Survival Trends After Surgery for Spinal Metastatic Tumors: 20-Year Cancer Center Experience

Health- related quality of life after surgery for spinal metastases

Background

Surgery for spinal metastases is almost always palliative and part of a multidisciplinary approach that has determined a significant increase of life expectancy in the last decade; thus, an improvement in health-related quality of life (HRQOL) is the main goal of the treatment of spinal metastases. We report here the results of a prospective study conducted with the aim of evaluating the impact of spinal surgery on HRQOL, measured by Patient-Reported Outcomes Measures (PROMs). We analyzed clinical outcomes (ambulatory status, performance status, pain, neurological status) and HRQOL scores (VAS, EQ5D, SF36) during the follow-up period and focused on factors that could affect quality of life, considering both psychological and physical issues.

Methods

169 patients (96 males, 73 females) with vertebral metastases who underwent surgery at a tertiary referral center were consecutively enrolled from August 2018 to October 2022. Clinical and surgical data were prospectively collected, and PROMs (VAS, EQ-5D and SF-36) were registered before surgery and during follow up.

Results

The overall survival was 22 months, and a 61 % survival rate was registered at 1 year follow-up. We observed a significant improvement in walking ability, general performance status, pain and HRQOL after surgery, which was maintained during the follow up. Multivariate analysis identified three independent variables, capable of influencing the trend of HRQOL after surgery: the presence of pathological fracture, the preoperative neurological status and the local recurrence of disease.

Discussion

This study confirms the effectiveness of surgery for spinal metastases in improving patients' performance status and demonstrates an overall improvement in HRQOL, which is maintained over time.

Evaluation of fusion status in patients with minimum 1-year survival post-oncologic spinal fusion

BACKGROUND CONTEXT

Oncologic patients have significant medical comorbidities which may impact arthrodesis after spine surgery. Furthermore, there is a paucity of published data describing fusion rates, and arthrodesis quality.

PURPOSE

In this study, we present institutional data for patients with minimum 1-year survival who underwent spinal fusion secondary to treatment of metastatic spine disease.

STUDY DESIGN/SETTING

Retrospective cohort study done at a single tertiary medical center.

PATIENT SAMPLE

Patients were selected from a single institution between 2012 and 2022. Included patients had spinal fusion as part of oncologic treatment, minimum of 1 year follow up, and postoperative Computed Tomography (CT) scan at minimum 1 year.

OUTCOME MEASURES

Patient outcomes included fusion status and Hounsfield units (HU) on CT scan at 1 year.

METHODS

Retrospective chart review was performed collecting demographic and treatment information including postoperative oncologic and radiation treatment as well as HU along the cranial and caudal pedicles bilaterally on the 1-year CT scan. Indications for surgery included symptomatic metastatic disease. All surgeries were performed by 1 of 3 surgeons at a single tertiary medical center. Statistical analysis was performed using the Student T-Test and Chi-Squared Test.

RESULTS

There were 74 patients presenting with metastatic spine disease who met inclusion criteria. Demographics included an average age of 61.9 years at time of surgery, median construct length of 6 levels, and median survival was 43.2 months. Our cohort demonstrated complete and partial fusion rates of 11.1% and 59.5%, respectively. There was a significant difference in average HU for patients demonstrating fusion at 1 year, 444.2 compared to those demonstrating a lack of fusion, 285.8 (p<.0001). Patients who received postoperative radiation had higher postoperative HU than those who did not receive radiotherapy (411.1 vs. 304.9, p=.042). There was no significant difference in fusion status based on postoperative chemotherapy status, p=.127. Additionally, there was no difference in HU based on SBRT versus conventional radiotherapy, p=.588.

CONCLUSION

Partial fusion was seen in over half of the study cohort at 1-year follow-up; complete fusion was seen in 11% of patients. Fused patients and those who received postoperative chemotherapy had significantly higher HU on 1-year CT. Maximizing control of cancer burden as well as improving bone quality may help patients with metastatic spine disease demonstrate bony fusion. More research is indicated to evaluate causal implications of survival in patients with metastatic spine disease that have undergone spinal fusion.

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

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

Analysis of Early Post-Radiation Surgical Management of Metastatic Spinal Tumors

Background/Objectives: Radiotherapy is one of the various treatment options for patients with metastatic spinal tumors (MST). However, it is difficult to say that this is definitely an optimal treatment for MST, and there are several patients who need surgical treatment because pain or neurologic deficits occur even after radiotherapy. Therefore, this study aimed to analyze which patients received early operative treatment after radiotherapy. Methods: We included 81 patients who underwent decompression and fusion surgery after radiotherapy for MST. Patients who underwent surgery within 6 months after radiotherapy were classified as the early operation group (group E, n = 47), while surgery cases after 6 months after radiotherapy were assigned to the late operation group (group L, n = 34). Risk factor analysis using multivariate regression analysis for early operative treatment after radiotherapy was performed. Also, we analyzed the period from radiotherapy to surgery according to the Bilsky grade. Results: In multivariate analysis, pathologic fractures and semirigid (thoracic) lesions were more frequent in group E than group L (adjusted odds ratio, 4.282, 10.524; p = 0.001, 0.039). In subgroup analysis, there was a difference in the period from radiotherapy to surgery in Bilsky grades above 2 than Bilsky grade 1 (grade 1, 13.6 ± 11.4 months, grade 2, 6.9 ± 6.8 months, grade 3, 6.6 ± 7.5 months; grade 1 vs. 2, p = 0.049, grade 1 vs. 3, p = 0.047). Conclusions: Although the information in this study may only be limited to patients who underwent surgery, early operative treatment after radiotherapy is highly likely for patients with MST accompanied by a Bilsky grade above 2, pathologic fracture and thoracic lesion. In these patients, surgical treatment could be considered as the primary treatment.

Early versus late construct failure in spine metastatic disease: implications for surgical strategy and oncologic outcome

PURPOSE

This study aimed to identify variables that portend early construct failure requiring surgical revision in patients undergoing instrumented fusion for spine metastases.

METHODS

A detailed retrospective chart review was performed. Demographic, surgical, and oncologic variables were collected and analyzed via independent samples t-testing, chi-square testing, and Kaplan-Meier method with log-rank testing. Significance was determined as p < 0.05.

RESULTS

482 spinal fusion operations for solid tumor metastases were performed between 2012 and 2022. Of these, 24 (5.0%) required revision surgery for construct failure. There were no major differences between the revision and non-revision patients in terms of several surgical characteristics. Thirteen (54.1%) were revised within 3 months of index surgery. These early construct failures were more likely to have functional neurological deficits at surgery (6/13 vs. 0/11 [p = 0.009]), longer constructs (mean 6.4±2.4 vs. 4.2 ± 1.4 levels [p = 0.015]), and cement-augmented pedicle screws (4/13 vs. 0/11 [p = 0.044)) compared to late construct failures (> 3 months after index surgery). Additionally, 17 symptomatic failures were identified, compared to 7 asymptomatic failures which were identified incidentally with routine follow-up imaging. All 7 asymptomatic construct failures occurred in the early revisions group [p = 0.004]. Revision surgery for early construct failure was associated with significantly reduced median overall survival compared to late failure (p = 0.010).

CONCLUSION

Construct failures in our cohort were not associated with any classical characteristics of patients undergoing revision spine surgery. Early revision (< 3 months) portends a reduction in overall survival when compared with late revisions, and early revised patients were more likely to have had more extensive surgery and poorer neurological status at the time of index cases.

Overview of Molecular Prognostication for Common Solid Tumor Histologies - What the Surgeon Should Know

STUDY DESIGN

Narrative Literature review.

OBJECTIVE

To provide a general overview of important molecular markers and targeted therapies for the most common neoplasms (lung, breast, prostate and melanoma) that metastasize to the spine and offer guidance on how to best incorporate them in the clinical setting.

METHODS

A narrative review of the literature was performed using PubMed, Google Scholar, Medline databases, as well as the histology-specific National Comprehensive Cancer Network guidelines to identify relevant articles limited to the English language. Relevant articles were reviewed for commonly described molecular mutations or targeted therapeutics, as well as associated clinical outcomes, and surgery-related risks.

