Epithelioid neoplasm of the spinal cord in a child with spinal muscular atrophy treated with onasemnogene abeparvovec.

Spinal muscular atrophy is an autosomal recessive disease resulting in motor neuron degeneration and progressive life-limiting motor deficits when untreated. Onasemnogene abeparvovec is an adeno-associated virus serotype 9-based gene therapy that improves survival, motor function, and motor milestone achievement in symptomatic and presymptomatic patients. Although the adeno-associated virus genome is maintained as an episome, theoretical risk of tumorigenicity persists should genomic insertion occur. We present the case of a 16-month-old male with spinal muscular atrophy who was diagnosed with an epithelioid neoplasm of the spinal cord approximately 14 months after receiving onasemnogene abeparvovec. In situ hybridization analysis detected an onasemnogene abeparvovec nucleic acid signal broadly distributed in many but not all tumor cells. Integration site analysis on patient formalin-fixed, paraffin-embedded tumor samples failed to detect high-confidence integration sites of onasemnogene abeparvovec. The finding was considered inconclusive because of limited remaining tissue/DNA input. The improved life expectancy resulting from innovative spinal muscular atrophy therapies, including onasemnogene abeparvovec, has created an opportunity to analyze the long-term adverse events and durability of these therapies as well as identify potential disease associations that were previously unrecognized because of the premature death of these patients.

Nomogram for predicting postoperative pulmonary complications in spinal tumor patients.

OBJECTIVES: Although several independent risk factors for postoperative pulmonary complications (PPCs) after spinal tumor surgery have been studied, a simple and valid predictive model for PPC occurrence after spinal tumor surgery has not been developed. PATIENTS AND METHODS: We collected data from patients who underwent elective spine surgery for a spinal tumor between 2013 and 2020 at a tertiary hospital in China. Data on patient characteristics, comorbidities, preoperative examinations, intraoperative variables, and clinical outcomes were collected. We used univariable and multivariable logistic regression models to assess predictors of PPCs and developed and validated a nomogram for PPCs. We evaluated the performance of the nomogram using the area under the receiver operating characteristic curve (ROC), calibration curves, the Brier Score, and the Hosmer-Lemeshow (H-L) goodness-of-fit test. For clinical use, decision curve analysis (DCA) was conducted to identify the model's performance as a tool for supporting decision-making. RESULTS: Among the participants, 61 (12.4%) individuals developed PPCs. Clinically significant variables associated with PPCs after spinal tumor surgery included BMI, tumor location, blood transfusion, and the amount of blood lost. The nomogram incorporating these factors showed a concordance index (C-index) of 0.755 (95% CI: 0.688-0.822). On internal validation, bootstrapping with 1000 resamples yielded a bias-corrected area under the receiver operating characteristic curve of 0.733, indicating the satisfactory performance of the nomogram in predicting PPCs. The calibration curve demonstrated accurate predictions of observed values. The decision curve analysis (DCA) indicated a positive net benefit for the nomogram across most predicted threshold probabilities. CONCLUSIONS: We have developed a new nomogram for predicting PPCs in patients who undergo spinal tumor surgery.

Perioperative complications of en bloc resection and anterior column reconstruction for thoracic and lumbar spinal tumors.

PURPOSE: To evaluate the perioperative clinical outcomes of en bloc resection and anterior column reconstruction for thoracolumbar spinal tumors. METHODS: This study conducted a retrospective analysis of prospective data collection of 86 consecutive patients, including 40 males and 46 females, with an average age of 39 years (ranged from 10 to 71 years). There were 35 cases of a malignant primary tumor,42 cases of an aggressive benign tumor, and nine cases of metastases. The main lesions were located in 65 cases of thoracic spine, 17 cases of lumbar spine, and 4 cases of thoracolumbar spine. Tumors involved one level in 45 patients, two levels in 12 patients, three levels in 21 patients, four levels in five patients, five levels in two patients, and six levels in one patient. RESULTS: According to the Weinstein-Boriani-Biagini surgical staging system, all patients achieved en bloc resections, including 74 cases of total en bloc spondylectomy and 12 cases of sagittal resections. The mean surgical time was 559 min (210-1208 min), and the mean total blood loss was 1528 ml (260-5500 ml). A total of 122 complications were observed in 62(72.1%) patients, of which 18(20.9%) patients had 25 major complications and one patient (1.2%) died of complications. The combined approach (P = 0.002), total blood loss (P = 0.003), staged surgery (P = 0.004), previous surgical history (P = 0.045), the number of involved vertebrae (P = 0.021) and lumbar location (P = 0.012) were statistically significant risk factors for major complication. When all above risk factors were incorporated in multivariate analysis, only the combined approach (P = 0.052) still remained significant. CONCLUSIONS: En bloc resection and anterior column reconstruction is accompanied by a high incidence of complications, especially when a combined approach is necessary.

