulates the current state-of-the-art, evidence-based data on the treatment of spinal metastases and integrates these data into a decision framework, NOMS, which is based on four sentinel pillars of decision making in metastatic spine tumors: Neurological status, Oncologic tumor behavior, Mechanical stability, and Systemic disease burden and medical co-morbidities.

The NOMS approach to metastatic tumors: Integrating new technologies to improve outcomes

Treatment paradigms for patients with spine metastases have evolved significantly over the past two decades. The most transformative change to these paradigms has been the integration of spinal stereotactic radiosurgery (sSRS). sSRS allows for the delivery of tumoricidal radiation doses with sparing of nearby organs at risk, particularly the spinal cord. Evidence supports the safety and efficacy of radiosurgery as it currently offers durable local tumor control with low complication rates even for tumors previously considered radioresistant to conventional external beam radiation therapy. The role for surgical intervention remains consistent, but a trend has been observed toward less aggressive, often minimally invasive techniques. Using modern technologies and improved instrumentation, surgical outcomes continue to improve with reduced morbidity. Additionally, targeted agents such as biologics and checkpoint inhibitors have revolutionized cancer care by improving both local control and patient survival. These advances have brought forth a need for new prognostication tools and a more critical review of long-term outcomes. The complex nature of current treatment schemes necessitates a multidisciplinary approach including surgeons, medical oncologists, radiation oncologists, interventionalists and pain specialists. This review recapitulates the current state-of-the-art, evidence-based data on the treatment of spinal metastases and integrates these data into a decision framework, NOMS, which is based on four sentinel pillars of decision making in metastatic spine tumors: neurological status, Oocologic tumor behavior, mechanical stability and systemic disease burden and medical co-morbidities.

Risk Factors for Postoperative Unfavorable Ambulatory Status After Spinal Surgery for Metastatic Spinal Tumor

STUDY DESIGN

A retrospective comparative study.

OBJECTIVE

This study aimed to investigate factors associated with postoperative unfavorable ambulatory status following surgery for metastatic spinal tumors using a nationwide in-hospital database.

SUMMARY OF BACKGROUND DATA

Surgical treatment for metastatic spinal tumors can improve the ambulatory status and quality of life. However, some patients fail to regain the ability to walk, thereby resulting in poor quality of life. No large-scale study has previously evaluated factors associated with postoperative poor ambulatory status in this clinical context.

MATERIALS AND METHODS

The Diagnosis Procedure Combination database from 2018 to 2019 was used to extract data from patients who underwent surgical procedures for spinal metastasis. Postoperative unfavorable ambulatory status was defined as (1) nonambulatory at discharge or (2) a decreased mobility score of the Barthel Index between admission and discharge. Multivariable logistic regression was used to evaluate factors associated with postoperative unfavorable ambulatory status while adjusting for confounders.

RESULTS

This study analyzed 1786 eligible patients. Of whom, 1061 (59%) patients were ambulatory on admission and 1249 (70%) on discharge. Postoperative unfavorable ambulatory status was observed in 597 (33%) patients, with a significantly lower rate of discharge to home (41%/81%, P <0.001) and a longer postoperative hospital stay (46.2 days/31.4 days, P <0.001). Multivariable regression analysis revealed male sex [odds ratio (OR): 1.43, P =0.002], laminectomy without fusion (OR: 1.55, P =0.034), Charlson Comorbidity Index of ≥7 (OR: 1.37, P =0.014), and preoperative nonambulatory status (OR: 6.61, P <0.001) as factors associated with postoperative unfavorable ambulatory status.

CONCLUSIONS

Our large-scale database analysis revealed that 33% of patients experienced unfavorable ambulatory status following spinal metastasis surgery. Laminectomy without fusion and preoperative nonambulatory status were among several factors influencing the prospect of unfavorable ambulatory status following surgery.

Can the Unipedicular Approach Replace Bipedicular Percutaneous Balloon Kyphoplasty for the Management of Metastatic Vertebral Lesions?

RATIONALE AND OBJECTIVES

To compare the clinical and radiographic results of bipedicular and unipedicular approaches(UPK and BPK) in the management of metastatic vertebral lesions MATERIALS AND METHODS: Eighty-two patients with 159 metastatic vertebral lesions who underwent UPK(25 cases, 69 lesions) or BPK(57 cases, 90 lesions) were retrospectively evaluated. Clinical results were assessed mainly depending on the Visual Analogue Scale(VAS) score, Oswestry Disability Index(ODI) and Quality of Life(QoL). Radiographic outcomes were evaluated primarily on the basis of bone cement distribution and changes in vertebral body height(VBH). Major and minor complications were systematically evaluated and compared to assess the safety of the 2 procedures.

RESULTS

No statistically significant differences were observed in age, sex, types of lesions, location of lesions, posterior vertebral body and/or pedicle involvement, percentage of vertebra invasion between the groups(p=0.17-0.83). The radiographic parameter VBH was similarly improved in both groups(p=0.26-0.93). There was a significant improvement in the clinical parameters VAS score, ODI, and QoL at each follow-up examination compared with the preoperative results(p<0.001). Significant improvement was observed in the VBH at each follow-up point(p<0.05) compared to pre-procedure. UPK was superior to BPK in terms of the operative duration(p<0.001), cement volume(p=0.004), and surgical complications(p=0.04).

CONCLUSION

Both UPK and BPK resulted in similar clinical and radiographic outcomes in patients with metastatic vertebral lesions. The UPK had advantages including a shorter operation and lower cement volume than the BPK, which may have played an important role in reducing the incidence of complications. UPK can replace BPK in the treatment of metastatic vertebral lesions.

Does re-ossification after palliative radiotherapy for spinal bone metastases help maintain vertebral body height?

BACKGROUND CONTEXT

After palliative radiotherapy of spinal bone metastases, re-ossification is sometimes observed in bone with osteolytic changes. However, it remains unknown whether the re-ossification that is observed after radiotherapy is associated with preservation of vertebral body height.

PURPOSE

To investigate whether re-ossification observed after palliative radiotherapy can contribute to the preservation of vertebral body height.

STUDY DESIGN

This is a retrospective observational study.

