Surgical treatment of intramedullary spinal cord metastases: functional outcome and complications-a multicenter study

An overview of intramedullary spinal cord metastases accompanied by a 2D intraoperative video

Background

Metastatic intramedullary spinal cord metastases (IMSCMs) constitute <2% of spinal cord tumors. IMSCM is a late-stage manifestation of cancer with a highly variable presentation and poor survival rate. Here, we present an operative video involving gross total resection of an IMSCM (i.e., non-small-cell lung cancer [NSCLC]) in a 74-year-old male.

Case Description

A functionally independent 74-year-old male with a history of renal cell carcinoma (i.e., prior nephrectomy) and NSCLC presented with progressive right-sided hemiparesis/hemisensory loss. The patient's magnetic resonance imaging showed a right-eccentric metastatic lesion extending from the inferior of C3 to the superior of C5. The patient underwent a laminectomy with C2-C6 instrumentation for focal en bloc resection of the tumor (i.e., pathologically proven to be NSCLC). During surgery, dorsal column mapping defined the electrophysiological midline before proceeding with the midline myelotomy. Five months postoperatively, the patient's right-sided motor function continued to improve, and he was able to continue adjunctive therapies for his NSCLC.

Conclusion

This study documents the efficacy/utility of gross total en bloc resection in preserving/improving the neurological function of IMSCM lesions in elderly patients.

Understanding metastatic involvement of the conus medullaris: a systematic review of clinical presentations, diagnostic approaches, treatment options, and patient outcomes

INTRODUCTION

Metastasis to the conus medullaris (CM) is a rare but devastating condition. This systematic review aimed to evaluate the clinical presentation, diagnostic workup, treatment options, and outcomes of patients with CM metastasis. By synthesizing the available evidence, this study seeks to improve our understanding of this condition and inform clinical practice.

MATERIALS AND METHODS

A systematic review adhering to PRISMA guidelines analyzed literature on CM metastasis from 1997 to January 2024. Human studies in English were included, focusing on primary research articles. Screening criteria ensured a homogeneous study population, with data analyzed using SPSS 26 and assessed for quality using the JBI checklist.

RESULTS

The study analyzed 88 patients with conus medullaris metastasis. Common symptoms included back pain (49.3%), sensory impairment (75%), and bladder dysfunction (60.3%). MRI was the primary diagnostic tool, revealing lesions above L1 (37%) or between L1 and L2 (29%). Treatment involved surgery with laminectomy, and combined therapy (surgery plus radiotherapy) in 81.3%. Postoperative outcomes showed improved motor function in 59.6% of patients, while combined therapy yielded better sensory and bowel/bladder function recovery. Median survival was 100 days.

CONCLUSION

Metastasis to the conus medullaris is rare but significant. Surgical resection can improve motor function, while combined therapy (surgery plus radiotherapy) is effective in improving sensory manifestations and bowel/bladder functions. Despite these treatments, the median survival remains around 100 days, which is shorter compared to other types of intramedullary spinal cord metastases.

Intramedullary Metastases to Conus Medullaris: A Review of the Literature with a Case Illustration

Introduction: Intramedullary metastases to the conus medullaris spinalis (IMCM) pose a rare problem in neurosurgical oncology and are usually encountered as a complicated clinical scenario in the setting of advanced systemic malignancy with poor overall survival. Despite the progress in interdisciplinary oncological care, their management remains complicated. Research Question: We performed a PRISMA-guided literature search to achieve a pooled analysis of all previously reported IMCM cases that contained detailed clinical data on this problem to investigate the currently employed management options and respective outcomes. We obtained a clinical vignette and performed a comprehensive narrative review of IMCM management. Materials and Methods: The PubMed/MEDLINE/Google Scholar, Cochrane and Embase databases were systematically searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All relevant publications retrieved were subjected to full-text analysis in detail and pertinent information was extracted. Results: The most common systemic primary tumor site as the origin of IMCM was the lung, followed by the breast. Overall, the pooled median survival was 6 months (range 0.5-36 months). Patients who received both surgery and radiation therapy had the longest overall survival (OS) (mean 9.9 months) and those who received no oncological treatment (neither surgery nor adjuvant therapy) had the shortest OS (mean 3.6 months). In cases where surgical resection was performed as part of the treatment plan for metastases, those with partial tumor resection had a more favorable neurological outcome than patients who underwent aggressive gross total resection. Conclusions: Based on the results of our analysis, we find that diligent microsurgical resection (subtotal or total) followed by radiation therapy appears as an effective and suitable treatment in select patients with IMCM. When surgery is not feasible as part of the treatment algorithm, radiation therapy alone (conventional or radiosurgery) also appears to be a suitable treatment option that confers a benefit to the patient.