Complications and local recurrence of chondrosarcoma and chordoma treated by total tumor resection in thoracic and lumbar spine.

BACKGROUND: En bloc resection of spinal tumors is challenging and associated with a high incidence of complications; however, it offers the potential to reduce the risk of recurrence when a wide margin is achieved. This research aims to investigate the safety and efficacy of en bloc resection in treating thoracic and lumbar chondrosarcoma/chordoma. METHODS: Data from patients diagnosed with chondrosarcoma and chordoma in the thoracic or lumbar region, who underwent total en bloc or piecemeal resection at our institution over a 7-year period, were collected and regularly followed up. The study analyzed overall perioperative complications and compared differences in complications and local tumor recurrence between the two surgical methods. RESULTS: Seventeen patients were included, comprising 12 with chondrosarcoma and 5 with chordoma. Among them, 5 cases underwent intralesional piecemeal resection, while the remaining 12 underwent planned en bloc resection. The average surgical time was 684 min (sd = 287), and the mean estimated blood loss was 2300 ml (sd = 1599). Thirty-five complications were recorded, with an average of 2.06 perioperative complications per patient. 82% of patients (14/17) experienced at least one perioperative complication, and major complications occurred in 64.7% (11/17). Five patients had local recurrence during the follow-up, with a mean recurrence time of 16.2 months (sd = 7.2) and a median recurrence time of 20 months (IQR = 12.5). Hospital stays, operation time, blood loss, and complication rates did not significantly differ between the two surgical methods. The local recurrence rate after en bloc resection was lower than piecemeal resection, although not statistically significant (P = 0.067). CONCLUSIONS: The complication rates between the two surgical procedures were similar. Considering safety and local tumor control, en bloc resection is recommended as the primary choice for patients with chondrosarcoma/chordoma in the thoracic and lumbar regions who are eligible for this treatment.

Effectiveness of gelatin matrix with human thrombin for reducing blood loss in palliative decompressive surgery with posterior spinal fusion for metastatic spinal tumors.

BACKGROUND: This study aimed to investigate the effect of gelatin matrix with human thrombin (GMHT) on blood loss and survival time in patients with metastatic spinal tumors treated with palliative decompression surgery with posterior spinal fusion. METHODS: We retrospectively reviewed 67 consecutive patients with metastatic spinal tumors who underwent palliative decompression surgery with posterior spinal fusion. We compared patients in whom GMHT was not used during surgery with those in whom GMHT was used. The following baseline characteristics were evaluated: age, height, weight, sex, metastatic tumor diagnosis, medical history, use of antiplatelet drug, use of anticoagulant drug, use of NSAIDs, smoking, preoperative PLT value, preoperative APTT, preoperative PT-INR, Karnofsky Performance Status score, Charlson comorbidities index score, the percentage of patients who received perioperative chemotherapy, main tumor level, Frankel category, revised Tokuhashi score, spinal instability neoplastic score (SINS), number of fusion segments, operation time, intraoperative blood loss, drainage blood loss, red blood cell transfusion, hemoglobin level, total protein (TP), albumin values, total blood loss (TBL), hidden blood loss, postoperative bed rest and postoperative survival time. Perioperative complications were assessed. RESULTS: Age, height, weight, sex, metastatic tumor diagnosis, medical history, use of antiplatelet drug, use of anticoagulant drug, use of NSAIDs, smoking, preoperative PLT value, preoperative APTT, preoperative PT-INR, CCI score, main level of tumors, SINS score, preoperative Tokuhashi score and number of fusion segments did not differ significantly between the two groups. Operation time, intraoperative blood loss, postoperative drainage blood loss, and TBL were significantly decreased in the group with GMHT than in the group without GMHT. The total number of perioperative complications was significantly lesser in the group with GMHT than in the group without GMHT. The median postoperative survival time was significantly longer in the GMHT group than in the group without GMHT. CONCLUSION: GMHT should be considered a valid option for the treatment of patients with metastatic spinal tumors with a short life expectancy.