PATIENTS SAMPLE

We investigated 111 vertebral bodies in 54 patients that underwent palliative radiotherapy at a single center for painful osteolytic/mixed metastatic spinal tumors in solid tumors between 2016 and 2020.

OUTCOME MEASURES

The outcome measures were the presence of re-ossification and vertebral body height reduction on the CT image.

METHODS

Re-ossification was evaluated according to the MD Anderson response classification criteria, and sagittal CT images were used to evaluate vertebral body height. A vertebral body ID was assigned to the irradiated vertebral body, and continuous CT images obtained for each vertebral body ID were evaluated. The median number of evaluation periods for each vertebral body was 4, and the total number of periods was 463. Logistic regression analysis was performed to investigate factors related to the occurrence of vertebral body height reduction before the subsequent CT. As a subanalysis, factors related to re-ossification were investigated.

RESULTS

The following primary cancer types were observed: lung cancer, 41 vertebral bodies; breast cancer, 19; renal cell cancer, 15; other, 36. A total of 62.2% showed re-ossification. The median time to confirmation of re-ossification by CT was 2 months. Factors significantly associated with vertebral body height reduction were presence of vertebral body height reduction before radiotherapy (odds ratio [OR] 6.8, 95% confidence interval [CI] 2.0-63, p=.01) and no re-ossification (OR 137, 95% CI 22-3469, p<.01). Factors associated with re-ossification were the type of cancer and total radiation dose. Those with lung cancer and those with a total radiation dose of 20 Gy or less were more prone to re-ossification.

CONCLUSIONS

Re-ossification was observed in 62.2% of vertebral bodies after palliative radiotherapy for painful osteolytic/mixed metastatic spinal tumors. The re-ossification group demonstrated significantly less vertebral body height reduction when compared with the non-re-ossification group. The presence of re-ossification may potentially serve an important role in maintaining vertebral body height.

Clinical Characteristics and Surgical Outcomes of Metastatic Spine Tumors in the Very Elderly: A Prospective Cohort Study in a Super-Aged Society

The number of advanced-age patients with spinal metastases is rising. This study was performed to clarify the characteristics and surgical outcomes of spinal metastases in advanced-age patients. We prospectively analyzed 216 patients with spinal metastases from 2015 to 2020 and divided them into three age groups: <70 years (n = 119), 70-79 years (n = 73), and ≥80 years (n = 24). Although there were no significant intergroup differences in preoperative characteristics and surgery-related factors except for age, patients aged ≥80 years tended to have a worse performance status (PS), Barthel index, and EuroQol-5 dimension (EQ-5D) before and after surgery than the other two groups. Although the median PS, mean Barthel index and mean EQ-5D greatly improved postoperatively in each group, the median PS and mean Barthel index at 6 months and the mean EQ-5D at 1 month postoperatively were significantly poorer in the ≥80-year group than the 70-79-year group. The rates of postoperative complications and re-deterioration of the EQ-5D were significantly higher in the oldest group than in the other two groups. Although surgery for spinal metastases improved the PS, Barthel index, and EQ-5D regardless of age, clinicians should be aware of the poorer outcomes and higher complication rates in advanced-age patients.

Clinical Outcomes of Total En Bloc Spondylectomy for Previously Irradiated Spinal Metastases: A Retrospective Propensity Score-Matched Comparative Study

This study aimed to investigate the clinical outcomes of total en bloc spondylectomy (TES) for spinal metastases previously treated with radiotherapy (RT). This study enrolled 142 patients who were divided into two groups: those with and those without an RT history. Forty-two patients were selected from each group through propensity score matching, and postoperative complications, local recurrence, and overall survival rates were compared. The incidence of postoperative complications was significantly higher in the group with an RT history than in the group without an RT history (57.1% vs. 35.7%, respectively). The group with an RT history had a higher local recurrence rate than the group without an RT history (1-year rate: 17.5% vs. 0%; 2-year rate: 20.8% vs. 2.9%; 5-year rate: 24.4% vs. 6.9%). The overall postoperative survival tended to be lower in the group with an RT history; however, there was no significant difference between the two groups (2-year survival: 64.3% vs. 66.7%; 5-year survival: 47.3% vs. 57.1%). When planning a TES for irradiated spinal metastases, the risk of postoperative complications and local recurrence should be fully considered.

Fully Endoscopic Spine Separation Surgery in Metastatic Disease-Case Series, Technical Notes, and Preliminary Findings

Objective: This report aims to describe the surgical methodology and potential effectiveness of endoscopic separation surgery (ESS) in patients with metastatic spine disease. This concept may reduce the invasiveness of the procedure, which can potentially speed up the wound healing process and, thus, the possibility of faster application of radiotherapy. Materials and Methods: In this study, separation surgery for preparing patients for stereotactic body radiotherapy (SBRT) was performed with fully endoscopic spine surgery (FESS) followed by percutaneous screw fixation (PSF). Results: Three patients with metastatic spine disease in the thoracic spine were treated with fully endoscopic spine separation surgery. The first case resulted in the progression of paresis symptoms that resulted in disqualification from further oncological treatment. The remaining two patients achieved satisfactory clinical and radiological effects and were referred for additional radiotherapy. Conclusions: With advancements in medical technology, such as endoscopic visualization, and new tools for coagulation, we can treat more and more spine diseases. Until now, spine metastasis was not an indication for the use of endoscopy. This method is very technically challenging and risky, especially at such an early stage of application, due to variations in the patient's condition, morphological diversity, and the nature of metastatic lesions in the spine. Further trials are needed to determine whether this new approach to treating patients with spine metastases is a promising breakthrough or a dead end.

