With continued improvements in systemic cancer therapies, there has been an increase in the survivorship of patients with spinal metastases. However, many patients with spinal metastases are frail and may not be able to tolerate the morbidity of open surgery. For these patients, percutaneous ablation techniques offer a minimally invasive approach that can facilitate local tumor control and pain relief. Here we describe the currently employed modalities—radiofrequency ablation (RFA), microwave ablation (MWA), cryoablation, and laser interstitial thermal therapy (LITT)—summarize the clinical support for their use, and overview the relative risks and benefits for each. All these technologies offer to help improve local tumor control and improve oncologic pain associated with vertebral metastases, and they have become a staple of multidisciplinary spine metastasis care at many centers. As clinical experience with these technologies continues to grow, their use will likely become more widely adopted, and so understanding of their indications, risks, and benefits will become increasingly important to the practicing spine oncologist.
Utilization of Machine Learning to Model Important Features of 30-day Readmissions following Surgery for Metastatic Spinal Column Tumors: The Influence of Frailty
Study Design Retrospective cohort study Objective The aim of this study was to determine the relative importance and predicative power of the Hospital Frailty Risk Score (HFRS) on unplanned 30-day readmission after surgical intervention for metastatic spinal column tumors. Methods All adult patients undergoing surgery for metastatic spinal column tumor were identified in the Nationwide Readmission Database from the years 2016 to 2018. Patients were categorized into 3 cohorts based on the criteria of the HFRS: Low(<5), Intermediate(5-14.9), and High(≥ 15). Random Forest (RF) classification was used to construct predictive models for 30-day patient readmission. Model performance was examined using the area under the receiver operating curve (AUC), and the Mean Decrease Gini (MDG) metric was used to quantify and rank features by relative importance. Results There were 4346 patients included. The proportion of patients who required any readmission were higher among the Intermediate and High frailty cohorts when compared to the Low frailty cohort ( Low:33.9% vs. Intermediate:39.3% vs. High:39.2%, P < .001). An RF classifier was trained to predict 30-day readmission on all features (AUC = .60) and architecturally equivalent model trained using only ten features with highest MDG (AUC = .59). Both models found frailty to have the highest importance in predicting risk of readmission. On multivariate regression analysis, Intermediate frailty [ OR:1.32, CI(1.06,1.64), P = .012] was found to be an independent predictor of unplanned 30-day readmission. Conclusion Our study utilizes machine learning approaches and predictive modeling to identify frailty as a significant risk-factor that contributes to unplanned 30-day readmission after spine surgery for metastatic spinal column metastases.
Hospital Frailty Risk Score and Healthcare Resource Utilization After Surgery for Primary Spinal Intradural/Cord Tumors
Objective The Hospital Frailty Risk Score (HFRS) is a metric that measures frailty among patients in large national datasets using ICD-10 codes. While other metrics have been utilized to demonstrate the association between frailty and poor outcomes in spine oncology, none have examined the HFRS. The aim of this study was to investigate the impact of frailty using the HFRS on complications, length of stay, cost of admission, and discharge disposition in patients undergoing surgery for primary tumors of the spinal cord and meninges. Methods A retrospective cohort study was performed using the Nationwide Inpatient Sample database from 2016 to 2018. Adult patients undergoing surgery for primary tumors of the spinal cord and meninges were identified using ICD-10-CM codes. Patients were categorized into 2 cohorts based on HFRS score: Non-Frail (HFRS<5) and Frail (HFRS≥5). Patient characteristics, treatment, perioperative complications, LOS, discharge disposition, and cost of admission were assessed. Results Of the 5955 patients identified, 1260 (21.2%) were Frail. On average, the Frail cohort was nearly 8 years older ( P < .001) and experienced more postoperative complications ( P = .001). The Frail cohort experienced longer LOS ( P < .001), a higher rate of non-routine discharge ( P = .001), and a greater mean cost of admission ( P < .001). Frailty was found to be an independent predictor of extended LOS ( P < .001) and non-routine discharge ( P < .001). Conclusion Our study is the first to use the HFRS to assess the impact of frailty on patients with primary spinal tumors. We found that frailty was associated with prolonged LOS, non-routine discharge, and increased hospital costs.