RESULTS

Molecular markers and targeted therapies have dramatically improved the survival of cancer patients. The increasing importance of prognostic molecular markers and targeted therapies provides rationale for their incorporation into clinical decision-making for patients diagnosed with metastatic spine disease. In this review, we discuss the molecular markers/mutations and targeted therapies associated with the most common malignancies that metastasize to the spine and provide a framework that the surgeon can utilize when evaluating patients for potential intervention. Finally, we provide case examples that highlight the importance of molecular prognostication and therapies in surgical decision-making.

CONCLUSION

An integrated understanding of the implications of surgery, radiation, molecular markers and targeted therapies that guide prognostication and treatment is warranted in order to achieve the most favorable outcomes for patients with metastatic spine disease.

Radiation therapy, radiosurgery, chemotherapy and targeted therapies for metastatic spine tumors: WFNS Spine committee recommendations

OBJECTIVE

This review aims to formulate the most current, evidence-based recommendations regarding radiation therapy, radiosurgery, and chemotherapy for patients with metastatic spine tumors.

METHODS

A systematic literature using PRISMA methodology was performed from 2010-2023 using the search terms "radiosurgery," "radiation therapy," "external beam radiation therapy," or "stereotactic body radiation therapy" in conjunction with "spinal," "spine," "metastasis," "metastases," or "metastatic."

RESULTS

Spinal metastases should be managed in a multidisciplinary team consisting of spine surgeons, radiation oncologists, radiologists and oncologists. Patients identified as potential candidates for SRS/EBRT using internationally recognized frameworks and criteria should be assessed by surgeons to see if surgical cyto-reduction/ separation surgery can be achieved. Choices for treatment of recurrence include re-irradiation with SBRT vs EBRT, surgical debulking, additional chemotherapy or palliative care. There is a lack of current clinical evidence to support the routine use of targeted therapies in the management of metastatic spinal tumors.

CONCLUSIONS

Improving the management of spinal metastasis will lead to increased quality of life and improved survival. This review provides current, evidence-based guidelines on radiation therapy, radiosurgery, and chemotherapy for patients with metastatic spine tumors.

Can Preoperative Hounsfield Unit Measurement Help Predict Mechanical Failure in Metastatic Spinal Tumor Surgery?

Background/Objectives: This study aimed to identify risk factors associated with mechanical failure in patients undergoing spinal instrumentation without fusion for metastatic spinal tumors. Methods: We retrospectively evaluated data from 220 patients with spinal tumors who underwent instrumentation without fusion. Propensity scores were used to match preoperative variables, resulting in the inclusion of 24 patients in the failure group (F group) and 72 in the non-failure group (non-F group). Demographic, surgical, and radiological characteristics were compared between the two groups. Logistic regression and Kaplan-Meier survival analyses were conducted to identify predictors of mechanical failure. Results: Propensity score matching resulted in a balanced distribution of covariates. Lower Hounsfield unit (HU) values at the lowest instrumented vertebra (LIV) were the only independent predictor of implant failure (p = 0.037). A cutoff value of 127.273 HUs was determined to predict mechanical failure, with a sensitivity of 59.1%, specificity of 73.4%, and area under the curve of 0.655 (95% confidence interval: 0.49-0.79). A significant difference in survival was observed between the groups with HU values above and below the cutoff (p = 0.0057). Cement-augmented screws were underutilized, with an average of only 0.2 screws per patient in the F group. Conclusions: Preoperative LIV HU values < 127.273 were strongly associated with an increased risk of mechanical failure following spinal instrumentation without fusion. Alternative surgical strategies including the use of cement-augmented screws are recommended for patients with low HU values.

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.

Separation Operation Followed by Stereotactic Radiotherapy in the Treatment of Spinal Metastasis From Hepatocellular Carcinoma: A Retrospective Cohort Study

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Spinal metastasis from hepatocellular carcinoma is rapidly progressive and predisposes to spinal disability, cord compression and further neural injury, leading to poor prognosis. Currently, it is still challenging to look for a treatment strategy that can improve the quality of life of patients and even directly prolong the survival time. This study attempts to evaluate the clinical efficacy of separation operation combined with postoperative stereotactic radiotherapy (SRT/SRS) in the treatment of hepatocellular carcinoma patients developing spinal metastasis and epidural spinal cord compression.

METHODS

Patients with metastases spinal cord compression from hepatocellular carcinoma were studied retrospectively and divided into two groups, the SO group (who undergo separation operations combined with postoperative SRS, n = 32) and RT group (who received only SRS, n = 28). The visual Analogue Scale (VAS) pain score, Frankel grade, Karnofsky performance score, and Quality of Life (SF-36) score were comparatively analyzed between the two groups.

RESULTS

Significantly higher VAS pain scores, Frankel grades, Karnofsky performance scores and Quality of Life (SF-36) scores were demonstrated in patients with combination treatment than in patients with SRS alone.

CONCLUSION

Separation operations are effective surgical procedure for the treatment of spinal metastatic tumor from hepatocellular carcinoma with spinal cord compression. The combination with postoperative SRS can significantly improve the quality of life in this patient population via spinal canal decompression and spinal stability reconstruction.

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

Introduction

Osteolytic spinal metastases (SM) have a higher risk of fracture. In this study we aim to confirm the remineralization of lytic SM after radiation therapy. Secondary the influence of SBRT compared to cEBRT and tumor type will be analyzed.

Methods

A retrospective cohort study was performed.

Results

87 patients, 100 SM were included. 29 received SBRT, 71 cEBRT. Most common primary tumors were breast (35 %), lung (26 %) and renal (11 %). Both cEBRT and SBRT resulted in a significant increase of bone mineral density (BMD) (83.76 HU ± 5.72 → 241.41 HU ± 22.58 (p < 0.001) and 82.45 ± 9.13 → 179.38 ± 47.83p = 0.026). There was a significant increase in absolute difference of BMD between the SM and reference vertebrae (p < 0.001). There was no significant difference between SBRT and cEBRT. There was no increase of BMD in renal lytic SM after radiation therapy (pre-treatment: 85.96 HU ± 19.07; 3 m 92.00 HU ± 21.86 (p = 0.882); 6 m 92.06 HU ± 23.94 (p = 0.902); 9 m 70.44 HU ± 7.45 (p = 0.213); 12 m 98.08 HU ± 11.24 (p = 0.740)). In all other primary tumors, a significant increase of BMD after radiation therapy was demonstrated (p < 0,05).

Conclusion

We conclude that the BMD of lytic SM increases significantly after radiation therapy. Lytic SM of primary renal tumors are the exception; there is no significant remineralization of renal lytic SM after radiation therapy. There is no benefit of SBRT over cEBRT in this remineralization. These findings should be taken into account when deciding on surgery in the potentially unstable group defined by the spinal instability neoplastic score.

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

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

Assessing Cross-Cultural Adaptation of the Spine Oncology Study Group Outcomes Questionnaire 2.0: A Methodological Systematic Review Regard to Consensus-Based Standards for the Selection of Health Measurement Instruments Guideline

STUDY DESIGN

systematic review of cross-cultural adaptation.

OBJECTIVES

SOSGOQ 2.0 was widely used to assess the HRQQOL of patients with spinal metastasis. Due to the lack of methodological quality assessment, it is a challenge to use the questionnaire in routine practice. This study aims to comprehensively evaluate the translation procedures and measurement attributes of SOSGOQ 2.0 according to COSMIN guidelines.

METHODS

The literature was reviewed adhering to the PRISMA guidelines. Each translation process and different cultural adaptation methods were classified according to the guidelines for Cross cultural Adaptation Process of Self Reporting Measures, and the methodological quality of the identified research was evaluated according to the consensus based on the selection criteria of health measurement tools.

RESULTS

6 publications finally met the inclusion criteria. As for the evaluation of translation procedures and cross-cultural adaptability, two adaptations did not report the detailed information in translation and cross-cultural adaptation (synthesis, back translation, review by expert committee, pre-test), factor analysis and sample size calculation were only mentioned in two studies, and only one adaptation met the minimum sample size standard. Regard to the methodological quality assessment of measurement attributes, all adaptations completed internal consistency, structural effectiveness and reliability. However, none of the adaptations reported measurement errors and only one reported response sensitivity.

CONCLUSIONS

We found that the methodological quality of the current adaptation was uneven, and the report of measurement attribute results was not comprehensive. We recommend higher quality German, Italian and Chinese adaptation.