Sagittal en bloc resection of thoracolumbar tumours: a report of thirty one cases.

PURPOSE: To develop a novel classification of sagittal en bloc resection (SEBR) based on anatomical locations for thoracolumbar spine tumors and assess the clinical outcomes of this surgical procedure. METHODS: 31 patients with thoracolumbar tumours treated with SEBR were enrolled in this study. The individualized surgical strategy was adopted based on our surgical classification. Demographics, perioperative outcomes, complications and postoperative outcomes were assessed. RESULTS: Based on our surgical classifications, patients were divided into four types. All bony resection margins were negative, wide resection was achieved in 25 patients, marginal resection in four, and intralesional resection in two. 18 patients underwent anterior reconstruction. Complications were encountered in five patients, and instrumentation failure occurred in one patient. The median follow-up was 24 (range, 6-72) months and recurrence was found in only one patient. CONCLUSION: SEBR is a safe and effective surgical procedure for patients with thoracolumbar spinal tumours in specific anatomical locations. The proposed surgical classification covers all SEBR types and is easy to apply, it may assist surgical decision-making in patients with spinal tumours.

MRI-based radiomics nomogram for differentiation of solitary metastasis and solitary primary tumor in the spine.

BACKGROUND: Differentiating between solitary spinal metastasis (SSM) and solitary primary spinal tumor (SPST) is essential for treatment decisions and prognosis. The aim of this study was to develop and validate an MRI-based radiomics nomogram for discriminating SSM from SPST. METHODS: One hundred and thirty-five patients with solitary spinal tumors were retrospectively studied and the data set was divided into two groups: a training set (n = 98) and a validation set (n = 37). Demographics and MRI characteristic features were evaluated to build a clinical factors model. Radiomics features were extracted from sagittal T1-weighted and fat-saturated T2-weighted images, and a radiomics signature model was constructed. A radiomics nomogram was established by combining radiomics features and significant clinical factors. The diagnostic performance of the three models was evaluated using receiver operator characteristic (ROC) curves on the training and validation sets. The Hosmer-Lemeshow test was performed to assess the calibration capability of radiomics nomogram, and we used decision curve analysis (DCA) to estimate the clinical usefulness. RESULTS: The age, signal, and boundaries were used to construct the clinical factors model. Twenty-six features from MR images were used to build the radiomics signature. The radiomics nomogram achieved good performance for differentiating SSM from SPST with an area under the curve (AUC) of 0.980 in the training set and an AUC of 0.924 in the validation set. The Hosmer-Lemeshow test and decision curve analysis demonstrated the radiomics nomogram outperformed the clinical factors model. CONCLUSIONS: A radiomics nomogram as a noninvasive diagnostic method, which combines radiomics features and clinical factors, is helpful in distinguishing between SSM and SPST.

Technical note-in situ laminotomy: preserving posterior tension band in surgery of pediatric multilevel spinal tumor.

BACKGROUND: Laminotomy has been introduced in surgical practice to reduce complications of laminectomy after surgery of tumors in the spinal canal. However, the posterior ligament complex, which is routinely interrupted to remove the laminoplasty segment and gain access to the spinal canal, has a tendency not to heal and can lead to progressive kyphosis and collapse. CASE PRESENTATION: A 5-month-old boy affected by a thoracolumbar extradural tumor extending along seven spinal levels was operated on. The tumor was exposed and completely resected by a one-piece laminotomy with preservation of the integrity of the posterior tension band at both extremities. After 1-year radiological examination ruled out spinal deformity. CONCLUSION: The technique herein presented, which we named in situ laminotomy, allows to fully preserve the posterior tension band without reducing the exposure of the spinal canal in multilevel tumors. Additionally, the technique makes also the reconstruction of the spine elements very easy and rapid. However, longer follow-up is necessary to prove the effectiveness of this procedure in preventing long-term deformity and instability.

