Survival rates of patients with metastatic spinal cancer after scintigraphic detection of abnormal radioactive accumulation

Sociodemographic Characteristics of Patients Undergoing Surgery for Metastatic Disease of the Spine

INTRODUCTION

Some patients, particularly those who are socioeconomically deprived, are diagnosed with primary and/or metastatic cancer only after presenting to the emergency department. Our objective was to determine sociodemographic characteristics of patients undergoing surgery for metastatic spine disease at our institution.

METHODS

This retrospective case series included patients 18 years and older who presented to the emergency department with metastatic spine disease requiring surgery. Demographics and survival data were collected. Sociodemographic characteristics were estimated using the Social Deprivation Index (SDI) and Area Deprivation Index (ADI) for the state of California. Univariate log-rank tests and Kaplan-Meier curves were used to assess differences in survival for predictors of interest.

RESULTS

Between 2015 and 2021, 64 patients underwent surgery for metastatic disease of the spine. The mean age was 61.0 ± 12.5 years, with 60.9% being male (n = 39). In this cohort, 89.1% of patients were non-Hispanic (n = 57), 71.9% were White (n = 46), and 62.5% were insured by Medicare/Medicaid (n = 40). The mean SDI and ADI were 61.5 ± 28.0 and 7.7 ± 2.2, respectively. 28.1% of patients (n = 18) were diagnosed with primary cancer for the first time while 39.1% of patients (n = 25) were diagnosed with metastatic cancer for the first time. During index hospitalization, 37.5% of patients (n = 24) received palliative care consult. The 3-month, 6-month, and all-time mortality rates were 26.7% (n = 17), 39.5% (n = 23), and 50% (n = 32), respectively, with 10.9% of patients (n = 7) dying during their admission. Payor plan was significant at 3 months ( P = 0.02), and palliative consultation was significant at 3 months ( P = 0.007) and 6 months ( P = 0.03). No notable association was observed with SDI and ADI in quantiles or as continuous variables.

DISCUSSION

In this study, 28.1% of patients were diagnosed with cancer for the first time. Three-month and 6-month mortality rates for patients undergoing surgery were 26.7% and 39.5%, respectively. Furthermore, mortality was markedly associated with palliative care consultation and insurance status, but not with SDI and ADI.

LEVEL OF EVIDENCE

Retrospective case series, Level III evidence.

The role of percutaneous vertebral augmentation in patients with metastatic breast cancer: Literature review including report of two cases

Patients with metastatic breast cancer are at high risk for developing vertebral compression fractures due to underlying bone metastases and bone density loss. Vertebral augmentation techniques including percutaneous vertebroplasty and percutaneous balloon kyphoplasty are techniques used to stabilize compression fractures and improve pain. However, rare complications from these interventions have been observed, including spinal cord compression, nerve root compression, venous cement embolism, and pulmonary cement embolism. These complications pose unique potential challenges for patients with cancer who may already have decreased lung function and potential for venous thromboembolism. In this review, we first describe the role of percutaneous vertebral augmentations in patients with metastatic cancer, with a particular focus on patients with breast cancer. Then, we describe complications of vertebral augmentation in two patients with metastatic breast cancer including long-term symptomatic and radiographic follow-up.

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Balloon kyphoplasty and percutaneous vertebroplasty are used to stabilize compression fractures and improve pain.

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Leakage of bone cement can cause cement emboli which can depsit in locations such as the pulmonary and renal vasculature.

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Management of cement emboli depends on the amount of cement embolized and the severity of symptoms.

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Future studies are needed to better understand the long-term radiographic and clinical consequences of cement emboli.

The Rates of Cement Leakage Following Vertebroplasty in Osteoporotic versus Metastatic Disease

Introduction  Percutaneous vertebroplasty is used for symptomatic osteoporotic fractures and osteolytic neoplasms. We performed a retrospective study to analyze the pattern of leaks in the two cohorts.

Material and Methods  Vertebroplasties performed over a 7-year period at a tertiary orthopaedic center were included in the study and divided into osteoporotic and neoplastic groups. The incidence and pattern of cement leaks in each group were documented and analyzed.

Results  There were 75 leaks of a cohort of 211 vertebroplasties with a relatively equal proportion in osteoporotic and neoplastic groups. The incidence of discal leaks was comparable between the two groups. Lateral and posterior leaks were more common in the neoplastic group.

Conclusion  We report the incidence and type of leaks in osteoporotic and neoplastic groups. Understanding the fracture pattern and preoperative management are both essential in preventing cement leakage. Using highly viscous cement or allowing the cement to harden prior to injection, with use of low pressure, decreases the risk and incidence of cement leakage.

Radiomics biopsy signature for predicting survival in patients with spinal bone metastases (SBMs)

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Prediction of survival is crucial for guiding patient-tailored treatment.

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Radiomics can be described as the next era of possibilities in precision medicine.

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Radiomics model had an inferior performance with no added predictive power to the clinical predictive model.

Study design

Retrospective analysis of a registered cohort of patients treated and irradiated for metastases in the spinal column in a single institute.

Objective

This is the first study to develop and internally validate radiomics features for predicting six-month survival probability for patients with spinal bone metastases (SBM).

Background data

Extracted radiomics features from routine clinical CT images can be used to identify textural and intensity-based features unperceivable to human observers and associate them with a patient survival probability or disease progression.

Methods

A study was conducted on 250 patients treated for metastases in the spinal column irradiated for the first time between 2014 and 2016, at the MAASTRO clinic in Maastricht, the Netherlands. The first 150 available patients were used to develop the model and the subsequent 100 patient were considered as a test set for the model. A bootstrap (B = 400) stepwise model selection, which combines both the forward and backward variable elimination procedure, was used to select the most useful predictive features from the training data based on the Akaike information criterion (AIC). The stepwise selection procedure was applied to the 400 bootstrap samples, and the results were plotted as a histogram to visualize how often each variable was selected. Only variables selected more than 90 % of the time over the bootstrap runs were used to build the final model.

A prognostic index (PI) called radiomics score (radscore) and clinical score (clinscore) was calculated for each patient. The prognostic index was not scaled, the original values were used which can be extracted from the model directly or calculated as a linear combination of the variables in the model multiplied by the respective beta value for each patient.

Results

The clinical model had a good discrimination power. The radiomics model, on the other hand, had an inferior performance with no added predictive power to the clinical model. The internal imaging characteristics do not seem to have a value in the prediction of survival. However, the Shape features were excluded from further analyses in our study since all biopsies had a standard shape hence no variability.

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

Purpose

Methods and Materials

Results

Conclusions

Spine metastasis in patients with prostate cancer: Survival prognosis assessment

BACKGROUND

Patients presenting spine metastasis (SpM) from prostate cancer (PC) form a heterogeneous population, through this study, we aimed to clarify and update their prognostic assessment.

METHODS

The patient data used in this study was obtained from a French national multicenter database of patients treated for PC with SpM between 2014 and 2017. A total of 72 patients and 365 SpM cases were diagnosed.

RESULTS

The median overall survival time for all patients following the event of SpM was 28.8 months. First, we identified three significant survival prognostic factors of PC patients with SpM: good Eastern Cooperative Oncology Group/World Health Organization personnel status (Status 0 hazard ratio [HR]: 0.031, 95% confidence interval [CI]: 0.008-0.127; p < .0001) or (Status 1 HR: 0.163, 95% CI: 0.068-0.393; p < .0001) and SpM radiotherapy (HR: 2.923, 95% CI: 1.059-8.069; p < .0001). Secondly, the presence of osteolytic lesions of the spine (vs. osteoblastic) was found to represent an independent prognosis factor for longer survival [HR: 0.424, 95% CI: 0.216-0.830; p = .01]. Other factors including the number of SpM, surgery, extraspinal metastasis, synchrone metastasis, metastasis-free survival, and SpM recurrence were not identified as being prognostically relevant to the survival of patients with PC.

CONCLUSION

Survival and our ability to estimate it in patients presenting PC with SpM have improved significantly. Therefore, we advocate the relevance of updating SpM prognostic scoring algorithms by incorporating data regarding the timeline of PC as well as the presence of osteolytic SpM to conceive treatments that are adapted to each patient.