A critical appraisal of clinical practice guidelines on surgical treatments for spinal metastasis

PURPOSE

As an important treatment for spinal metastasis, surgery has strict applicable conditions. Although various organizations have formulated different guidelines on surgical treatment for spinal metastasis (SM), there are certain differences in the content, standardization and quality of the guidelines and it is necessary to make a critical appraisal of them. We aim to systematically review and appraise the current guidelines on surgical treatments of SM and summarize the related recommendations with the quality evaluation of supporting evidence, as to provide a reference for the standardization of surgical treatment plans, and help clinical front-line medical workers can make safe and effective clinical decisions faster.

METHODS

We searched Pubmed, Web of Science, and Embase for three major databases and online guideline databases. According to certain inclusion and exclusion criteria, the latest guidelines on the surgical treatment of SM were sorted out. AGREE II was used to evaluated the guideline's quality, and we extracted and compared the recommended treatment content of each guideline with evaluating by the evidence-grading scale.

RESULTS

Eight guidelines from 2013 to 2019 were included. Seven guidelines are comprehensive guidelines and one related to the reconstructive surgery of SM. Five guidelines were evaluated as "recommended," and three guidelines were evaluated as "recommended with modifications." Regarding the indications of surgery with SM, four guidelines, seven guidelines, seven guidelines, three guidelines and three guidelines recommended surgical treatment for patients with SM with intractable pain, mechanical instability, metastatic epidural spinal cord compression (MESCC), recurrent spinal metastasis (RSM), and survival predication, respectively. Regarding the surgical strategies, three guidelines recommended minimally invasive therapy but had strict indications. Six guidelines and five guidelines recommend palliative surgery and with receiving radiation therapy, respectively. For the aggressive surgery, only one guideline recommended to apply to patients in good general conditions who has isolated symptomatic SM. Regarding the surgical reconstructions, one guideline didn't recommend iliac bone graft and three guidelines recommended PMMA bone cement.

CONCLUSION

Most of the guidelines do not provide clear criteria for surgical application and provide more of a basic framework. The level of evidence for these surgical recommendations ranges from LOE B to D, and almost all guidelines recommend vertebroplasty and kyphoplasty, but for palliative and more aggressive surgery, which recommended to personalize specific surgical strategies with multidisciplinary collaboration.

Spinal intramedullary uterine carcinosarcoma metastasis

Intramedullary spinal cord metastases (ISCM) are a rare and challenging manifestation of metastatic cancer that have devastating impacts on the individual's neurological function, survival expectancy and overall quality of life. Given the rarity and poor prognosis, there is a lack of consensus in management. Uterine carcinosarcoma itself is a rare cancer, accounting for less than 3% of all uterine cancers. It carries a poor prognosis, with only one-third of patients surviving beyond 5 years. There are no previous reports of uterine carcinosarcoma metastases to the spinal cord. Here, we present the case of a woman in her late 70s with a uterine carcinosarcoma intramedullary metastasis that was refractory to radiotherapy treatment and responded favourably to surgical debulking.

Animal models of brain and spinal cord metastases of NSCLC established using a brain stereotactic instrument

Objective

Animal models of brain and spinal cord metastases of non-small cell lung cancer were established through the intracranial injection of PC-9 Luc cells with a brain stereotaxic device. This method provides a reliable modeling method for studying brain and spinal cord metastases of non-small cell lung cancer.

Methods

PC-9 Luc cells at logarithmic growth stage were injected into the skulls of 5-week-old BALB/c nude mice at different cell volumes (30 × 104, 80 × 104) and different locations (using anterior fontanel as a location point, 1 mm from the coronal suture, and 1.5 mm from the sagittal suture on the right upper and right lower side of the skull). After 1 week of cell inoculation, fluorescence signals of tumor cells in the brain and spinal were detected using the IVIS Xenogen Imaging system. After 4 weeks, brain and spinal tissues from the nude mice were harvested. Following paraffin-embedded sectioning, HE staining was performed on the tissues.

