The surgical treatment of metastatic disease of the spine

Does Timing of Radiation Therapy Impact Wound Healing in Patients Undergoing Metastatic Spine Surgery?

INTRODUCTION

The impact of radiation on wound healing after metastatic spine surgery remains an active area of research. In patients undergoing metastatic spine surgery, we sought to (1) assess the relationship between preoperative and/or postoperative radiation on wound complications, and (2) evaluate the relationship between the timing of postoperative radiation and wound complications.

METHODS

A single-center, retrospective, cohort study of patients undergoing metastatic spine surgery was conducted from 2010 to 2021. The primary exposure variable was the use/timing of radiation. Radiation included both external beam radiotherapy (EBRT) and stereotactic body radiotherapy (SBRT). Patients were trichotomized into the following groups: (1) preoperative radiation only, (2) postoperative radiation only, and (3) no radiation. The primary outcome variable was wound complications, which was defined as dehiscence requiring reoperation, infection requiring antibiotics, or infection requiring surgical debridement. Multivariable logistic/linear regression controlled for age, tumor size, primary organ of origin, and the presence of other organ metastases.

RESULTS

A total of 207 patients underwent surgery for extradural spinal metastasis. Participants were divided into three groups: preoperative RT only (N = 29), postoperative RT only (N = 91), and no RT (N = 178). Patients who received postoperative RT only and no RT were significantly older than patients who received preoperative RT only (p = 0.009) and were less likely to be white (p < 0.001). No other significant differences were found in basic demographics, tumor characteristics, or intraoperative variables. Wound-related complications occurred in two (6.9%) patients with preoperative RT only, four patients (4.4%) in postoperative RT only, and 11 (6.2%) patients with no RT, with no significant difference among the three groups (p = 0.802). No significant difference was found in wound-related complications, reoperation, and time to wound complications between patients with preoperative RT only and no RT, and between postoperative RT only and no RT (p > 0.05). Among the postoperative-RT-only group, no difference in wound complications was seen between those receiving SBRT (5.6%) and EBRT (4.1%) (p > 0.999). However, patients who received preoperative RT only had a longer time to wound complications in comparison to those who received postoperative RT only (43.5 ± 6.3 vs. 19.7 ± 3.8, p = 0.004). Regarding timing of postoperative RT, the mean (SD) time to RT was 28.7 ± 10.0 days, with a median of 28.7 (21-38) days. No significant difference was found in time to postoperative RT between patients with and without wound complications (32.9 ± 12.3 vs. 29.0 ± 9.7 days, p = 0.391).

CONCLUSION

In patients undergoing metastatic spine surgery, a history of previous RT or postoperative RT did not significantly affect wound complications. However, those with previous RT prior to surgery had a longer time to wound complications than patients undergoing postoperative RT only. Moreover, timing of RT had no impact on wound complications, indicating that earlier radiation may be safely employed to optimize tumor control without fear of compromising wound healing.

Diagnostic Approach and Differences between Spinal Infections and Tumors

STUDY DESIGN

A systematic review of the literature about differential diagnosis between spine infection and bone tumors of the spine.

BACKGROUND AND PURPOSE

The differential diagnosis between spine infection and bone tumors of the spine can be misled by the prevalence of one of the conditions over the other in different areas of the world. A review of the existing literature on suggestive or even pathognomonic imaging aspects of both can be very useful for correctly orientating the diagnosis and deciding the most appropriate area for biopsy. The purpose of our study is to identify which imaging technique is the most reliable to suggest the diagnosis between spine infection and spine bone tumor.

METHODS

A primary search on Medline through PubMed distribution was made. We identified five main groups: tuberculous, atypical spinal tuberculosis, pyogenic spondylitis, and neoplastic (primitive and metastatic). For each group, we evaluated the commonest localization, characteristics at CT, CT perfusion, MRI, MRI with Gadolinium, MRI diffusion (DWI) and, in the end, the main features for each group.

RESULTS

A total of 602 studies were identified through the database search and a screening by titles and abstracts was performed. After applying inclusion and exclusion criteria, 34 articles were excluded and a total of 22 full-text articles were assessed for eligibility. For each article, the role of CT-scan, CT-perfusion, MRI, MRI with Gadolinium and MRI diffusion (DWI) in distinguishing the most reliable features to suggest the diagnosis of spine infection versus bone tumor/metastasis was collected.

CONCLUSION

Definitive differential diagnosis between infection and tumor requires biopsy and culture. The sensitivity and specificity of percutaneous biopsy are 72% and 94%, respectively. Imaging studies can be added to address the diagnosis, but a multidisciplinary discussion with radiologists and nuclear medicine specialists is mandatory.

Establishing the Swiss Spinal Tumor Registry (Swiss-STR): a prospective observation of surgical treatment patterns and long-term outcomes in patients with primary and metastatic spinal tumors

Background

Tumors of the vertebral column consist of primary spinal tumors and malignancies metastasizing to the spine. Although primary spine tumors are rare, metastases to the spine have gradually increased over past decades because of aging populations and improved survival for various cancer subtypes achieved by advances in cancer therapy. Metastases to the vertebral column occur in up to 70% of cancer patients, with 10% of patients demonstrating epidural spinal cord compression. Therefore, many cancer patients may face spinal surgical intervention during their chronic illness; such interventions range from simple cement augmentation over decompression of neural elements to extended instrumentation or spinal reconstruction. However, precise surgical treatment guidelines do not exist, likely due to the lack of robust, long-term clinical outcomes data and the overall heterogeneous nature of spinal tumors. Objectives of launching the Swiss Spinal Tumor Registry (Swiss-STR) are to collect and analyze high-quality, prospective, observational data on treatment patterns, clinical outcomes, and health-related quality of life (HRQoL) in adult patients undergoing spinal tumor surgery. This narrative review discusses our rationale and process of establishing this spinal cancer registry.

Methods

A REDCap-based registry was created for the standardized collection of clinical, radiographic, surgical, histological, radio-oncologial and oncological variables, as well as patient-reported outcome measures (PROMs).

Discussion

We propose that the Swiss-STR will inform on the effectiveness of current practices in spinal oncology and their impact on patient outcomes. Furthermore, the registry will enable better categorization of the various clinical presentations of spinal tumors, thereby facilitating treatment recommendations, defining the socio-economic burden on the healthcare system, and improving the quality of care. In cases of rare tumors, the multi-center data pooling will fill significant data gaps to yield better understanding of these entities. Finally, our two-step approach first implements a high-quality registry with efficient electronic data capture strategies across hospital sites in Switzerland, and second follows with potential to expand internationally, thus fostering future international scientific collaboration to further push the envelope in cancer research.

A Novel Prognostication System for Spinal Metastasis Patients Based on Network Science and Correlation Analysis

AIMS

During the progress of oncological diseases, there is an increased probability that spinal metastases may develop, requiring personalised treatment options. Risk calculator systems aim to provide assistance in the therapeutic decision-making process by estimating survival chances. The predictive ability of such calculators can be improved, thereby optimising the choice of personalised therapy. The aim of this research was to create a new risk assessment system and show a method with which other centres can develop their own local score.

MATERIALS AND METHODS

We created a database by retrospectively processing 454 patients. The prognostic factors were selected via a network science-based correlation analysis that maximises Uno's C-index, keeping only a small number of predictors. To validate the new system, we calculated the D-statistic, the Integrated Discrimination Index, made a five-fold cross-validation and also calculated the integrated time-dependent Brier score.

RESULTS

As a result of multivariate Cox analysis, we found five independent prognostic factors suitable for the design of the risk calculator. This new system has a better predictive ability compared with six other well-known systems with an average C-index of 0.706 at 10 years (95% confidence interval 0.679-0.733).

CONCLUSIONS

An accurate estimation of the life expectancy of cancer patients is essential for the implementation of personalised medicine. The training performance of our system is encouraging, indicating the benefit of a network science-based visualisation step. We believe that in order to further improve the prediction ability, it is necessary to systematise previously 'unknown' factors (e.g. radiological morphology).

Development and external validation of predictive algorithms for six-week mortality in spinal metastasis using 4,304 patients from five institutions

BACKGROUND CONTEXT

Historically, spine surgeons used expected postoperative survival of 3-months to help select candidates for operative intervention in spinal metastasis. However, this cutoff has been challenged by the development of minimally invasive techniques, novel biologics, and advanced radiotherapy. Recent studies have suggested that a life expectancy of 6 weeks may be enough to achieve significant improvements in postoperative health-related quality of life.

PURPOSE

The purpose of this study was to develop a model capable of predicting 6-week mortality in patients with spinal metastases treated with radiation or surgery.

STUDY DESIGN/SETTING

A retrospective review was conducted at five large tertiary centers in the United States and Taiwan.

PATIENT SAMPLE

The development cohort consisted of 3,001 patients undergoing radiotherapy and/or surgery for spinal metastases from one institution. The validation institutional cohort consisted of 1,303 patients from four independent, external institutions.

OUTCOME MEASURES

The primary outcome was 6-week mortality.

METHODS

Five models were considered to predict 6-week mortality, and the model with the best performance across discrimination, calibration, decision-curve analysis, and overall performance was integrated into an open access web-based application.