ACR Appropriateness Criteria® Management of Vertebral Compression Fractures: 2022 Update

Vertebral compression fractures (VCFs) can have a variety of etiologies, including trauma, osteoporosis, or neoplastic infiltration. Osteoporosis related fractures are the most common cause of VCFs and have a high prevalence among all postmenopausal women with increasing incidence in similarly aged men. Trauma is the most common etiology in those >50 years of age. However, many cancers, such as breast, prostate, thyroid, and lung, have a propensity to metastasize to bone, which can lead to malignant VCFs. Indeed, the spine is third most common site of metastases after lung and liver. In addition, primary tumors of bone and lymphoproliferative diseases such as lymphoma and multiple myeloma can be the cause of malignant VCFs. Although patient clinical history could help raising suspicion for a particular disorder, the characterization of VCFs is usually referred to diagnostic imaging. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

The Identification of Risk Factors for Symptomatic Spinal Metastasis Onset: A Prospective Cohort Study of 128 Asymptomatic Spinal Metastasis Patients

Background: Symptomatic spinal metastasis (SSM) decreases the activities of daily living (ADL) and quality of life of cancer patients. However, the risk factors for SSM onset remain unclear. This prospective cohort study aimed to statistically analyze the significant risk factors. Methods: From 2016 to 2018, 210 consecutive patients with spinal metastases were prospectively registered. Patients with SSM at the first consultation and those who were unable to be followed-up owing to poor general condition were excluded. The demographic factors (age, sex, primary cancer, performance status, and ADL), clinical factors (radiation therapy, chemotherapy, molecularly targeted drugs, and bone-modifying agents (BMAs)), and Spinal Neoplastic Instability Score (SINS) were evaluated. Multivariate analysis was performed to identify the risk factors for SSM onset. Furthermore, the threshold was calculated from the receiver operating characteristic curve using the Youden index. Results: Thirty-nine patients who presented with SSM at the first consultation and 43 patients who were unable to be followed-up owing to poor general condition were excluded. Finally, 128 asymptomatic patients were included. Thirty-seven patients (28.9%) developed SSM during the follow-up period. The total SINS (OR: 1.739; 95% CI: 1.345-2.250) was identified as the most significant factor. The cut-off value of the SINS was 9.5 (sensitivity: 67.6%; specificity: 83.5%). Twenty-five (62.5%) of the forty patients with a SINS ≥ 10 developed SSM within a mean of 5.5 months (95% CI: 1.17-9.83). Furthermore, all patients with a SINS ≥ 13 developed SSM (n = 5) within a mean of 1.37 months (95% CI: 0.0-3.01). Conclusions: This study identified the significant risk factors for SSM onset and the threshold of the SINS. If long-term survival is expected, patients with a SINS ≥ 10 should be considered for intervention to prevent SSM.

Risk of Myelopathy Following Second Local Treatment after Initial Irradiation of Spine Metastasis

Metastatic lesions of the spine occur in up to 40% of cancer patients and are a frequent source of pain and neurologic deficit due to cord compression. Palliative radiotherapy is the main first-intent local treatment in the form of single-fraction radiotherapy or fractionated courses. Reirradiation is a viable option for inoperable patients where spinal decompression is needed but with an increased risk of radiation-induced myelopathy (RM) and subsequent neurologic damage. This review summarizes reported data on local treatment options after initial irradiation in patients with relapsed spine metastasis and key dosimetric correlations between the risk of spinal cord injury and reirradiation technique, total dose, and time between treatments. The Linear Quadratic (LQ) model was used to convert all the published doses into biologically effective doses and normalize them to EQD2. For 3D radiotherapy, authors used cumulative doses from 55.2 Gy2/2 to 65.5 Gy2/2 EQD2 with no cases of RM mentioned. We found little evidence of RM after SBRT in the papers that met our criteria of inclusion, usually at the median reported dose to critical neural tissue around 93.5 Gy2/2. There is a lack of consistency in reporting the spinal cord dose, which leads to difficulty in pooling data.

Spinal metastases of bronchopulmonary cancers: interest of balloon kyphoplasty in the control of mechanical rachialgia

Introduction

Spinal metastases are a classic complication of lung cancer. New palliative treatment modalities have emerged. Among them are minimally invasive approaches such as balloon kyphoplasty. With the aim of evaluating the efficiency of balloon kyphoplasty in the control of spinal pain during these lesions, we report a series of 24 patients.

Methods and materials

Over a period of 6 years, we retrospectively studied 24 files of patients suffering from vertebral compression of metastatic pulmonary origin and treated by balloon kyphoplasty from January 2009 to December 2014 in the neurosurgery department of the North Hospital of Marseille (France).

Results

The mean age was 66.2 years (39–80 years) with a sex ratio of 5. Dorsal location was predominantly 17 cases. Balloon kyphoplasty involved one level in 14 patients. The general condition (Karnofski) was bad in 16 patients. Survival prediction was less than 6 months in 22 patients. The indication was mainly pain with a mean visual analog scale of 7.7. The evolution was marked by the regression of the painful symptomatology in all patients with a mean visual analog scale of 2.2 postoperatively. Postoperative complications were noted in two cases (pulmonary embolism, compression of the left iliac vein).

Conclusion

Our short series shows the efficacy and low morbidity of balloon kyphoplasty in the control of spinal pain secondary to vertebral metastases of bronchopulmonary cancers.

Application of Artificial Intelligence Methods for Imaging of Spinal Metastasis

Spinal metastasis is the most common malignant disease of the spine. Recently, major advances in machine learning and artificial intelligence technology have led to their increased use in oncological imaging. The purpose of this study is to review and summarise the present evidence for artificial intelligence applications in the detection, classification and management of spinal metastasis, along with their potential integration into clinical practice. A systematic, detailed search of the main electronic medical databases was undertaken in concordance with the PRISMA guidelines. A total of 30 articles were retrieved from the database and reviewed. Key findings of current AI applications were compiled and summarised. The main clinical applications of AI techniques include image processing, diagnosis, decision support, treatment assistance and prognostic outcomes. In the realm of spinal oncology, artificial intelligence technologies have achieved relatively good performance and hold immense potential to aid clinicians, including enhancing work efficiency and reducing adverse events. Further research is required to validate the clinical performance of the AI tools and facilitate their integration into routine clinical practice.

Radiofrequency Ablation and Augmentation in the Management of Spinal Metastases: Clinical Experience in 41 Patients

OBJECTIVE

To evaluate functional outcome after combined radiofrequency ablation and vertebral augmentation in patients with metastatic spinal tumors using visual analog scale and Oswestry Disability Index scores.

METHODS

This retrospective study included 41 patients with metastatic spinal tumors. There were 19 women and 22 men with a mean age of 67 years (range, 45-87 years). Visual analog scale and Oswestry Disability Index were used to assess the intensity of pain and quality of life. The assessments were performed before the procedure and at 1 week and 1, 2, 3, and 6 months after the procedure.