Results

The fluorescence signals revealed that both brain and spinal cord metastasis occurred in the mice where the cells were injected at the lower right side of the skull. There was only brain metastasis in the nude mice injected with 30 × 104 cells at the upper right side of the skull. Both brain and spinal cord metastasis occurred in the nude mice injected with 80 × 104 cells. The HE staining revealed that both brain and spinal cord metastasis occurred in the mice injected with different amounts of PC-9 Luc cells, consistent with the results detected using the IVIS Xenogen Imaging system, thereby demonstrating the reliability of detecting fluorescent signals in vivo to determine tumor growth.

Conclusion

It is a reliable method to establish the animal model of brain and spinal cord metastases of non-small cell lung cancer by injecting different quantities of cells from different positions with a brain stereotaxic device. The IVIS Xenogen Imaging system has high reliability in detecting the fluorescence signals of brain and spinal cord metastatic tumors.

Survival and neurological outcomes following management of intramedullary spinal metastasis patients: a case series with comprehensive review of the literature

Intramedullary spinal cord metastasis (ISCM), though rare, represents a potentially debilitating manifestation of systemic cancer. With emerging advances in cancer care, ISCMs are increasingly being encountered in clinical practice. Herein, we describe one of the larger retrospective single institutional case series on ISCMs, analyze survival and treatment outcomes, and review the literature. All surgically evaluated ISCMs at our institution between 2005 and 2023 were retrospectively reviewed. Demographics, tumor features, treatment, and clinical outcome characteristics were collected. Neurological function was quantified via the Frankel grade and the McCormick score (MCS). The pre- and post-operative Karnofsky performance scores (KPS) were used to assess functional status. Descriptive statistics, univariate analysis, log-rank test, and the Kaplan-Meier survival analysis were performed. A total of 9 patients were included (median age 67 years (range, 26-71); 6 were male). Thoracic and cervical spinal segments were most affected (4 patients each). Six patients (75%) underwent surgical management (1 biopsy and 5 resections), and 3 cases underwent chemoradiation only. Post-operatively, 2 patients had an improvement in their neurological exam with one patient becoming ambulatory after surgery; three patients maintained their neurological exam, and 1 had a decline. There was no statistically significant difference in the pre- and post-operative MCS and median KPS scores in surgically treated patients. Median OS after ISCM diagnosis was 7 months. Absence of brain metastasis, tumor histology (renal and melanoma), cervical/thoracic location, and post-op KPS ≥ 70 showed a trend toward improved overall survival. The incidence of ISCM is increasing, and earlier diagnosis and treatment are considered key for the preservation of neurological function. When patient characteristics are favorable, surgical resection of ISCM can be considered in patients with rapidly progressive neurological deficits. Surgical treatment was not associated with an improvement in overall survival in patients with ISCMs.

[Stereotactic high-dose irradiation for intramedullary metastases]

Intramedullary metastases (IMM) lead to severe neurological symptoms. They are extremely rare in clinical practice. Optimal management of such patients is not clearly defined. Surgery, chemo- and radiotherapy are the main options.

OBJECTIVE

To study the results of stereotactic high-dose irradiation for IMM considering local control of metastases, neurological status and life expectancy.

MATERIAL AND METHODS

Nineteen patients with 29 IMMs underwent high-dose irradiation (Cyber Knife G4 and TrueBeam STx devices) between 2016 and 2022. There were 1-10 fractions, radiation dose 14.0-35.0 Gy with isodose 70-100%. Local control and new spinal cord metastases were assessed using contrast-enhanced MRI. Clinical status and neurological functions were assessed using the Karnofsky and McCormick scales.

RESULTS

Local control rates were 91% and 78% after 6 and 12 months, respectively. Overall survival after treatment was 7.3 months, 6- and 12-month overall survival - 58% and 37%, respectively. In addition, 8 patients were available for follow-up. Of these, 6 ones demonstrated improvement or stabilization of neurological function after treatment. The main cause of death was progression of the underlying disease. No significant treatment-related toxic effects were observed.

CONCLUSION

High-dose irradiation is a safe, effective and time-saving treatment for IMM. Considering unadvisable surgical methods and chemotherapy for this pathology, we can recommend high-dose irradiation for patients with spinal cord metastases.