RESULTS

The most important variables for prediction of 6-week mortality were albumin, primary tumor histology, absolute lymphocyte, three or more spine metastasis, and ECOG score. The elastic-net penalized logistic model was chosen as the best performing model with AUC 0.84 on evaluation in the independent testing set. On external validation in the 1,303 patients from the four independent institutions, the model retained good discriminative ability with an area under the curve of 0.81. The model is available here: https://sorg-apps.shinyapps.io/spinemetssurvival/.

CONCLUSIONS

While this study does not advocate for the use of a 6-week life expectancy as criteria for considering operative management, the algorithm developed and externally validated in this study may be helpful for preoperative planning, multidisciplinary management, and shared decision-making in spinal metastasis patients with shorter life expectancy.

Prognostic Factors for Bone Survival and Functional Outcomes in Patients With Breast Cancer Spine Metastases

According to the Global Cancer Statistics 2020 report, breast cancer is the most commonly diagnosed cancer worldwide. Patients with mammary cancer live longer due to the continuous optimization of chemotherapy, targeted drugs, and hormone therapy, which will inevitably lead to an increase in the prevalence of metastatic bone tumors. Bone metastasis affects approximately 8% of patients with mammary cancer, with the spine being the most common site. Metastatic neoplasms can invade the centrum and its attachments, leading to local pain, spinal instability, vertebral pathological fractures, spinal cord compression, impaired neurological function, and paralysis, ultimately reducing the quality of life. Multidisciplinary and personalized management using analgesic drugs, endocrine therapy, corticosteroid therapy, chemotherapy, bisphosphonates, immunotherapy, targeted drugs, radiotherapy, and surgery has been advocated for the treatment of spinal metastases. Multiple paradigms and systems have been proposed to determine suitable treatments. In the early stages, the occurrence of metastasis indicates a terminal stage of the tumor process in patients with malignant tumors, implying that their lifespan is limited. As a result, the choice of treatment is heavily influenced by longevity. However, with the development of treatment methods, the lifespan of patients with tumors has considerably increased in recent years. This leads to the choice of patient's treatment, which depends not only on the patient's survival, but also on the radiotherapy or postoperative functional outcomes. Nevertheless, they fall short of determining the variables that affect survival and functional outcomes in histology-specific subgroups of breast cancer. To accurately predict the bone survival and functional outcomes of patients with breast cancer spine metastases a review of prognostic factors was performed.

Differential immune landscapes in appendicular versus axial skeleton

Roughly 400,000 people in the U.S. are living with bone metastases, the vast majority occurring in the spine. Metastases to the spine result in fractures, pain, paralysis, and significant health care costs. This predilection for cancer to metastasize to the bone is seen across most cancer histologies, with the greatest incidence seen in prostate, breast, and lung cancer. The molecular process involved in this predilection for axial versus appendicular skeleton is not fully understood, although it is likely that a combination of tumor and local micro-environmental factors plays a role. Immune cells are an important constituent of the bone marrow microenvironment and many of these cells have been shown to play a significant role in tumor growth and progression in soft tissue and bone disease. With this in mind, we sought to examine the differences in immune landscape between axial and appendicular bones in the normal noncancerous setting in order to obtain an understanding of these landscapes. To accomplish this, we utilized mass cytometry by time-of-flight (CyTOF) to examine differences in the immune cell landscapes between the long bone and vertebral body bone marrow from patient clinical samples and C57BL/6J mice. We demonstrate significant differences between immune populations in both murine and human marrow with a predominance of myeloid progenitor cells in the spine. Additionally, cytokine analysis revealed differences in concentrations favoring a more myeloid enriched population of cells in the vertebral body bone marrow. These differences could have clinical implications with respect to the distribution and permissive growth of bone metastases.

Clinical outcomes of dose-escalated hypofractionated external beam radiotherapy (5 Gy x 5 fractions) for spine metastasis

Purpose

Methods and Materials

Results

Conclusions

Cement-Augmented Carbon Fiber-Reinforced Pedicle Screw Instrumentation for Spinal Metastases: Safety and Efficacy

OBJECTIVE

To investigate the complication rates and long-term implant failure rates in a monocentric study of a consecutive cohort of patients with thoracolumbar spinal metastases after posterior instrumentation with a fenestrated carbon fiber-reinforced poly-ether-ether-ketone (CFRP) pedicle screw system.

METHODS

We retrospectively reviewed demographics, Karnofsky Performance Status Scale scores, complications, and implant failure rates.

RESULTS

Between June 2016 and November 2019, 51 consecutive patients underwent cement-augmented CFRP pedicle screw instrumentation at our institution. Mean age was 68 years (standard deviation 10.5), the median preoperative Karnofsky Performance Status Scale of 80 increased to 90 postoperatively (P = 0.471). Most common primary entities were breast (25.5%), lung (15.7%), and prostate (13.7%) cancers. Of 428 placed screws, 293 (68.5%) were augmented with polymethylmethacrylate, a mean 6 per patient (standard deviation ±2). Screws were inserted via a minimally invasive system technique in 54.9% of cases. In total, 11.8% of patients had immediate postoperative sequelae related to the cement. Pulmonary cement embolisms were noted in 3 patients, 2 had paravertebral extravasation, and 1 had an embolism into a segmental artery. Of these 6, 2 patients with pulmonary embolisms reported related symptoms. Follow-up was available for 80.4%. After a mean 9.8 months, screw loosening was noted in 11.8% of cases on computed tomography, although it was asymptomatic in all but 1 patient. Screw pull-out did not occur. Neither cement-related (P = 0.353) nor general complication rates (P = 0.507) differed significantly between open and minimally invasive system techniques.

CONCLUSIONS

Percutaneous cement-augmented CFRP pedicle screw instrumentation facilitates artifact-reduced postoperative imaging, while maintaining a risk profile and implant failure rates comparable to conventional metallic instrumentation.

Dura promotes metastatic potential in prostate cancer through the CXCR2 pathway

PURPOSE

Spinal metastases are common in cancer. This preferential migration/growth in the spine is not fully understood. Dura has been shown to affect the surrounding microenvironment and promote cancer growth. Here, we investigate the role of dural cytokines in promoting the metastatic potential of prostate cancer (PCa) and the involvement of the CXCR2 signaling pathway.

METHODS

The role of dural conditioned media (DCM) in proliferation, migration and invasion of five PCa cell lines with various hormone sensitivities was assessed in the presence or absence of the CXCR2 inhibitor, SB225002. CXCR2 surface protein was examined by FACS. Cytokine levels were measured using a mouse cytokine array.

RESULTS

We observed high levels of cytokines produced by dura and within the vertebral body bone marrow, namely CXCL1 and CXCL2, that act on the CXCR2 receptor. All prostate cell lines treated with DCM demonstrated significant increase in growth, migration and invasion regardless of androgen sensitivity, except PC3, which did not significantly increase in invasiveness. When treated with SB225002, the growth response to DCM by cells expressing the highest levels of CXCR2 as measured by FACS (LNCaP and 22Rv1) was blunted. The increase in migration was significantly decreased in all lines in the presence of SB225002. Interestingly, the invasion increase seen with DCM was unchanged when these cells were treated with the CXCR2 inhibitor, except PC3 did demonstrate a significant decrease in invasion.

CONCLUSION

DCM enhances the metastatic potential of PCa with increased proliferation, migration and invasion. This phenomenon is partly mediated through the CXCR2 pathway.

Comprehensive surgical treatment strategy for spinal metastases

The management of patients with spinal metastases (SM) requires a multidisciplinary team of specialists involved in oncological care. Surgical management has evolved significantly over the recent years, which warrants reevaluation of its role in the oncological treatment concept. Any patient with a SM was screened for study inclusion. We report baseline characteristics, surgical procedures, complication rates, functional status and outcome of a large consecutive cohort undergoing surgical treatment according to an algorithm. 667 patients underwent 989 surgeries with a mean age of 65 years (min/max 20–94) between 2007 and 2018. The primary cancers mostly originated from the prostate (21.7%), breast (15.9%) and lung (10.0%). Surgical treatment consisted of dorsoventral stabilization in 69.5%, decompression without instrumentation in 12.5% and kyphoplasty in 18.0%. Overall survival reached 18.4 months (95% CI 9.8–26.9) and the median KPS increased by 10 within hospital stay. Surgical management of SMs should generally represent the first step of a conclusive treatment algorithm. The need to preserve long-term symptom control and biomechanical stability requires a surgical strategy currently not supported by level I evidence.