RESULTS

No serious complications were seen in the periprocedural period. Two patients (4.8%) had transient neurological motor deficits without cement leakage, and 1 patient had a pulmonary embolism with transient mild symptoms. The comparison of preprocedural visual analog scale and Oswestry Disability Index scores with postprocedural scores up to 6 months after treatment revealed significant pain control and good functional state.

CONCLUSIONS

Spinal metastasis is a frequent entity in the growing population of patients with cancer. A multidisciplinary approach using several nonsurgical and minimally invasive methods (e.g., radiofrequency ablation, vertebroplasty, balloon kyphoplasty) is key to successful management, and combining these procedures is effective against spinal metastatic pain.

Medium to Long-Term Clinical Outcomes of Spinal Metastasectomy

The prolonged survival of metastatic cancer patients highlights the importance of the local control of spinal metastases, which reduce patient performance status. This retrospective study examined the medium to long-term outcomes of spinal metastasectomy by evaluating 124 patients who underwent metastasectomy for isolated spinal metastases (2006-2018) with a postoperative follow-up for a minimum of 3 years. The findings present information on patient demographics (i.e., performance status, location of non-spinal metastases, and history of systemic therapy) and postoperative outcomes, including perioperative complications, disease progression of non-operated metastases, and additional excisional surgeries. Additionally, postoperative survival, local tumor control in the operated spine, and maintenance of spinal reconstruction without instrumentation failure were determined using Kaplan-Meier analyses. The primary malignancy was kidney and thyroid cancer in 51 and 14 patients, respectively, low-grade sarcoma and lung cancer in 13 patients, breast cancer in 12 patients, and other malignancies in 21 patients. The 3-year and 5-year survival rates were 70% and 60%, respectively. We found that patients with thyroid cancer had the best survival results, with local tumor recurrence and instrumentation failure at 10% and 22%, respectively. These findings suggest that for certain patients with isolated and removable spine metastases, metastasectomy can improve function and survival.

The Addition of Radiofrequency Tumor Ablation to Kyphoplasty May Reduce the Rate of Local Recurrence in Spinal Metastases Secondary to Breast Cancer

BACKGROUND

Approximately 10% of all cancer patients develop spinal metastases. When a symptomatic compression fracture occurs without associated deformity or neurologic deficit, it can be treated with kyphoplasty with or without radiofrequency ablation (RFA). Treatment with kyphoplasty is well established but does not address the underlying oncologic disease.

METHODS

Retrospective medical chart analysis of breast cancer patients (n = 23) with metastatic spinal fractures (n = 50 vertebral levels) who underwent RFA and kyphoplasty was undertaken. Key variables of interest included: fracture location, pain levels, and local recurrence. Local recurrence data were compared to published rates of recurrence in breast cancer-related metastatic spinal fractures treated with vertebroplasty or kyphoplasty alone. Data were analyzed using χ² and t test statistical analyses.

RESULTS

The mean preoperative pain level for this cohort was 6.9 on a 10-point visual analogue scale. Significant reductions in pain levels were observed postoperatively, at discharge (3.5; P < 0.05), at 1-month follow-up (2.8; P < 0.05), at 3-month follow-up (1.1; P < 0.05), and at 6-month follow-up (0.7 P < 0.05). Compared with published data of breast cancer patients with metastatic spinal fractures treated with vertebroplasty or kyphoplasty alone, the addition of RFA resulted in reduced local tumor recurrence (2% vs. 14%; P < 0.05). Average length of follow-up was 39 months.

CONCLUSIONS

The results suggest that the addition of RFA to kyphoplasty may reduce local tumor recurrence while providing similar pain relief benefits. The extrapolation of this added benefit to metastases from other primary cancers should be examined in future studies.

The role of surgery in the treatment of metastatic bone tumor

Surgery for bone metastasis has two primary goals-palliative care to relieve pain, instability and paralysis, and tumor resection for curing the disease. Oncologically en bloc resection, followed by a reconstruction of the bone defect is the treatment of choice in single bone metastasis from renal cell carcinoma or thyroid cancer. Bone metastases may occur in the extremities, pelvis, or spine, and different resection and reconstruction methods depend on the regional anatomy. For instance, multiple options are available for reconstruction of the pelvis, especially for the acetabulum, including anatomical reconstruction using custom-made implants or recycled autologous bone grafting when a long-term prognosis is expected. Recently, for the spine, total en bloc spondylectomy is extensively performed despite the initial limitations of surgical invasiveness, such as blood loss. Principally, palliative surgery aims to maintain lasting bony stability with minimal surgical invasiveness. Intramedullary nails and plate fixation are frequently used in the extremities but the postoperative failure rate is relatively high. Therefore, surgeons should consider the use of long intramedullary nails and long-type stems for endoprosthesis reconstruction along with cement fixation to reduce the failure rate. Although short-term complications, such as dislocation, have been observed with endoprosthesis reconstruction, it is stable in the long-term follow-up. Percutaneous bone cement injection into the spine and pelvis is also effective and less invasive.

Adjunctive Topical Tranexamic Acid for Blood Salvage Does Not Reduce Postoperative Blood Loss Compared with Placebo in Patients Who Undergo Palliative Decompressive Spinal Metastasis Surgery: A Randomized Controlled Trial

STUDY DESIGN

Randomized controlled trial.

OBJECTIVE

To evaluate the efficacy of adjunctive topical tranexamic acid (tTXA) in reducing postoperative blood loss and packed red cell (PRC) transfusion in patients who underwent palliative decompressive spinal metastasis surgery for malignant epidural spinal cord compression.

SUMMARY OF BACKGROUND DATA

Palliative decompressive spinal metastasis surgery is associated with massive postoperative blood loss and increased transfusion rate. tTXA reduces blood loss in traumatic or degenerative spinal surgery; however, the role of topical TXA in decompressive spinal metastasis surgery remains controversial.