Surgical management and prognostic factors of spinal metastatic tumors

Objective

This study aims to evaluate different prognostic factors after surgical management of metastatic spinal tumors regarding clinical condition, preoperative investigations, histopathological results, and surgical data.

Methods

Seventy patients diagnosed as metastatic spinal tumors with neurological deficits and/or unstable spine operated for spinal decompression with or without instrumental fixation according to Spinal Instability Neoplastic Score (SINS) at our institute during the period from May 2014 to October 2018 with follow-up at least 9 months.

Results

Lymphoma metastases were the commonest spinal metastases of 23% with significant p value = 0.001, males and ages above 50 years old were significantly affected. High vascularity and bone invasion were significant operative findings. Significant good prognostic factors for both survival and Klekampe score improvement were paretic patients, > 15 preoperative Klekampe score, early surgery, ≤ 3 vertebral affection, extradural tumor location, gross total resection, and metastatic tumors from multiple myeloma, thyroid gland, lymphoma, and prostatic gland.

Conclusion

Early surgeries aiming neural decompression and keeping spinal stability according to Spinal Instability Neoplastic Score for patients with spinal metastases are the main hope for better survival and neurological improvement.

Perspectives on Spinal Precautions in Patients Who Have Cancer and Spinal Metastasis

Bones are the third most common site for cancer metastases, and the axial skeleton is the most frequent skeletal location. In a postmortem study, bone metastases were reported in 70% of breast and prostate cancer patients. Bone metastases from breast, lung, prostate, thyroid, and kidney cancers account for 80% of all bone metastases. Bone lesions exist in 60% of newly diagnosed multiple myeloma patients. With increasing numbers of people who have survived cancer, many patients with cancer and axial skeletal bony metastases will be seen by physical and occupational therapists. Guidelines are lacking on how to perform physical examinations and provide exercise programs for these patients without compromising the diseased spine. In this article, we discuss the available evidence for similar spinal conditions, the biomechanics of spinal load, and changes associated with posture and weight load. We provide recommendations on how to assess a patient's strength, how to strengthen without compromising the diseased spine, and how to teach patients to use correct body mechanics during mobility and activities of daily living.

Percutaneous vertebral augmentation procedures in the management of spinal metastases

Bone metastasis is a common complication of cancer, and bone is the third most common metastatic site following the lung and liver. Among the various bones, spine is the most common site of metastatic tumors. The treatment goals of patients with spinal metastases are mostly palliative, with the aim of reducing pain and improving quality of life. The treatment of spinal metastases has made significant progress over the past few decades. Each new technology has tried to solve the shortcomings of its predecessors. Currently, there are no mature algorithms or specific techniques that have proven to be the best for spinal metastases, and the treatment method often relies on operator and institutional preferences or biases in some cases. Percutaneous vertebral augmentation has unique value in the management of spinal metastases, understanding its indications, surgical techniques, uses, advantages and complications is critical to providing optimal patient care. We believe that the application of percutaneous vertebral augmentation alone or combined with other techniques can achieve optimal pain relief and functional improvement in the patients with spinal metastases.

Efficacy and complications of 125I seeds combined with percutaneous vertebroplasty for metastatic spinal tumors: A literature review

To review the efficacy and complications of ¹²⁵I seeds combined with percutaneous vertebroplasty for the treatment of metastatic spinal tumors. We searched PubMed/MEDLINE from its inception to November 2018 for articles on metastatic spinal tumors treated with ¹²⁵I seeds combined with percutaneous vertebroplasty. A total of 273 articles were identified in PubMed/MEDLINE based on the search criteria. After deleting duplicate articles including two retrospective studies and three case control studies, five studies were included in this systematic review. In total, 161 patients aged from 49.2 to 62 years were included. The operative levels consisted of the thoracic vertebrae and lumbar vertebrae. Bone cement leakage occurred in 7 cases. None of the patients developed radiation myelopathy. Percutaneous vertebroplasty plus ¹²⁵I seeds implantation is an effective palliative treatment and can alleviate back pain and enhance vertebral body strength in patients with end-stage spinal metastatic tumors. In future research, the effective dosage of ¹²⁵I seeds implantation, the anchoring of seeds with safe distance, and the bone cement distribution in the vertebral body will be next research hotspot.

Predicting survival for metastatic spine disease: a comparison of nine scoring systems

BACKGROUND CONTEXT

Despite advances in spinal oncology, research in patient-based prognostic calculators for metastatic spine disease is lacking. Much of the literature in this area investigates the general predictive accuracy of scoring systems in heterogeneous populations, with few studies considering the accuracy of scoring systems based on patient specifics such as type of primary tumor.

PURPOSE

The aim of the present study was to compare the ability of widespread scoring systems to estimate both overall survival at various time points and tumor-specific survival for patients undergoing surgical treatment for metastatic spine disease in order to provide surgeons with information to determine the most appropriate scoring system for a specific patient and timeline.

STUDY DESIGN

This is a retrospective study.

PATIENT SAMPLE

Patients who underwent surgical resection for metastatic spine disease at a single institution were included.

OUTCOME MEASURES

Areas under the receiver operating characteristic curves were generated from comparison of actual survival of patients and survival as predicted by application of prevalent scoring systems.

METHODS

A preoperative score for all 176 patients was retrospectively calculated utilizing the Skeletal Oncology Research Group (SORG) Classic Scoring Algorithm, SORG Nomogram, original Tokuhashi, revised Tokuhashi, Tomita, original Bauer, modified Bauer, Katagiri, and van der Linden scoring systems. Univariate and multivariate Cox proportional hazard models were constructed to assess the association of patient variables with survival. Receiver operating characteristic analysis modeling was utilized to quantify the accuracy of each test at different end points and for different primary tumor subgroups. No funds were received in support of this work. The authors have no conflicts of interest to disclose.

RESULTS

Among all patients surgically treated for metastatic spine disease, the SORG Nomogram demonstrated the highest accuracy at predicting 30-day (area under the curve [AUC] 0.81) and 90-day (AUC 0.70) survival after surgery. The original Tokuhashi was the most accurate at predicting 365-day survival (AUC 0.78). Multivariate analysis demonstrated multiple preoperative factors strongly associated with survival after surgery for spinal metastasis. The accuracy of each scoring system in determining survival probability relative to primary tumor etiology and time elapsed since surgery was assessed.

CONCLUSIONS

Among the nine scoring systems assessed, the present study determined the most accurate scoring system for short-term (30-day), intermediate (90-day), and long-term (365-day) survival, relative to primary tumor etiology. The findings of the present study may be utilized by surgeons in a personalized effort to select the most appropriate scoring system for a given patient.

Comparative analysis of the surgical treatment results for multiple myeloma bone disease of the spine and the long bone/soft tissue

The present retrospective study was designed to compare the pain relief, surgery duration, life quality, survival time and relative prognostic factors in multiple myeloma (MM) bone disease patients with different surgical sites. A total of 65 cases were enrolled and divided into two groups. Group A included patients with lesions located in the spine, while Group B included patients with lesions located in the long bone or soft tissue. Pain relief was measured by the visual analogue scale (VAS), neurological impairment was determined according to Frankel classification, and survival was assessed by the Kaplan-Meier method. Cox regression analysis was also used to estimate the effect of factors on the prediction of survival. The hospitalization time, preoperative duration of symptoms, method of surgery, complications, recurrence and survival time were evaluated and compared retrospectively. Pain relief and improvement of life quality were observed in all the patients in groups A and B. No significant differences were detected for the majority of parameters compared between groups A and B, with the exception of the surgery duration, as well as the postoperative VAS score at 1 and 6 months after surgery. The multivariate Cox regression analysis revealed several risk factors significantly associated with survival, including the preoperative VAS score, postoperative chemotherapy, prothrombin time activity (PTA), albumin, lactate dehydrogenase and urine protein level. In conclusion, surgical treatment was an effective therapeutic method in patients with MM. Postoperative analgesic use should be individualized according to the different surgical sites and postoperative periods. Furthermore, preoperative pain, PTA, albumin, urine protein level and postoperative chemotherapy are associated with prognosis.