Performance assessment and external validation of specific thresholds of total psoas muscle cross-sectional area as predictors of mortality in oncologic spine surgery for spinal metastases.

PURPOSE: The purpose of this study was to assess the utility of low muscle mass (LMM) in predicting 90-day and 12-month mortality after spinal tumor surgery. METHODS: We identified 115 patients operated on for spinal metastases between April 2012 and August 2022 who had available perioperative abdominal or lumbar spine CT scans and minimum 90-day follow-up. LMM was defined as a total psoas muscle cross-sectional area (TPA) at the L4 pedicle level less than 10.5 cm2 for men and less than 7.2 cm2 for women based on previously reported thresholds. A secondary analysis was performed by analyzing TPA as a continuous variable. The primary endpoint was 90-day mortality, and the secondary endpoint was 12-month mortality. Multivariate logistic regression analyses were performed. RESULTS: The 90-day mortality was 19% for patients without and 42% for patients with LMM (p = 0.010). After multivariate analysis, LMM was not independently associated with increased odds of 90-day mortality (odds ratio 2.16 [95% confidence interval 0.62 to 7.50]; p = 0.223). The 12-month mortality was 45% for patients without and 71% for patients with LMM (p = 0.024). After multivariate analysis, LMM was not independently associated with increased odds of 12-month mortality (OR 1.64 [95% CI 0.46 to 5.86]; p = 0.442). The secondary analysis showed no independent association between TPA and 90-day or 12-month mortality. CONCLUSION: Patients with LMM had higher rates of 90-day and 12-month mortality in our study, but this was not independent of other parameters such as performance status, hypoalbuminemia, or primary cancer type.

Clinical management and prognosis of spinal myxopapillary ependymoma: a single-institution cohort of 72 patients.

PURPOSE: Myxopapillary ependymoma (MPE) was classified as grade 2 tumor in the 2021 World Health Organization central nervous system classification because of its high recurrence probability. This study aimed to investigate predictive factors and management of tumor recurrence. METHODS: Seventy-two patients with spinal MPE underwent initial surgical treatment at our hospital between 2011 and 2021. Kaplan-Meier curves and Cox regression were used to analyze the correlation between clinical variables and progression-free survival (PFS). RESULTS: The median age at diagnosis was 33.5 years (range 8-60 years). Twenty-one patients (29.2%) had preoperative spinal drop metastases. Gross total resection (GTR) was performed in 37 patients (51.4%). The median follow-up was 7.2 years, and the follow-up rate was 88.9% (64 of 72 cases). Twelve of the 64 patients (18.9%) relapsed, and preoperative drop metastasis occurred in 7 patients (58.3%). The estimated 5-year and 10-year PFS rates were 82% and 77%, respectively. Univariate analysis showed that GTR was associated with improved PFS (hazard ratio [HR] 0.149, p = 0.014), while preoperative drop metastasis (HR 3.648, p = 0.027) and tumor involvement sacrococcygeal region (HR 7.563, p = 0.003) were associated with tumor recurrence. Adjuvant radiotherapy (RT) was significantly associated with improved PFS in patients with preoperative drop metastasis (p = 0.039). CONCLUSION: Complete surgical resection under the premise of protecting neurological function is an important factor in reducing spinal MPE recurrence. Adjuvant RT is recommended when the tumor invades the capsule with preoperative drop metastasis or adhesion to the nerve and cannot reach GTR.

Comparison of the prognostic factors of total en bloc spondylectomy and total piecemeal spondylectomy in patients with Enneking stage III giant cell tumor in the thoracic and lumbar spine.

