Moon-Jun Sohn

SPINAL RADIOSURGICAL TREATMENT FOR THORACIC EPIDURAL CAVERNOUS HEMANGIOMA PRESENTING AS RADICULOMYELOPATHY: TECHNICAL CASE REPORT

OBJECTIVEImage-guided stereotactic radiosurgery (SRS) was applied to a case of spinal epidural cavernous hemangioma in the thoracic spine. This report demonstrates the potential for spinal SRS in treating diseases that have previously required extensive invasive surgery. CLINICAL PRESENTATIONA 27-year-old woman with gait disturbance and shoulder pain radiating into the right upper arm and back presented for clinical evaluation. Magnetic resonance imaging revealed an extraforaminal epidural mass compressing the spinal cord at the T1–T2 and T2–T3 levels of the intervertebral foramen. The patient had previously undergone a decompressive laminectomy and open biopsy. Several months after this surgery, her radiculomyelopathy had not improved and appeared to be progressing. INTERVENTIONIntensity-modulated hypofractionated radiosurgery was performed on the lesion. The patients radicular pain was remarkably improved within days, and associated neurological symptoms had largely disappeared within a few months. Subsequent follow-up magnetic resonance imaging at 12 and 36 months showed that the tumor mass was greatly reduced. No evidence of any complications associated with irradiation was apparent, and the patient continued to demonstrate a positive prognosis. CONCLUSIONA thoracic epidural cavernous hemangioma of proven pathology was successfully treated using state-of-the-art, spinal image-guided SRS. Based on our experience with other types of tumors, we determined that an effective treatment modality for this pathology would be a hypofractionated dose of 32 Gy in 4 fractions. This treatment protocol delivered rapid clinical benefits and long-term tumor control demonstrating the viability of SRS in the treatment of this difficult and rare condition.

Findings from CT, MRI, and PET/CT of a primary malignant melanoma arising in a spinal nerve root

Primary spinal malignant melanoma is an extremely rare condition. We here describe a case of a 71-year-old Asian female presenting with left upper extremity tingling sensation. Computed tomography (CT) showed a homogeneously enhanced mass occupying the left neural foramen at the C6-7 level. Magnetic resonance imaging revealed enhanced mass in intra- and extradural space compressing the spinal cord at this level. It also widened the neural foramen mimicking neurofibroma or schwannoma. Partial resection of the mass was performed. Pathologic diagnosis of the mass was malignant melanoma. Postoperative whole body positron emission tomography/CT scan demonstrated an intense 18F-FDG uptake at the residual mass site without abnormal uptake at other sites in the body.

Clinical analysis of spinal stereotactic radiosurgery in the treatment of neurogenic tumors

OBJECT In this study the authors sought to evaluate clinical outcomes after using stereotactic radiosurgery (SRS) to treat benign and malignant spinal neurogenic tumors. METHODS The authors reviewed a total of 66 procedures of spinal SRS performed between 2001 and 2013 for 110 tumors in 58 patients with spinal neurogenic tumors, which included schwannomas, neurofibromas, and malignant peripheral nerve sheath tumors (MPNSTs). The clinical and radiological findings were evaluated in patients with benign neurogenic tumors. For the 4 patients with MPNSTs, the authors reported overall survival and results of additional immunohistochemical staining to predict the survival difference among the patients. RESULTS Of the 92 benign neurogenic tumors, 65 tumors that were serially followed up using MRI after SRS showed significant change in mean tumor volume, from a mean of 12.0 ± 2.6 cm3 pre-SRS to 10.8 ± 2.5 cm3 post-SRS (p = 0.027), over an average of 44 months. The local control rate of benign neurogenic tumors was 95.4%. The 34 patients who presented with clinical symptoms of pain showed a significant symptomatic improvement. The initial mean visual analog scale (VAS) score was 6.0 and decreased dramatically to 1.0 after SRS during an average follow-up period of 10.9 months (median of 8.1 months). Although the proportions of transient swelling and loss of intramural enhancement were significantly different among the groups, there was no statistically significant correlation between those 2 factors and local tumor control (p = 0.253 and 0.067, respectively; Fishers exact text). Cross-table analysis also indicated that there was no statistically significant relationship between groups with loss of intramural enhancement and transient swelling. The median survival of neurofibromatosis Type 1 (NF1)-related and sporadic MPNSTs was 1.13 and 5.8 years, respectively. Immunohistochemical results showed that S100 was expressed in a sporadic MPNST or neurofibroma, whereas topoisomerase-IIa was expressed in NF1-related MPNSTs. CONCLUSIONS SRS is an effective treatment modality for benign neurogenic tumors, while MPNSTs showed heterogeneity in their responses to SRS.