Circulating Tumour Cell Release after Cement Augmentation of Vertebral Metastases

Cement augmentation via percutaneous vertebroplasty or kyphoplasty for treatment of spinal metastasis is a well-established treatment option. We assessed whether elevated intrametastatic pressure during cement augmentation results in an increased dissemination of tumour cells into the vascular circulation. We prospectively collected blood from patients with osteolytic spinal column metastases and analysed the prevalence of circulating tumour cells (CTCs) at three time-points: preoperatively, 20 minutes after cement augmentation, and 3–5 days postoperatively. Enrolling 21 patients, including 13 breast- (61.9%), 5 lung- (23.8%), and one (4.8%) colorectal-, renal-, and prostate-carcinoma patient each, we demonstrate a significant 1.8-fold increase of EpCAM+/K+ CTCs in samples taken 20 minutes post-cement augmentation (P < 0.0001). Despite increased mechanical CTC dissemination due to cement augmentation, follow-up blood draws demonstrated that no long-term increase of CTCs was present. Array-CGH analysis revealed a specific profile of the CTC collected 20 minutes after cement augmentation. This is the first study to report that peripheral CTCs are temporarily increased due to vertebral cement augmentation procedures. Our findings provide a rationale for the development of new prophylactic strategies to reduce the increased release of CTC after cement augmentation of osteolytic spinal metastases.

A New Vertebral Body Replacement Strategy Using Expandable Polymeric Cages

We have developed a novel polymeric expandable cage that can be delivered via a posterior-only surgical approach for the treatment of noncontained vertebral defects. This approach is less invasive than an anterior-only or combined approach and much more cost-effective than currently used expandable metal cages. The polymeric expandable cage is composed of oligo poly(ethylene glycol) fumarate (OPF), a hydrogel that has been previously shown to have excellent nerve and bone tissue biocompatibility. OPF hydrogel cages can expand to twice their original diameter and length within a surgical time frame following hydration. Modulation of parameters such as polymeric network crosslink density or the introduction of charge to the network allowed for precise expansion kinetics. To meet specific requirements due to size variations in patient vertebral bodies, we fabricated a series of molds with varied diameters and explored the expansion kinetics of the OPF cages. Results showed a stable expansion ratio of approximately twofold to the original size within 20 min, regardless of the absolute value of the cage size. Following implantation of a dried OPF cage into a noncontained vertebral defect and its in situ expansion with normal saline, other augmentation biomaterials, such as poly(propylene fumarate) (PPF), can be injected to the lumen of the OPF cage and allowed to crosslink in situ. The OPF/PPF composite scaffold can provide the necessary rigidity and stability to the augmented spine.

Effect of Polyether Ether Ketone on Therapeutic Radiation to the Spine: A Pilot Study

STUDY DESIGN

Cadaveric model.

OBJECTIVES

To compare the effect of PEEK versus conventional implants on scatter radiation to a simulated tumor bed in the spine SUMMARY OF BACKGROUND DATA.: Given the highly vasculature nature of the spine, it is the most common place for bony metastases. After surgical treatment of a spinal metastasis, adjuvant radiation therapy is typically administered. Radiation dosing is primarily limited by toxicity to the spinal cord. The scatter effect caused by metallic implants decreases the accuracy of dosing and can unintentionally increase the effective dose seen by the spinal cord. This represents a dose-limiting factor for therapeutic radiation postoperatively.

METHODS

A cadaveric thorax specimen was utilized as a metastatic tumor model with two separate three-level spine constructs (one upper thoracic and one lower thoracic). Each construct was examined independently. All four groups compared included identical posterior instrumentation. The anterior constructs consisted of either: an anterior polyether ether ketone (PEEK) cage, an anterior titanium cage, an anterior bone cement cage (polymethyl methacrylate), or a control group with posterior instrumentation alone. Each construct had six thermoluminescent detectors to measure the radiation dose.

RESULTS

The mean dose was similar across all constructs and locations. There was more variability in the upper thoracic spine irrespective of the construct type. The PEEK construct had a more uniform dose distribution with a standard deviation of 9.76. The standard deviation of the others constructs was 14.26 for the control group, 19.31 for the titanium cage, and 21.57 for the cement (polymethyl methacrylate) construct.

CONCLUSION

The PEEK inter-body cage resulted in a significantly more uniform distribution of therapeutic radiation in the spine when compared with the other constructs. This may allow for the application of higher effective dosing to the tumor bed for spinal metastases without increasing spinal cord toxicity with either fractionated or hypofractionated radiotherapy.

LEVEL OF EVIDENCE

N/A.

Percutaneous Selective Vertebroplasty: State of the Art Management in Well-Confined Metastatic Vertebral Lesions

Study Design

Prospective cohort study.

Purpose

To evaluate the clinical and radiological results of percutaneous selective vertebroplasty (PSV) as first-line treatment options in the setting of well-confined spinal metastases.

Overview of Literature

Recent technological advances combined with innovative interventional techniques enable an alternative less invasive treatment option for many patients with malignant vertebral body infiltration. Percutaneous vertebral augmentation procedures offer less invasive but effective pain relief to many patients with symptomatic spinal metastatic disease.

Methods

Eleven patients with 21 well-confined metastatic vertebral lesions that had been treated with PSV were included. Pain was evaluated one week, one month, 3 months and 6 months post-procedure using a 10-point visual analogue scale (VAS). A statistical analysis including repeated measures analysis of variance test was used to collectively indicate the presence of any significant differences between different time sequences. Medication usage and range of mobility were also evaluated.

Results

The 11 patients had an average age of 42 years and 54.5% were male. Highly significant improvements in VAS scores at rest and with activity (p<0.001) were evident. There was a significant decrease in rate of medication consumption post-procedure (p<0.05).

Conclusions

PSV can be used successfully as the first-line treatment for well-confined metastatic vertebral lesions. It is also an effective method to decrease pain, increase mobility, and decrease narcotic administration in such patients.

The 100 most cited articles in metastatic spine disease

OBJECTIVE

Despite the growing neurosurgical literature, a subset of pioneering studies have significantly impacted the field of metastatic spine disease. The purpose of this study was to identify and analyze the 100 most frequently cited articles in the field.

METHODS

A keyword search using the Thomson Reuters Web of Science was conducted to identify articles relevant to the field of metastatic spine disease. The results were filtered based on title and abstract analysis to identify the 100 most cited articles. Statistical analysis was used to characterize journal frequency, past and current citations, citation distribution over time, and author frequency.

RESULTS

The total number of citations for the final 100 articles ranged from 74 to 1169. Articles selected for the final list were published between 1940 and 2009. The years in which the greatest numbers of top-100 studies were published were 1990 and 2005, and the greatest number of citations occurred in 2012. The majority of articles were published in the journals Spine (15), Cancer (11), and the Journal of Neurosurgery (9). Forty-four individuals were listed as authors on 2 articles, 9 were listed as authors on 3 articles, and 2 were listed as authors on 4 articles in the top 100 list. The most cited article was the work by Batson (1169 citations) that was published in 1940 and described the role of the vertebral veins in the spread of metastases. The second most cited article was Patchell's 2005 study (594 citations) discussing decompressive resection of spinal cord metastases. The third most cited article was the 1978 study by Gilbert that evaluated treatment of epidural spinal cord compression due to metastatic tumor (560 citations).

CONCLUSIONS

The field of metastatic spine disease has witnessed numerous milestones and so it is increasingly important to recognize studies that have influenced the field. In this bibliographic study the authors identified and analyzed the most influential articles in the field of metastatic spine disease.