PURPOSE: To compare total en bloc spondylectomy with marginal margins against piecemeal spondylectomy with intralesional margins in the surgical treatment of Enneking stage III spinal giant cell tumor (GCT) in terms of local recurrence. METHODS: A retrospective survival analysis of patients with Enneking stage III GCT who underwent TES with marginal margins or total piecemeal spondylectomy with intralesional margins was performed between January 2006 and April 2020. Local recurrence-free survival (LRFS) was the time between the date of surgery and recurrence. Factors with p-values < 0.05 in the univariate analysis were included in the multivariate analysis using proportional hazard analysis. RESULTS: Sixty patients (25 men and 35 women) with a mean age of 35.6 (range 11-71) years were included. The mean follow-up duration was 93 (range 24-198) months. Two patients were lost to follow-up 6 and 14 years after the procedure. Over a 10-year period, the recurrence rate was 13.3%. The 2-, 5-, and 10-year LRFS rates were 95%, 88%, and 78%, respectively. Univariate analysis identified total piecemeal spondylectomy and no adjuvant radiotherapy as prognostic factors for LRFS. Multivariate Cox-regression models showed a significant association between local recurrence and total piecemeal spondylectomy and no adjuvant radiotherapy. CONCLUSION: TES with marginal margins is better than total piecemeal spondylectomy with intralesional margins owing to its lower postoperative recurrence rate. Adjuvant radiotherapy should be administered to reduce postoperative recurrence rates.

Benign Spinal Tumors.

Benign spinal intradural tumors are relatively rare and include intramedullary tumors with a favorable histology such as low-grade astrocytomas and ependymomas, as well as intradural extramedullary tumors such as meningiomas and schwannomas. The effect on the neural tissue is usually a combination of mass effect and neuronal involvement in cases of infiltrative tumors. The new understanding of molecular profiling of different tumors allowed us to better define central nervous system tumors and tailor treatment accordingly. The mainstay of management of many intradural spinal tumors is maximal safe surgical resection. This goal is more achievable with intradural extramedullary tumors; yet, with a meticulous surgical approach, many of the intramedullary tumors are amenable for safe gross-total or near-total resection. The nature of these tumors is benign; hence, a different way to measure outcome success is pursued and usually depends on functional rather than oncological or survival outcomes.

Surgical outcomes and risk factors for surgical complications after en bloc resection following reconstruction with 3D-printed artificial vertebral body for thoracolumbar tumors.

BACKGROUND: The outcomes of patients with tumors of the thoracolumbar spine treated with en bloc resection (EBR) using three-dimensional (3D)-printed endoprostheses are underreported. METHODS: We retrospectively evaluated patients with thoracolumbar tumors who underwent surgery at our institution. Logistic regression analysis was performed to identify the potential risk factors for surgical complications. Nomograms to predict complications were constructed and validated. RESULTS: A total of 53 patients with spinal tumors underwent EBR at our hospital; of these, 2 were lost to follow-up, 45 underwent total en bloc spondylectomy, and 6 were treated with sagittal en bloc spondylectomy. The anterior reconstruction materials included a customized 3D-printed artificial vertebral body (AVB) in 10 cases and an off-the-shelf 3D-printed AVB in 41 cases, and prosthesis mismatch occurred in 2 patients reconstructed with the off-the-shelf 3D-printed AVB. The median follow-up period was 21 months (range, 7-57 months). Three patients experienced local recurrence, and 5 patients died at the final follow-up. A total of 50 perioperative complications were encountered in 29 patients, including 25 major and 25 minor complications. Instrumentation failure occurred in 1 patient, and no prosthesis subsidence was observed. Using a combined surgical approach was a dependent predictor of overall complications, while Karnofsky performance status score, lumbar spine lesion, and intraoperative blood loss ≥ 2000 mL were predictors of major complications. Nomograms for the overall and major complications were constructed using these factors, with C-indices of 0.850 and 0.891, respectively. CONCLUSIONS: EBR is essential for the management of thoracolumbar tumors; however, EBR has a steep learning curve and a high complication rate. A 3D-printed AVB is an effective and feasible reconstruction option for patients treated with EBR.

Isolated neural arch tuberculosis with tuberculomas: case report.

