Diagnosis and treatment of epidural metastases

Dural and Leptomeningeal Diseases: Anatomy, Causes, and Neuroimaging Findings

Meningeal lesions can be caused by various conditions and pose diagnostic challenges. The authors review the anatomy of the meninges in the brain and spinal cord to provide a better understanding of the localization and extension of these diseases and summarize the clinical and imaging features of various conditions that cause dural and/or leptomeningeal enhancing lesions. These conditions include infectious meningitis (bacterial, tuberculous, viral, and fungal), autoimmune diseases (vasculitis, connective tissue diseases, autoimmune meningoencephalitis, Vogt-Koyanagi-Harada disease, neuro-Behçet syndrome, Susac syndrome, and sarcoidosis), primary and secondary tumors (meningioma, diffuse leptomeningeal glioneuronal tumor, melanocytic tumors, and lymphoma), tumorlike diseases (histiocytosis and immunoglobulin G4-related diseases), medication-induced diseases (immune-related adverse effects and posterior reversible encephalopathy syndrome), and other conditions (spontaneous intracranial hypotension, amyloidosis, and moyamoya disease). Although meningeal lesions may manifest with nonspecific imaging findings, correct diagnosis is important because the treatment strategy varies among these diseases. ©RSNA, 2023 Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. Quiz questions for this article are available through the Online Learning Center.

Electrochemotherapy in radiotherapy-resistant epidural spinal cord compression in metastatic cancer patients

OBJECTIVE

To report efficacy and safety of percutaneous electrochemotherapy (ECT) in patients with radiotherapy-resistant metastatic epidural spinal cord compression (MESCC).

MATERIAL/ METHODS

This retrospective study analyzed all consecutive patients treated with bleomycin-based ECT between February-2020 and September-2022 in a single tertiary referral cancer center. Changes in pain were evaluated with the Numerical Rating Score (NRS), in neurological deficit with the Neurological Deficit Scale, and changes in epidural spinal cord compression were evaluated with the epidural spinal cord compression scale (ESCCS) using an MRI.

RESULTS

Forty consecutive solid tumour patients with previously radiated MESCC and no effective systemic treatment options were eligible. With a median follow-up of 5.1 months [1-19.1], toxicities were temporary acute radicular pain (25%), prolonged radicular hypoesthesia (10%), and paraplegia (7.5%). At 1 month, pain was significantly improved over baseline (median NRS: 1.0 [0-8] versus 7.0 [1.0-10], P < .001) and neurological benefits were considered as marked (28%), moderate (28%), stable (38%), or worse (8%). Three-month follow-up (21 patients) confirmed improved over baseline (median NRS: 2.0 [0-8] versus 6.0 [1.0-10], P < .001) and neurological benefits were considered as marked (38%), moderate (19%), stable (33.5%), and worse (9.5%). One-month post-treatment MRI (35 patients) demonstrated complete response in 46% of patients by ESCCS, partial response in 31%, stable disease in 23%, and no patients with progressive disease. Three-month post-treatment MRI (21 patients) demonstrated complete response in 28.5%, partial response in 38%, stable disease in 24%, and progressive disease in 9.5%.

CONCLUSIONS

This study provides the first evidence that ECT can rescue radiotherapy-resistant MESCC.

Simple and Reliable Magnetic Resonance Imaging Parameter to Predict Postoperative Ambulatory Function in Patients With Metastatic Epidural Spinal Cord Compression

STUDY DESIGN

Retrospective case-control study.

OBJECTIVES

The aim of this study was to develop a simple and reliable imaging parameter to predict postoperative ambulatory status in patients with metastatic epidural spinal cord compression (MESCC).

METHODS

Sixty-three patients with MESCC underwent spine surgery because of neurologic deficits were included. On preoperative axial MRI, the cord compression ratio was analyzed for postoperative ambulatory status. The relationship between other imaging features, such as fracture of the affected vertebra and increased T2 signal intensity of the spinal cord at the compression level, and the postoperative ambulatory status were also analyzed.