Are There Differences in The Progression of Ossification of The Posterior Longitudinal Ligament Following Laminoplasty Versus Fusion? A Meta-Analysis.

Study Design. Systematic review and meta-analysis of studies for the treatment of cervical myelopathy with ossification of the posterior longitudinal ligament (OPLL) treated with laminoplasty or fusion. Objective. To delineate whether OPLL continues to progress after laminoplasty compared with fusion and to clarify the relationship between radiological progression of OPLL and neurological decline. Summary of Background Data. Laminoplasty is usually performed in patients with multilevel OPLL due to the surgical morbidity of anterior surgery. However, the disadvantage of laminoplasty is that the remaining OPLL can progress after the surgery. Methods. A literature search of PubMed, Embase, Web of Science, and the Cochrane library was performed to identify investigations concerning the progression of OPLL after laminoplasty or fusion. The pooled results were analyzed by calculating the effect size based on the event rate and the logit event rate. Results. We included data from 11 studies involving 530 patients, of whom 429 underwent laminoplasty and 101 underwent fusion surgery. The prevalence of radiological OPLL progression was 62.5% (95% confidence interval [CI] 55.3%–69.3%) for the laminoplasty group and 7.6% (95% CI 3.4%–15.9%) for the fusion group. The laminoplasty displayed substantially high prevalence of the progression of OPLL compared with the fusion group. In the laminoplasty group, the prevalence of OPLL progression increased with time and reached 60% at about 10-year follow-up. The prevalence for neurological decline was similar for about 2 years, 8.3% (95% CI 3.7%–17.9%) for the laminoplasty group and 3.8% (95% CI 1.3%–10.2%) for the fusion group. Conclusion. Laminoplasty frequently induces progression of OPLL compared with fusion surgery, but does not make significant clinical deterioration. However, laminoplasty may not be recommended for OPLL patient because it can be getting worse with time. Level of Evidence: 1

Analysis of Risk Factors and Management of Cerebrospinal Fluid Morbidity in the Treatment of Spinal Dysraphism

Objective Spinal dysraphism defects span wide spectrum. Wound dehiscence is a common postoperative complication, and is a challenge in the current management of cerebrospinal fluid (CSF) leaks and wound healing. The purpose of this study is to evaluate the risks of CSF-related morbidity in the surgical treatment of spinal dysraphism. Methods Ten patients with spinal dysraphism were included in this retrospective study. The median age of the cohort was 4.8 months. To assess the risk of CSF morbidity, we measured the skin lesion area and the percentage of the skin lesion area relative to the back surface for each patient. We then analyzed the relationship between morbidity and the measured skin lesion area or related factors. Results The overall median skin lesion area was 36.2 cm2 (n=10). The percentage of the skin lesion area relative to the back surface ranged from 0.6% to 18.1%. During surgical reconstruction, 4 patients required subsequent operations to repair CSF morbidity. The comparison of the mean area of skin lesions between the CSF morbidity group and the non-CSF morbidity group was statistically significant (average volume skin lesion of 64.4±32.5 cm2 versus 27.7±27.8 cm2, p<0.05). CSF morbidity tended to occur either when the skin lesion area was up to 44.2 cm2 or there was preexisting fibrosis before revision with an accompanying broad-based dural defect. Conclusion Measuring the lesion area, including the skin, dura, and related surgical parameters, offers useful information for predicting wound challenges and selecting appropriate reconstructive surgery methods.