Prognostic scoring system for surgical treatment of intramedullary spinal cord metastases

Although rare, intramedullary spinal cord metastases (ISCMs) are on the rise, most likely due to prolonged survival and improved outcomes as a result of the advances in cancer treatment for cancer patients. While the management of these lesions remains controversial, surgery for ISCM has recently been advocated for selected patients. We performed a retrospective analysis on 30 patients who were surgically treated for intramedullary spinal cord metastases in order to determine a preoperative prognostic scoring system to guide patient selection for surgical interventions. The scoring system was designed to decide between surgery or other therapeutic procedures. The five parameters selected and employed in the assessment system were: 1) patient's general condition, 2) age, 3) primary site of the cancer, 4) number of other extramedullary metastases and 5) severity of neurologic symptoms. Prognosis could not be predicted from a single parameter. These five factors were added together to give a prognostic score between 1 and 10. The average survival period of patients with a prognostic score between 1 and 3 points was 3 months; 11 patients with a score of 4 and 5 points had a mean survival of 7.63 months, while patients with a prognostic score between 6 and 10 was 14.8 months. According to our prognostic scoring system for surgical treatment of ISCM, surgery should be performed in those patients who score above 6 points, while radiotherapy/chemotherapy or palliative care is recommended for those who score between 1 and 3 points. A prognostic score of 4 and 5 represents a grey area where surgeons must use their judgment on whether to intervene either medically or surgically. This scoring system could facilitate decision-making in the management of patients with intramedullary spinal cord metastases.

Impact of surgical treatment for intramedullary spinal cord metastasis on neurological function and survival: A multicenter retrospective study by the Neurospinal Society of Japan

BACKGROUND

This retrospective multicenter study aimed to analyze the characteristics and surgical outcomes of intramedullary spinal cord metastasis (ISCM) and to discuss the controversy regarding its surgical indications.

METHODS

This study included 29 ISCM patients who underwent surgery between 2009 and 2020. Biopsy cases were excluded from analysis. For functional and neurological functional assessments, Karnofsky Performance Status (KPS, %) and modified McCormick Scale (MMS, 5-grade scale) scores were determined before and after surgery. Patients were divided into two groups: a mild-to-moderate disability group with preoperative MMS grades 1 to 3, and a severe disability group with preoperative MMS grades 4 to 5.

RESULTS

The mean preoperative KPS was 45.9, and the mean duration from symptom onset to surgical intervention was 1 month. The ISCM was located in the cervical spine in 10 cases and the thoracic spine in 19 cases. The access route (myelotomy) for ISCM removal was via the posterior median sulcus in 9 cases and via the posterior lateral sulcus in 11 cases, while others were not recorded. The degree of removal was gross total resection in 20 patients (69%), subtotal resection in 0 patients, and partial removal in 9 patients (31%). No significant complications related to the surgical procedures were recorded. Postoperative adjuvant therapy included radiotherapy in 17 patients (58.6%) and chemotherapy or molecular targeted therapy in 13 patients (44.8%). Pathological findings of ISCM showed that colorectal cancer was the most common in 9 cases, followed by lung cancer in 7, renal cell carcinoma in 5, and breast cancer in 2. Twenty-one of the 29 patients (72.4%) were confirmed to have survived 6 months after surgery: 8 of the 10 patients (80%) in the mild-to-moderate disability group and 13 of the 19 patients (68.4%) in the severe disability group. At 6 months after surgery, 3 of the 8 patients (38%) in the mild-to-moderate group were able to maintain or improve their function. Eleven of the 13 patients (85%) in the severe disability group maintained their function despite being severely disabled.

CONCLUSIONS

This study suggests that surgical treatment can maintain or improve neurological function in a limited number of patients with ISCM, although it had minimal impact on improving the survival rate after surgery.

Indications for Fusion With Intradural Spine Tumor Resection in Adults: A Systematic Review and Meta-analysis

BACKGROUND

The evidence for instrumented fusion in the setting of degenerative, traumatic, or congenital deformity is well established. Data on fusion indications in intradural spinal tumors (IDST) are scarce and reduced to retrospective studies. The objective of this work is to systematically review the published literature since 2015 and analyze the change of practice patterns for stabilization and fusion after intradural tumor resection in adults.

METHODS

A systematic literature review was performed via PubMed with the terms: "intradural spinal tumors", "intramedullary spinal tumors", and "intraspinal tumors". The analysis was limited to adult patients with IDST and studies with more than 10 patients. Data on the proportion of patients who underwent instrumentation and had postoperative deformity was pooled in a meta-analysis.

RESULTS

A total of 1073 articles were identified and 47 papers were selected. All the studies were retrospective series and a total of 2473 patients were included. The follow-up ranged from 1 to 96 months, the pooled spinal fixation rate was 6% (95% CI 4.5%-7.6%), the pooled laminoplasty rate was 14.4% (95% CI 5.9%-23%), the pooled rate of postoperative deformity or malalignment in patients with a follow up of at least 6 months was 2.1% (95% CI 1.2%-3%) and just 7 patients were reoperated due to progressive deformity.