RESULTS

Cord compression ratio and increased T2 signal change of the spinal cord were significantly different between the postoperative ambulatory group and the non-ambulatory group. Receiver operating characteristic analysis showed that the optimal cut-off value was 0.84. In the multivariate regression analysis, only a cord compression ratio of more than 0.84 was significantly associated with postoperative ambulatory status (odds ratio = 10.80; 95% confidence interval = 2.79-41.86; P = .001). Interobserver/intraobserver agreements were strong for the cord compression ratio, however those agreements were weak for increased T2 signal intensity.

CONCLUSIONS

On preoperative MRI, the cord compression ratio may predict postoperative ambulatory status in patients with MESCC. The measurement of this imaging parameter was simple and reliable. This imaging predictor may be helpful for both clinicians and patients.

Multidisciplinary Management of Brain Metastasis from Breast Cancer

The management of patients with breast cancer and brain metastases (BMs) is exquisitely multidisciplinary. Patients presenting with a symptomatic BM may be offered neurosurgical resection, followed by radiation. Stereotactic radiosurgery (SRS) is preferred over whole-brain radiotherapy (WBRT) in most patients presenting with a limited number of BMs, whereas WBRT with hippocampal-sparing and concomitant memantine is preferred for patients with multiple BMs. There is a growing role for systemic therapy, in some cases in lieu of local therapy, particularly in patients with HER2+ breast cancer.

Deep learning assessment compared to radiologist reporting for metastatic spinal cord compression on CT

Introduction

Metastatic spinal cord compression (MSCC) is a disastrous complication of advanced malignancy. A deep learning (DL) algorithm for MSCC classification on CT could expedite timely diagnosis. In this study, we externally test a DL algorithm for MSCC classification on CT and compare with radiologist assessment.

Methods

Retrospective collection of CT and corresponding MRI from patients with suspected MSCC was conducted from September 2007 to September 2020. Exclusion criteria were scans with instrumentation, no intravenous contrast, motion artefacts and non-thoracic coverage. Internal CT dataset split was 84% for training/validation and 16% for testing. An external test set was also utilised. Internal training/validation sets were labelled by radiologists with spine imaging specialization (6 and 11-years post-board certification) and were used to further develop a DL algorithm for MSCC classification. The spine imaging specialist (11-years expertise) labelled the test sets (reference standard). For evaluation of DL algorithm performance, internal and external test data were independently reviewed by four radiologists: two spine specialists (Rad1 and Rad2, 7 and 5-years post-board certification, respectively) and two oncological imaging specialists (Rad3 and Rad4, 3 and 5-years post-board certification, respectively). DL model performance was also compared against the CT report issued by the radiologist in a real clinical setting. Inter-rater agreement (Gwet's kappa) and sensitivity/specificity/AUCs were calculated.

Results

Overall, 420 CT scans were evaluated (225 patients, mean age=60 ± 11.9[SD]); 354(84%) CTs for training/validation and 66(16%) CTs for internal testing. The DL algorithm showed high inter-rater agreement for three-class MSCC grading with kappas of 0.872 (p<0.001) and 0.844 (p<0.001) on internal and external testing, respectively. On internal testing DL algorithm inter-rater agreement (κ=0.872) was superior to Rad 2 (κ=0.795) and Rad 3 (κ=0.724) (both p<0.001). DL algorithm kappa of 0.844 on external testing was superior to Rad 3 (κ=0.721) (p<0.001). CT report classification of high-grade MSCC disease was poor with only slight inter-rater agreement (κ=0.027) and low sensitivity (44.0), relative to the DL algorithm with almost-perfect inter-rater agreement (κ=0.813) and high sensitivity (94.0) (p<0.001).

Conclusion

Deep learning algorithm for metastatic spinal cord compression on CT showed superior performance to the CT report issued by experienced radiologists and could aid earlier diagnosis.