Patient outcomes and survival following surgery for spinal metastases

Context: There is no consensus on the preferred treatment for patients with spinal metastases. Little is known about the outcomes of surgery for this population. The objectives of this paper are to examine the outcomes of surgery among patients with spinal metastases suffering from cord compression (CC) or intractable pain (IP).Design: Retrospective, descriptive (level 4) case series.Setting: Rabin Medical Center, Israel.Participants: 61 patients undergoing surgery for spinal metastasis in a tertiary care hospital. Patients were divided into two groups: those with spinal CC and those with IP only.Interventions: Surgery due to CC or IP among patients with spinal metastases.Outcome measures: Frankel scale to assess neurological status, ambulatory and incontinence status, which were examined before surgery, at discharge and at last follow-up. Endpoints were death or latest follow-up visit. Survival and postoperative complications were documented.Results: There was no significant difference in Frankel score before and after surgery among patients with CC (mean score 3.5 and 3.4 respectively, P = 0.62). Complete incontinence rates significantly increased in patients with CC between preoperative and last follow-up examinations (13.6% vs. 20%, respectively, P = 0.05). Median survival of CC and IP groups was 201 and 402 days, respectively (P = 0.32). Complication rate was 41.4%.Conclusion: In our cohort, Frankel score and walking capability of patients with CC did not change postoperatively, but continence status deteriorated over time. Surgeons should advise patients on expected surgical outcomes, especially in non-ambulatory and incontinent patients.

Features of Spinal Metastases: A Retrospective View

BACKROUND

The present study aimed to determine the frequency of spinal metastases, to evaluate the features of spinal metastases, and to reveal clues to shed light on the origin of spinal metastases with unknown primary.

METHODS

The data of patients who were followed up with the diagnosis of cancer in Istanbul Oncology Hospital between 2017 and 2019 were analyzed retrospectively. A total of 156 patients with spinal metastases and without visceral metastases were included in the study by applying inclusion and exclusion criteria. Clinical data, pathological diagnostic reports, and positron emission tomography-computed tomography results of 156 patients were evaluated. The groups were evaluated in terms of age, gender, number of spinal metastases (single focus, multiple focus), and localization of spinal metastasis. The spinal localization evaluation included both the main anatomical localizations and a detailed evaluation of each spine.

RESULTS

The most common metastasis region was the thoracic spine in respiratory system cancers (28.38%), the thoracic + lumbar spine in breast (42.42%), prostate (50.00%), and gynecologic (40.00%) cancers, and the lumbar spine in gastrointestinal (37.50%) and urinary (30.00%) tract cancers (P = .313). C5 spinal metastasis percentages were significantly higher in breast and gastrointestinal tract cancers than the others (P = .042). T5 spinal metastasis percentage was significantly higher in gynecologic tumors than in the other cancers (P = .002). T10 spinal metastasis percentages were significantly higher in prostate and gynecologic tumors than the others (P = .016). L1 spinal metastasis percentage was significantly higher in breast tumors (P = .009). L2 spinal metastasis percentages were significantly higher in breast, prostate, and gynecologic tumors (P = .011). L4 spinal metastasis percentages were significantly higher in breast and prostate tumors (P = .041). L5 spinal metastasis percentage was significantly higher in prostate tumors (P = .029) than the other cancers.

CONCLUSIONS

It was observed that primary cancers were often prone to metastasis to nearby spine. The results obtained by detailed examination of spinal metastases may provide a clinical benefit by providing clues in investigation of primary unknown cancers.

LEVEL OF EVIDENCE

3.

Percutaneous thermal ablation of sacral metastases: Assessment of pain relief and local tumor control

PURPOSE

To retrospectively report on safety, pain relief and local tumor control achieved with percutaneous ablation of sacral bone metastases.

MATERIALS AND METHODS

From February 2009 to June 2020, 23 consecutive patients (12 women and 11 men; mean age, 60±8 [SD] years; median, 60; range: 48-80 years) with 23 sacral metastases underwent radiofrequency (RFA) or cryo-ablation (CA), with palliative or curative intent at our institution. Patients' demographics and data pertaining to treated metastases, procedure-related variables, safety, and clinical evolution following ablation were collected and analyzed. Pain was assessed with numerical pain rating scale (NPRS).

RESULTS

Sixteen (70%) patients were treated with palliative and 7 (30%) with curative intent. Mean tumor diameter was 38±19 (SD) mm (median, 36; range: 11-76). External radiation therapy had been performed on five metastases (5/23; 22%) prior to ablation. RFA was used in 9 (39%) metastases and CA in the remaining 14 (61%). Thermo-protective measures and adjuvant bone consolidation were used whilst treating 20 (87%) and 8 (35%) metastases, respectively. Five (22%) minor complications were recorded. At mean 31±21 (SD) (median, 32; range: 2-70) months follow-up mean NPRS was 2±2 (SD) (median, 1; range: 0-6) vs. 5±1 (median, 5; range: 4-8; P<0.001) at the baseline. Three metastases out of 7 (43%) undergoing curative ablation showed local progression at mean 4±4 (SD) (median, 2; range: 1-8) months follow-up.

CONCLUSION

Percutaneous ablation of sacral metastases is safe and results in significant long-lasting pain relief. Local tumor control seems sub-optimal; however, further investigations are needed to confirm these findings due to paucity of data.

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

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

Initial Report of an Intradural Extramedullary Metastasis of a Pancreatic Neuroendocrine Tumor to the Cervical Spine: A Case Report and Review of the Literature

BACKGROUND

Pancreatic neuroendocrine tumors (pNETs) are known to frequently metastasize to the liver and lymphatics; however, metastasis to the spine is exceedingly rare. We report the first case of an intradural, extramedullary pNET metastasis to the upper cervical spine.

CASE DESCRIPTION

A 75-year-old Hispanic male patient with history of stage IV pNET with metastasis to the liver and lymph nodes and new-onset lymphadenopathy seen on CT of the chest was found on positron emission tomography scan to have a lesion in the cervical spine. The patient was neurologically intact on physical examination, yet given the patient's medical history, magnetic resonance imaging of the cervical spine was performed, revealing a right-sided intradural, extramedullary mass at the C1-C2 level with associated mass effect on the spinal cord, likely representing a schwannoma. Due to the tumor size, mass effect, and the need for definitive tissue diagnosis, a partial C1-C2 laminectomy with intradural resection of the tumor was performed. The histology was consistent with the patient's known pNET.

CONCLUSIONS

As treatment for pNETs has evolved, there has been a surge in unique presentations of systemic well-differentiated pNETs being reported. It is vital that patients diagnosed with pNET be monitored for metastases, and when discovered, treated promptly.

Clinical outcomes and significant factors in the survival rate after decompression surgery for patients who were non-ambulatory due to spinal metastases

BACKGROUND

The development of effective chemotherapy regimens and molecular targeting agents are improving the overall survival rates in patients with cancer. However, patients who are non-ambulatory due to metastatic epidural spinal cord compression (MESCC) may be assessed as unable to tolerate chemotherapy secondary to poor performance status. This means that the ambulatory status of patients with cancer might be significant for survival time.

METHODS

We investigated the functional outcomes and factors influencing overall survival in 31 patients who were non-ambulatory due to MESCC and underwent decompression surgery. The functional outcome was determined by the Frankel grading system.

RESULT

Twenty-one patients (68%) improved by at least 1 Frankel grade; 17 patients (55%) became ambulatory postoperatively. Most of postoperatively ambulatory patients could undergo postoperative chemotherapy (14/17, 82%). On the other hand, only a few postoperatively non-ambulatory patients could undergo postoperative chemotherapy (2/15, 13%). We observed a complication rate of 35.5% with specific complications including wound infection, pneumonia, and deep vein thrombosis/pulmonary embolus. The median survival duration was 7.0 months. Factors that significantly affected the overall survival in univariate analyses were revised Tokuhashi score (RTS) ≥ 4, postoperative chemotherapy, ambulatory status, and complications (RTS ≥ 4, P < 0.05; postoperative chemotherapy, P < 0.001; ambulatory status, P < 0.001; complications, P < 0.01).

CONCLUSIONS

Decompression surgery for patients who are non-ambulatory due to MESCC directly contributes to functional outcomes and may indirectly contribute to overall survival. If non-ambulatory patients who are assessed as unable to tolerate chemotherapy due to poor performance status regain the ability to walk by decompression surgery, they will have a chance to receive postoperative chemotherapy, thereby increasing their chances of prolonging survival. However, postoperative complications may shorten their survival; therefore, we should carefully consider the surgical indications. RTS is useful for judging the surgical indication.

Instrumentation Failure after Partial Corpectomy with Instrumentation of a Metastatic Spine

OBJECTIVE

To identify the perioperative factors associated with instrument failure in patients undergoing a partial corpectomy with instrumentation (PCI) for spinal metastasis.

METHODS

We assessed the one hundred twenty-four patients with who underwent PCI for a metastatic spine from 1987 to 2011. Outcome measure was the risk factor related to implantation failure. The preoperative factors analyzed were age, sex, ambulation, American Spinal Injury Association grade, bone mineral density, use of steroid, primary tumor site, number of vertebrae with metastasis, extra-bone metastasis, preoperative adjuvant chemotherapy, and preoperative spinal radiotherapy. The intraoperative factors were the number of fixed vertebrae, fixation in osteolytic vertebrae, bone grafting, and type of surgical approach. The postoperative factors included postoperative adjuvant chemotherapy and spinal radiotherapy. This study was supported by the National Research Foundation grant funded by government. There were no study-specific biases related to conflicts of interest.