Enhancing palliative care in vulnerable patients: Robot-assisted radiofrequency ablation for multiple spinal metastases - Technical insights and preliminary outcomes

Background

Radiofrequency thermal ablation (RFA) coupled with vertebroplasty or kyphoplasty offers a minimally invasive, safe, and efficacious approach to palliate polymetastatic spine disease, particularly in medically fragile individuals. However, the application of robotic assistance to RFA for spinal metastases remains unexplored. This study elucidates the technical viability of robot-assisted RFA combined with vertebroplasty in patients afflicted by multiple spinal metastases and presents preliminary outcomes. An illustrative case was also presented.

Materials and Methods

Ten patients aged over 65 years with multiple vertebral metastases were enrolled in this study. Preoperatively, patients exhibited a median Visual Analog Scale (VAS) pain score of 6 and a Median Oswestry Disability Index (ODI) score of 58%. From February 2021 to April 2022, all patients underwent RFA, followed by vertebroplasty for spinal metastases. Surgical procedures were executed using the ExcelsiusGPS® robotic platform.

Results

Patients experienced substantial pain relief, with a median VAS score of 2.5 at 24 h postoperatively (Δ --3.5; P < 0.001) and a median VAS score of 2 at 1 month postoperatively (Δ -4; P < 0.001). All patients were discharged on the first postoperative day and continued their oncological treatments. In addition, the median ODI score at 1 month postoperatively was 34% (Δ --24%; P = 0.006), indicating an enhanced quality of life and a satisfactory impact on daily activities. No procedural or postoperative complications were documented.

Conclusions

This case series represents the inaugural successful application of robot-assisted RFA in conjunction with concurrent vertebroplasty/kyphoplasty. Our preliminary experience demonstrates that patients with oligo- and polymetastatic conditions can derive benefits from this minimally invasive intervention, characterized by rapid postoperative recovery and effective short- to medium-term pain management, without encountering complications.

The Depside Derivative Pericodepside Inhibits Cancer Cell Metastasis and Proliferation by Suppressing Epithelial-Mesenchymal Transition

A depside derivative, named pericodepside (2), along with the known depside proatranorin III (1), was isolated from the solid cultivation of an Ascochyta rabiei strain that heterologously expresses atr1 and atr2 that are involved in the biosynthesis of atranorin in a fruticose lichen, Stereocaulon alpinum. The structure of 2 was determined by 1D and 2D NMR and MS spectroscopic data. The structure of 2 consisted of a depside-pericosine conjugate, with the depside moiety being identical to that found in 1, suggesting that 1 acted as an intermediate during the formation of 2 through the esterification process. Pericodepside (2) strongly suppressed cell invasion and proliferation by inhibiting epithelial-mesenchymal transition and the transcriptional activities of β-catenin, STAT, and NF-κB in U87 (glioma cancer), MCF-7 (breast cancer), and PC3 (prostate cancer) cell lines.

Prophylactic Radiotherapy Of MInimally Symptomatic Spinal Disease (PROMISSeD): study protocol for a randomized controlled trial

BACKGROUND

Early palliative/pre-emptive intervention improves clinical outcomes and quality of life for patients with metastatic cancer. A previous signal-seeking randomized controlled trial (RCT) demonstrated that early upfront radiotherapy to asymptomatic or minimally symptomatic high-risk osseous metastases led to reduction in skeletal-related events (SREs), a benefit driven primarily by subgroup of high-risk spine metastasis. The current RCT aims to determine whether early palliative/pre-emptive radiotherapy in patients with high-risk, asymptomatic or minimally symptomatic spine metastases will lead to fewer SREs within 1 year.

METHODS

This is a single-center, parallel-arm, in-progress RCT in adults (≥ 18 years) with ECOG performance status 0-2 and asymptomatic or minimally symptomatic (not requiring opioids) high-risk spine metastases from histologically confirmed solid tumor malignancies with > 5 sites of metastatic disease on cross-sectional imaging. High-risk spine metastases are defined by the following: (a) bulkiest disease sites ≥ 2 cm; (b) junctional disease (occiput to C2, C7-T1, T12-L2, L5-S1); (c) posterior element involvement; or (d) vertebral body compression deformity > 50%. Patients are randomized 1:1 to receive either standard-of-care systemic therapy (arm 1) or upfront, early radiotherapy to ≤ 5 high-risk spine lesions plus standard-of-care systemic therapy (arm 2), in the form of 20-30 Gy of radiation in 2-10 fractions. The primary endpoint is SRE, a composite outcome including spinal fracture, spinal cord compression, need for palliative radiotherapy, interventional procedures, or spinal surgery. Secondary endpoints include (1) surrogates of health care cost, including the number and duration of SRE-related hospitalizations; (2) overall survival; (3) pain-free survival; and (4) quality of life. Study instruments will be captured pre-treatment, at baseline, during treatment, and at 1, 3, 6, 12, and 24 months post-treatment. The trial aims to accrue 74 patients over 2 years to achieve > 80% power in detecting difference using two-sample proportion test with alpha < 0.05.

DISCUSSION

The results of this RCT will demonstrate the value, if any, of early radiotherapy for high-risk spine metastases. The trial has received IRB approval, funding, and prospective registration (NCT05534321) and has been open to accrual since August 19, 2022. If positive, the trial will expand the scope and utility of spine radiotherapy.

TRIAL REGISTRATION

ClinicalTrials.Gov NCT05534321 . Registered September 9, 2022.

TRIAL STATUS

Version 2.0 of the protocol (2021-KOT-002), revised last on September 2, 2022, was approved by the WCG institutional review board (Study Number 1337188, IRB tracking number 20223735). The trial was first posted on ClinicalTrials.Gov on September 9, 2022 (NCT05534321). Patient enrollment commenced on August 19, 2022, and is expected to be completed in 2 years, likely by August 2024.

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

PURPOSE

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

METHODS

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

RESULT

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

CONCLUSIONS

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

Surgical management of spinal metastases from primary thyroid carcinoma: Demographics, clinical characteristics, and treatment outcomes - A retrospective analysis

Objective

Metastatic spinal tumors represent a rare but concerning complication of primary thyroid carcinoma. We identified demographics, metastatic features, outcomes, and treatment strategies for these tumors in our institutional cohort.

Materials and Methods

We retrospectively reviewed patients surgically treated for spinal metastases of primary thyroid carcinoma. Demographics, tumor characteristics, and treatment modalities were collected. The functional outcomes were quantified using Nurik, Modified Rankin, and Karnofsky Scores.

Results

Twelve patients were identified who underwent 17 surgeries for resection of spinal metastases. The primary thyroid tumor pathologies included papillary (4/12), follicular (6/12), and Hurthle cell (2/12) subtypes. The average number of spinal metastases was 2.5. Of the primary tumor subtypes, follicular tumors averaged 2.8 metastases at the highest and Hurthle cell tumors averaged 2.0 spinal metastases at the lowest. Five patients (41.7%) underwent preoperative embolization for their spinal metastases. Seven patients (58.3%) received postoperative radiation. There was no significant difference in progression-free survival between patients receiving surgery with adjuvant radiation and surgery alone (P = 0.0773). Five patients (41.7%) experienced postoperative complications. Two patients (16.7%) succumbed to disease progression and two patients (16.7%) experienced tumor recurrence following resection. Postsurgical mean Nurik scores decreased 0.54 points, mean Modified Rankin scores decreased 0.48 points, and mean Karnofsky scores increased 4.8 points.

Conclusion

Surgery presents as an important treatment modality in the management of spinal metastases from thyroid cancer. Further work is needed to understand the predictive factors for survival and outcomes following treatment.

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.

Microwave ablation versus radiofrequency ablation for treating spinal metastases

BACKGROUND

This study aimed to compare the clinical efficacy and safety of microwave ablation (MWA) and radiofrequency ablation (RFA) for the treatment of spinal metastases.

METHODS

A literature search was performed using the PubMed, Web of Science, and Cochrane Library databases according to the PRISMA statement (as of September 20, 2022). Two independent investigators screened articles based on the inclusion and exclusion criteria and included studies with primary outcomes of pain relief, tumor control, and complications. Article quality was assessed using the Risk Of Bias In Non-randomized Studies of Interventions tool.

RESULTS

Sixteen articles were finally included in this study, including 630 patients with spinal metastases, with ages ranging from 51.4 to 71.3 years. Of these, 393 (62.4%) underwent MWA and 237 (37.6%) underwent RFA. After MWA and RFA treatment, visual analog scale scores significantly decreased, and the local tumor control rates were all above 80%. Complications were reported in 27.4% of patients treated with MWA compared with 10.9% of patients treated with RFA.