A Rare Occurrence of Primarily Extranodal Spinal Epidural Lymphoma With Spinal Cord Compression and Invasion to the Thoracic Cavity

A 41-year-old man suffered from progressive radiculomyelopathy caused by spinal epidural mass primarily encasing the spinal cord at the cervicothoracic vertebrae that extended into the thoracic cavity through the neural foramen. An urgent decompressive laminectomy and epidural tumor resection were performed to prevent neurological deterioration and effective spinal cord decompression. The histopathologic diagnosis was diffuse large B-cell lymphoma. As first-line treatment for stage II extranodal lymphoma, he received 6 cycles of R-CHOP (rituximab/cyclophosphamide, hydroxydaunorubicin, Oncovin, and prednisone) chemotherapy. Consequently, follow-up positron-emission tomography CT and MR images demonstrated a complete metabolic response (Deauville score 1). This rare occurrence of primarily extranodal spinal epidural lymphoma with limited disease will be presented in a literature review.

Imaging of metastatic epidural spinal cord compression

Metastatic epidural spinal cord compression develops in 5-10% of patients with cancer and is becoming more common as advancement in cancer treatment prolongs survival in patients with cancer (1-3). It represents an oncological emergency as metastatic epidural compression in adjacent neural structures, including the spinal cord and cauda equina, and exiting nerve roots may result in irreversible neurological deficits, pain, and spinal instability. Although management of metastatic epidural spinal cord compression remains palliative, early diagnosis and intervention may improve outcomes by preserving neurological function, stabilizing the vertebral column, and achieving localized tumor and pain control. Imaging serves an essential role in early diagnosis of metastatic epidural spinal cord compression, evaluation of the degree of spinal cord compression and extent of tumor burden, and preoperative planning. This review focuses on imaging features and techniques for diagnosing metastatic epidural spinal cord compression, differential diagnosis, and management guidelines.

Deep Learning Model for Grading Metastatic Epidural Spinal Cord Compression on Staging CT

Background: Metastatic epidural spinal cord compression (MESCC) is a disastrous complication of advanced malignancy. Deep learning (DL) models for automatic MESCC classification on staging CT were developed to aid earlier diagnosis. Methods: This retrospective study included 444 CT staging studies from 185 patients with suspected MESCC who underwent MRI spine studies within 60 days of the CT studies. The DL model training/validation dataset consisted of 316/358 (88%) and the test set of 42/358 (12%) CT studies. Training/validation and test datasets were labeled in consensus by two subspecialized radiologists (6 and 11-years-experience) using the MRI studies as the reference standard. Test sets were labeled by the developed DL models and four radiologists (2−7 years of experience) for comparison. Results: DL models showed almost-perfect interobserver agreement for classification of CT spine images into normal, low, and high-grade MESCC, with kappas ranging from 0.873−0.911 (p < 0.001). The DL models (lowest κ = 0.873, 95% CI 0.858−0.887) also showed superior interobserver agreement compared to two of the four radiologists for three-class classification, including a specialist (κ = 0.820, 95% CI 0.803−0.837) and general radiologist (κ = 0.726, 95% CI 0.706−0.747), both p < 0.001. Conclusion: DL models for the MESCC classification on a CT showed comparable to superior interobserver agreement to radiologists and could be used to aid earlier diagnosis.

Combined local treatments for vertebral metastases with limited epidural extension

OBJECTIVES

Vertebral metastases with limited epidural extension (VMLEE) are frequently encountered in cancer patients; they can cause severe and debilitating symptoms including pain and neurological impairment and are usually treated by radiotherapy. In this study, we mainly evaluated the safety of combined local treatments (CLT), associating radiofrequency ablation (RFA) with vertebroplasty and radiotherapy (RT) to treat VMLEE. Also, we aimed to evaluate the short-term efficacy of CLT on bone metastases palliation and long-term prevention of skeletal-related events.

METHODS

We retrospectively reviewed treatment complications, pain palliation, and skeletal complications after combined local treatments (CLT) for vertebral metastasis with limited epidural extension (VMLEE).