Percutaneous kyphoplasty for the treatment of spinal metastases

The bones are the most common location for metastases, which may cause severe pain and damage, including osteolytic destruction and fractures. Pathological fractures of the spine are extremely painful and cause significant disability and morbidity in patients. Traditional open surgery has numerous complications, and radiation therapy may take weeks to become effective. To avoid the trauma and complication of open surgery, percutaneous kyphoplasty (PKP) is a minimally invasive procedure that has played a great role in the treatment of spinal metastases over the past several years. To evaluate the efficacy and safety of the treatment of spinal metastasis using PKP, the present study evaluated 282 patients who had received PKP between April 2009 and June 2014. The efficacy of PKP was evaluated using the visual analog scale for pain (VAS), Karnofsky performance score (KPS) and quality of life (QOL) score (short form with 36 questions). The KPS and QOL were measured pre-operatively and 3 months post-operatively. In addition, radiographical data, including the degree of restoration of the kyphotic angle and the anterior vertebral height, and leakage of bone cement, were measured. The safety of the surgery was assessed by complications and side effects reported during or subsequent to surgery. The present study measured the parameters prior to the surgery and at 24 h, 3 months, 6 months and 1 year post-surgery, as well as at the last follow-up date. The range of the follow-up time was between 105 days and 15 months (mean, 401 days). The 282 patients underwent successful operations and the pain felt by the patients prior to the surgery was significantly alleviated. In addition, the analgesic intake of patients greatly decreased following PKP. KPS improved prior to and 3 months after the surgery. QOL also improved prior to and 3 months after the surgery. Radiographical data demonstrated that the kyphotic angle decreased following PKP, and the anterior vertebral height increased. Paravertebral leakage of bone cement occurred in 10 patients through a cortical defect, but without spinal cord compression or pulmonary embolism. Therefore, as a minimally invasive procedure, PKP may not only rapidly relieve the pain and disability experienced by patients, but it may also restore the kyphotic angle observed at the 1-year follow-up. Notably, PKP may safely improve the QOL of patients.

Incidence and outcome of bone metastatic disease at University Malaya Medical Centre

INTRODUCTION

Morbidity and mortality from malignant diseases are usually the result of metastasis. The bone is the third most common site of metastasis.

METHODS

This is a retrospective study of patients with metastatic bone disease who were referred to the Orthopaedic Department of University Malaya Medical Centre, Malaysia, between January 2004 and October 2009.

RESULTS

A total of 151 patients (51.0% men, 49.0% women) had metastatic bone disease, with the highest incidence at the age range of 50-59 years. The commonest primary cancer was breast (23.3%), followed by lung (21.2%), prostate (9.3%), thyroid (7.3%) and renal cell carcinoma (5.3%); unknown primary cancer was 6.6%. There was long bone involvement in 52.7% of cases, axial bone in 44.5%, and both long and axial bones in 2.8%. The majority (90.1%) were symptomatic, with pain as the commonest symptom. 106 (70.2%) patients had pathological fractures. Neurological deficit was reported in 90.7% of patients, with 41.1% having extraskeletal metastases. 67.8% of the lesions were osteolytic, 24.3% were sclerotic, and 7.9%, mixed. Palliative and therapeutic interventions were undertaken for 62.0% of patients. The mean survival times were: breast 21.0; thyroid 20.7; prostate 20.3; lung 16.0; and unknown primary cancer 32.6 months.

CONCLUSION

In our study, breast and lung cancers were the commonest primary cancers in metastatic bone disease. Most patients had more than one site of involvement, pain at presentation and pathological fractures. Surgery is beneficial to relieve pain and improve function and neurology. Duration of survival depends on the type of primary cancer and whether systemic metastasis is present.

Tokuhashi score and other prognostic factors in 260 patients with surgery for vertebral metastases

BACKGROUND

Metastatic disease of the spine is an increasingly common public health problem. Surgery should be an integral component of the overall cancer treatment plan and, importantly, must neither delay not jeopardize any of the other components. The prognosis governs the choice of the surgical strategy. Tokuhashi et al. developed a prognostic score in 1990, then revised it in 2000 and 2005. Here, our objective was to evaluate the performance of the Tokuhashi score in a cohort of 260 patients and to look for other variables that might improve preoperative outcome prediction.

MATERIAL AND METHOD

We retrospectively established a single-centre cohort of 260 patients who underwent spinal metastasis surgery between 1998 and 2008. For each patient, the following data were collected prospectively: socio-demographic features, history of the malignancy, variables needed to determine the Tokuhashi score, and treatments used. SAS 9.0 software was chosen for the statistical analysis. Variables were described as mean ± SD, overall survival was estimated using the Kaplan-Meier method, and survivals in subgroups were compared by the log-rank test. To assess agreement between survival predicted by the Tokuhashi score and observed survival, we computed Cohen's kappa and interpreted the results according to Landis and Koch.

RESULTS

There were 143 females and 117 males with a mean age of 59 years and overall median survival of 10 months. Median observed survivals in the three Tokuhashi score categories (< 6, 6-12, and > 12 months predicted survival) were 5, 10, and 36 months, respectively. These survival times differed significantly (P < 0.0001). Cohen's kappa indicated moderate agreement between predicted and observed survivals. Other factors associated with significant survival differences were time from cancer diagnosis to metastasis diagnosis (synchronous, < 2 years, 2-5 years, or > 5 years; P < 0.0001) and age (< 70 years or ≥ 70 years, P = 0.0053).

CONCLUSION

Our cohort study supports the validity and reproducibility of the Tokuhashi score. Our finding that shorter time to metastasis diagnosis and age ≥ 70 years were also significantly associated with survival in our population invites further efforts to improve and update the Tokuhashi score.

Status and prospects of percutaneous vertebroplasty combined with ¹²⁵I seed implantation for the treatment of spinal metastases

Metastatic spinal tumours are the most common type of bone metastasis. Various methods have been used to treat metastatic spinal lesions, including radiotherapy, chemotherapy, isotope therapy, bisphosphonate therapy, analgesics, and surgery. Conservative treatments such as radiotherapy and chemotherapy are not appropriate and usually are ineffective in patients with vertebral fractures and/or spinal instability. Minimally invasive surgical treatments using non-vascular interventional technology, such as percutaneous vertebroplasty (PVP), have been successfully performed in the clinical setting. PVP is a non-invasive procedure that creates small wounds and is usually associated with only minor complications. In the present study, we will review the clinical status and prospects for the use PVP combined with ¹²⁵I seed implantation (PVPI) to treat spinal metastases. The scientific evidence for this treatment, including safety, efficacy, and outcome measures, as well as comparisons with other therapies, was analysed in detail. PVPI effectively alleviates pain in metastatic spinal tumour patients, and the use of interstitial ¹²⁵I seed implants can enhance the clinical outcomes. In conclusion, PVPI is a safe, reliable, effective, and minimally invasive treatment. The techniques of PVP and ¹²⁵I seed implantation complement each other and strengthen the treatment’s effect, presenting a new alternative treatment for spinal metastases with potentially wide application.

In vitro and in vivo effects of photodynamic therapy on metastatic breast cancer cells pre-treated with zoledronic acid

BACKGROUND

Photodynamic therapy (PDT), a non-ionizing, minimally invasive drug-light treatment, has recently been shown to successfully ablate tumor within rat vertebrae with concurrent improvements in bone strength and architecture. The bisphosphonate zoledronic acid (zol), a current drug for patients with skeletal metastases, primarily works by inhibiting osteoclast activity, but direct anti-tumor effects have also been reported. However, it is unknown if or how pre-treatment with zol may alter the tumorcidal effect of PDT. The aim of this study was to evaluate the effect of PDT, both in vitro and in vivo, on zol-pretreated cancer cells.

MATERIALS AND METHODS

Human metastatic breast cancer cells (MT-1) were cultured in vitro and treated with zol (10μM) for 24h, followed by PDT treatment. Cell viability was assessed by fluorescence microscopy and flow cytometry. In vivo, MT-1 cells were injected (intracardiac) into athymic rats. On day 7, zol (60μg/kg) was administered subcutaneously. On day 14, PDT was applied (1mg/kg verteporfin; 75J; 690nm) to lumbar vertebrae. Histomorphometric assessment of tumor burden was evaluated on day 21.

RESULTS

The cell viability measured in vitro after PDT treatment decreased in cells pre-incubated with zol up to 20% compared to treatment with PDT alone. Zol alone had no influence on the MT-1 cell viability. In vivo, all treatments, either alone or combined, had a tumorcidal effect.

CONCLUSIONS

Pre-treatment with zol in vivo did not yield a synergistic effect on tumor ablation in contrast to the in vitro results, but neither did it abrogate the positive tumorcidal effect of PDT, so that those therapies may be applied in combination.