CONCLUSION

The results of this systematic review suggest that MWA alone or in combination with surgery and RFA in combination with other modalities may improve pain caused by primary tumor metastasis to the spine, and MWA alone or in combination with surgery may have better local tumor control. However, MWA appears to result in more major complications than RFA in combination with other treatment modalities.

Overall Survival of Non-Small Cell Lung Cancer With Spinal Metastasis: A Systematic Review and Meta-Analysis

OBJECTIVE

The long-term survival data of lung cancer patients with spinal metastases are crucial for informed treatment decision-making. However, most studies in this field involve small sample sizes. Moreover, survival benchmarking and an analysis of changes in survival over time are required, but data are unavailable. To meet this need, we performed a metaanalysis of survival data from small studies to obtain a survival function based on largescale data.

METHODS

We performed a single-arm systematic review of survival function following a published protocol. Data of patients who received surgical, nonsurgical, and mixed modes of treatment were meta-analyzed separately. Survival data were extracted from published figures with a digitizer program and then processed in R. Median survival time was used as an effect size for moderator analysis to explain the heterogeneity.

RESULTS

Sixty-two studies with 5,242 participants were included for pooling. The survival functions showed a median survival of 6.72 months for surgery (95% confidence interval [CI], 61.9-7.01; 2,367 participants; 36 studies), 5.99 months for nonsurgery (95% CI, 5.33-6.47; 891 participants; 12 studies), and 5.96 months for mixed (95% CI, 5.67-6.43; 1,984 participants; 18 studies). Patients enrolled since 2010 showed the highest survival rates.

CONCLUSION

This study provides the first large-scale data for lung cancer with spinal metastasis that allows survival benchmarking. Data from patients enrolled since 2010 had the best survival and thus may more accurately reflect current survival. Researchers should focus on this subset in future benchmarking and remain optimistic in the management of these patients.

A Comparison of Prognostic Models to Facilitate Surgical Decision-Making for Patients With Spinal Metastatic Disease

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

Compare the performance of and provide cutoff values for commonly used prognostic models for spinal metastases, including Revised Tokuhashi, Tomita, Modified Bauer, New England Spinal Metastases Score (NESMS), and Skeletal Oncology Research Group model, at three- and six-month postoperative time points.

SUMMARY OF BACKGROUND DATA

Surgery may be recommended for patients with spinal metastases causing fracture, instability, pain, and/or neurological compromise. However, patients with less than three to six months of projected survival are less likely to benefit from surgery. Prognostic models have been developed to help determine prognosis and surgical candidacy. Yet, there is a lack of data directly comparing the performance of these models at clinically relevant time points or providing clinically applicable cutoff values for the models.

MATERIALS AND METHODS

Sixty-four patients undergoing surgery from 2015 to 2022 for spinal metastatic disease were identified. Revised Tokuhashi, Tomita, Modified Bauer, NESMS, and Skeletal Oncology Research Group were calculated for each patient. Model calibration and discrimination for predicting survival at three months, six months, and final follow-up were evaluated using the Brier score and Uno's C, respectively. Hazard ratios for survival were calculated for the models. The Contral and O'Quigley method was utilized to identify cutoff values for the models discriminating between survival and nonsurvival at three months, six months, and final follow-up.

RESULTS

Each of the models demonstrated similar performance in predicting survival at three months, six months, and final follow-up. Cutoff scores that best differentiated patients likely to survive beyond three months included the Revised Tokuhashi score=10, Tomita score=four, Modified Bauer score=three, and NESMS=one.

CONCLUSION

We found comparable efficacy among the models in predicting survival at clinically relevant time points. Cutoff values provided herein may assist surgeons and patients when deciding whether to pursue surgery for spinal metastatic disease.

LEVEL OF EVIDENCE

4.

The Impact of Targetable Mutations on Clinical Outcomes of Metastatic Epidural Spinal Cord Compression in Patients With Non-Small-Cell Lung Cancer Treated With Hybrid Therapy (Surgery Followed by Stereotactic Body Radiation Therapy)

BACKGROUND

In treatment of metastatic epidural spinal cord compression (MESCC), hybrid therapy, consisting of separation surgery, followed by stereotactic body radiation therapy, has become the mainstay of treatment for radioresistant pathologies, such as non-small-cell lung cancer (NSCLC).

OBJECTIVE

To evaluate clinical outcomes of MESCC secondary to NSCLC treated with hybrid therapy and to identify clinical and molecular prognostic predictors.

METHODS

This is a single-center, retrospective study. Adult patients (≥18 years old) with pathologically confirmed NSCLC and spinal metastasis who were treated with hybrid therapy for high-grade MESCC or nerve root compression from 2012 to 2019 are included. Outcome variables evaluated included overall survival (OS) and progression-free survival, local tumor control in the competing risks setting, surgical and radiation complications, and clinical-genomic correlations.

RESULTS

One hundred and three patients met inclusion criteria. The median OS for this cohort was 6.5 months, with progression of disease noted in 5 (5%) patients at the index tumor level requiring reoperation and/or reirradiation at a mean of 802 days after postoperative stereotactic body radiation therapy. The 2-year local control rate was 94.6% (95% CI: 89.8-99.3). Epidermal growth factor receptor (EGFR) treatment-naïve patients who initiated EGFR-targeted therapy after hybrid therapy had significantly longer OS (hazard ratio 0.47, 95% CI 0.23-0.95, P = .04) even after adjusting for smoking status. The presence of EGFR exon 21 mutation was predictive of improved progression-free survival.

CONCLUSION

Hybrid therapy in NSCLC resulted in 95% local control at 2 years after surgery. EGFR treatment-naïve patients initiating therapy after hybrid therapy had significantly improved survival advantage. EGFR-targeted therapy initiated before hybrid therapy did not confer survival benefit.

Conditional survival after surgery for metastatic tumors of the spine: does prognosis change over time?

PURPOSE

Conditional survival (CS) provides a dynamic prediction of patient survival by incorporating the time an individual has already survived given their disease specific characteristics. The objective of the current study was to estimate CS among patients after surgery for spinal cord compression or spinal instability, as well as stratify CS according to relevant patient- and disease-related characteristics.

METHODS

The clinical outcomes of 361 patients undergoing surgical management of metastatic spinal tumors were retrospectively analyzed. Stratification of this cohort according to disease and surgery-specific characteristics allowed for univariate and multivariate statistical analyses of our study population. Observed overall and conditional survival estimates were calculated by the Kaplan-Meier method.

RESULTS

12-month conditional survival in patients undergoing surgical management of metastatic spine tumors increased from 57% at baseline to 70% at 24 months following spine surgery. Overall survival (OS) was influenced by CCI grade, Katagiri tumor type, presence of lung metastasis, type of spine surgery, presence of postoperative systemic therapy and ambulatory status at follow-up. Analyses of OS and CS by prognostic strata were similar with exception of stratification by surgery type. Differences in survival between strata tend to converge over time. Unfavorable factors for OS appear to be less relevant after a period of 24 months following spine surgery.

CONCLUSION

Patients after surgery for metastatic tumors of the spine can expect a positive trend in conditional survival as survivorship increases. Even patients with a more severe disease can be encouraged with gains in conditional survival over time.

LEVEL OF EVIDENCE

Level IV (retrospective cohort study).

Trends in Survival and Surgical Methods in Patients Surgically Treated for Metastatic Spinal Tumors: 25-Year Experience in a Single Institution

Background

This study aimed to examine trends in postoperative survival and surgical methods over a 25-year period in patients surgically treated for metastatic spinal tumors.

Methods

We performed a retrospective study of patients who underwent surgical treatment for metastatic spinal tumors between 1996 and 2020. For trend analysis, the study cohort was divided into three groups according to the year of surgery: 1996-2004, 2005-2012, and 2013-2020. A Kaplan-Meier survival analysis was performed to examine survival, and the log-rank test was used to compare the survival of the top six common cancers among the periods. The surgical methods were grouped and examined as follows: fixation only, palliative decompression and fixation, gross total removal and fixation, and total en bloc spondylectomy.