RESULTS

Eighteen consecutive patients had CLT for 24 VMLEE, between June 2016 and January 2021. No major post-treatment complication was recorded. Nine patients had pain before the initiation of CLT. One month after CLT, only 3 patients had residual pain with a significant decrease of visual analogue scale (VAS), from 7.3 ± 2.4 to 2 ± 0 (p = .008), as well as the mean morphine milligram equivalent dose from 196.6 ± 135.7 to 38.5 ± 26, p = .008. Mean follow-up was 16.7 ± 11.5 months. Only one vertebra showed an increase of a preexisting vertebral fracture. Nine VMLEE had evidence of residual disease, including 2 which resulted in spinal cord compression (2, 11 months).

CONCLUSION

CLT was safe and effective for pain palliation and long-term prevention of skeletal-related events for treatment of patients with VMLEE. The effectiveness of this combined treatment on tumor control and epidural involvement on the long term needs further investigation.

Myelopathies from Neoplasms

Benign and malignant tumors can be an important cause of myelopathy. Patients may present with a wide range of neurologic symptoms including back and neck pain, weakness, sensory abnormalities, and bowel and bladder dysfunction. Management can be challenging depending on the location and underlying biology of the tumor. Neuroimaging of the spine is an important component of diagnostic evaluation and patient management both during initial evaluation and when monitoring after treatment. This article provides a systematic and practical review of neoplasms that can cause myelopathy. Unique imaging and biological features of distinct tumors are discussed, and their management strategies are reviewed.

Development and Validation of a Scoring System for Differential Diagnosis of Tuberculosis and Metastatic Tumor in the Spine

Purpose

Spinal tuberculosis (TB) and metastatic tumor (MT) are common diseases with similar manifestations. Although pathological evaluation is the gold standard to confirm diagnosis, performing biopsies in all patients is not feasible. This study is aimed to create a scoring system to facilitate the differential diagnosis of spinal TB and MT before invasive procedures.

Methods

Altogether, 447 patients with spinal TB (n=198) and MT (n=249) were retrospectively analyzed. Patients were randomly assigned at 2:1 ratio to a training cohort and a validation cohort. Clinical, laboratory, and radiological diagnostic factors were identified by χ² and multiple logistic regression analyses. The scoring system was then established based on the identified independent diagnostic factors scored by regression coefficient β value, with the cut-off value being determined by ROC curve. The sensitivity and specificity of the system was calculated by comparing the predicted diagnosis with their actual pathological diagnosis.

Results

This scoring system was composed of 5 items: pain worsens at night (0 or 2 points), CRP value (0 or 3 points), tumor marker values (0 or 2 points), skip lesions (0 or 3 points), and intervertebral space destruction (0 or 3 points). Patients scoring higher than 7.5 could be diagnosed as spinal TB, otherwise, MT. According to the internal validation, the sensitivity and specificity of the system were 87.9% and 91.6%, respectively.

Conclusion

This study established and validated a scoring system which could be used to differentiate spinal TB from MT, thus helping clinicians in quick and accurate differential diagnosis.

Neoplastic Myelopathies

PURPOSE OF REVIEW

This article reviews the current classification system of primary spinal cord tumors and explores evolving diagnostic and therapeutic strategies for both primary tumors and metastatic tumors to various compartments of the spinal cord.

RECENT FINDINGS

The 2016 World Health Organization classification system allows for more precise prognostication of and therapy for spinal cord tumors and has identified new entities, such as the diffuse midline glioma, H3 K27M mutant. Whole-exome sequencing reveals that the genetic background of primary glial spinal cord neoplasms differs from that of their intracranial histologic counterparts in ways that can potentially influence therapy. Targeted and immune checkpoint therapies have improved survival for patients with melanoma and lung cancer and have simultaneously produced novel complications by enhancing radiation toxicity in some cases and by facilitating the emergence of novel autoimmune and paraneoplastic syndromes involving the spinal cord, such as neuromyelitis optica spectrum disorder and syndromes associated with anti-Hu and collapsin response mediator protein-5 (CRMP-5) antibodies. These conditions must be distinguished from tumor or infection. Epidural spinal cord compression treatment paradigms have changed with the advent of robotic surgery and advances in radiation therapy.