[Solitary spinal metastases. Is aggressive surgical management justified?]

Advances in oncological and surgical therapies have led to a significant increase in life expectancy of cancer patients and also prolonged survival of patients with isolated or multiple metastases. Among the skeletal manifestations the spine is the most often affected site. Using novel imaging techniques with higher resolution and use of metabolic signatures, the screening of cancer patients has improved considerably. Consequently, the diagnosis of metastases is becoming increasingly more sensitive. Therefore, but also due to more effective polychemotherapy protocols, singular or solitary metastases are more frequently observed either in the early stages or as a result of a controlled malignant tumor entity (stable disease). The questions whether a solitary metastasis really exists (illusion or reality?) and its radical oncological and surgical treatment as a circumscribed singular tumor manifestation, is really relevant for the overall prognosis, remains controversial. However, it seems evident that a biologically favorable underlying tumor biology, radical treatment of the primary tumor and a long metastasis-free interval are valid predictors of a good oncological outcome. In the presence of a solitary metastasis under these circumstances (typical example: solitary metastasis of renal cell carcinoma many years after radical tumor nephrectomy) a radical surgical procedure (en bloc spondylectomy) can significantly improve the long-term prognosis of this patient group in combination with adjuvant chemotherapy and/or radiotherapy. However, a thorough evaluation of the overall survival prognosis, a detailed and complete staging followed by a treatment consensus in the interdisciplinary tumor board has to precede any therapeutical decisions.

Is surgery for spine metastasis reasonable in patients older than 60 years?

BACKGROUND

Spinal metastases are common in patients older than 60 years with cancer. Because of the uncertainty of survival and the high incidence of fatal complications, however, chemotherapy and radiotherapy generally have been considered preferable and surgery a treatment of last resort for these patients. Further, the selection criteria indicating surgery and reliable prognostic factors for survival remain controversial.

QUESTIONS/PURPOSES

We therefore assessed surgical complications, postoperative function, and risk factors affecting their overall survival.

METHODS

We retrospectively reviewed 92 patients 60 years or older (range, 60-81 years) who had surgery for spinal metastases. The surgical complications were recorded and a VAS pain score, Frankel grade, and Karnofsky score were obtained. Statistical analyses were performed to identify factors associated with survival. The minimum followup was 6 months (mean, 22 months; range, 6-78 months).

RESULTS

Surgical complications occurred in 21 patients. Pain levels decreased postoperatively in 90% of patients and neurologic function improved in 78%. The Karnofsky status improved in 58 patients giving an improvement rate of 63%. The overall survival rates at 1 year and 3 years were 61% and 35% with a median of 15 months. Primary tumor type and Tokuhashi score independently predicted survival in patients with spinal metastases.

CONCLUSION

Our findings suggest surgery for spinal metastasis can achieve pain relief, neurologic improvement, and restoration of general condition but with a high risk of complications. Primary tumor type and Tokuhashi scoring independently predicted survival in patients with spinal metastases after surgery.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Single-stage posterior decompression and stabilization for metastasis of the thoracic spine: prognostic factors for functional outcome and patients' survival

BACKGROUND CONTEXT

There are limited data analyzing radiological and clinical factors for the functional outcomes of surgery for spinal metastasis. Also, there are few studies to investigate the relationship between the functional outcome and the patients' survival. Thus, analysis of both functional outcomes and the survival with their relationship in a possibly homogenous group of patients is worth being reported.

PURPOSE

To assess treatment outcomes of single-stage posterior decompression and stabilization (PDS) with or without corpectomy for thoracic vertebral metastases and to analyze factors affecting both the functional outcome and the patients' survival after the surgical intervention.

STUDY DESIGN

Retrospective observational study.

PATIENT SAMPLE

A consecutive series of 105 patients, who underwent the previously stated surgery for metastatic spinal cord compression (MSCC) of thoracic spine, were included and retrospectively analyzed.

OUTCOME MEASURES

The postoperative functional outcomes were evaluated using visual analog scale and Frankel grade at postoperative 2 weeks, and all patients were followed for survival analysis.

METHODS

An institutional database was searched to identify all patients who underwent single-stage PDS for thoracic metastatic spinal tumors between March 2002 and June 2010. Demographic data as well as preoperative and postoperative medical conditions were collected from medical records. Radiological findings were confirmed on electronic archive. Survival data were obtained either on medical records or with a reference to governmental cancer registry system.

RESULTS

Postoperative pain improvement was more evident in patients receiving anterior column reconstruction and four or more levels of fixation (p=.02 and <0.01, respectively). Twenty-one patients (20%) showed improvement of the Frankel grade, and 10 of 21 Frankel C patients became ambulatory. The preoperative Karnofsky Performance Scale (≥70) and ambulatory status were significant predictors for the postoperative ambulatory function. After surgery, the median overall survival of the patients was 6.0 months. In the univariate analysis, the patient's age (younger than 60 years), type of primary cancer (ie, moderate and slow growth), no visceral metastases, less than three levels of spinal metastases, and postoperative adjuvant therapy were positively significant for the patients' survival (p<.05). In the multivariate analysis, limited (less than three levels) spinal metastases and postoperative adjuvant therapy were proven to significantly prolong the patient's survival (hazard ratios of 0.53 and 0.48, respectively, p<.05). Although the functional outcomes did not directly influence the patients' survival, the patients with better functional outcome showed increased chance of receiving postoperative adjuvant therapy (p<.01).

CONCLUSIONS

Single-stage PDS with or without corpectomy effectively improved the functional status of patients with MSCC of the thoracic spine and also afforded the patients to have more chances of postoperative adjuvant therapy, which was significant for patients' survival. Therefore, we suggest that the role of surgery in the management of MSCC could be not only a symptomatic palliation but also a strategy to prolong patients' survival.

Surgical treatment of sacral metastases: indications and results

OBJECT

Hematogenous metastases to the sacrum can produce significant pain and lead to spinal instability. The object of this study was to evaluate the palliative benefit of surgery in patients with these metastases.

METHODS

The authors retrospectively reviewed all cases involving patients undergoing surgery for metastatic disease to the sacrum at a single tertiary cancer center between 1993 and 2005.

RESULTS

Twenty-five patients (21 men, 4 women) were identified as having undergone sacral surgery for hematogenous metastatic disease during the study period. Their median age was 57 years (range 25-71 years). The indications for surgery included palliation of pain (in 24 cases), need for diagnosis (in 1 case), and spinal instability (in 3 cases). The most common primary disease was renal cell carcinoma. Complications occurred in 10 patients (40%). The median overall survival was 11 months (95% CI 5.4-16.6 months). The median time from the initial diagnosis to the diagnosis of metastatic disease in the sacrum was 14 months (95% CI 0.0-29.3 months). The numerical pain scores (scale 0-10) were improved from a median of 8 preoperatively to a median of 3 postoperatively at 90 days, 6 months, and 1 year (p < 0.01). Postoperative modified Frankel grades improved in 8 cases, worsened in 3 (due to disease progression), and remained unchanged in 14 (p = 0.19). Among patients with renal cell carcinoma, the median overall survival was better in those in whom the sacrum was the sole site of metastatic disease than in those with multiple sites of metastatic disease (16 vs 9 months, respectively; p = 0.053).

CONCLUSIONS

Surgery is effective to palliate pain with acceptable morbidity in patients with metastatic disease to the sacrum. In the subgroup of patients with renal cell carcinoma, those with the sacrum as their solitary site of metastatic disease demonstrated improved survival.

A novel murine model of human renal cell carcinoma spinal metastasis

There is currently no reproducible animal model of renal cell carcinoma (RCC) spinal metastasis that allows for laboratory study of the human disease. In this report, we describe an animal model that reliably reproduces RCC spinal metastasis using a human tumor cell line. A posterior surgical approach was used to implant tumor cells into the lamina of immunosuppressed mice. Histology sections were analyzed 12 weeks after tumor cell implantation to quantify the location and extent of tumor growth. RCC xenografts grew in treated animals (8 mice) with a reproducible pattern of growth. After implantation, tumor growth occurred primarily in the antero-posterior dimension. At 8 weeks after tumor cell implantation, there was visible tumor growth in all treated mice. Histologic correlation at 12 weeks after tumor cell implantation confirmed tumor growth involving primarily the paraspinal region and lamina. Our investigation resulted in an orthotopic model of human RCC spinal metastasis. Ultimately this will allow testing of targeted therapies for RCC with spinal involvement. Furthermore, this model can be expanded to develop similar spinal metastasis models for other tumor cell lines.