Population description and clinical response assessment for spinal metastases: part 2 of the SPIne Response Assessment in Neuro-Oncology (SPINO) group report

Background Approximately 40% of metastatic cancer patients will develop spinal metastases. The current report provides recommendations for standardization of metrics used for spinal oncology patient population description and outcome assessment beyond local control endpoints on behalf of the SPIne response assessment in Neuro-Oncology (SPINO) group. Methods The SPINO group survey was conducted in order to determine the preferences for utilization of clinician-based and patient-reported outcome measures for description of patients with spinal metastases. Subsequently, ClinicalTrials.gov registry was searched for spinal oncology clinical trials, and measures for patient description and outcome reporting were identified for each trial. These two searches were used to identify currently used descriptors and instruments. A literature search was performed focusing on the measures identified in the survey and clinical trial search in order to assess their validity in the metastatic spinal tumor patient population. References for this manuscript were identified through PubMed and Medline searches. Results Published literature, expert survey, and ongoing clinical trials were used to synthesize recommendations for instruments for reporting of spinal stability, epidural tumor extension, neurological and functional status, and symptom severity. Conclusions Accurate description of patient population and therapy effects requires a combination of clinician-based and patient-reported outcome measures. The current report provides international consensus recommendations for the systematic reporting of patient- and clinician-reported measures required to develop trials applicable to surgery for spinal metastases and postoperative spine stereotactic body radiotherapy (SBRT).

Phenytoin versus levetiracetam as prophylaxis for postcraniotomy seizure in patients with no history of seizures: systematic review and meta-analysis

OBJECTIVEDe novo seizure following craniotomy (DSC) for nontraumatic pathology may adversely affect medical and neurological outcomes in patients with no history of seizures who have undergone craniotomies. Antiepileptic drugs (AEDs) are commonly used prophylactically in patients undergoing craniotomy; however, evidence supporting this practice is limited and mixed. The authors aimed to collate the available evidence on the efficacy and tolerability of levetiracetam monotherapy and compare it with that of the classic AED, phenytoin, for DSC.METHODSPubMed, Embase, Web of Science, and the Cochrane Library were searched for studies that compared levetiracetam with phenytoin for DSC prevention. Inclusion criteria were adult patients with no history of epilepsy who underwent craniotomy with prophylactic usage of phenytoin, a comparator group with levetiracetam treatment as the main treatment difference between the two groups, and availability of data on the numbers of patients and seizures for each group. Patients with brain injury and previous seizure history were excluded. DSC occurrence and adverse drug reaction (ADR) were evaluated. Seizure occurrence was calculated using the Peto odds ratio (POR), which is the relative effect estimation method of choice for binary data with rare events.RESULTSData from 7 studies involving 803 patients were included. The DSC occurrence rate was 1.26% (4/318) in the levetiracetam cohort and 6.60% (32/485) in the phenytoin cohort. Meta-analysis showed that levetiracetam is significantly superior to phenytoin for DSC prevention (POR 0.233, 95% confidence interval [CI] 0.117-0.462, p < 0.001). Subgroup analysis demonstrated that levetiracetam is superior to phenytoin for DSC due to all brain diseases (POR 0.129, 95% CI 0.039-0.423, p = 0.001) and tumor (POR 0.282, 95% CI 0.117-0.678, p = 0.005). ADRs in the levetiracetam group were cognitive disturbance, thrombophlebitis, irritability, lethargy, tiredness, and asthenia, whereas rash, anaphylaxis, arrhythmia, and hyponatremia were more common in the phenytoin group. The overall occurrence of ADR in the phenytoin (34/466) and levetiracetam (26/432) groups (p = 0.44) demonstrated no statistically significant difference in ADR occurrence. However, the discontinuation rate of AEDs due to ADR was 53/297 in the phenytoin group and 6/196 in the levetiracetam group (POR 0.266, 95% CI 0.137-0.518, p < 0.001).CONCLUSIONSLevetiracetam is superior to phenytoin for DSC prevention for nontraumatic pathology and has fewer serious ADRs that lead to discontinuation. Further high-quality studies that compare levetiracetam with placebo are necessary to provide evidence for establishing AED guidelines.