Results

This study included a total of 608 patients. There were 78 patients in 1996-2004, 236 in 2005-2012, and 294 in 2013-2020. Regarding the overall survival trend, the group 2013-2020 had a significantly improved survival as compared to the other two groups (p < 0.001). According to specific cancer sites, significant survival improvement was observed in patients with lung, kidney, and breast cancers (p < 0.001, p < 0.001, and p = 0.022, respectively). There were no significant changes in the primary sites of the liver, colorectum, or prostate. Regarding surgical methods, the proportion of gross total tumor removal declined, whereas the proportion of palliative decompression and fixation and fixation only procedures increased.

Conclusions

During the past 25 years, significant survival improvement was observed in patients with lung, kidney, and breast cancers. There was no improvement in survival in patients with liver, colorectal, and prostate cancers. In terms of surgical techniques, palliative decompression and fixation only procedures increased, while gross total tumor removal declined.

Characteristics and risk factors of instrumentation failure following total en bloc spondylectomy

AIMS

The aim of this study was to investigate the incidence and characteristics of instrumentation failure (IF) after total en bloc spondylectomy (TES), and to analyze risk factors for IF.

METHODS

The medical records from 136 patients (65 male, 71 female) with a mean age of 52.7 years (14 to 80) who underwent TES were retrospectively reviewed. The mean follow-up period was 101 months (36 to 232). Analyzed factors included incidence of IF, age, sex, BMI, history of chemotherapy or radiotherapy, tumour histology (primary or metastasis; benign or malignant), surgical approach (posterior or combined), tumour location (thoracic or lumbar; junctional or non-junctional), number of resected vertebrae (single or multilevel), anterior resection line (disc-to-disc or intravertebra), type of bone graft (autograft or frozen autograft), cage subsidence (CS), and local alignment (LA). A survival analysis of the instrumentation was performed, and relationships between IF and other factors were investigated using the Cox regression model.

RESULTS

A total of 44 patients (32.4%) developed IF at a median of 31 months (interquartile range 23 to 74) following TES. Most IFs were rod fractures preceded by a mean CS of 6.1 mm (2 to 18) and LA kyphotic enhancement of 10.8° (-1 to 36). IF-free survival rates were 75.8% at five years and 56.9% at ten years. The interval from TES to IF peaked at two to three years postoperatively and continued to occur over a period of time thereafter; the early IF-developing group had greater CS at one month postoperatively (CS1M) and more lumbar TES. CS1M ≥ 3 mm and sole use of frozen autografts were identified as independent risk factors for IF.

CONCLUSION

IF is a common complication following TES. We have demonstrated that robust spinal reconstruction preventing CS, and high-quality bone grafting are necessary for successful reconstruction.Cite this article: Bone Joint J 2023;105-B(2):172-179.

Assessment of Spinal Metastases Surgery Risk Stratification Tools in Breast Cancer by Molecular Subtype

BACKGROUND

Breast cancer molecular features and modern therapies are not included in spine metastasis prediction algorithms.

OBJECTIVE

To examine molecular differences and the impact of postoperative systemic therapy to improve prognosis prediction for spinal metastases surgery and aid surgical decision making.

METHODS

This is a retrospective multi-institutional study of patients who underwent spine surgery for symptomatic breast cancer spine metastases from 2008 to 2021 at the Massachusetts General Hospital and Brigham and Women's Hospital. We studied overall survival, stratified by breast cancer molecular subtype, and calculated hazard ratios (HRs) adjusting for demographics, tumor characteristics, treatments, and laboratory values. We tested the performance of established models (Tokuhashi, Bauer, Skeletal Oncology Research Group, New England Spinal Metastases Score) to predict and compare all-cause.

RESULTS

A total of 98 patients surgically treated for breast cancer spine metastases were identified (100% female sex; median age, 56 years [IQR, 36-84 years]). The 1-year probabilities of survival for hormone receptor positive, hormone receptor positive/human epidermal growth factor receptor 2+, human epidermal growth factor receptor 2+, and triple-negative breast cancer were 63% (45 of 71), 83% (10 of 12), 0% (0 of 3), and 12% (1 of 8), respectively ( P < .001). Patients with triple-negative breast cancer had a higher proportion of visceral metastases, brain metastases, and poor physical activity at baseline. Postoperative chemotherapy and endocrine therapy were associated with prolonged survival. The Skeletal Oncology Research Group prognostic model had the highest discrimination (area under the receiver operating characteristic, 0.77 [95% CI, 0.73-0.81]). The performance of all prognostic scores improved when preoperative molecular data and postoperative systemic treatment plans was considered.

CONCLUSION

Spine metastases risk tools were able to predict prognosis at a significantly higher degree after accounting for molecular features which guide treatment response.

Antifibrinolytics use during surgery for oncological spine diseases: A systematic review

Background

Data exist of the benefits of antifibrinolytics such as tranexamic acid (TXA) in general spine surgery. However, there are limited data of its use in oncological spine patients.

Methods

A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Cochrane, OVID, and Embase databases were searched. Search terms: "tranexamic acid", "aprotinin," "aminocaproic acid," "spine surgery," "spine tumors," and "spine oncology." Included studies were full text publications written in English with patients treated with either agent or who had surgery for oncological spine disease (OSD).

Results

Seven hundred results were reviewed form the different databases, seven were selected. A total of 408 patients underwent spine surgery for OSD and received antifibrinolytics. There was a male predominance (55.2%) and mean age ranged from 43 to 62 years. The most common tumor operated was metastatic renal cancer, followed by breast and lung. Most studies administered TXA as a bolus followed by an infusion during surgery. Median blood loss was of 667 mL (253.3-1480 mL). Patients with TXA required 1-2 units less of transfusion and had 56-63 mL less of postoperative drainage versus no TXA. The median incidence of deep venous thrombosis (DVT) was 2.95% (0-7.9%) and for pulmonary embolism (PE) was 4.25% (0-14.3%). The use of TXA reduced intraoperative blood loss, transfusions and reduced postoperative surgical drainage output compared to no TXA use in patients with OSD.

Conclusion

In this review, we found that TXA may diminish intraoperative blood loss, the need for transfusion and postoperative drainage from surgical drains when used in OSD without major increase in rates of DVT or PE.

Cross-cultural adaptation and validation of simplified Chinese version of the Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ) 2.0 with its assessment in clinical setting

BACKGROUND CONTEXT

The treatment of spinal metastases (SM) has been significantly improved in recent years, which gives health-related quality of life (HRQOL) further significance in management of SM. The Spine Oncology Study Group Outcomes Questionnaire version 2.0 (SOSGOQ 2.0) was a specific targeted SM HRQOL criterion that was previously reported to pose good reliability and validity. However, there is no culturally adapted, reliable, and validated version of SOSGOQ 2.0 in mainland China.

PURPOSE

The current study aimed to translate the SOSGOQ 2.0 in a cross-cultural fashion, before evaluating the reliability and validity of the adapted simplified Chinese version of (SC-SOSGOQ 2.0) for patients with spinal metastases (SM).

STUDY DESIGN/SETTING

Translation, cross-cultural adaptation, and validation were performed on the Chinese version of the SOSGOQ 2.0.

PATIENT SAMPLE

Patients who were diagnosed with metastatic spinal disease, posing at least 6-years experience of education and the ability to read and speak Chinese.

OUTCOME MEASURES

Reliability and Validity of the SC-SOSGOQ 2.0 were measured to assess HRQOL in patients with SM.

METHODS

The cross-cultural adaptation of the SOSGOQ 2.0 was conducted following international guidelines. The reliability and validity of the SC-SOSGOQ 2.0 was assessed in a multi-center, prospective observational study. The test-retest reliability was assessed by comparing the results of the first and final SC-SOSGOQ 2.0 scales, with 2 weeks apart. The discriminative, concurrent, and construct validity of the cross-culturally adapted questionnaire was individually evaluated. The relationship among the SC-SOSGOQ 2.0, SC-EQ-5D-5L and SC-SF-36 was assessed using the correlation coefficients.

RESULTS

One hundred and twenty patients were included in this study. No floor or ceiling effects were observed for the SC-SOSGOQ 2.0. The Cronbach's α for domains of neurological function, pain, mental health, social function, and post-therapy were 0.825, 0.876, 0.896, 0.897, 0.943, and 0.835, respectively. The value of inter-class correlation coefficient ranged from 0.55 to 0.83, which reflected a satisfactory test-retest reliability. Concurrent assessment of criterion validity demonstrated a moderate-to-strong correlation in all domains of SC-SOSGOQ 2.0 with the SC-EQ-5D-5L (0.34-0.74) and SC-SF-36 (0.33-0.76). The best-correlated domain was physical function (0.741 in the EQ-5D-5L and 0.722 in the SF-36).