METHOD

A total of 65 patients who underwent palliative decompressive thoracolumbar spinal metastasis surgery were included in this study. In 33 patients, 1 g of tTXA (20 mL) was soaked in an absorbable gelatin sponge and placed lateral to the decompressive site. The remaining 32 patients in the control group received the same procedures with normal saline at the same volume, instead of TXA. All of the patients received standard 1 g intravenous TXA, just before initiating the operation. The primary outcome was postoperative blood loss, and the secondary outcomes were postoperative PRC transfusion and complications.

RESULTS

No differences were found in postoperative blood loss between tTXA and placebo group (P50 778 mL [IQR 347, 1,122 mL] versus P50 490 mL [IQR 295, 920 mL]; P = 0.238). The number of patients requiring postoperative PRC transfusion were quite similar in tTXA and placebo groups (PRC transfusion in 15 patients [45.45%] versus 16 patients [50%]; P = 0.585). No complications related to TXA and absorbable gelatin sponge were observed.

CONCLUSION

We do not recommend tTXA as an adjunctive treatment for patients undergoing decompressive spinal metastasis surgery since it does not provide additional benefit to prophylactic intravenous TXA in postoperative blood loss and transfusion rate.Level of Evidence: 2.

EphrinB2-EphB4 Signaling in Neurooncological Disease

EphrinB2-EphB4 signaling is critical during embryogenesis for cardiovascular formation and neuronal guidance. Intriguingly, critical expression patterns have been discovered in cancer pathologies over the last two decades. Multiple connections to tumor migration, growth, angiogenesis, apoptosis, and metastasis have been identified in vitro and in vivo. However, the molecular signaling pathways are manifold and signaling of the EphB4 receptor or the ephrinB2 ligand is cancer type specific. Here we explore the impact of these signaling pathways in neurooncological disease, including glioma, brain metastasis, and spinal bone metastasis. We identify potential downstream pathways that mediate cancer suppression or progression and seek to understand it´s role in antiangiogenic therapy resistance in glioma. Despite the Janus-faced functions of ephrinB2-EphB4 signaling in cancer Eph signaling remains a promising clinical target.

Prophylactic Effect of Liaison Treatment on the Occurrence of Skeletal-Related Events in Patients with Metastatic Spinal Tumours: An Exploratory Interrupted Time Series Study

Introduction

There is a growing momentum for the collaboration between multiple disciplines for the prevention and treatment of skeletal-related events (SREs) in patients with metastatic spinal tumors. However, the effectiveness of multidisciplinary approaches remains unclear. Hence, we conducted an exploratory study to examine the impact of liaison treatment for metastatic spinal tumor (LMST) on the prevention of SREs among patients with a metastatic spinal tumor.

Methods

This study was an exploratory interrupted time series conducted in a single medical center. Overall, 1,043 patients with a metastatic spinal tumor diagnosed between January 2011 and December 2020 were included. The LMST was implemented in January 2014. The LMST team consisted of the orthopedic surgery, thoracic surgery, breast and thyroid surgery, clinical oncology, urology, and radiology departments. Monthly joint conferences were held for patients with spinal instability, and the incidence of SRE was measured at 6-month intervals.

Results

Throughout the study period, we identified 66 SRE incidences. After the implementation of the LMST, a level change of −5.2% (95% confidence interval [CI]: −11.7 to 1.3, p = 0.11) was observed. Subsequently, a post-implementation trend change of −0.3% (95% CI: −2.0 to 1.5, p = 0.75) beyond the baseline was noted.

Conclusions

We suggest both immediate and gradual effects of the introduction of the LMST on deterring the development of SREs. Our results support the global trend of introducing a multidisciplinary approach for the treatment of metastatic spinal tumors.

IMPACT OF SURGERY ON AMBULATORY STATUS IN PATIENTS WITH SYMPTOMATIC NEOPLASTIC SPINAL CORD COMPRESSION IN SOUTHERN BRAZIL

ABSTRACT Background: Spinal cord compression is a common complication of spine metastasis and multiple myeloma. About 30% of patients with cancer develop symptomatic spinal metastases during their illness. Prompt diagnosis and surgical treatment of these lesions, although palliative, are likely to reduce the morbidity and improve quality of life by improving ambulatory function. Study Design: Retrospective review of medical records. Objective: To evaluate postoperative functional recovery and the epidemiological profile of neoplastic spinal cord compression in two neurosurgical centers in southern Brazil. Methods: We retrospectively analyzed the data of all patients who underwent palliative surgery for symptomatic neoplastic spine lesion from metastatic cancer, in two neurosurgical centers, between January 2003 and July 2021. The variables age, sex, neurological status, histological type, affected segment, complications and length of hospitalization were analyzed. Results: A total of 82 patients were included. The lesions occurred in the thoracic spine in 60 cases. At admission, 95% of the patients had neurological deficits, most of which were Frankel C (37%). At histopathological analysis, breast cancer was the most common primary site. After surgery, the neurological status of 46 patients (56%) was reclassified according to the Frankel scale. Of these, 22 (47%) regained ambulatory capacity. Conclusion: Surgical treatment of metastatic spinal cord compression improved neurological status and ambulatory ability in our sample. Level of evidence II; Retrospective study.

Interventional Procedures for Vertebral Diseases: Spinal Tumor Ablation, Vertebral Augmentation, and Basivertebral Nerve Ablation-A Scoping Review

Low back pain is consistently documented as the most expensive and leading cause of disability. The majority of cases have non-specific etiologies. However, a subset of vertebral diseases has well-documented pain generators, including vertebral body tumors, vertebral body fractures, and vertebral endplate injury. Over the past two decades, specific interventional procedures targeting these anatomical pain generators have been widely studied, including spinal tumor ablation, vertebral augmentation, and basivertebral nerve ablation. This scoping review summarizes safety and clinical efficacy and discusses the impact on healthcare utilization of these interventions. Vertebral-related diseases remain a top concern with regard to prevalence and amount of health care spending worldwide. Our study shows that for a subset of disorders related to the vertebrae, spinal tumor ablation, vertebral augmentation, and basivertebral nerve ablation are safe and clinically effective interventions to decrease pain, improve function and quality of life, and potentially reduce mortality, improve survival, and overall offer cost-saving opportunities.