CONCLUSIONS

Based on existing evidence, the rate of fusion during resection of intradural spinal tumors is low. Prophylactic fixation is often unnecessary and only indicated in unique cases that require extensive bony resection.

Bilateral Posterolateral Sulcus Approach for the Removal of Spinal Intramedullary Metastatic Adenocarcinoma: A Technical Case Report

Spinal intramedullary metastasis is an extremely rare event that occurs in advanced cancer. The surgical indications for spinal intramedullary metastasis are highly limited because of surgical difficulty and poor prognosis. In this technical case report, we present a rare case of spinal intramedullary metastasis from the lung that recurred late after local radiation to the spinal cord. The patient progressively experienced relapsed buttock pain and developed gait and urination disorders late after treatment for lung cancer. Imaging examinations suggested the recurrence of spinal intramedullary metastasis in the conus medullaris. Systemic examinations revealed no apparent recurrence in other organs, including the primary lung lesions. Gross total resection of the tumor within the conus medullaris was safely performed using the unilateral posterolateral (PLS) approach and by addition of the contralateral PLS approach. To the best of our knowledge, this is the first case in which a spinal intramedullary metastatic tumor was successfully removed using a bilateral PLS approach.

Clinical Features, Treatments, and Prognosis of Intramedullary Spinal Cord Metastases From Lung Cancer: A Case Series and Systematic Review

Objective

Intramedullary spinal cord metastasis from lung cancer (ISCM-LC) are increasing in prevalence. We aim to investigate its clinical features, treatments and prognosis.

Methods

We reported 6 ISCM-LC cases and conducted a systematic review. Descriptive summarization, survival analysis, and multivariate Cox regression analysis were performed to comprehensively study the disease.

Results

All 6 patients had surgery. One used chemotherapy and the other had targeted drugs. Two patients died of ISCM-LC, 1 died of pulmonary embolism, 1 was alive, and 2 were lost to follow-up. We identified 197 ISCM-LC cases in literature with a mean age of 58 years and male preponderance. Small cell lung cancer accounted for 39.1%. The median interval from lung cancer to ISCM-LC was 7 months. Limb weakness was the most common symptom, and 45% cases progressed rapidly. Concomitant brain, leptomeningeal, and vertebral metastasis occurred to 55.8%, 20%, and 19.5%, respectively. Peritumoral edema appeared in 83.3%. Through survival analysis, we found sex, extraspinal metastasis, pathology, and improved symptoms affected the overall survival. Additionally, gross total resection (GTR) shared similar effectiveness with non-GTR, and other treatments following surgery hardly added extra effect. Surgery, improved symptoms, and sex were 3 independent prognostic factors after adjusting for confounding. The estimated median survival time was 5 months.

Conclusion

The overall survival of ISCM-LC remains poor. Surgery is an independent protective factor for survival. Surgery should be considered once tolerated, and GTR might not be necessary. In addition, female patients with improved symptoms after intervention might have better overall survival.

Surgical treatment of solitary intradural extramedullary spinal cord metastases from solid cancers of non-neurogenic origin. A multicenter study

PURPOSE

Intradural extramedullary spinal metastases (IESM) represent an extremely rare manifestation of systemic cancer. We evaluated the surgical indications, complications and outcome in a series of 43 patients with solitary intradural extramedullary metastases originating from solid cancer of non-neurogenic origin.

METHODS

Patients' age, histopathological diagnoses of primary cancer, tumor size, spinal location, and extramedullary tumor dissemination were collected. Preoperative functional status, pre- and post-operative neurological status, extent of the tumor resection were also analyzed.

RESULTS

The majority of IEMS occurred in the thoracic area, with the most common presenting symptoms ranging from motor (76.7%) to sensory (72%) deficits. Gross total resection was achieved in 55.8% of cases, while In 44.2% of patients a subtotal resection was performed due to strong adherence between the tumor and neural tissue. After surgery, 72.1% of patients exhibited improvement of symptoms in terms of pain relief and partial recovery of motor and/or sensory deficits, while neurologic functional status was severely affected postoperatively in 3 patients.

CONCLUSION

Although there was no statistical significance between the different parameters and overall survival, KPS and the presence of other metastases were the strongest prognostic factors for overall survival and postoperative neurologic outcome.