Early surgical experience with minimally invasive percutaneous approach for patients with metastatic epidural spinal cord compression (MESCC) to poor prognoses

PURPOSE

This study was designed to assess the impact of minimally invasive surgery (MIS) for the treatment of patients with metastatic epidural spinal cord compression (MESCC) and vertebral body fracture, in terms of feasibility, clinical improvement, and morbidity.

METHODS

Twenty-five consecutive patients with diagnosis of MESCC from solid primary tumors were treated between January 2008 and June 2010 at our institution. All patients, after multidisciplinary assessment, were considered with poor prognosis because of their disease's extension and/or other clinical conditions. Mini-invasive percutaneous surgery was performed in all patients followed by radiotherapy within 2 weeks postoperatively. Clinical outcome was evaluated by modified visual analog scale for pain, Frankel Scale for neurologic deficit, and magnetic resonance imaging or computed tomography scan.

RESULTS

Clinical remission of pain was obtained in the vast majority of patients (96%). Improvement of neurological deficit was observed in 22 patients (88%). No major morbidity or perioperative mortality occurred. The average hospital stay was 6 days. Local recurrence occurred in two patients (8%). Median survival was 10 (range, 6-24) months. Overall survival at 1 year was 43%.

CONCLUSIONS

For patients with MESCC and body fracture, with limited life expectancy, minimally invasive spinal surgery followed by radiotherapy, is feasible and provides clinical benefit in most of patients, with low morbidity. We believe that a minimally invasive approach can be an alternative surgical method compared with more aggressive or demanding procedures, which in selected patients with metastatic spinal cord compression with poor prognosis could represent overtreatment.

Predictors of survival in patients with prostate cancer and spinal metastasis

Object

Prostate cancer is the second most common malignancy to cause death in men, with metastases to the spine being the most common site of metastatic burden. A retrospective observational study was performed to determine survival of patients in whom spinal metastasis from prostate cancer had been diagnosed.

Methods

The patient population was obtained from the Prostate Clinical Research Information System (CRIS) at the Dana-Farber Cancer Institute. Patients were observed over a period of 19 years, between June 1990 and April 2009. Clinical covariates were studied in their relationship to overall survival, the primary outcome, by using the Kaplan-Meier method and Cox regression.

Results

Of a total of 9010 patients in the Prostate CRIS database, 333 were identified as having developed spinal metastases. The median overall survival after diagnosis of spinal metastasis was 24 months (95% CI 21–28 months). The estimated 1-year overall survival was 73% (95% CI 67%–77%). In 85% of patients, at least 1 additional site of metastasis was documented. Among 28 patients who had no additional sites of metastases, the median survival was 55.9 months, whereas an increasing burden of disease was associated with shorter survival (p = 0.0001). The association was observed regardless of whether the metastatic burden was characterized as the presence of additional (nonspinal) bone metastasis, the presence of additional nonbone metastasis, or as the number of concomitant metastatic sites (all p = 0.0001). In multivariate analysis, a higher prostate-specific antigen level at the diagnosis of spinal metastasis, a longer duration between the diagnosis of prostate cancer and spinal metastasis, and the presence of additional metastasis at the time of diagnosis of spinal metastasis (all p = 0.0001) were independently associated with a shorter overall survival.

Conclusions

The results of this study are important for oncologists, neurosurgeons, and primary care physicians who have patients with prostate cancer that metastasizes to the spine, because these results can be used to form a prognosis and guide the physician in making appropriate decisions regarding the patient's treatment. Future work should include building a predictive model that accurately determines survival in patients with metastatic disease, because this would guide the physician in devising the most appropriate treatment plan for each patient.

Survival prognostic factors and clinical outcomes in patients with spinal metastases

PURPOSE

In patients with metastatic disease to the spine, patient selection for surgery and the extent of surgery to perform thereafter remains controversial, with the patient's survival prognosis the most important consideration. For this reason, we conducted a prospective study investigating prognostic factors and clinical outcomes in a consecutive series of patients with vertebral metastases.

METHODS

A total of 142 consecutive patients with vertebral metastases referred to us for consideration of surgery were prospectively enrolled into this study. Of these, 118 patients subsequently underwent palliative surgery for intractable pain or radiculopathy, bony instability or spinal cord compression. Patients were followed up for 12 months or until death. A multivariate analysis of the patients was conducted using the Cox proportional hazards model. The survival predictive accuracy of the Tokuhashi score was also investigated. For the patients who underwent surgery, pre- and post-operative outcomes were assessed on pain, neurological deficit, function and overall quality of life.

RESULTS

The overall 12-month mortality rate was 50.7% and the median survival was 5 months. Multivariate analysis showed that independent prognostic factors for survival after spinal metastases include primary tumour type, Karnofsky functional status, ASA score and pain. Neither the original nor revised Tokuhashi scores were reliable in predicting survival in our European population. In the patients who underwent operative intervention, there was an immediate and prolonged improvement in pain, neurological deficit, function and quality of life in the majority of cases.

CONCLUSIONS

The potential for rapid and maintained improvement in clinical outcome and quality of life should be considered when selecting patients with metastatic disease to the spine for surgery rather than basing decisions solely on survival prognostic factors comprising current scoring systems.

Survival prognostic factors and clinical outcomes in patients with spinal metastases

PURPOSE

In patients with metastatic disease to the spine, patient selection for surgery and the extent of surgery to perform thereafter remains controversial, with the patient's survival prognosis the most important consideration. For this reason, we conducted a prospective study investigating prognostic factors and clinical outcomes in a consecutive series of patients with vertebral metastases.

METHODS

A total of 142 consecutive patients with vertebral metastases referred to us for consideration of surgery were prospectively enrolled into this study. Of these, 118 patients subsequently underwent palliative surgery for intractable pain or radiculopathy, bony instability or spinal cord compression. Patients were followed up for 12 months or until death. A multivariate analysis of the patients was conducted using the Cox proportional hazards model. The survival predictive accuracy of the Tokuhashi score was also investigated. For the patients who underwent surgery, pre- and post-operative outcomes were assessed on pain, neurological deficit, function and overall quality of life.

RESULTS

The overall 12-month mortality rate was 50.7% and the median survival was 5 months. Multivariate analysis showed that independent prognostic factors for survival after spinal metastases include primary tumour type, Karnofsky functional status, ASA score and pain. Neither the original nor revised Tokuhashi scores were reliable in predicting survival in our European population. In the patients who underwent operative intervention, there was an immediate and prolonged improvement in pain, neurological deficit, function and quality of life in the majority of cases.

CONCLUSIONS

The potential for rapid and maintained improvement in clinical outcome and quality of life should be considered when selecting patients with metastatic disease to the spine for surgery rather than basing decisions solely on survival prognostic factors comprising current scoring systems.

Repeat decompression surgery for recurrent spinal metastases

Object

In this paper, the authors' goal was to determine the outcome of reoperation for recurrent epidural spinal cord compression in patients with metastatic spine disease.

Methods

A retrospective chart review was conducted of all patients who underwent spine surgery at the Memorial Sloan-Kettering Cancer Center between 1996 and 2007. Thirty-nine patients who underwent reoperation of the spine at the level previously treated with surgery were identified. Only patients whose reoperation was performed because of tumor recurrence leading to high-grade epidural spinal cord compression or recurrence with no further radiation options were included in the study. Patients who underwent reoperations exclusively for instrumentation failure were excluded. All patients underwent additional decompression via a posterolateral approach without removal of the spinal instrumentation.

Results

Patients underwent 1–4 reoperations at the same level. A median survival time of 12.4 months was noted after the first reoperation, and a median survival time of 9.1 months was noted after the last reoperation. At last follow-up 22 (65%) of 34 patients were ambulatory at the time of last follow-up or death, and the median time between loss-of-ambulation and death was 1 month. Functional status was maintained or improved by one Eastern Cooperative Oncology Group grade in 97% of patients. A major surgical complication rate of 5% was noted.