RESULTS

There were 15 instrumentation failures (15/124, 12.1%). Preoperative ambulatory status and primary tumor site were not significantly related to the development of implant failure. There were no significant associations between insertion of a bone graft into the partial corpectomy site and instrumentation failure. The preoperative and operative factors analyzed were not significantly related to instrumentation failure. In univariable and multivariable analyses, postoperative spinal radiotherapy was the only significant variable related to instrumentation failure (p=0.049 and 0.050, respectively).

CONCLUSION

When performing PCI in patients with spinal metastasis followed by postoperative spinal radiotherapy, the surgeon may consider the possibility of instrumentation failure and find other strategies for augmentation than the use of a bone graft for fusion.

Functional and survival outcomes in patients undergoing surgical treatment for metastatic disease of the spine

Background

Retrospective review of a prospective database. Spine metastasis has been shown to occur in 40% of cancer patients with an annual incidence of over 18,000 cases in North America alone. In this study, we sought to explore the functional and survival outcomes of patients undergoing surgical treatment for metastatic disease of the spine.

Methods

A retrospective cohort study of a prospective database at a major cancer center was conducted. A total of 55 patients who met the inclusion criteria from January 2010 to December 2015 were included. Functional status was assessed through patient's ambulatory status. Patient and tumor characteristics were analyzed and regression analyses were performed.

Results

Renal cell carcinoma (RCC) was the most common subtype encountered (27.3%). Excluding patients who had spinal metastasis at time of diagnosis, the median time to spinal metastasis from cancer diagnosis was 2.5 years. Median overall survival (OS) time was 1.8 years post diagnosis and 1.6 years post-surgical intervention. Age and tumor subtype were independent predictors of death (P<0.05). Post-surgical intervention, only 3.6% of patients were unable to ambulate-an improvement from 12.7% seen in the immediate preoperative period, P=0.0253. However, at the time of final follow-up, this number had risen to nearly 37%, P<0.0001.

Conclusions

Spinal metastasis portends a debilitating prognosis. Ambulatory status is improved or maintained in the post-surgical period. However, long-term outlook remains dismal with median survival at only 1.8 years following diagnosis of spinal metastasis and ambulatory status declining precipitously at the time of final follow-up.

Treatment plan quality and delivery accuracy assessments on 3 IMRT delivery methods of stereotactic body radiotherapy for spine tumors

Stereotactic body radiotherapy (SBRT) for spine tumors has demonstrated clinical effectiveness. The treatment planning and delivery techniques have evolved from dynamic conformal arc therapy, to fixed gantry angle intensity modulated radiotherapy (IMRT), and most recently to volumetric modulated arc therapy (VMAT). A hybrid-arc (HARC) planning and delivery method combining dynamic conformal arc therapy delivery with a number of equally spaced IMRT beams is proposed. In this study we investigated plan quality, delivery accuracy, and efficiency of 3 delivery techniques: IMRT, HARC, and VMAT. Patients who underwent spine SBRT treatments were randomly selected from an Institutional Review Board-approved registry. For each patient, the prescription dose was 14 to 16 Gy in a single fraction to cover >90% of the tumor (without planning margin) while constraining V_10Gy ≤ 10% of the spinal cord and the maximum point dose (MPD) of the spinal cord ≤ 14 Gy. All cases were clinically treated with fixed gantry step-shoot IMRT plans and then re-planned with VMAT using Pinnacle 9.0 and with HARC using Brainlab iPlan 4.5. Student t-test was used to compare the dosimetric end points, including V_16Gy to the planning target volume, homogeneity index, MPD_PTV, the conformity index, V_10Gy of the spinal cord, and MPD_cord. To compare the accuracy of delivery, we delivered all plans on a phantom and conducted gamma index (GI) comparisons with 3 mm/3% and 2 mm/2% criteria. All plans met our clinical requirements. Among 3 techniques, there were no differences on dose coverage to the tumor volume, maximum dose to the spinal cord, and plan homogeneity index (p > 0.05). The average V_10Gy of the spinal cord was 6.66 ± 0.03%, 5.49 ± 0.03%, and 4.76 ± 0.02% for IMRT, HARC, and VMAT plans, respectively. Accordingly, the conformity indices were 1.30 ± 0.11 and 1.29 ± 0.20, 1.53 ± 0.29, respectively. VMAT plans were significantly (p < 0.05) less conformal but significantly (p < 0.05) lower V_10Gy of the spinal cord than those from HARC and IMRT plans. With delivery accuracy measured by GIs, the average GIs of 3%/3 mm were 92.6 ± 1.1%, 96.5 ± 2.7%, 99.0 ± 1.1% for IMRT, HARC, and VMAT plans, respectively. The differences were significant (p < 0.05). Accordingly, the average monitor units were 9238 ± 2242, 9853 ± 2548 and 5091 ± 910. The plan quality created from the 3 planning techniques can meet the clinical requirement. Adding arc beams in delivery such as in HARC and VMAT plans improves the delivery accuracy. VMAT is the most efficient delivery method.

Prognostic Factors of Surgical Complications and Overall Survival of Patients with Metastatic Spinal Tumor

OBJECTIVE

Oncologic treatments increase the incidence of spinal metastases. Surgical treatment of spinal metastases results in a high complication rate, which must set against the expected benefits. The aim of this article was to study the effect of several prognostic factors on surgical complications and survival time using an extended database of patients with spinal metastases.

METHODS

This retrospective study comprised 337 patients with spinal metastases who were surgically treated between 2008 and 2015. Demographic and clinical features, oncologic histories, surgical interventions, and end results were collected. Descriptive statistical methods were used to analyze the cohort of patients. Kaplan-Meier formula and log-rank test were used to examine overall survival times.

RESULTS

Median overall survival time was 222 days (range, 175-274 days). Age, preoperative motor disorders, preoperative Frankel grade categories, Karnofsky performance scale, type of primary tumor, and presence of internal metastasis had a significant negative effect on overall survival. Complications such as bleeding or need for intensive care could be predicted preoperatively based on preoperative performance status, type of primary tumor, affected vertebral levels, and type of surgical interventions.

CONCLUSIONS

Spinal metastatic disease is a challenging surgical problem. If the exact prognostic factors are known preoperatively, surgical outcome and overall survival can be predicted more precisely. Our results could provide a basis for a future multicenter prospective study to determine the best treatment protocol for patients with spinal metastases.

Surgical treatment indications and outcomes in patients with spinal metastases in the cervicothoracic junction (CTJ)

Background

The cervicothoracic junction (CTJ) site accounts for approximately 10% of all spinal metastases. The complex anatomical and biomechanical features increase the difficulty in surgical treatment of the CTJ metastases. However, few studies in the literature on surgical treatment for spinal metastases are focusing on this special area. The aim of this study was to evaluate the surgical outcome of patients with CTJ metastases and analyze the prognostic factor for the postoperative survival.

Methods

Total of 34 patients with CTJ metastases who underwent surgery in our department were retrospectively analyzed. We evaluated records for the details of medical history, treatment, surgery, radiographic imaging, and follow-up. Outcomes were assessed by overall survival as well as modified Tokuhashi score, SINS, Frankel grade, visual analog scale (VAS), and Karnofsky Performance Status (KPS).

Results

The entire patients’ median survival time was 12.4 months (range, 3.5–36.2 months). Pain improved in 32 patients (94.12%), and the postoperative VAS scores were significantly improved compared with preoperative data. Majority of patients (71%) maintained or improved their Frankel scores 1 year after surgery. KPS scores improved in 13 patients (38%), remained stable in 19 (56%), and worsened in 2 (6%) postoperatively. Notably, patients with neurological deficit that did not improve after surgery had significantly worse median survival than those who had either no deficit or who improved after surgery. There were no instrumentation failures in this study.

Conclusions

Surgical treatment is effective for patients of CTJ metastases, with a tolerable rate of complications. Remained or regained ambulatory status predicted overall survival. Thus, prompt and aggressive decompressive surgery is recommended for CTJ metastases patients with neurological impairment.

Metastatic Bone Disease in the Era of Bone-Targeted Therapy: Clinical Impact

Advances in the diagnosis and treatment of tumors by surgery, chemotherapy, biotherapy, radiotherapy and other modalities have increased the survival of cancer patients over the last 20 years. As a consequence, bone now represents the third most common site of metastatic involvement after the lung and liver. Approximately 20–25% of patients with neoplastic disease develop clinically evident bone metastases (BMs) during the natural course of their illness, with a further 50% of such lesions being identified during autopsy. BMs are the major cause of morbidity in cancer patients because of their epidemiological and clinical impact. Pain is the most frequent symptom in about 75% of patients but other serious complications can also occur, such as pathological fractures, spinal cord compression, hypercalcemia and bone marrow suppression. These complications worsen the patient's general condition and reduce patients’ mobility, facilitating the development of lung infections, skin ulcers, deep vein thrombosis, etc., and ultimately reducing prognosis and quality of life. The frequency of serious complications depends on the site and type of lesions and the treatment administered. Over the last 10 years, the introduction of bisphosphonates for the treatment of patients with BMs has led to a marked decrease in the frequency of complications, thus improving quality of life and clinical outcome. Furthermore, progress in understanding the pathophysiology of bone metastases has resulted in the development of new bone-targeted molecules such as denosumab. We therefore felt it would be useful to report on the epidemiological, clinical and economic impact of bone disease in a cancer setting.