The Prevalence and Characterization of Cerebral Microbleeds in Young People Having Intracerebral Hemorrhage

Objective Cerebral microbleeds (CMBs) are known as the neuroimaging markers of risk in stroke and dementia. Many studies on CMBs in elderly patients with hemorrhagic or ischemic stroke have been reported; however, reports on CMBs in young populations with intracerebral hemorrhage (ICH) are lacking. Materials and Methods A total of 272 patients aged 18–54 years presented to our hospital with ICH between December 2009 and August 2017. Among these, CMB presence, count, and topography with respect to ICH were evaluated on magnetic resonance imaging (MRI) gradient echo images (GREs). We also evaluated the prevalence and risk factors of CMBs. Results Among 272 patients, only 66 underwent GRE T2-weighted MRI. CMBs were detected in 40 patients (61%), with 29 (73%) being of the multifocal type. Among the 219 CMBs, 150 (68.5%) were of the deep type and 69 (31.5%) of the lobar type. CMB prevalence was higher in men. In multivariate logistic regression analysis, history of hypertension (adjusted odds ratio [aOR], 4.048; 95% confidence interval [CI], 1.14–14.32; p = 0.030), and male sex (aOR, 4.233; 95% CI, 1.09–16.48; p = 0.037) were independently associated with CMBs. Conclusion In young patients who presented with spontaneous ICH, CMBs were highly prevalent in 61% of patients and strongly associated with history of hypertension and male sex.

Hypofractionated Shaped Beam Radiosurgery for Cranial and Spinal Chordomas

Chordomas are rare, malignant tumors that account for between 1 and 4% of all malignant spinal tumors and can occur anywhere between the clivus and the coccyx. The majority of chordomas are found in the rostral (skull base 25–35%) and caudal (sacrococcygeal, 50%) regions, but around 15% of chordomas occur in the mobile spine. Histologically, chordomas present as a lobular arrangement of cells with a mucinous matrix and tend to grow in cords, irregular bands or pseudoacinar forms. Chordomas occur about twice as frequently in males as in females and are predominantly found in adults and the elderly (Cohen-Gadol and Al-Mefty 2008; Pamir and Ozduman 2008; McMaster et al. 2001).

Three Dimensional Dose Verification of Intensity Modulated Radiosurgery Using Polymer-Gel Dosimetry

Polymer gel 3D dosimetry was used to confirm the accuracy of treatment plans produced by the treatment planning software and assess the dosimetric uncertainties of the radiosurgery procedures. The aim of this study is to investigate the 3D dose distribution of intensity-modulated radiosurgery(IMRS) treatment using polymer gel dosimeter for a selected radiosurgery case. A spherical glass flask(160mm-radius) filled with the polymer gel dosimeter was fixed with in the stereotactic head frame. And the intensity modulated radiosurgery(IMRS) treatment procedure was simulated to a selected preclinical concave shaped pituitary tumor closed to the optic pathway. Images of the gel dosimeter were acquired using a Simens 1.5T MR imager. The images transferred to a planning computer for which a data analysis and compare to dose distribution produced by planning software. Reasonable agreement was observed at medium and high doses (50%-80% isodose lines) although differences of up to 10% were observed at low doses (30% isodose line) between the treatment planning system calculation of relative dose distribution and the gel measured data. The gel dosimeter measured dose profiles of pre-planned beams agree within 3% with the beam profiles produced by planning software. The polymer gel dosimeter in combination with MR imaging has been shown to be a valuable devices for verifying three dimensional IMRS dose distribution.