Ablation Techniques in Cancer Pain

Painful bone metastases are a frequently encountered problem in oncology practice. The skeletal system is the third most common site of metastatic disease and up to 85% of patients with breast, prostate, and lung cancer may develop bone metastases during the course of their disease.

Imaging in spinal posterior epidural space lesions: A pictorial essay

Spinal epidural space is a real anatomic space located outside the dura mater and within the spinal canal extending from foramen magnum to sacrum. Important contents of this space are epidural fat, spinal nerves, epidural veins and arteries. Due to close proximity of posterior epidural space to spinal cord and spinal nerves, the lesions present with symptoms of radiculopathy and/or myelopathy. In this pictorial essay, detailed anatomy of the posterior epidural space, pathologies affecting it along with imaging pearls to accurately diagnose them are discussed. Various pathologies affecting the posterior epidural space either arising from the space itself or occurring secondary to vertebral/intervertebral disc pathologies. Primary spinal bone tumors affecting the posterior epidural space have been excluded. The etiological spectrum affecting the posterior epidural space ranges from degenerative, infective, neoplastic - benign or malignant to miscellaneous pathologies. MRI is the modality of choice in evaluation of these lesions with CT scan mainly helpful in detecting calcification. Due to its excellent soft tissue contrast, Magnetic Resonance Imaging is extremely useful in assessing the pathologies of posterior epidural space, to know their entire extent, characterize them and along with clinical history and laboratory data, arrive at a specific diagnosis and guide the referring clinician. It is important to diagnose these lesions early so as to prevent permanent neurological complication.

Ligand-Dependent and Ligand-Independent Effects of Ephrin-B2-EphB4 Signaling in Melanoma Metastatic Spine Disease

Tumor–endothelial cell interactions represent an essential mechanism in spinal metastasis. Ephrin-B2–EphB4 communication induces tumor cell repulsion from the endothelium in metastatic melanoma, reducing spinal bone metastasis formation. To shed further light on the Ephrin-B2–EphB4 signaling mechanism, we researched the effects of pharmacological EphB4 receptor stimulation and inhibition in a ligand-dependent/independent context. We chose a preventative and a post-diagnostic therapeutic window. EphB4 stimulation during tumor cell seeding led to an increase in spinal metastatic loci and number of disseminated melanoma cells, as well as earlier locomotion deficits in the presence of endothelial Ephrin-B2. In the absence of endothelial Ephrin-B2, reduction of metastatic loci with a later manifestation of locomotion deficits occurred. Thus, EphB4 receptor stimulation affects metastatic dissemination depending on the presence/absence of endothelial Ephrin-B2. After the manifestation of solid metastasis, EphB4 kinase inhibition resulted in significantly earlier manifestation of locomotion deficits in the presence of the ligand. No post-diagnostic treatment effect was found in the absence of endothelial Ephrin-B2. For solid metastasis treatment, EphB4 kinase inhibition induced prometastatic effects in the presence of endothelial Ephrin-B2. In the absence of endothelial Ephrin-B2, both therapies showed no effect on the growth of solid metastasis.

Surgical Metastasectomy in the Spine: A Review Article

BACKGROUND

The use of surgical metastasectomy (SM) has increased across cancer types in recent decades despite the increasing efficacy of modern systemic treatment modalities. Symptomatic spinal metastases severely compromise patients' performance status. However, as spinal SM is a complex surgery with potentially significant complications, it is not considered the treatment of choice.

METHODS

We reviewed the articles on SM in several primary cancers with different types of metastatic lesions and extracted the data from relevant articles to provide a comprehensive review including the surgical techniques, indications, reported outcomes, and future prospects of SM in spinal metastases.

RESULTS

Total en bloc spondylectomy (TES) is a method of spinal SM associated with a lower risk of tumor recurrence and complications. Intralesional transpedicular osteotomy using a fine threadwire saw allows prevention of spinal cord and nerve root injuries. Spinal SM is considered suitable for patients with controlled primary disease having no evidence of disseminated extraspinal metastases, a completely resectable solitary lesion in the spine, and adequate cardiopulmonary reserve to tolerate the surgery. Metastatic lesions from kidney and thyroid cancers have been reported as the best candidates for spinal SM. Although data about spinal SM are limited, the reported outcomes are favorable with acceptable local recurrence rates in long-term follow-up.

CONCLUSION

In patients with isolated resectable spinal metastases, complete SM including TES is a useful option as it can improve function and survival. However, appropriate patient selection and surgical feasibility remain the most important aspects of management.

IMPLICATIONS FOR PRACTICE

Surgical metastasectomy for spinal metastases may be a potentially curative treatment option with a low risk of local recurrence and lead to prolonged long-term survival if appropriate patients are selected and if the surgery is carried out by experienced surgeons in high-volume centers.

Evaluation of open and minimally invasive spinal surgery for the treatment of thoracolumbar metastatic epidural spinal cord compression: a systematic review

BACKGROUND

Metastatic epidural spinal cord compression (MESCC) is a debilitating sequela of cancer that results in pain, disability, and neurologic deficits. Surgical techniques have included open surgical (OS) techniques with anterior and/or posterior decompression and fusion procedures. Further technical evolution has led to minimally invasive spinal (MIS) decompression and fusion. The objective of this study is to compare MIS to OS techniques in the treatment of thoracolumbar MESCC.

METHODS

A review of the literature was performed using PubMed database. Inclusion criteria included patients 18 years or older, thoracolumbar MESCC, and surgeries with instrumented fusion. A total of 451 articles met the inclusion criteria and further analysis narrowed them down to 81 articles. Variables collected included blood loss, length of stay, operative time, pre- and postoperative Frankel grade, and complications.

RESULTS

A total of 5726 papers were collected, with a total of 81 papers meeting final inclusion criteria: 26 papers with MIS technique and 55 with OS. A total of 2267 patients were evaluated. They were split into three surgical subtypes of MIS and OS: posterior decompression and fusion, partial corpectomy, and complete corpectomy. Overall, MIS had lower operative time, blood loss, and complications compared to OS. A timeline analysis showed reduction of complication rates in MIS surgery between papers published over a 28-year period.

CONCLUSION

MESCC carries significant morbidity and mortality. Surgical approaches for palliative treatment should account for this fact. We conclude that MIS techniques offer a viable alternative to traditional OS approaches with lower overall morbidity and complications.