Dose escalation by image-guided intensity-modulated radiotherapy leads to an increase in pain relief for spinal metastases: a comparison study with a regimen of 30 Gy in 10 fractions

PURPOSE

Under the existing condition that the optimum radiotherapy regimen for spinal metastases is controversial, this study investigates the benefits of dose escalation by image-guided intensity-modulated radiotherapy (IG-IMRT) with 60-66 Gy in 20-30 fractions for spinal metastases.

RESULTS

In the dose-escalation group, each D50 of planning gross tumor volume (PGTV) was above 60 Gy and each Dmax of spinal cord planning organ at risk volume (PRV) was below 48 Gy. The median biological effective dose (BED) of Dmax of spinal cord was lower in the dose-escalation group compared with that in the 30-Gy group (69.70 Gy vs. 83.16 Gy, p < 0.001). After one month and three months of the radiotherapy, pain responses were better in the dose-escalation group than those in the 30-Gy group (p = 0.005 and p = 0.024), and the complete pain relief rates were respectively 73.69% and 34.29% (p = 0.006), 73.69% and 41.38% (p = 0.028) in two compared groups. In the dose-escalation group, there is a trend of a longer duration of pain relief, a longer overall survival and a lower incidence of acute radiation toxicities. No late radiation toxicities were observed in both groups.

MATERIALS AND METHODS

Dosimetric parameters and clinical outcomes, including pain response, duration of pain relief, radiation toxicities and overall survival, were compared among twenty-five metastatic spinal lesions irradiated with the dose-escalation regimen and among forty-four lesions treated with the 30-Gy regimen.

CONCLUSIONS

Conventionally-fractionated IG-IMRT for spinal metastases could escalate dose to the vertebral lesions while sparing the spinal cord, achieving a better pain relief without increasing radiation complications.

Prospective Cohort Study of Performance Status and Activities of Daily Living After Surgery for Spinal Metastasis

STUDY DESIGN

A prospective cohort study of performance status (PS) and activities of daily living (ADL) in patients with spinal metastasis.

OBJECTIVE

To identify the effect of spinal surgery on PS and ADL in patients with spinal metastasis.

SUMMARY OF BACKGROUND DATA

Spinal metastasis causes severe neurological deficits, resulting in drastic loss of patients' PS and ADL. However, the effect of spine surgery on PS and ADL is not well known.

MATERIALS AND METHODS

Seventy patients with spinal metastasis were enrolled in this study. Forty-six patients desired and underwent spine surgery ("surgery" group) and 24 patients did not desire surgery ("nonsurgery" group). Both groups received optimal treatments, including radiation, chemotherapy, and palliative care services. Evaluation was performed at 1, 3, and 6 months after study enrollment using the Eastern Cooperative Oncology Group PS, the Barthel index (BI) for ADL, and Frankel classification for neurological status.

RESULTS

There was no significant difference in baseline PS, the BI, or Frankel classification between the groups. The surgery group showed significant improvement in PS, maintaining grade 2 or less throughout the duration of the study, as well as in ADL, exceeding 70 points of the BI, compared with the nonsurgery group (P<0.05). Significantly improved neurological condition was also observed in the surgery group over the following 6 months. More than 95% of patients who underwent surgery improved their PS, the BI, and neurological status. Furthermore, >80% of these patients maintained improvement in PS, the BI, and neurological status for at least 6 months. In contrast, PS, the BI, and neurological status of patients in the "nonsurgery" group deteriorated throughout the study period.

CONCLUSIONS

Spine surgery improves PS, ADL, and neurological status in patients with spinal metastasis for a minimum 6 months. This indicates that these patients can acquire an independent daily life.

Spinal Metastasis of Unknown Primary Accompanied by Neurologic Deficit or Vertebral Instability

BACKGROUND AND OBJECTIVE

Spinal bone metastases are common. They are mostly localized to the lumbar, thoracic, and cervical spine. The most common primaries to result in spinal metastases include lung, breast, and prostate carcinomas in adults as opposed to leukemia, Ewing sarcoma, rhabdomyosarcoma, and neuroblastoma in children. In patients diagnosed with cancer, bone metastases are found in 40% and spinal metastases in 10%. In this study, we reviewed 25 patients diagnosed with a spinal metastasis of unknown primary who presented with low back pain or acute-onset neurologic deficits and underwent operative treatment.

METHODS

The retrospective study included 25 patients with a spinal metastasis of unknown primary who presented to our clinic with acute-onset vertebral fracture or neurologic deficit. Statistical descriptions were obtained for each patient. Survival analysis was performed using the Kaplan-Meier method.

RESULTS

The 25 patients included 17 men (68%) and 8 women (32%), with a mean age of 55 years (range, 14-81 years). Eleven patients (44%) presented with varying degrees of motor deficits ranging from flaccid paralysis to paraplegia. Motor deficits were completely reversed in 4 patients postoperatively. The tumors were localized to the upper thoracic spine (T1-4) in 2 patients, in the midthoracic spine (T5-8) in 2 patients, in the lower thoracic spine (T9-12) in 8 patients, in the cervical 7 in 1 patient, and in the lumbar spine in 12 patients. In 10 patients, the tumor affected multiple spinal regions. Nonosseous tumors were not present in 10 patients. Ten patients had an extradural tumor. Costal involvement was detected in 2 patients. The tumors were pathologically identified as lung cancer (n = 3), lymphoma (n = 5), breast cancer (n = 3), gastric cancer (n = 2), liver cancer (n = 2), prostate cancer (n = 2), renal cell carcinoma (n = 2), malignant melanoma (n = 1), plasmacytoma (n = 1), bladder cancer (n = 1), paraganglioma (n = 1), Ewing sarcoma (n = 1), and yolk sac carcinoma (n = 1). Posterior instrumentation was performed in patients with instability. In addition, decompression was performed in patients with neurologic deficit.

CONCLUSIONS

Considering that 10% of patients with cancer are diagnosed by vertebral metastasis, presence of malignancy should be suspected and a detailed examination should be performed in patients presenting with vertebral fractures caused by no or minor trauma. Moreover, in patients presenting with neurologic deficit, soft tissue metastases leading to spinal cord compression should be kept in mind and further examinations should be promptly administered.

Risk for surgical complications after previous stereotactic body radiotherapy of the spine

OBJECT

Stereotactic body radiotherapy (SBRT) for vertebral metastases has emerged as a promising technique, offering high rates of symptom relief and local control combined with low risk of toxicity. Nonetheless, local failure or vertebral instability may occur after spine SBRT, generating the need for subsequent surgery in the irradiated region. This study evaluated whether there is an increased incidence of surgical complications in patients previously treated with SBRT at the index level.

METHODS

Based upon a retrospective international database of 704 cases treated with SBRT for vertebral metastases, 30 patients treated at 6 different institutions were identified who underwent surgery in a region previously treated with SBRT.

RESULTS

Thirty patients, median age 59 years (range 27-84 years) underwent SBRT for 32 vertebral metastases followed by surgery at the same vertebra. Median follow-up time from SBRT was 17 months. In 17 cases, conventional radiotherapy had been delivered prior to SBRT at a median dose of 30 Gy in median 10 fractions. SBRT was administered with a median prescription dose of 19.3 Gy (range 15-65 Gy) delivered in median 1 fraction (range 1-17) (median EQD2/10 = 44 Gy). The median time interval between SBRT and surgical salvage therapy was 6 months (range 1-39 months). Reasons for subsequent surgery were pain (n = 28), neurological deterioration (n = 15) or fracture of the vertebral body (n = 13). Open surgical decompression (n = 24) and/or stabilization (n = 18) were most frequently performed; Five patients (6 vertebrae) were treated without complications with vertebroplasty only. Increased fibrosis complicating the surgical procedure was explicitly stated in one surgical report. Two durotomies occurred which were closed during the operation, associated with a neurological deficit in one patient. Median blood loss was 500 ml, but five patients had a blood loss of more than 1 l during the procedure. Delayed wound healing was reported in two cases. One patient died within 30 days of the operation.

CONCLUSION

In this series of surgical interventions following spine SBRT, the overall complication rate was 19%, which appears comparable to primary surgery without previous SBRT. Prior spine SBRT does not appear to significantly increase the risk of intra- and post-surgical complications.

Spinal Radiosurgery for Metastatic Disease of the Spine

Background

Metastatic tumor in the spinal column is common, causing symptomatic spinal cord compression in approximately 25,000 patients annually. Although surgical treatment of spinal metastases has become safer, less invasive, and more efficacious in recent years, there remains a subset of patients for whom other treatment modalities are needed. Stereotactic radiosurgery, which has long been used in the treatment of intracranial lesions, has recently been applied to the spine and enables the effective treatment of metastatic lesions.

Methods

We review the evolution of stereotactic radiosurgery and its applications in the spine, including a description of two commercially available systems.

Results

Although a relatively new technique, the use of stereotactic radiosurgery in the spine has advanced rapidly in the past decade. Spinal stereotactic radiosurgery is an effective and safe modality for the treatment of spinal metastatic disease.