CONCLUSIONS

The SC-SOSGOQ 2.0 demonstrated an excellent acceptability, score distribution, internal consistency, test-retest reliability and validity. It was therefore considered as a tool effective for evaluating HRQOL of Chinese patients with SM.

Patient outcomes following implementation of an enhanced recovery after surgery pathway for patients with metastatic spine tumors

BACKGROUND

Metastatic spine tumor surgery consists of palliative operations performed on frail patients with multiple medical comorbidities. Enhanced recovery after surgery (ERAS) programs involve an evidence-based, multidisciplinary approach to improve perioperative outcomes. This study presents clinical outcomes of a metastatic spine tumor ERAS pathway implemented at a tertiary cancer center.

METHODS

The metastatic spine tumor ERAS program launched in April 2019, and data from January 2018 to May 2020 were reviewed. Measured outcomes included the following: hospital length of stay (LOS), time to ambulation, urinary catheter duration, time to resumption of diet, intraoperative fluid intake, estimated blood loss (EBL), and intraoperative and postoperative day 0-5 cumulative opioid use (morphine milligram equivalent [MME]).

RESULTS

A total of 390 patients were included in the final analysis: 177 consecutive patients undergoing metastatic spine tumor surgery enrolled in the ERAS program and 213 consecutive pre-ERAS patients. Although the mean case durations were similar in the ERAS and pre-ERAS cohorts (265 vs. 274 min; p = .22), the ERAS cohort had decreased EBL (157 vs. 215 ml; p = .003), decreased postoperative day 0-5 cumulative mean opioid use (178 vs. 396 MME; p < .0001), earlier ambulation (mean, 34 vs. 57 h; p = .0001), earlier discontinuation of urinary catheters (mean, 36 vs. 56 h; p < .001), and shorter LOS (5.4 vs. 7.5 days; p < .0001).

CONCLUSIONS

The implementation of a multidisciplinary ERAS program designed for metastatic spine tumor surgery led to improved clinical quality metrics, including shorter hospitalizations and significant reductions in opioid consumption.

Fifty-year history of the evolution of spinal metastatic disease management

Spine metastases are a significant source of morbidity in oncology. Treatment of these spine metastases largely remains palliative, but advances over the past 50 years have improved the effectiveness of interventions for preserving functional status and obtaining local control while minimizing morbidity. While the field began with conventional external beam radiation as the primary treatment modality, a series of paradigm shifts and technological advances in the 2000s led to a change in treatment patterns. These advances allowed for an increased role of surgical decompression of neural elements, a shift in the stereotactic capabilities of radiation oncologists, and an improved understanding of the radiobiology of metastatic disease. The result was improved local control while minimizing treatment morbidity. These advances fit within the larger framework of metastatic spine tumor management known as the Neurologic, Oncologic, Mechanical, and Systemic disease decision framework. This dynamic framework takes into account the neurological function of the patient, the radiobiology of their tumor, their degree of mechanical instability, and their systemic disease control and treatment options to help determine appropriate interventions based on the individual patient. Herein, we describe the 50-year evolution of metastatic spine tumor management and the impact of various advances on the field.

Evaluating frailty, mortality, and complications associated with metastatic spine tumor surgery using machine learning-derived body composition analysis

OBJECTIVE

Cancer patients with spinal metastases may undergo surgery without clear assessments of prognosis, thereby impacting the optimal palliative strategy. Because the morbidity of surgery may adversely impact recovery and initiation of adjuvant therapies, evaluation of risk factors associated with mortality risk and complications is critical. Evaluation of body composition of cancer patients as a surrogate for frailty is an emerging area of study for improving preoperative risk stratification.

METHODS

To examine the associations of muscle characteristics and adiposity with postoperative complications, length of stay, and mortality in patients with spinal metastases, the authors designed an observational study of 484 cancer patients who received surgical treatment for spinal metastases between 2010 and 2019. Sarcopenia, muscle radiodensity, visceral adiposity, and subcutaneous adiposity were assessed on routinely available 3-month preoperative CT images by using a validated deep learning methodology. The authors used k-means clustering analysis to identify patients with similar body composition characteristics. Regression models were used to examine the associations of sarcopenia, frailty, and clusters with the outcomes of interest.

RESULTS

Of 484 patients enrolled, 303 had evaluable CT data on muscle and adiposity (mean age 62.00 ± 11.91 years; 57.8% male). The authors identified 2 clusters with significantly different body composition characteristics and mortality risks after spine metastases surgery. Patients in cluster 2 (high-risk cluster) had lower muscle mass index (mean ± SD 41.16 ± 7.99 vs 50.13 ± 10.45 cm2/m2), lower subcutaneous fat area (147.62 ± 57.80 vs 289.83 ± 109.31 cm2), lower visceral fat area (82.28 ± 48.96 vs 239.26 ± 98.40 cm2), higher muscle radiodensity (35.67 ± 9.94 vs 31.13 ± 9.07 Hounsfield units [HU]), and significantly higher risk of 1-year mortality (adjusted HR 1.45, 95% CI 1.05-2.01, p = 0.02) than individuals in cluster 1 (low-risk cluster). Decreased muscle mass, muscle radiodensity, and adiposity were not associated with a higher rate of complications after surgery. Prolonged length of stay (> 7 days) was associated with low muscle radiodensity (mean 30.87 vs 35.23 HU, 95% CI 1.98-6.73, p < 0.001).

CONCLUSIONS

Body composition analysis shows promise for better risk stratification of patients with spinal metastases under consideration for surgery. Those with lower muscle mass and subcutaneous and visceral adiposity are at greater risk for inferior outcomes.

Utility of expanded anterior column resection versus decompression-alone for local control in the management of carcinomatous vertebral column metastases undergoing adjuvant stereotactic radiotherapy

BACKGROUND CONTEXT

With improvements in adjuvant radiotherapy and minimally invasive surgical techniques, separation surgery has become the default surgical intervention for spine metastases at many centers. However, it is unclear if there is clinical benefit from anterior column resection in addition to simple epidural debulking prior to stereotactic body radiotherapy (SBRT).

PURPOSE

To examine the effect of anterior column debulking versus epidural disease resection alone in the local control of metastases to the bony spine.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

Ninety-seven patients who underwent open surgery followed by SBRT for spinal metastases at a single comprehensive cancer center.

OUTCOME MEASURES

Local tumor recurrence following surgery and SBRT.

METHODS

Data were collected regarding radiation dose, cancer histology, extent of anterior column resection, and recurrence. Tumor involvement was categorized using the International Spine Radiosurgery Consortium guidelines. Univariable analyses were conducted to determine predictors of local recurrence and time to local recurrence.

RESULTS

Among the 97 included patients, mean age was 60.5±11.4 years and 51% of patients were male. The most common primary tumor types were lung (20.6%), breast (17.5%), kidney (13.4%) and prostate (12.4%). Recurrence was seen in 17 patients (17.5%) and local control rates were: 85.5% (1-year), 81.1% (2-year), and 54.9% (5-year). Overall predictors of local recurrence were tumor pathology (p<.01; renal cell carcinoma and colorectal adenocarcinoma associated with poorest PFS) and undergoing anterior column debulking versus epidural decompression-alone (p=.03). Only tumor pathology predicted time to local recurrence (p<.01), though inspection of Kaplan-Meier functions showed superior long-term local control in patients with radiosensitive tumor pathologies, no previous irradiation of the metastasis, and who underwent anterior column resection versus epidural removal alone. Median time to recurrence was 288 days with 100% of lesions showing anterior column recurrence and recurrence in the epidural space.

CONCLUSIONS

With the increasing shift towards surgery as a neoadjuvant to radiotherapy for patients with spinal column metastases, the role for surgical debulking has become less clear. In the present study, we find that anterior column debulking as opposed to epidural debulking-alone decreases the odds of local recurrence and improves long-term local control.

Patient Reported Outcomes in Metastatic Spine Disease: Concurrent Validity of PROMIS with the Spine Oncology Study Group Outcome Questionnaire

STUDY DESIGN

Cross-sectional prospective study.

OBJECTIVE

To evaluate the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF), Pain Interference (PI), and Depression domains in comparison to the Spine Oncology Study Group-Outcomes Questionnaire (SOSG-OQ) in patients with metastatic spine disease.