Interventional Therapies for Pain in Cancer Patients: a Narrative Review

PURPOSE OF REVIEW

Pain is a prevalent symptom in the lives of patients with cancer. In light of the ongoing opioid epidemic and increasing awareness of the potential for opioid abuse and addiction, clinicians are progressively turning to interventional therapies. This article reviews the interventional techniques available to mitigate the debilitating effects that untreated or poorly treated pain have in this population.

RECENT FINDINGS

A range of interventional therapies and technical approaches are available for the treatment of cancer-related pain. Many of the techniques described may offer effective analgesia with less systemic toxicity and dependency than first- and second-line oral and parenteral agents. Neuromodulatory techniques including dorsal root ganglion stimulation and peripheral nerve stimulation are increasingly finding roles in the management of oncologic pain. The goal of this pragmatic narrative review is to discuss interventional approaches to cancer-related pain and the potential of such therapies to improve the quality of life of cancer patients.

Clinical Therapy of Metastatic Spinal Tumors

Metastatic spinal tumors (MST) have high rates of morbidity and mortality. MST can destroy the vertebral body or compress the nerve roots, resulting in an increased risk of pathological fractures and intractable pain. Here, we elaborately reviewed the currently available therapeutic options for MST according to the following four aspects: surgical management, minimally invasive therapy (MIT), radiation therapy, and systemic therapy. In particular, these aspects were classified and introduced to show their developmental process, clinical effects, advantages, and current limitations. Furthermore, with the improvement of treatment concepts and techniques, we discovered the prevalent trend toward the use of radiation therapy and MIT in clinic therapies. Finally, the future directions of these treatment options were discussed. We hoped that along with future advances and study will lead to the improvement of living standard and present status of treatment in patients with MST.

Stereotactic Body Radiation Therapy for Spinal Metastases: Tumor Control Probability Analyses and Recommended Reporting Standards

PURPOSE

We sought to investigate the tumor control probability (TCP) of spinal metastases treated with stereotactic body radiation therapy (SBRT) in 1 to 5 fractions.

METHODS AND MATERIALS

PubMed-indexed articles from 1995 to 2018 were eligible for data extraction if they contained SBRT dosimetric details correlated with actuarial 2-year local tumor control rates. Logistic dose-response models of collected data were compared in terms of physical dose and 3-fraction equivalent dose.

RESULTS

Data were extracted from 24 articles with 2619 spinal metastases. Physical dose TCP modeling of 2-year local tumor control from the single-fraction data were compared with data from 2 to 5 fractions, resulting in an estimated α/β = 6 Gy, and this was used to pool data. Acknowledging the uncertainty intrinsic to the data extraction and modeling process, the 90% TCP corresponded to 20 Gy in 1 fraction, 28 Gy in 2 fractions, 33 Gy in 3 fractions, and (with extrapolation) 40 Gy in 5 fractions. The estimated TCP for common fractionation schemes was 82% at 18 Gy, 90% for 20 Gy, and 96% for 24 Gy in a single fraction, 82% for 24 Gy in 2 fractions, and 78% for 27 Gy in 3 fractions.

CONCLUSIONS

Spinal SBRT with the most common fractionation schemes yields 2-year estimates of local control of 82% to 96%. Given the heterogeneity in the tumor control estimates extracted from the literature, with variability in reporting of dosimetry data and the definition of and statistical methods of reporting tumor control, care should be taken interpreting the resultant model-based estimates. Depending on the clinical intent, the improved TCP with higher dose regimens should be weighed against the potential risks for greater toxicity. We encourage future reports to provide full dosimetric data correlated with tumor local control to allow future efforts of modeling pooled data.

Strategies for posterior-only minimally invasive surgery in thoracolumbar metastatic epidural spinal cord compression

Background:

Metastatic epidural spinal cord compression (MESCC) is a debilitating sequela of cancer. Here, we evaluated various subtypes of posterior-only minimally invasive spinal (MIS) procedures utilized to address different cancers.

Methods:

Within this retrospective review, we analyzed the treatment of thoracolumbar MESCC treated with three MIS techniques: decompression and fusion (Subgroup A), partial corpectomy (Subgroup B), and full corpectomy (Subgroup C).

Results:

There were 51 patients included in the study; they averaged 58.7 years of age, and 51% were females. Most tumors were in the thoracic spine (51%). The average preoperative Frankel grade was D (62.7%); 69% (35) improved postoperatively. The patients were divided as follows: subgroup A (15 patients = 29.4%), B (19 patients = 37.3%), and C (17 patients = 33.3%). The length of hospitalization was similar (~5.4 days) for all groups. The overall complication rate was 31%, while blood loss was lower in Subgroups A and B versus C.

Conclusion:

Different MIS surgical techniques were utilized in patients with thoracic and/or lumbar MESCC. Interestingly, clinical outcomes were similar between MIS subgroups, in this study, with a trend toward higher complications and greater blood loss associated with those undergoing more aggressive MIS procedures (e.g., full corpectomy and fusion).

Outcomes after reirradiation of spinal metastasis with stereotactic body radiation therapy (SBRT): a retrospective single institutional study

This study was aimed at assessing the feasibility and toxicity of using stereotactic body radiation therapy (SBRT) for reirradiation of spinal metastatic tumors. We conducted a retrospective review, from our institutional database, of the data of patients who received reirradiation, with overlap of some prescribed isodose lines to the vertebra from the initial radiation therapy, between 2007 and 2019. We identified 40 patients with spinal metastatic tumors, of whom 2 had 2 metastatic vertebral lesions each, totaling up to 42 target lesions. The median dose to spinal cord at the initial radiation therapy was 30 Gy. SBRT based on the intensity-modulated radiation therapy (IMRT) technique was used for reirradiation to spare the spinal cord. All patients received a prescription dose of 25 Gy in 5 fractions to the planning target volume (PTV). Among the 40 cases who had pain, pain relief was obtained in 24 (60%) after reirradiation. Neurologic improvement was obtained in 8 of 15 cases (53%). The adverse events were evaluated using the Common Terminology Criteria for Adverse Events Version 5.0. Reirradiation was well-tolerated, with only 2 patients experiencing adverse events ≥grade 2 in severity, including 1 patient with grade 3 pain, and another patient with grade 3 spinal fracture. None of the patients developed radiation myelopathy. Our data demonstrated that reirradiation of spinal metastasis using SBRT provided effective pain relief and neurologic improvement, with minimal toxicity.