Conclusions

Future challenges involve the refinement of noninvasive fiducial tracking systems and the discernment of optimal doses needed to treat various lesions. Additionally, dose-tolerance limits of normal structures need to be further developed. Increased experience will likely make stereotactic radiosurgery of the spine an important treatment modality for a variety of metastatic lesions.

Surgery for metastatic spine tumors in the elderly. Advanced age is not a contraindication to surgery!

BACKGROUND

With recent advances in oncologic treatments, there has been an increase in patient survival rates and concurrently an increase in the number of incidence of symptomatic spinal metastases. Because elderly patients are a substantial part of the oncology population, their types of treatment as well as the possible impact their treatment will have on healthcare resources need to be further examined.

PURPOSE

We studied whether age has a significant influence on quality of life and survival in surgical interventions for spinal metastases.

STUDY DESIGN

We used data from a multicenter prospective study by the Global Spine Tumor Study Group (GSTSG). This GSTSG study involved 1,266 patients who were admitted for surgical treatments of symptomatic spinal metastases at 22 spinal centers from different countries and followed up for 2 years after surgery.

PATIENT SAMPLE

There were 1,266 patients recruited between March 2001 and October 2014.

OUTCOME MEASURES

Patient demographics were collected along with outcome measures, including European Quality of Life-5 Dimensions (EQ-5D), neurologic functions, complications, and survival rates.

METHODS

We realized a multicenter prospective study of 1,266 patients admitted for surgical treatment of symptomatic spinal metastases. They were divided and studied into three different age groups: <70, 70-80, and >80 years.

RESULTS

Despite a lack of statistical difference in American Society of Anesthesiologists (ASA) score, Frankel neurologic score, or Karnofsky functional score at presentation, patients >80 years were more likely to undergo emergency surgery and palliative procedures compared with younger patients. Postoperative complications were more common in the oldest age group (33.3% in the >80, 23.9% in the 70-80, and 17.9% for patients <70 years, p=.004). EQ-5D improved in all groups, but survival expectancy was significantly longer in patients <70 years old (p=.02). Furthermore, neurologic recovery after surgery was lower in patients >80 years old.

CONCLUSIONS

Surgeons should not be biased against operating elderly patients. Although survival rates and neurologic improvements in the elderly patients are lower than for younger patients, operating the elderly is compounded by the fact that they undergo more emergency and palliative procedures, despite good ASA scores and functional status. Age in itself should not be a determinant of whether to operate or not, and operations should not be avoided in the elderly when indicated.

Solitary vertebral metastasis of primary clear cell carcinoma of the liver: a case report and review of literature

Primary clear cell carcinoma of liver (PCCCL) is an uncommon variant of primary hepatocellular carcinoma. Though the literature describes a better prognosis in relation to the proportion of clear cells in the tumour when compared to the other variants, there is no general consensus in the management due to its rarity and unclear clinicopathological and prognostic factors. There is dearth of evidence with regard to the metastasizing nature of PCCCL and its management. In addition, the management of recurrent spinal tumours both primary and metastatic is not clear as the available evidence is mostly based on case reports. We describe an unusual presentation of PCCCL with solitary spinal metastasis and further complicated by tumour recurrence in a 71-year-old male. Such presentation has never been described before. He presented with low back pain and incomplete neurological deficits involving both lower limbs. On detailed evaluation, he was found to have a solitary metastasis at L3 vertebra secondary to PCCCL. He underwent radical excision of tumour and reconstruction for the solitary metastasis at L3 vertebral body and trans arterial chemo embolisation (TACE) for the hepatic lesion. Pt was asymptomatic until 9 months post operatively when he developed tumour recurrence at L3 vertebra. Patient subsequently underwent 2 stage palliative surgery followed by radiotherapy and chemotherapy. At his latest follow-up (1 year), the patient's overall general condition has improved with residual neurological deficits in the lower limb. PCCCL is a rare type of hepatocellular carcinoma which can present as "solitary metastasis" to the spine. Although the literature suggests a good prognosis for this histological type, this case did not have a good outcome. In addition to providing information for the management of similar cases in the future, this case report highlights that every patient has to be managed on a case-by-case basis.

Postoperative quality-of-life assessment in patients with spine metastases treated with long-segment pedicle-screw fixation

OBJECTIVE In recent decades, progress in the medical management of cancer has been significant, resulting in considerable extension of survival for patients with metastatic disease. This has, in turn, led to increased attention to the optimal surgical management of bone lesions, including metastases to the spine. In addition, there has been a shift in focus toward improving quality of life and reducing hospital stay for these patients, and many minimally invasive techniques have been introduced with the aim of reducing the morbidity associated with more traditional open approaches. The goal of this study was to assess the efficacy of long-segment percutaneous pedicle screw stabilization for the treatment of instability associated with thoracolumbar spine metastases in neurologically intact patients. METHODS This study was a retrospective review of data from a prospective database. The authors analyzed cases in which long-segment percutaneous pedicle screw fixation was performed for the palliative treatment of thoracolumbar spinal instability due to spinal metastases in neurologically intact patients. All of the patients included in the study underwent surgery between January 2014 and May 2015 at the authors' institution. Postoperative radiation therapy was planned within 10 days following the stabilization in all cases. Clinical and radiological follow-up assessments were planned for 3 days, 3 weeks, 6 weeks, 3 months, 6 months, and 1 year after surgery. Outcome was assessed by means of standard postoperative evaluation and oncological and spinal quality of life measures (European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Version 3.0 [EORTC QLQ-C30] and Oswestry Disability Index [ODI], respectively). Moreover, 5 patients were given an activity monitoring device for recording the distance walked daily; preoperative and postoperative daily distances were compared. RESULTS Data from 17 cases were analyzed. There were no complications, and patients showed improvement in pain level and quality of life from the early postoperative period on. The mean ODI score was 62.7 (range 40-84) preoperatively, 35.4 (range 24-59) on postoperative Day 3, and 46.1 (range 30-76) at 3 weeks, 37.6 (range 25-59) at 6 weeks, 34.0 (range 24-59) at 3 months, 39.1 (range 22-64) at 6 months, and 30.0 (range 20-55) at 1 year after screw placement. The mean ODI was significantly improved in the first 45 days (p < 0.001). Improvement was also evident in scores for functional and symptomatic scales of the EORTC QLQ-C30. All patients underwent postoperative radiation therapy within 10 days (mean 7.5). All patients (n = 5) with an activity monitoring device showed improvement in daily walking distance. CONCLUSIONS Less-invasive palliative treatment for advanced spinal metastases is promising as part of a multidisciplinary approach to the care of patients with metastatic disease. The results of this study indicate that percutaneous surgery may allow for rapid improvement in quality of life and walking ability for patients with thoracolumbar instability due to spine metastases. Long-segment percutaneous screw fixation followed by early radiation therapy appears to be a safe and effective treatment option for providing solid and durable stability and improved quality of life for these patients.

Decompression surgery for spinal metastases: a systematic review

OBJECTIVE The aim of this study was to systematically review the literature on reported outcomes following decompression surgery for spinal metastases. METHODS The authors conducted MEDLINE, Scopus, and Web of Science database searches for studies reporting clinical outcomes and complications associated with decompression surgery for metastatic spinal tumors. Both retrospective and prospective studies were included. After meeting inclusion criteria, articles were categorized based on the following reported outcomes: survival, ambulation, surgical technique, neurological function, primary tumor histology, and miscellaneous outcomes. RESULTS Of the 4148 articles retrieved from databases, 36 met inclusion criteria. Of those included, 8 were prospective studies and 28 were retrospective studies. The year of publication ranged from 1992 to 2015. Study size ranged from 21 to 711 patients. Three studies found that good preoperative Karnofsky Performance Status (KPS ≥ 80%) was a significant predictor of survival. No study reported a significant effect of time-to-surgery following the onset of spinal cord compression symptoms on survival. Three studies reported improvement in neurological function following surgery. The most commonly cited complication was wound infection or dehiscence (22 studies). Eight studies reported that preoperative ambulatory or preoperative motor status was a significant predictor of postoperative ambulatory status. A wide variety of surgical techniques were reported: posterior decompression and stabilization, posterior decompression without stabilization, and posterior decompression with total or subtotal tumor resection. Although a wide range of functional scales were used to assess neurological outcomes, four studies used the American Spinal Injury Association (ASIA) Impairment Scale to assess neurological function. Four studies reported the effects of radiation therapy and local disease control for spinal metastases. Two studies reported that the type of treatment was not significantly associated with the rate of local control. The most commonly reported primary tumor types included lung cancer, prostate cancer, breast cancer, renal cancer, and gastrointestinal cancer. CONCLUSIONS This study reports a systematic review of the literature on decompression surgery for spinal metastases. The results of this study can help educate surgeons on the previously published predictors of outcomes following decompression surgery for metastatic spinal disease. However, the authors also identify significant gaps in the literature and the need for future studies investigating the optimal practice with regard to decompression surgery for spinal metastases.