Conclusions

Reoperation represents a viable option in patients with high-grade epidural spinal cord compression who have recurrent metastatic tumors at previously operated spinal levels. In carefully selected patients, reoperation can prolong ambulation and result in good functional and neurological outcomes.

Outcome of Surgical Treatment for Metastatic Vertebra Bone Tumor in Advanced Lung Cancer

Background

Spinal metastases of patients with advanced stage lung cancer are an important target for palliative therapy, because their incidence is high, and they often cause severe symptoms and worsen the quality of life. Surgery is one of the most effective treatment options, but the indication of surgery is unclear as the procedure is invasive and patients with spinal metastasis have a rather short life expectancy. Furthermore, there have been few studies that have focused on lung cancer with poor prognosis.

Methods

We reviewed all of the cases of lung cancer from January 1999 to July 2007 in the Department of Respiratory Medicine, Kyoto University Hospital, Japan. Thirteen patients with metastatic spinal tumor of lung cancer underwent surgery, and all of them had a poor performance status score (3 or 4).

Results

Neurological improvement by at least 1 Frankel grade was seen in 10 of 14 cases (71%). Improvement of the movement capacity was noted in 9 of 14 cases (64%), and pain improvement was noted in 12 of 14 (86%). Median postoperative survival was 5 months (1–25 months). In particular, the group with a good postoperative performance status score (0–2) was shown to have a better median postoperative survival of 13 months.

Conclusions

Surgical treatment for symptomatic metastatic spinal tumor of lung cancer can improve quality of life in a substantially high percentage of patients. Surgery should be considered even if preoperative performance status is poor.

Review of metastatic spine tumour classification and indications for surgery: the consensus statement of the Global Spine Tumour Study Group

Choosing the right operation for metastatic spinal tumours is often difficult, and depends on many factors, including life expectancy and the balance of the risk of surgery against the likelihood of improving quality of life. Several prognostic scores have been devised to help the clinician decide the most appropriate course of action, but there still remains controversy over how to choose the best option; more often the decision is influenced by habit, belief and subjective experience. The purpose of this article is to review the present systems available for classifying spinal metastases, how these classifications can be used to help surgical planning, discuss surgical outcomes, and make suggestions for future research. It is important for spinal surgeons to reach a consensus regarding the classification of spinal metastases and surgical strategies. The authors of this article constitute the Global Spine Tumour Study Group: an international group of spinal surgeons who are dedicated to studying the techniques and outcomes of surgery for spinal tumours, to build on the existing evidence base for the surgical treatment of spinal tumours.

Survival rate and neurological outcome after operation for advanced spinal metastasis (Tomita's classification > or = type 4)

PURPOSE

We investigated whether primary malignancy entities and the extent of tumor resection have an effect on the survival rate and neurological improvement in patients with spinal metastases that extend beyond the vertebral compartment (Tomita's classification > or = type 4).

MATERIALS AND METHODS

We retrospectively reviewed 87 patients with advanced spinal metastasis who underwent surgery. They were divided into groups 1 and 2 according to whether they responded to adjuvant therapy or not, respectively. They were subdivided according to the extent of tumor resection: group 1, gross total resection (G1GT); group 1, subtotal resection (G1ST); group 2, gross total resection (G2GT); and group 2, subtotal resection (G2ST). The origin of the tumor, survival rate, extent of resection, and neurological improvement were analyzed.

RESULTS

Group 1 had a better survival rate than group 2. The G1GT subgroup showed a better prognosis than the G1ST subgroup. In group 2, the extent of tumor resection (G2GT vs. G2ST) did not affect survival rate. In all subgroups, neurological status improved one month after surgery, however, the G2ST subgroup had worsened at the last follow-up. There was no local recurrence at the last follow-up in the G1GT subgroup. Four out of 13 patients in the G2GT subgroup showed a local recurrence of spinal tumors and progressive worsening of neurological status.

CONCLUSION

In patients with spinal metastases (Tomita's classification > or = type 4), individuals who underwent gross total resection of tumors that responded to adjuvant therapy showed a higher survival rate than those who underwent subtotal resection. For tumors not responding to adjuvant therapy, we suggest palliative surgical decompression.

An orthotopic murine model of human spinal metastasis: histological and functional correlations

OBJECT

There is currently no reproducible animal model of human spinal metastasis that allows for laboratory study of the human disease. Consequently, the authors sought to develop an orthotopic model of spinal metastasis by using a human lung cancer cell line, and to correlate neurological decline with tumor growth.

METHODS

To establish a model of spinal metastasis, the authors used a transperitoneal surgical approach to implant PC-14 lung tumors into the L-3 vertebral body of nude mice via a drill hole. In 24 animals, motor function was scored daily by using the validated semiquantitative Basso-Beattie-Bresnahan (BBB) scale. A second group of 26 animals (6 or 7 per time point) were sacrificed at specific times, and the spines were removed, sectioned, and stained. Canal compromise was analyzed quantitatively by determining the ratio of the area of the neural elements to the area of the spinal canal on histological sections (neural/canal ratio). Correlations between BBB score and histological evaluation of tumor growth were assessed.

RESULTS

Lung cancer xenografts grew in all animals undergoing functional evaluation (24 mice) according to a reliable and reproducible time course, with paraplegia occurring at a median interval of 30 days following tumor implantation (95% CI 28.1-31.9 days). Importantly, the analysis defined 4 key milestones based on components of the BBB score; these were observed in all animals, were consistent, and correlated with histological progression of tumor. From Days 1 to 14, the mean BBB score declined from 21 to 19. The animals progressed from normal walking with the tail up to walking with the tail constantly touching the ground (milestone 1). The median time to tail dragging was 12 days (95% CI 10.8-13.2). Histological studies on Day 14 demonstrated that tumor had progressed from partial to complete VB infiltration, with initial compression of the neural elements and epidural tumor extension to adjacent levels (mean neural/canal ratio 0.32 +/- 0.05, 7 mice). From Days 15 to 20/21 (left/right leg), the mean BBB score declined from 19 to 14. Animals showed gait deterioration, with the development of dorsal stepping (milestone 2). The median time to dorsal stepping was 21 days (95% CI 19.4-22.6) in the left hindlimb and 23 days (95% CI 20.6-25.4) in the right hindlimb. Histological studies on Day 21 demonstrated an increase in the severity of the neural element compression, with tumor extending to adjacent epidural and osseous levels (mean neural/canal ratio 0.19 +/- 0.05, 6 mice). From Days 22 to 26/27 (left/right leg), the mean BBB score declined from 14 to 8. Animals had progressive difficulty ambulating, to the point where they showed only sweeping movements of the hindlimb (milestone 3). The median time to hindlimb sweeping was 26 days (95% CI 23.6-28.4) and 28 days (95% CI 27.1-28.9) in the left and right hindlimbs, respectively. Histological studies on Day 28 revealed progressive obliteration of the spinal canal (mean neural/canal ratio 0.09 +/- 0.01, 7 mice). From Days 29 to 36, the animals progressed to paralysis (milestone 4). The median time to paralysis was 29 days (95% CI 27.6-30.4) and 30 days (95% CI 28.1-31.9) in the left and right hindlimbs, respectively.

CONCLUSIONS

The authors have developed an orthotopic murine model of human spinal metastasis in which neurological decline reproducibly correlates with severity of tumor progression. Although developed for lung cancer, this model can be expanded to study other types of metastatic or primary spinal tumors. Ultimately, this will allow testing of targeted therapies against specific tumor types.

Thoracic spinal cord compression secondary to metastatic synovial sarcoma: case report

Synovial sarcoma is an uncommon malignant soft tissue neoplasm, occurring primarily in adolescents and young adults. It is prevalent in the periarticular soft tissues near large joints of the extremities and rarely involves the trunk. Metastases are not uncommon and usually involve the lungs; metastasis to the thoracic spine is rare. We report the case of a 47-year-old man with a history of synovial sarcoma of the lower back, with subsequent metastases to the lung, penis, and perineum (all previously resected), presenting with a 3-month history of low back pain and lower extremity paresthesias. Magnetic resonance imaging (MRI) demonstrated multiple lesions involving multiple contiguous vertebral bodies, with the mass at T12 compressing the spinal cord. The patient underwent T11-T12 laminectomy, transpedicular decompression, tumor debulking, and posterior fixation and fusion. The patient died six months later due to disease progression. Although not curative, decompression and stabilization of the spine are often necessary in patients who present spinal cord compression.