SUMMARY OF BACKGROUND DATA

While there remains a significant movement toward incorporating patient-reported outcome measures (PROMs) into clinical care, there are few validated PROMs for patients with metastatic spine disease. The SOSG-OQ was designed and validated for metastatic spine tumor patients. However, the use of general symptom-based PROMs, such as PROMIS domains, may reduce both patient and physician burden and improve interdisciplinary care if shown to be concurrently valid.

METHODS

Metastatic spine tumor patients from January 2017 to July 2021 at a single academic medical center were asked to complete PROMIS PF, PI, and Depression domains and the SOSG-OQ. Spearman correlation (p) coefficients were calculated.

RESULTS

A total of 103 unique visits, representing 79 patients met our inclusion criteria. A majority were men (59; 57%) and Caucasian (93; 90%), and the average age was 64-years-old (range: 34-87). There were 13 different types of histologies reported, with multiple myeloma, breast cancer, and prostate cancer representing 28 (27%), 26 (25%), and 13 (13%), respectively. Additional cancers included renal cell carcinoma, lung cancer, colon cancer, thyroid cancer, large B-cell lymphoma, nonHodgkin lymphoma, esophageal cancer, plasmacytoma, metastatic paraganglioma, and metastatic spindle cell sarcoma. SOSG-OQ was strongly correlated with PROMIS PI (ρ = 0.78) and PROMIS PF (ρ = 0.71), and moderately correlated with PROMIS Depression (ρ = 0.58).

CONCLUSION

PROMIS PF, PI, and Depression appear to capture similar clinical insight as the SOSG-OQ. Spine surgeons can consider using these PROMIS domains in lieu of the SOSG-OQ in metastatic spine tumor patients.

Level of Evidence: NA.

Pancreatic Cancer Metastasis to the Spine: A Systematic Review of Management Strategies and Outcomes with Case Illustration

OBJECTIVE

We aim to provide a thorough review of the literature regarding patient characteristics, treatment options, and outcomes of pancreatic cancer metastasis to the spine. We also provide an illustrative case from our institution of a patients with pancreatic adenocarcinoma presenting initially as cervical radiculopathy with an isolated cervical spine lesion.

METHODS

Using the PRISMA guidelines, the literature in PubMed, Google Scholar, and Web of Science databases was searched. We excluded systematic reviews and meta-analyses that did not provide novel cases, as well as reports of metastatic disease from other nonpancreatic primary cancers.

RESULTS

Thirty-two patients across 21 studies met the inclusion criteria. The patients were predominantly male (58%), with a mean age of 59 years. Of patients, 64% presented with back pain, 39% with motor deficits, and 15% with bladder or bowel dysfunction. For treatment, chemotherapy was used in 55% of cases and radiotherapy in 42%. Surgical treatment was performed in 42% of cases, with complete tumor resection achieved in 24% of cases. The mean patient survival after treatment was 28 weeks (range, 1-83 weeks), with patients undergoing treatment involving surgery having increased survival (44 weeks) compared with noninvasive treatment alone (18 weeks).

CONCLUSIONS

Spinal metastasis of pancreatic cancer is rare and typically portends a poor prognosis. It is vital to recognize the presence of spinal involvement early in the disease course and initiate treatment.

Management of Spinal Bone Metastases With Radiofrequency Ablation, Vertebral Reinforcement and Transpedicular Fixation: A Retrospective Single-Center Case Series

Spine is a frequent site of bone metastases, with a 8.5 months median survival time after diagnosis. In most cases treatment is only palliative. Several advanced techniques can ensure a better Quality of Life (QoL) and increase life expectancy. Radiofrequency ablation (RFA) uses alternating current to produce local heating and necrosis of the spinal lesion, preserving the healthy bone. RFA is supported by vertebral reinforcement through kyphoplasty and vertebroplasty in order to stabilize the fracture with polymethylmethacrylate (PMMA) injection, restoring vertebral body height and reducing the weakness of healthy bone. The aim of this study is to demonstrate the efficacy and advantages of RFA plus vertebral reinforcement through PMMA vertebroplasty and fixation in patients affected by bone spinal metastases. We retrospectively analyzed 54 patients with thoraco-lumbar metastatic vertebral fractures admitted to our Unit between January 2014 and June 2020. Each patient underwent RFA followed by PMMA vertebroplasty and transpedicle fixation. We evaluated pain relief through the Visual Analogue Scale (VAS) Score and PMMA vertebral filling based on the mean Saliou filling score. Analysis of variance (ANOVA) was used to test pain relief with statistical significance for p<0.05. A total of 54 patients (median age 63,44 years; range 34-86 years), with a total of 63 infiltrated vertebrae, were treated with RFA, PMMA vertebroplasty and transpedicular screw fixation; average operative time was 60.4 min (range 51–72). The preoperative average VAS score decreased significantly from 7.81 to 2.50 (p < 0.05) after 12 months. Based on Saliou filling score, filling was satisfactory (12–18) in 20 vertebrae (31,7%), mediocre (6–11) in 33 vertebrae (52,4%), inadequate (0–5) in 10 vertebrae (15,9%). A consistent PMMA filling of vertebral bodies was successfully achieved with significant pain relief. Concomitant RFA, PMMA vertebroplasty and pedicle screw fixation represent a safe and effective technique for the management of spinal metastases, improving clinical outcome and pain control.

10-Year Trends in the Surgical Management of Patients with Spinal Metastases: A Scoping Review

BACKGROUND

Spinal metastases are present in approximately 20% of patients with cancer, giving a risk for neurologic dysfunction and instability. In already frail patients, surgeons strive to improve quality of life. Our goal was to review a 10-year trend in the surgical management of spinal metastases.

METHODS

A scoping review was performed systematically using PubMed to assess trends in surgical treatment for spinal metastases. The search terms used were: metastas∗, "neoplasm metastasis"[Mesh], "Spine"[Mesh], spine, spinal, "vertebral column," "vertebral body," laser, robot, radiofrequency, screws, fixation, "separation surgery," corpectomy, vertebrectomy, spondylectomy, vertebroplasty, kyphoplasty, surgery, "open surgery," "mini open surgery," "minimally invasive surgery," endoscopy, thoracoscopy, corpectom∗, vertebrectom∗, spondylectom∗, "en bloc," and MIS. The variables of interest were neurologic improvement, tumor recurrence, reoperation, and overall survival.

RESULTS

A total of 2132 articles were found within the primary query. Fifty-six studies were selected for final review. The results were organized into main surgical practices: decompression, mechanical stabilization, and pain management. For separation surgery, clinical outcomes were overall 1-year survival, 40.7%-78.4%; recurrence rate, 4.3%-22%; reoperation, 5%; and complications, 5.4%-14%. For corpectomy, clinical outcomes were overall 1-year survival, 30%-92%; reoperation, 1.1%-50%; and recurrence rate, of 1.1%-28%. Complications and reoperations with spinal instrumentation were 0%-13.6% and 0%-15%, respectively. Cement augmentation achieved pain reduction rates of 56%-100%, neurologic improvement/stability 84%-100%, and complication rates 6%-56%. Laser achieved local tumor control rate of 71%-82% at 1 year follow-up, reoperation rate of 15%-31%, and complication rate of 5%-26%.

CONCLUSIONS

Minimally invasive techniques for decompression and stabilization seem to be the preferred method to surgically treat metastatic spine disease, with good outcomes. More research with high level of evidence is required to support the long-term outcomes of these approaches.

Anterior Corpectomy and Plating with Carbon-PEEK Instrumentation for Cervical Spinal Metastases: Clinical and Radiological Outcomes

Background: Anterior cervical corpectomy and plating has been recognized as a valuable approach for the surgical treatment of cervical spinal metastases. This study aimed to report the surgical, clinical and radiological outcomes of anterior carbon-PEEK instrumentations for cervical spinal metastases. Methods: Demographical, clinical, surgical and radiological data were collected from 2017 to 2020. The Neck Disability Index (NDI) questionnaire for neck pain, EORTC QLQ-C30 questionnaire for quality of life, Nurick scale for myelopathy and radiological parameters (segmental Cobb angle and cervical lordosis) were collected before surgery, at 6 weeks postoperatively and follow-up. Results: Seventeen patients met inclusion criteria. Mean age was 60.9 ± 7.6 years and mean follow-up was 12.9 ± 4.0 months. The NDI (55.4 ± 11.7 to 25.1 ± 5.4, p < 0.001) scores and the EORTC QLQ-C30 global health/QoL significantly improved postoperatively and at the last follow-up. The segmental Cobb angle (10.7° ± 5.6 to 3.1° ± 2.2, p < 0.001) and cervical lordosis (0.9° ± 6.7 to −6.2 ± 7.8, p = 0.002) significantly improved postoperatively. Only one minor complication (5.9%) was recorded. Conclusions: Carbon/PEEK implants represent a safe alternative to commonly used titanium ones and should be considered in cervical spinal metastases management due to their lower artifacts in postoperative imaging and radiation planning. Further larger comparative and cost-effectiveness studies are needed to confirm these results.