Is there a correlation between the spinal instability neoplastic score and mechanical pain in patients with metastatic spinal cord compression? A prospective cohort study

INTRODUCTION

The decision for selecting patients for surgical treatment of metastatic spinal cord compression (MSCC) is challenging even for experienced surgeons. Recently, the spinal instability neoplastic score (SINS) has been proposed to help surgeons in the evaluation of spinal stability in the setting of spinal metastases. This study aimed to evaluate the correlation between SINS and preoperative visual analog scale (VAS), as well as the pre- and post-operative association of the VAS and neurological function.

METHODS

A prospective cohort study was conducted in a tertiary referral cancer center. Seventy-nine patients with MSCC were surgically treated from June 2012 to March 2015. Pain status before and after surgery was assessed using VAS score, and neurological status was evaluated using the American Spine Injury Association Impairment Scale (AIS) before and after surgery. Pain was classified as VAS (0-4) none or mild pain; VAS (5-8) moderate pain; and VAS (9-10) as severe pain. Neurological function was scored as AIS A: Complete deficits, AIS B-D: Incomplete deficits, AIS E: Neurologically intact. SINS degrees were classified as 0-6-stable; 7-12 potentially unstable, and 13-18-unstable. Spearman's correlation coefficient test was utilized for correlation between pain and SINS; Chi-square association test was utilized for evaluating pre- and post-operative pain and AIS, as well as the association between SINS and tumor types.

RESULTS

A higher SINS correlates with severe mechanical pain preoperatively (ρ = 0.38, P = 0.001); surgical procedure improved neurological function (P = 0.0001), and decrease pain (P = 0.84). Finally, a higher SINS was also associated with osteolytic tumors (P = 0.03).

CONCLUSIONS

The SINS correlates with mechanical pain. Surgery provides a significant improvement in pain and neurological status, especially in patients who presented higher SINS scores and some degree of preoperative neurological function.

Modern Palliative Treatments for Metastatic Bone Disease: Awareness of Advantages, Disadvantages, and Guidance

BACKGROUND

Metastatic disease is the most common malignancy of the bone. Prostate, breast, lung, kidney, and thyroid cancer account for 80% of skeletal metastases. Bone metastases are associated with significant skeletal morbidity including severe bone pain, pathologic fractures, spinal cord or nerve roots compression, and malignant hypercalcemia. These events compromise greatly the quality of life of the patients. The treatment of cancer patients with bone metastases is mostly aimed at palliation.

OBJECTIVE

This article aims to present these palliative treatments for the patients with bone metastases, summarize the clinical applications, and review the techniques and results.

METHODS

It gives an extensive overview of the possibilities of palliation in patients with metastatic cancer to the bone.

RESULTS AND DISCUSSION

Currently, modern treatments are available for the palliative management of patients with metastatic bone disease. These include modern radiation therapy, chemotherapy, embolization, electrochemotherapy, radiofrequency ablation, and high-intensity focused ultrasound. As such it is of interest for all physicians with no experience with these developments to make palliative procedures safer and more reliable.

Stereotactic Body Radiotherapy for Spinal Metastases: What are the Risks and How Do We Minimize Them?

STUDY DESIGN

Systematic literature review.

OBJECTIVES

To summarize the risks of 3 key complications of stereotactic body radiotherapy (SBRT) for spinal metastases, that is, radiation myelopathy (RM), vertebral compression fracture (VCF), and epidural disease progression, and to discuss strategies for minimizing them.

SUMMARY OF BACKGROUND DATA

RM, VCF and epidural disease progression are now recognized as important risks following SBRT for spine metastases. It is unclear at this stage exactly how large these risks are and what strategies can be employed to minimize these risks.

METHODS

A systematic review of the literature using MEDLINE and a review of the bibliographies of reviewed articles on SBRT for spinal metastases were conducted.

RESULTS

The initial literature search revealed a total of 376 articles, of which 38 were pertinent to the study objectives. The risk of RM following SBRT was found to be dependent on the maximum dose to the spinal cord and estimated to be ≤5% if the recommended published thecal sac dose constraints are adhered to. The crude risk of VCF was 13.7% (range: 0.7%-40.5%), and, on average, 45% were surgically salvaged. It has been shown that the risk of VCF is dependent on several anatomic and tumor-related factors including the SBRT dose per fraction. The crude risk of local failure at 1 year was 21.4% (range: 12%-27%) of which 67% (range: 38%-96%) occurred within the epidural space. The grade of epidural disease has been shown to be associated with the risk of local failure.

CONCLUSION

The risk of RM after spinal SBRT is low in particular if recommended dose metrics are adhered to. There is a significant risk of both VCF and epidural disease progression after spinal SBRT. These risks can potentially be minimized by identifying the risk factors for these complications, and performing careful radiotherapy and surgical planning.

LEVEL OF EVIDENCE

2.

Minimally Invasive Pedicle Screws Fixation and Percutaneous Vertebroplasty for the Surgical Treatment of Thoracic Metastatic Tumors With Neurologic Compression

STUDY DESIGN

A retrospective study.

OBJECTIVE

To describe minimally invasive pedicle screw fixation (MIPS) combined with percutaneous vertebroplasty (PVP), minimally invasive decompression and partial tumor resection for the treatment of thoracic metastasis with symptoms of neurologic compression and evaluate the feasibility, efficacy, and safety.

SUMMARY OF BACKGROUND DATA

Neurologic decompression, spinal tumor resection, and stabilization with instrumentation should be performed from an anterior, a posterior, or a combined approach for spinal metastatic tumors with symptoms of neurologic compression. These operations, however, have significant morbidity related to the surgical approach, potential blood loss, extensive dissection, or biomechanical instability.

METHODS

Eighteen patients who sustained single-level thoracic vertebral metastasis and neurologic compression underwent MIPS (The minimal-access in a paraspinal sacrospinalis muscle-splitting approach was performed to insert the pedicle screws into the vertebrae under direct vision and two rods of appropriate size were placed over the pedicle screws through subcutaneous soft tissues and muscles) combined with PVP, minimally invasive neurologic decompression, and partial tumor resection. The patients were evaluated preoperatively according to the Tomita, revised Tokuhashi, Bilsky grading system, and Spinal Instability Neoplastic Score. Pre- and postoperative VAS score, American Spinal Injury Association grade, ambulatory status, and urinary continence were also recorded. The Cobb angles, central, and anterior vertebral body height were measured on the lateral radiographs before surgery and during the follow-up.

RESULTS

Clinical follow-up was available for 17 patients in this study ranging from 12 to 16 months (mean time, 14.2 months), and 1 patient died 8 months after surgery. The Visual Analog Scale was significantly decreased after surgery. Improvement of paraplegia was observed after surgery in all of these patients. Spine stability was observed in all of the surviving patients during the follow-up.

CONCLUSION

MIPS combined with PVP, minimally invasive decompression, and partial tumor resection is a good choice of surgical treatment of thoracic metastatic tumors with neurologic compression.

LEVEL OF EVIDENCE

2.

Irreversible Electroporation in the Epidural Space of the Porcine Spine: Effects on Adjacent Structures

Purpose To determine the effects of irreversible electroporation (IRE) on the neural tissues after ablation in the epidural space of the porcine spine. Materials and Methods The institutional animal care and use committee approved this study. With the IRE electrode positioned in the right lateral recess of the spinal epidural space, 20 IRE ablations were performed with computed tomographic (CT) guidance by using different applied voltages in four animals that were euthanized immediately after magnetic resonance (MR) imaging of the spine, performed 6 hours after IRE (terminal group). Histopathologic characteristics of the neural tissues were assessed and used to select a voltage for a survival study. Sixteen CT-guided IRE ablations in the epidural space were performed by using 667 V in four animals that were survived for 7 days (survival group). Clinical characteristics, MR imaging findings (obtained 6 hours after IRE and before euthanasia), histopathologic characteristics, and simulated electric field strengths were assessed. A one-way analysis of variance was used to compare the simulated electric field strength to histologic findings. Results The mean distance between the IRE electrode and the spinal cord and nerve root was 1.71 mm ± 0.90 and 8.47 mm + 3.44, respectively. There was no clinical evidence of paraplegia after IRE ablation. MR imaging and histopathologic examination showed no neural tissue lesions within the spinal cord; however, five of 16 nerve roots (31.2%) demonstrated moderate wallerian degeneration in the survival group. The severity of histopathologic injury in the survival group was not significantly related to either the simulated electric field strength or the distance between the IRE electrode and the neural structure (P > .05). Conclusion Although the spinal cord appears resistant to the toxic effects of IRE, injury to the nerve roots may be a limiting factor for the use of IRE ablation in the epidural space. ^© RSNA, 2016 Online supplemental material is available for this article.

Pulmonary Complications following Thoracic Spinal Surgery: A Systematic Review

Study Design Systematic review. Objective To determine the frequency of pulmonary effusion, pneumothorax, and hemothorax in adult patients undergoing thoracic corpectomy or osteotomy for any condition and to determine if these frequencies vary by surgical approach (i.e., anterior, posterior, or lateral). Methods Electronic databases and reference lists of key articles were searched through September 21, 2015, to identify studies specifically evaluating the frequency of pulmonary effusion, pneumothorax, and hemothorax in patients undergoing thoracic spine surgery. Results Fourteen studies, 13 retrospective and 1 prospective, met inclusion criteria. The frequency across studies of pulmonary effusion ranged from 0 to 77%; for hemothorax, 0 to 77%; and for pneumothorax, 0 to 50%. There was no clear pattern of pulmonary complications with respect to surgical approach. Conclusions There is insufficient data to determine the risk of pulmonary complications following anterior, posterior, or lateral approaches to the thoracic spine. Methods for assessing pulmonary complications were not well reported, and data is sparse.