The Dancing Cord: Inherent Spinal Cord Motion and Its Effect on Cord Dose in Spine Stereotactic Body Radiation Therapy

BACKGROUND

Spinal cord dose limits are critically important for the safe practice of spine stereotactic body radiotherapy (SBRT). However, the effect of inherent spinal cord motion on cord dose in SBRT is unknown.

OBJECTIVE

To assess the effects of cord motion on spinal cord dose in SBRT.

METHODS

Dynamic balanced fast field echo (BFFE) magnetic resonance imaging (MRI) was obtained in 21 spine metastasis patients treated with SBRT. Planning computed tomography (CT), conventional static T2-weighted MRI, BFFE MRI, and dose planning data were coregistered. Spinal cord from the dynamic BFFE images (corddyn) was compared with the T2-weighted MRI (cordstat) to analyze motion of corddyn beyond the cordstat (Dice coefficient, Jaccard index), and beyond cordstat with added planning organ at risk volume (PRV) margins. Cord dose was compared between cordstat, and corddyn (Wilcoxon signed-rank test).

RESULTS

Dice coefficient (0.70-0.95, median 0.87) and Jaccard index (0.54-0.90, median 0.77) demonstrated motion of corddyn beyond cordstat. In 62% of the patients (13/21), the dose to corddyn exceeded that of cordstat by 0.6% to 13.8% (median 4.3%). The corddyn spatially excursed outside the 1-mm PRV margin of cordstat in 9 patients (43%); among these dose to corddyn exceeded dose to cordstat >+ 1-mm PRV margin in 78% of the patients (7/9). Corddyn did not excurse outside the 1.5-mm or 2-mm PRV cord cordstat margin.

CONCLUSION

Spinal cord motion may contribute to increases in radiation dose to the cord from SBRT for spine metastasis. A PRV margin of at least 1.5 to 2 mm surrounding the cord should be strongly considered to account for inherent spinal cord motion.

Asymptomatic Construct Failure after Metastatic Spine Tumor Surgery: A New Entity or a Continuum with Symptomatic Failure?

Study Design

Retrospective cohort study.

Purpose

To study the incidence, onset, underlying mechanism, clinical course, and factors leading to asymptomatic construct failure (AsCF) after metastatic spinal tumor surgery (MSTS).

Overview of Literature

The reported incidence rates for implant and/or construct failure after MSTS are low (1.9%–16%) and based on clinical presentations and revisions required for symptomatic failures (SFs). AsCF after MSTS has not been reported.

Methods

We conducted a retrospective analysis of 288 patients (246 for final analysis) who underwent MSTS between 2005–2015. Data collected were demographics and peri/postoperative clinical and radiological features. Early and late radiological AsCF were defined as presentation before and after 3 months, respectively. We analyzed patients with AsCF for risk factors and survival duration by performing competing risk regression analyses where AsCF was the event of interest, with SF and death as competing events.

Results

We observed AsCF in 41/246 patients (16.7%). The mean time to onset of AsCF after MSTS was 2 months (range, 1–9 months). Median survival of patients with AsCF was 20 and 41 months for early and late failures, respectively. Early AsCF accounted for 80.5% of cases, while late AsCF accounted for 19.5%. The commonest radiologically detectable AsCF mechanism was angular deformity (increase in kyphus) in 29 patients. Increasing age (p<0.02) and primary breast (13/41, 31.7%) (p<0.01) tumors were associated with higher AsCF rates. There was a non-significant trend towards AsCF in patients with a spinal instability neoplastic score ≥7, instrumentation across junctional regions, and construct lengths of 6–9 levels. None of the patients with AsCF underwent revision surgery.

Conclusions

AsCF after MSTS is a distinct entity. Most patients with early AsCF did not require intervention. Patients who survived and maintained ambulation for longer periods had late failure. Increasing age and tumors with a better prognosis have a higher likelihood of developing AsCF. AsCF is not necessarily an indication for aggressive/urgent intervention.

OPF/PMMA cage system as an alternative approach for the treatment of vertebral corpectomy

The spinal column is the most common site for bone metastasis. Vertebral metastases with instability have historically been treated with corpectomy of the affected vertebral body and adjacent intervertebral discs, and are more recently treated with separation surgery. With demographics shifting towards an elderly population, a less invasive surgical approach is necessary for the repair of vertebral defects. We have modified a previously reported expandable hollow cage composed of an oligo[poly(ethylene glycol) fumarate] (OPF) containment system that could be delivered via a posterior-only approach. Then, the polymer of interest, poly(methyl methacrylate) (PMMA) bone cement, was injected into the lumen of the cage after expansion to form an OPF/PMMA cage. We compared six different cage formulations to account for vertebral body and defect size, and performed a cage characterization via expansion kinetics and mechanical testing evaluations. Additionally, we investigated the feasibility of the OPF/PMMA cage in providing spine stability via kinematic analyses. The in-vitro placement of the implant using our OPF/PMMA cage system showed improvement and mechanical stability in a flexion motion. The results demonstrated that the formulation and technique presented in the current study have the potential to improve surgical outcomes in minimally invasive procedures on the spine.

Treatment Strategy for Metastatic Spinal Tumors: A Narrative Review

Metastatic spinal tumors are common, and their rising incidence can be attributed to the expanding aging population and increased survival rates among cancer patients. The decision-making process in the treatment of spinal metastasis requires a multidisciplinary approach that includes medical and radiation oncology, surgery, and rehabilitation. Various decision-making systems have been proposed in the literature in order to estimate survival and suggest appropriate treatment options for patients experiencing spinal metastasis. However, recent advances in treatment modalities for spinal metastasis, such as stereotactic radiosurgery and minimally invasive surgical techniques, have reshaped clinical practices concerning patients with spinal metastasis, making a demand for further improvements on current decision-making systems. In this review, recent improvements in treatment modalities and the evolution of decision-making systems for metastatic spinal tumors are discussed.