Percutaneous tumor curettage and interstitial delivery of samarium-153 coupled with kyphoplasty for treatment of vertebral metastases

Object

The object of this study was to investigate the use of a minimally invasive technique for treating metastatic tumors of the vertebral body, aimed at relieving pain, preventing further tumor growth, and minimizing the adverse effects of systemic use of samarium-153 (153Sm).

Methods

The procedure is performed in the same fashion as a kyphoplasty, using a unilateral extrapedicular approach under local anesthesia/mild general sedation, with the patient in the lateral decubitus position. The tumor is accessed as in a standard kyphoplasty. The side is chosen according to the location of the metastasis. Prior to inflation of the balloon the tumor is debulked by percutaneous curettage. Balloon inflation is carried out as per standard kyphoplasty in an attempt to create a larger space and reduce a possible kyphotic deformity. Three mCi of 153Sm-EDTMP (ethylenediaminetetramethylenephosphonic acid) is then mixed with bone cement (polymethylmethacrylate) and injected into the void created by the balloon tamp.

Results

Twenty-four procedures were performed in 19 patients. There was reliable and reproducible delivery of the radiolabeled 153Sm-EDTMP to the metastatic site, without spillage. The procedure was safe. There were no procedure-related complications. There was no hematological toxicity with the low doses of 153Sm used. Pain improved in all patients. The long-term results related to tumor control continue to be investigated.

Conclusions

Combined percutaneous debulking of confined vertebral metastases and administration of local 153Sm is feasible and safe. Furthermore, this technique leads to immediate relief of cancer-related pain and may help prevent or slow down the progression of vertebral metastatic tumors.

Metastatic carcinoma related long segment thoracic spinal epidural hematoma: a case report

STUDY DESIGN

Case report.

OBJECTIVE

To report a long segment epidural hematoma with thoracic cord compression caused by a metastatic carcinoma.

SUMMARY OF BACKGROUND DATA

To our knowledge, there have been no previous reports of spontaneous spinal epidural hematoma caused by metastatic carcinoma.

METHODS

A 60-year-old woman with back pain and progressive leg weakness suddenly developed complete paraplegia and anesthesia below T8. A thoracic spine MRI showed an epidural hematoma and metastatic tumor. We describe the clinical course, radiographic imaging, operative findings, and treatment results.

RESULTS

Despite immediate surgery, the patient failed to have any significant improvement in her neurologic symptoms. A previously unsuspected primary lung tumor was diagnosed. She died 6 months after spine surgery.

CONCLUSION

Spinal epidural hematoma can occur in association with metastatic tumors in that area.

Defining the therapeutic window of vertebral photodynamic therapy in a murine pre-clinical model of breast cancer metastasis using the photosensitizer BPD-MA (Verteporfin)

Breast cancer is known to cause metastatic lesions in the bone, which can lead to skeletal-related events. Currently, radiation therapy and surgery are the treatment of choice, but the success rate varies and additional adjuncts are desirable. Photodynamic therapy (PDT) has been applied successfully as a non-radiative treatment for numerous cancers. Earlier work has shown that the athymic rat model is suitable to investigate the effect of PDT on bone metastasis and benzoporphyrin-derivative monoacid ring A (BPD-MA; verteporfin) has been shown to be a selective photosensitizer. The aim of this study was to define the therapeutic window of photosensitizer with regard to drug and light dose. Human breast carcinoma cells (MT-1)-stable transfected with the luciferase gene-were injected intra-cardiacally into athymic rats. At 14 days, the largest vertebral lesion by bioluminescence imaging was targeted for single treatment PDT. A drug escalating-de-escalating scheme was used (starting drug dose and light energy of 0.2 mg/kg and 50 J, respectively). Outcomes included 48 h post-treatment bioluminescence of remaining viable tumour, histomorphometric assessment of tumour burden, and neurologic evaluation. The region of effect by bioluminescence and histology increased with increasing drug dose and light energy. A safe and effective drug-light dose combination in this model appears to be 0.5 mg/kg BPD-MA and applied light energy of less than 50 J for the thoracic spine and 1.0 mg/kg and 75 J for the lumbar spine. For translation to clinical use, it is an advantage that BPD-MA (verteporfin), a second-generation photosensitizer, is already approved to treat age-related macular degeneration. Overall, PDT represents an exciting potential new minimally-invasive local, safe and effective therapy in the management of patients with spinal metastases.

Effect of hyperglycemia on progressive paraparesis in a rat metastatic spinal tumor model

Object

Hyperglycemia has been shown to potentiate ischemic injury of the spinal cord by quenching vasodilators and potentiating tissue acidosis and free radical production. Steroid-induced hyperglycemia is a common event in the surgical management of metastatic epidural spinal cord compression (MESCC). The goal in this study was to determine whether experimentally induced hyperglycemia accelerates neurological decline in an established animal model of MESCC.

Methods

Sixteen Fischer 344 rats underwent a transabdominal approach for implantation of a CRL-1666 breast adenocarcinoma cell line within the vertebral body of L-6. After 72 hours of recovery from tumor implantation, the animals received intraperitoneal injections every 12 hours of either 2 g/kg dextrose in 5 ml 0.09% saline (hyperglycemia, 8 rats) or 5 ml 0.09% saline alone (normoglycemia, 8 rats). Weights were taken daily, and the hindlimb function was tested daily after tumor implantation by using the Basso-Beattie-Bresnahan (BBB) scale (score range 1–21). Animals were killed at time of paralysis (BBB Score < 7), and the volume of epidural tumor growth within the spinal canal was measured. To determine the degree of hyperglycemia induced by this dextrose regimen, a surrogate group of 10 Fischer 344 rats underwent intraperitoneal injections of 2 g/kg dextrose (5 rats) or 0.09% saline (5 rats) every 12 hours, and serum glucose levels were assessed 1, 3, 6, 8, 10, and 12 hours after injections for 24 hours.

Results

Dextrose versus saline injections resulted in elevated mean serum glucose at 3 (259 vs 103 μg/dl), 6 (219 vs 102 μg/dl), 8 (169 vs 102 μg/dl), and 10 hours (118 vs 99 μg/dl) after injection, returning to normal levels by 12 hours (96 vs 103 μg/dl) just prior to subsequent injection. All rats had normal hindlimb function for the first 8 days after tumor implantation. Hyperglycemic versus normoglycemic rats demonstrated a worsened median BBB score by postimplantation Day 9 (Score 20 vs 21, p = 0.023) through Day 16 (Score 8 vs 12, p = 0.047). Epidural tumor volume demonstrated a near-linear growth rate across both groups; however, hyperglycemic rats developed paralysis earlier (median 15.5 vs 17.5 days, p = 0.0035), with significantly less epidural tumor volume (2.75 ± 0.38 cm3 vs 4 ± 0.41 cm3, p < 0.001) at time of paralysis.

Conclusions

In a rat model of metastatic epidural spinal cord compression, rats maintained in a hyperglycemic state experienced accelerated time to paralysis. Also, less epidural tumor volume was required to cause paralysis in hyperglycemic rats. These results suggest that hyperglycemic states may contribute to decreased spinal cord tolerance to compression resulting from MESCC. Clinical studies evaluating the effect of aggressive glucose control in patients with MESCC may be warranted.

Solitary vertebral metastasis

As survival time increases for many cancers, it is likely that the incidence and prevalence of spinal metastases will increase also. Given that most patients first present with solitary lesions in the spine, proper initial diagnosis and management are of paramount importance in minimizing pain, improving neurologic function, and potentially lengthening survival. Although pain control and standard radiation are still used, spinal stereotactic radiosurgery, vertebroplasty and kyphoplasty, and spinal cord decompression and fusion are now consistently used in aggressive management and offer exciting preliminary results.