Minimally Invasive Spinal Stabilization Using Fluoroscopic-Guided Percutaneous Screws as a Form of Palliative Surgery in Patients with Spinal Metastasis

Study Design

Prospective cohort study.

Purpose

To report the outcome of 50 patients with spinal metastases treated with minimally invasive stabilization (MISt) using fluoroscopic guided percutaneous pedicle screws with/without minimally invasive decompression.

Overview of Literature

The advent of minimally invasive percutaneous pedicle screw stabilization system has revolutionized the treatment of spinal metastasis.

Methods

Between 2008 and 2013, 50 cases of spinal metastasis with pathological fracture(s) with/without neurology deficit were treated by MISt at our institution. The patients were assessed by Tomita score, pain score, operation time, blood loss, neurological recovery, time to ambulation and survival.

Results

The mean Tomita score was 6.3±2.4. Thirty seven patients (74.0%) required minimally invasive decompression in addition to MISt. The mean operating time was 2.3±0.5 hours for MISt alone and 3.4±1.2 hours for MISt with decompression. Mean blood loss for MISt alone and MISt with decompression was 0.4±0.2 L and 1.7±0.9 L, respectively. MISt provided a statistically significant reduction in visual analog scale pain score with mean preoperative score of 7.9±1.4 that was significantly decreased to 2.5±1.2 postoperatively (p=0.000). For patients with neurological deficit, 70% displayed improvement of one Frankel grade and 5% had an improvement of 2 Frankel grades. No patient was bed-ridden postoperatively, with the average time to ambulation of 3.4±1.8 days. The mean overall survival time was 11.3 months (range, 2–51 months). Those with a Tomita score <8 survived significantly longer than those a Tomita score ≥8 with a mean survival of 14.1±12.5 months and 6.8±4.9 months, respectively (p=0.019). There were no surgical complications, except one case of implant failure.

Conclusions

MISt is an acceptable treatment option for spinal metastatic patients, providing good relief of instability back pain with no major complications.

Survival and Clinical Outcomes in Surgically Treated Patients With Metastatic Epidural Spinal Cord Compression: Results of the Prospective Multicenter AOSpine Study

PURPOSE

Although surgery is used increasingly as a strategy to complement treatment with radiation and chemotherapy in patients with metastatic epidural spinal cord compression (MESCC), the impact of surgery on health-related quality of life (HRQoL) is not well established. We aimed to prospectively evaluate survival, neurologic, functional, and HRQoL outcomes in patients with MESCC who underwent surgical management.

PATIENTS AND METHODS

One hundred forty-two patients with a single symptomatic MESCC lesion who were treated surgically were enrolled onto a prospective North American multicenter study and were observed at least up to 12 months. Clinical data, including Brief Pain Inventory, ASIA (American Spinal Injury Association) impairment scale, SF-36 Short Form Health Survey, Oswestry Disability Index, and EuroQol 5 dimensions (EQ-5D) scores, were obtained preoperatively, and at 6 weeks and 3, 6, 9, and 12 months postoperatively.

RESULTS

Median survival time was 7.7 months. The 30-day and 12-month mortality rates were 9% and 62%, respectively. There was improvement at 6 months postoperatively for ambulatory status (McNemar test, P < .001), lower extremity and total motor scores (Wilcoxon signed rank test, P < .001), and at 6 weeks and 3, 6, and 12 months for Oswestry Disability Index, EQ-5D, and pain interference (paired t test, P < .013). Moreover, at 3 months after surgery, the ASIA impairment scale grade was improved (Stuart-Maxwell test P = .004). SF-36 scores improved postoperatively in six of eight scales. The incidence of wound complications was 10% and 2 patients required a second surgery (screw malposition and epidural hematoma).

CONCLUSION

Surgical intervention, as an adjunct to radiation and chemotherapy, provides immediate and sustained improvement in pain, neurologic, functional, and HRQoL outcomes, with acceptable risks in patients with a focal symptomatic MESCC lesion who have at least a 3 month survival prognosis.

The efficacy and risks of preoperative embolization of spinal tumors

Background

The goal of preoperative embolization of spinal tumors is to improve surgical outcomes by diminishing the vascular supply to the tumor to reduce intraoperative blood loss and operative time.

Objective

To report our institutional experience with spinal tumor embolization and review the present literature.

Methods

Clinical records from January 1, 2001 to December 31, 2012 were reviewed and analyzed. Angiograms were used to calculate the percentage reduction in tumor vascularity, and relevant clinical and operative data were collected and analyzed.

Results

Thirty-seven patients underwent preoperative spinal tumor embolization (24 metastatic and 13 primary lesions) and were included in the study. One complication resulted in transient lower extremity weakness and was attributed to post-embolization swelling, which fully resolved after surgical resection. The transient neurological complication rate was 1/37 (3%) and the permanent rate was 0/37 (0%). The average surgical estimated blood loss (EBL) was 1946 mL (100–7000 mL) and the average operative time was 330 min (range 164–841 min). After embolization, tumor blush was reduced by 83% on average. Average pre- and postoperative modified Rankin Scale scores were 2.10 and 1.36, respectively (p=0.03). Cases in which tumor blush was decreased by ≥90% (classes 1 or 2) after embolization had significantly less operative blood loss than those cases in which <90% (classes 3 or 4) was achieved (mean EBL 1391 vs 2296 mL, respectively, p=0.05).

Conclusions

Spinal tumor embolization is a safe procedure, is associated with few complications, and may improve surgical outcomes by limiting intraoperative blood loss and reducing operative time.

Correlation between actual survival and Tokuhashi and tomita scores in spine metastases

<sec><title>OBJECTIVE:</title><p> To evaluate the accuracy of the scores of Tokuhashi and Tomita and the actual survival of patients with vertebral metastases.</p></sec><sec><title>METHODS:</title><p> A retrospective assessment of 45 patients with spinal metastases. Thirty-one patients underwent surgical treatment and adjuvant therapy and 14 received conservative treatment (chemotherapy/radiotherapy) or palliative/supportive, depending on the scores of Tokuhashi and Tomita.</p></sec><sec><title>RESULTS:</title><p> In the study, 80% of patients were female and the mean age was 57.8 years (SD=11.3 years). The most frequent primary tumors were breast and prostate (68.9%). The accuracy of Tokuhashi scale was 53.4% and the Tomita, 64.5%. The concentration of Tomita range of correct classification was in the category of survival > 12 months (57.8%), while the Tokuhashi scale presented some adjustment in the other categories, < 6 months (15.6%) and 6 to 12 months (2.2%). The histological type of the primary tumor was the only variable that statistically influenced the survival time of patients (p<0.001), and patients with lung or liver tumor (most aggressive) presented a risk of death 9.89 times higher than patients with primary tumors of breast or prostate (less aggressive) (95% CI: 3.10 to 31.57).</p></sec><sec><title>CONCLUSION:</title><p> The Tokuhashi and Tomita scores showed good accuracy with respect to the actual survival of patients with tumor metastasis in the spine.</p></sec>

The effect of void creation prior to vertebroplasty on intravertebral pressure and cement distribution in cadaveric spines with simulated metastases

Background

For osteoporosis or spinal metastases, percutaneous vertebroplasty is effective in pain relief and improvement of mobility. However, the complication rate (cement extravasation and fat embolisms) is relatively higher in the treatment of spinal metastases. The presence of tumor tissue plays a significant role in intravertebral pressure and cement distribution and thereby affects the occurrence of complications. We investigated the effect of void creation prior to vertebroplasty on intravertebral pressure and cement distribution in spinal metastases.

Methods

Eighteen vertebrae (T8–L4) from five cadaveric spines were randomly allocated for two groups (group with and without void) of nine vertebrae each. Defect was created by removing a central core of cancellous bone in the vertebral body and then filling it with 30% or 100% fresh muscle paste by volume to simulate void creation or no void creation, respectively. Then, 20% bone cement by volume of the vertebral body was injected into each specimen through a unipedicular approach at a rate of 3 mL/min. The gender of the donor, vertebral body size, bone density, cement volume, and intravertebral pressure were recorded. Then, computed tomography scans and cross sections were taken to evaluate the cement distribution in vertebral bodies.

Results

No significant difference was found between the two groups in terms of the gender of the donor, vertebral body size, bone density, or bone cement volume. The average maximum intravertebral pressure in the group with void creation was significantly lower than that in the group without void creation (1.20 versus 5.09 kPa, P = 0.001). Especially during the filling of void, the difference was more pronounced. Void creation prior to vertebroplasty allowed the bone cement to infiltrate into the lytic defect.

Conclusions

In vertebroplasty for spinal metastases, void creation produced lower intravertebral pressure and facilitated cement filling. To reduce the occurrence of complication, it may be an alternative to eliminate the tumor tissue to create a void prior to cement injection.