SUMMARY

Neoplastic myelopathies subsume a wide spectrum of pathologies. Neoplastic cord involvement may be primary or secondary and may be approached diagnostically by the particular spinal cord compartment localization. Primary spinal cord tumors account for only 2% to 4% of primary central nervous system tumors, ranging from low-grade glial neoplasms to malignant tumors. Metastatic malignancy to the epidural or leptomeningeal spaces is more common than primary cord tumors. Differential diagnoses arising in the course of evaluation for cord tumors include myelopathies related to radiation or chemotherapy and paraneoplastic syndromes, all of which are sources of significant morbidity. Knowledge of genetic syndromes and the biologic behavior of diverse histologies together with selective application of surgery, radiation, and targeted therapies can facilitate diagnosis, minimize surgical morbidity, and prolong quality of life.

Metastatic spine oncology: symptom-directed management

Spinal tumors pose significant treatment challenges for the physicians treating them. Understanding the location of the tumor within the intramedullary, intradural extramedullary, or extradural (epidural) space is not only critical in determining a differential diagnosis but may also provide important information about current and future neurologic deficits. Despite significant advances in the treatment of spinal tumors over the past few decades, these patients may still experience significant symptoms related to the tumor or its treatment, such as pain, weakness, impaired sensation, and bowel and bladder dysfunction. Treatment of spinal tumors should involve a multidisciplinary team of neuro-oncologists, spine surgeons, medical and radiation oncologists, physiatrists, and pain specialists to provide comprehensive oncologic management, while optimizing the patient's functional status and quality of life.

Red flags of low back pain

Low back pain is a frequent complaint of patients seeking care at private offices, ambulatory clinics, and EDs. Key signs and symptoms can guide clinicians in differentiating acute and persistent mechanical low back pain from back pain resulting from a specific cause. Awareness of these findings can reduce the number of missed or incorrect diagnoses that lead to poor patient outcomes. The ability to recognize the red flag findings of serious causes of low back pain ensures prompt diagnosis and initiation of appropriate treatment. This article highlights the history and physical examination findings that will improve identification of red flags associated with emergency or serious causes.

Distribution and predictive value of initial presenting symptoms in spinal metastases from primary cancer patients

PURPOSE

Primary cancer patients may have some symptoms and develop spinal metastases in their disease progression. This study was to report the distribution and predictive value of specific initial presenting symptoms in patients with spine metastatic disease.

METHODS

The clinical information about patients with primary cancers was retrospectively collected and analyzed at their initial diagnosis from January 2008 to December 2017. The distribution and specific value of initial presenting symptoms were analyzed in predicting spinal metastases.

RESULTS

A total of 14,603 cancer patients were finally included, of whom 1665 (11.4%) cases were confirmed with spinal metastases. 41.55% (6067/14,603) patients had initial presenting symptoms, while 92.19% (1535/1665) patients with spinal metastases presented at least one initial presenting symptoms. Among 6269 patients with symptoms, 1535 (24.49%) were diagnosed with spinal metastases. Factors including primary tumor type, local pain, night-aggravating pain, limb numbness, limb weakness, unstable gait, claudication, loss of sphincter control, and weight loss are associated with the distribution of spinal metastases. The pooled sensitivity, specificity, positive predictive value, and negative predictive value were 90.9% (89.4-92.2%), 64.9% (64.0-65.7%), 24.99% (23.91-26.11%), and 98.23% (97.92-98.50%), respectively. Positive likelihood ratio of "night-aggravating pain" was 33.25 (12.65-87.36) and 17.26 (12.25-24.32) in patients < 45 and 45-64 years old, respectively.

CONCLUSIONS

The distribution of spinal metastases is associated with primary tumor type and initial presenting symptoms. The predictive value of initial presenting symptoms differs in age groups, but resembles in cancer types. The presence of night-aggravating pain had relative high value in predicting metastases in cancer patients under 65 years old.

Neoplastic Myelopathies

PURPOSE OF REVIEW

This article discusses the diagnosis and management of neoplasms that affect the spinal cord as well as spinal cord disorders that can occur due to cancer treatments.