Analysis of Short-Term versus Long-Term Readmission-Free Survival After Metastatic Spine Tumor Surgery

BACKGROUND

Readmission-free survival (ReAFS) is a novel clinical and quality metric after metastatic spine tumor surgery (MSTS). We believe that factors influencing ReAFS after index MSTS vary based on time. We considered 2 time frames and defined short-term ReAFS as survival without an unplanned hospital readmission up to 90 days and long-term ReAFS as survival without unplanned hospital readmission up to 1 year after MSTS.

METHODS

We retrospectively analyzed 266 patients who underwent MSTS between 2005 and 2016. All relevant oncologic, surgical and follow-up data were collected. Multivariate logistic regression analysis was used to analyze prognostic factors associated with higher probability of short-term ReAFS and long-term ReAFS.

RESULTS

Multivariate analysis showed that Eastern Cooperative Oncology Group score ≤2 (P = 0.011), preoperative hemoglobin (Hb) level >12 g/dL (P = 0.008), ≤3 comorbidities (P = 0.052), shorter index length of stay ≤10 days (P = 0.007), and absence of neurologic/hematologic complications during index stay (P = 0.015) significantly increased the probability of short-term ReAFS, whereas preoperative Hb level >12 g/dL (P = 0.003) or tumor primaries with advanced treatment modalities such as breast (P = 0.012), hematologic (P = 0.006), prostate (P = 0.004), and renal/thyroid (P = 0.038) as opposed to aggressive lung tumor primaries were associated with significantly higher probability of long-term ReAFS.

CONCLUSIONS

Patient and treatment factors predominantly influence ReAFS up to 90 days, whereas primary tumor-related factors alongside general health influence ReAFS beyond 90 days after index MSTS. Awareness of these factors may help oncologists and surgeons optimize treatment planning. The clinical significance of this study will continue to evolve, because we have been witnessing over the past decade that patients are becoming more involved in both their general health and understanding the natural history of the diseases that affect them.

Radiotherapy and Surgical Advances in the Treatment of Metastatic Spine Tumors: A Narrative Review

Spine tumors encompass a wide range of diseases with a commensurately broad spectrum of available treatments, ranging from radiation for spinal metastases to highly invasive en bloc resection for primary vertebral column malignancies. This high variability in treatment approaches stems both from variability in the goals of surgery (e.g., oncologic cure vs. symptom palliation) and from the significant advancements in surgical technologies that have been made over the past 2 decades. Among these advancements are improvements in surgical technique, namely minimally invasive approaches, increased availability of focused radiation modalities (e.g., proton therapy and linear accelerator devices), and new surgical technologies, such as carbon fiber-reinforced polyether ether ketone rods. In addition, several groups have described nonsurgical interventions, such as vertebroplasty and kyphoplasty for spinal instability secondary to pathologic fracture, and lesion ablation with spinal laser interstitial thermoablation, radiofrequency ablation, or cryoablation. We provide an overview of the latest technological advancements in spinal oncology and their potential usefulness for modern spinal oncologists.

Safety and efficacy of cement augmentation with fenestrated pedicle screws for tumor-related spinal instability

OBJECTIVE

Achieving rigid spinal fixation can be challenging in patients with cancer-related instability, as factors such as osteopenia, radiation, and immunosuppression adversely affect bone quality. Augmenting pedicle screws with cement is a strategy to overcome construct failure. This study aimed to assess the safety and efficacy of cement augmentation with fenestrated pedicle screws in patients undergoing posterior, open thoracolumbar surgery for spinal metastases.

METHODS

A retrospective review was performed for patients who underwent surgery for cancer-related spine instability from 2016 to 2019 at the Massachusetts General Hospital. Patient demographics, surgical details, radiographic characteristics, patterns of cement extravasation, complications, and prospectively collected Patient-Reported Outcomes Measurement Information System Pain Interference and Pain Intensity scores were analyzed using descriptive statistics. Logistic regression was performed to determine factors associated with cement extravasation.

RESULTS

Sixty-nine patients underwent open posterior surgery with a total of 502 cement-augmented screws (mean 7.8 screws per construct). The median follow-up period for those who survived past 90 days was 25.3 months (IQR 10.8-34.6 months). Thirteen patients (18.8%) either died within 90 days or were lost to follow-up. Postoperative CT was performed to assess the instrumentation and patterns of cement extravasation. There was no screw loosening, pullout, or failure. The rate of cement extravasation was 28.9% (145/502), most commonly through the segmental veins (77/145, 53.1%). Screws breaching the lateral border of the pedicle but with fenestrations within the vertebral body were associated with a higher risk of leakage through the segmental veins compared with screws without any breach (OR 8.77, 95% CI 2.84-29.79; p < 0.001). Cement extravasation did not cause symptoms except in 1 patient who developed a symptomatic thoracic radiculopathy requiring decompression. There was 1 case of asymptomatic pulmonary cement embolism. Patients experienced significant pain improvement at the 3-month follow-up, with decreases in Pain Interference (mean change 15.8, 95% CI 14.5-17.1; p < 0.001) and Pain Intensity (mean change 28.5, 95% CI 26.7-30.4; p < 0.001).

CONCLUSIONS

Cement augmentation through fenestrated pedicle screws is a safe and effective option for spine stabilization in the cancer population. The risk of clinically significant adverse events from cement extravasation is very low.

Performance assessment of the metastatic spinal tumor frailty index using machine learning algorithms: limitations and future directions

OBJECTIVE

Frailty is recognized as an important consideration in patients with cancer who are undergoing therapies, including spine surgery. The definition of frailty in the context of spinal metastases is unclear, and few have studied such markers and their association with postoperative outcomes and survival. Using national databases, the metastatic spinal tumor frailty index (MSTFI) was developed as a tool to predict outcomes in this specific patient population and has not been tested with external data. The purpose of this study was to test the performance of the MSTFI with institutional data and determine whether machine learning methods could better identify measures of frailty as predictors of outcomes.

METHODS

Electronic health record data from 479 adult patients admitted to the Massachusetts General Hospital for metastatic spinal tumor surgery from 2010 to 2019 formed a validation cohort for the MSTFI to predict major complications, in-hospital mortality, and length of stay (LOS). The 9 parameters of the MSTFI were modeled in 3 machine learning algorithms (lasso regularization logistic regression, random forest, and gradient-boosted decision tree) to assess clinical outcome prediction and determine variable importance. Prediction performance of the models was measured by computing areas under the receiver operating characteristic curve (AUROCs), calibration, and confusion matrix metrics (positive predictive value, sensitivity, and specificity) and was subjected to internal bootstrap validation.

RESULTS

Of 479 patients (median age 64 years [IQR 55-71 years]; 58.7% male), 28.4% had complications after spine surgery. The in-hospital mortality rate was 1.9%, and the mean LOS was 7.8 days. The MSTFI demonstrated poor discrimination for predicting complications (AUROC 0.56, 95% CI 0.50-0.62) and in-hospital mortality (AUROC 0.69, 95% CI 0.54-0.85) in the validation cohort. For postoperative complications, machine learning approaches showed a greater advantage over the logistic regression model used to develop the MSTFI (AUROC 0.62, 95% CI 0.56-0.68 for random forest vs AUROC 0.56, 95% CI 0.50-0.62 for logistic regression). The random forest model had the highest positive predictive value (0.53, 95% CI 0.43-0.64) and the highest negative predictive value (0.77, 95% CI 0.72-0.81), with chronic lung disease, coagulopathy, anemia, and malnutrition identified as the most important predictors of postoperative complications.

CONCLUSIONS

This study highlights the challenges of defining and quantifying frailty in the metastatic spine tumor population. Further study is required to improve the determination of surgical frailty in this specific cohort.