Nerve Root Sparing En Bloc Resection of Sacral Chondrosarcoma: Technical Note and Review of the Literature
Abstract BACKGROUND Total en bloc sacrectomy provides the best long-term local control for large primary bony sacral tumors, but often requires lumbosacral nerve root sacrifice leading to loss of ambulation and/or bowel, bladder, and/or sexual dysfunction. Nerve-sparing techniques may be an option for some patients that avoid these outcomes and accordingly improve postoperative quality of life. OBJECTIVE To describe the technique for a posterior-only en bloc hemisacrectomy with maximal nerve root preservation and to summarize the available literature. METHODS A 38-yr-old woman with a 7.7 × 5.4 × 4.5 cm biopsy-proven grade 2 chondrosarcoma involving the left L5-S2 posterior elements underwent a posterior-only left hemisacrectomy tri-rod L3-pelvis fusion. A systematic review of the English literature was also conducted to identify other descriptions of high sacrectomy with distal sacral nerve root preservation. RESULTS Computer-aided navigation facilitated an extracapsular resection that allowed preservation of the left-sided L5 and S3-Co roots. Negative margins were achieved and postoperatively the patient retained ambulation and good bowel/bladder function. Imaging at 9-mo follow-up showed no evidence of recurrence. The systematic review identified 4 prior publications describing 6 total patients who underwent nerve-sparing sacral resection. Enneking-appropriate resection was only obtained in 1 case though. CONCLUSION Here we describe a technique for distal sacral nerve root preservation during en bloc hemisacrectomy for a primary sacral tumor. Few prior descriptions exist, and the present technique may help to reduce the neurological morbidity of sacral tumor surgery.
Impact of Racial Disparities on All-Cause Mortality in Patients With Tumors of the Spinal Cord or Spinal Meninges: A Propensity-Score Analysis
Study Design: Retrospective cohort study. Objective: The influence that race has on mortality rates in patients with spinal cord tumors is relatively unknown. The aim of this study was to investigate the influence of race on the outcomes of patients with primary malignant or nonmalignant tumors of the spinal cord or spinal meninges. Methods: The Surveillance, Epidemiology, and End Results (SEER) Registry was used to identify all patients with a code for primary malignant or nonmalignant tumor of the spinal cord (C72.0) or spinal meninges (C70.1) from 1973 through 2016. Racial groups (African-American/Black vs. White) were balanced using propensity-score (PS) matching using a non-parsimonious 1:1 nearest neighbor matching algorithm. Overall survival (OS) estimates were obtained using the Kaplan-Meier method and compared across non-PS-matched and PS-matched groups using log-rank tests. Associations of survival with clinical variables was assessed using doubly robust Cox proportional-hazards (CPH) regression analysis. Results: There were a total of 7,498 patients identified with 648 (6.8%) being African American. African-American patients with primary intradural spine tumors were more likely to die of all causes than were White patients in both the non-PS-matched [HR: 1.26, 95% CI: (1.04, 1.51), P = 0.01] and PS-matched cohorts [HR: 1.64, 95% CI: (1.28, 2.11), P < 0.0001]. On multivariate CPH regression analysis age at diagnosis [HR: 1.03, 95% CI: (1.02, 1.05), P < 0.0001], race [HR: 1.82, 95% CI: (1.22, 2.74), P = 0.004), and receipt of RT [HR: 2.62, 95% CI: (1.56, 4.37), P = 0.0002) were all significantly associated with all-cause mortality, when controlling for other demographic, tumor, and treatment variables. Conclusions: Our study provides population-based estimates of the prognosis for patients with primary malignant or nonmalignant tumors of the spinal cord or spinal meninges and suggests that race may impact all-cause mortality.