We reported a case of atypical spinal tuberculosis on the posterior elements of lumbar spine in a 52-year-old female. It was easy to be misdiagnosed as spinal tumor due to its imaging characteristics. We performed puncture biopsy to initially consider tuberculosis, and then the patient was accepted surgical treatment. The intraoperative removed specimen was sent to pathological examination, microbial culture, Xpert MTB/RIF and metagenomic next-generation sequencing (mNGS) and then the diagnosis of neural arch tuberculosis was confirmed. After operation, the patient obtained stable effect by anti-tuberculosis drug treatment. In a word, the uncommon case had an important reference significance for the diagnosis of atypical spine tuberculosis and differentiation from spinal tumors. It is critical to make right preliminary diagnosis by appropriate examination as it determined the next diagnosis and treatment in special and rare clinical cases.

Malignant transformation of adult-onset pilocytic astrocytoma to diffuse leptomeningeal glioneuronal tumor within the thoracic spine: a case report and review of the literature.

We describe a 31-year-old male who presented with progressive myelopathy from a thoracic pilocytic astrocytoma (PA). Following multiple recurrences and resections, 10 years after his index surgery, pathology revealed diffuse leptomeningeal glioneuronal tumor (DLGNT) with high-grade features. We discuss his clinical course, management, histopathological findings, and present a comprehensive review of spinal PA undergoing malignant transformation in adults and adult-onset spinal DLGNT. To our knowledge, we present the first reported case of adult-onset spinal PA malignant transformation to DLGNT. Our case adds to the paucity of clinical data characterizing such transformations and highlights the importance of developing novel management paradigms.

Approaches to Incidental Intradural Tumors of the Spine in the Pediatric Population.

BACKGROUND: Incidental intradural tumors of the spine in the pediatric population are rare lesions whose management remains unclear. Surgeons must balance the risks of iatrogenic deficits and complications after surgical resection against the risks from progressive growth of the tumor. Moreover, the natural history of an incidental finding can be difficult to predict. Here, we review the literature on incidental intradural tumors of the spine and present considerations for their management. SUMMARY: Growth of the tumor or changes in radiographic features are usually indications for resection. Asymptomatic lesions can be found in patients with genetic syndromes that predispose to tumor formation, such as neurofibromatosis type 1 and 2, schwannomatosis, and Von-Hippel-Lindau syndrome, and careful workup of a genetic cause is warranted in any patient presenting with multiple tumors and/or cutaneous features. Close follow-up is generally favored given the heavy tumor burden; however, some recommend pre-emptive resection to prevent permanent neurological deficits. Incidental intradural tumors can also occur in association with hydrocephalus, significant syringomyelia, and cord compression, and surgical treatment is usually warranted. Tumors may also be discovered as part of the workup for scoliosis, where they are not truly incidental to the scoliosis but rather are contributing to curve deformation. KEY MESSAGES: Thorough workup of patients for associated genetic syndromes or comorbidities should be undertaken in pediatric patients with incidental intradural tumors. Further research is needed into the natural history of these incidental lesions. Incidental tumors can often be managed conservatively with close follow-up, with surgical intervention warranted for expanding tumors or new-onset symptoms.

Total en bloc spondylectomy of thoracic giant cell tumor with secondary aneurysmal bone cyst: case reports and review of literature.

Spinal giant cell tumor (GCT) combined with secondary aneurysmal bone cyst (ABC) is a locally aggressive primary bone tumor. Total en bloc spondylectomy has never been reported to treat thoracic GCT combined with secondary ABC. We retrospectively reviewed two cases of spinal GCT combined with secondary ABC. A 41-year-old male patient was presented with back pain due to irregular expansive bone destruction involving the T6 vertebral body and intraspinal space-occupying lesion. Total en bloc spondylectomy of T6 vertebra was performed with good neurological status after the surgery. A 29-year-old female patient was presented with right scapular region pain due to irregular expansive bone destruction involving the T5 vertebral body and intraspinal space-occupying lesion. Total en bloc spondylectomy of T5 vertebra was performed with good neurological status after the surgery. Adjuvant radiation therapy was applied after the surgery without local recurrence at the 12-month or 24-month follow-up. Spinal GCT combined with secondary ABC appears to have a high local recurrence rate. Therefore, total en bloc spondylectomy should be applied to treat thoracic GCT combined with secondary ABC.