RECENT FINDINGS

Neoplastic myelopathies are uncommon neurologic disorders but cause significant morbidity when they occur. Primary spinal cord tumors can be classified into intramedullary, intradural extramedullary, or extradural tumors. Diffuse gliomas and ependymal tumors are the most common intramedullary tumors. Diffuse gliomas include the World Health Organization (WHO) grade II and grade III astrocytomas, the grade II and grade III oligodendrogliomas, the grade IV glioblastomas, and newly recognized pediatric diffuse midline gliomas with H3 K27M mutation. The majority of diffuse and anaplastic astrocytomas are IDH-mutant tumors, whereas only 10% of glioblastomas are IDH-mutant. Oligodendrogliomas are typically IDH-mutant and are characterized by the molecular signature of 1p/19q codeletion. Nine distinct molecular subgroups of ependymomas have been identified based on their genetic features and location. NF2 mutations are frequently found in spinal cord ependymomas. Metastatic tumors are the most common tumors of the spine and can be extradural, leptomeningeal, or, rarely, intramedullary. Extradural metastatic spinal cord compression is a neurologic emergency and should be promptly diagnosed as pretreatment neurologic status dictates the posttreatment outcome.

SUMMARY

Neoplastic myelopathies encompass many diagnoses ranging from benign and malignant spinal tumors to paraneoplastic syndromes heralding cancers. The knowledge of the clinical features and management of neoplastic myelopathies is essential to practicing neurologists as early diagnosis and treatment can prevent devastating neurologic sequelae.

Epidural adipose tissue-derived mesenchymal stem cell activation induced by lung cancer cells promotes malignancy and EMT of lung cancer

BACKGROUND

Spinal metastasis is a major challenge in patients with advanced lung cancer, but the mechanisms in the organotropism of metastasis are still unclear. Adipose-derived mesenchymal stem cells (ADSCs) exhibit cancer-promoting properties that influence the tumour microenvironment; however, there is no research on ADSCs from epidural fat thus far.

METHODS

In this study, we isolated and identified ADSCs from epidural adipose tissue for the first time. We examined the activation of epidural ADSCs treated with lung cancer cell-conditioned medium by immunohistochemistry, western blot and qRT-PCR assays. The expression of interleukin (IL)-6 family cytokines in the supernatants of ADSCs were evaluated by enzyme-linked immunosorbent assay. The effects of epidural ADSCs on the growth and invasion of lung cancer cells were evaluated with the CCK-8 and Transwell assays. The expression of signal transducer and activator of transcription 3 (STAT3), matrix metalloprotease and epithelial-mesenchymal transition markers were measured by western blot assays.

RESULTS

Our results showed that ADSCs treated with lung cancer cell-conditioned medium expressed higher levels of the myofibroblast marker α-smooth muscle actin and fibroblast activation protein than ADSCs cultured alone. Then, we found that lung cancer cells induced ADSCs to secrete high levels of IL-6 family cytokines and activate the STAT3 signalling pathway. Moreover, activated epidural ADSCs exhibited the ability to promote lung cancer cell proliferation and invasion by elevating matrix metalloprotease expression and epithelial-mesenchymal transition in cancer cells. Furthermore, blocking IL-6 can counteract the differentiation and tumour-promoting effects of ADSCs.

CONCLUSION

Our results suggest that ADSCs respond to lung cancer cells and are involved in the crosstalk between primary tumours and pre-metastatic niches in epidural fat.

Development of Criteria Highly Suggestive of Spinal Tuberculosis

BACKGROUND

In a developing country there is a need for development of criteria that can be used for the diagnosis of spinal tuberculosis, which is common in that region.

METHODS

Demographic, clinical, and radiologic features of spinal tuberculosis and spinal epidural tumors have been compared statistically, and inferences have been drawn in terms of P values, sensitivity, specificity, positive predictive values, and negative predictive values.

RESULTS

A statistically significant relationship was found between spinal tuberculosis and spinal pain, fever, gradually progressive lower limb weakness, contrast-enhancing epidural ± paravertebral lesions, continuous levels affected, spinal deformity, and raised erythrocyte sedimentation rate.

CONCLUSIONS

These relationships were considered the most probable criteria for the diagnosis of spinal tuberculosis.