Respiratory motion tracking of spine stereotactic radiotherapy in prone position.

PURPOSE: The CyberKnife system is a specialized device for non-coplanar irradiation; however, it possesses the geometric restriction that the beam cannot be irradiated from under the treatment couch. Prone positioning is expected to reduce the dose to normal lung tissue in spinal stereotactic body radiotherapy (SBRT) owing to the efficiency of beam arrangement; however, respiratory motion occurs. Therefore, the Xsight spine prone tracking (XSPT) system is used to reduce the effects of respiratory motion. The purpose of this study was to evaluate the motion-tracking error of the spine in the prone position. MATERIALS AND METHODS: Data from all 25 patients who underwent spinal SBRT at our institution between April 2020 and February 2022 using CyberKnife (VSI, version 11.1.0) with the XSPT tracking system were retrospectively analyzed using log files. The tumor motion, correlation, and prediction errors for each patient were examined. Furthermore, to assess the potential relationships between the parameters, the relationships between the tumor-motion amplitudes and correlation or prediction errors were investigated using linear regression. RESULTS: The tumor-motion amplitudes in each direction were as follows: superior-inferior (SI), 0.51 ± 0.39 mm; left-right (LR), 0.37 ± 0.29 mm; and anterior-posterior (AP), 3.43 ± 1.63 mm. The overall mean correlation and prediction errors were 0.66 ± 0.48 mm and 0.06 ± 0.07 mm, respectively. The prediction errors were strongly correlated with the tumor-motion amplitudes, whereas the correlation errors were not. CONCLUSIONS: This study demonstrated that the correlation error of spinal SBRT in the prone position is sufficiently small to be independent of the tumor-motion amplitude. Furthermore, the prediction error is small, contributing only slightly to the tracking error. These findings will improve the understanding of how to compensate for respiratory-motion uncertainty in the prone position.

Spinal intravascular papillary endothelial hyperplasia. Case report and review of the literature.

Intravascular papillary endothelial hyperplasia (Masson's vegetated hemangioendothelioma) is a rare condition affecting the neuroaxis. In the literature, only eight cases of this lesion involving the vertebral canal with spinal cord compression has been reported. We present a 37-year-old man with thoracic location mimicking schwannoma. Differential diagnosis, management, and review of literature are discussed in this short report.

Intradural extramedullary tumor location in the axial view affects the alert timing of intraoperative neurophysiologic monitoring.

OBJECTIVE: Intraoperative neurophysiologic monitoring (IONM) reportedly helps prevent postoperative neurological complications following high-risk spinal cord surgeries. There are negative and positive reports about using IONM for intradural extramedullary (IDEM) tumors. We investigated factors affecting alerts of IONM in IDEM tumor surgery. METHODS: We analyzed 39 patients with IDEM tumors who underwent surgery using IONM at our hospital between January 2014 and March 2021. Neurological symptoms were evaluated pre- and postoperatively using the manual muscle test (MMT). All patients were evaluated to ascertain the tumor level and location in the axial view, the operative time, intraoperative bleeding volume, and histological type. Additionally, the intraoperative procedure associated with significant IONM changes in transcranial electrical stimulation muscle-evoked potential was investigated. RESULTS: There were 11 false-positive and 16 true-negative cases. There was one true-positive case and one false-negative case; the monitoring accuracy achieved a sensitivity of 50%, a specificity of 59%, a positive predictive value of 8%, and a negative predictive value of 94%. In the 22 alert cases, if the tumor was located anterolateral in the axial view, alerts were triggered with a significant difference (p = 0.02) during tumor resection. Alerts were generated for fifteen patients during tumor resection; nine (60%) showed waveform improvement by intervention and were classified as rescue cases. CONCLUSION: Alert is probably triggered during tumor resection for anterolaterally located tumors. Alerts during tumor resection procedures were more likely to be rescued than other procedures in IDEM tumor surgery.