Dong-Joon Lee

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.

Extraneural metastases of anaplastic oligodendroglioma

Extraneural metastases from primary central nervous system (CNS) tumors are unusual, and glioblastomas and medulloblastomas constitute the majority of these. That oligodendroglioma frequently seeds within the CNS is well known. However, extraneural metastases of anaplastic oligodendroglioma are rare. We report a 50-year-old woman who developed multiple lung and liver metastases 28 months after resection of a temporal lobe anaplastic oligodendroglioma.

Extracranial metastases of a supratentorial primitive neuroectodermal tumour.

Extracranial metastases from primary central nervous system (CNS) tumours have rarely been reported in the literature, and glioblastomas and medulloblastomas constitute the majority of these. The tendency of supratentorial primitive neuroectodermal tumours (PNET) to spread within the CNS is well-known, but few cases of extracranial metastases of supratentorial PNET have been reported. We report a 29-year-old man with a supratentorial PNET, which metastasized to his vertebral bodies and lung.

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.

Novalis Radiosurgery of Optic Gliomas in Children: Preliminary Report

Aim: To evaluate the effectiveness of Novalis radiosurgery (RS) in children with optic gliomas. Methods: Four pediatric patients (1 male and 3 female) were treated for optic gliomas with Novalis RS in our institution between February 2002 and July 2002. Their mean age was 12 (range 5–16) years at presentation for Novalis RS. The mean target dose was 44 (range 41–45) Gy, with a mean fractionation dose of 1.58 (range 1.5–1.65) Gy. Follow-up included magnetic resonance imaging and ophthalmologic and endocrine examinations. Results: The mean follow-up period was 54 (range 50–58) months. During the follow-up period, all patients were alive. Local control of the tumor was obtained in all patients. None of the patients showed clinically relevant morbidity, especially endocrine dysfunction. Conclusions: Novalis RS may be an excellent treatment method for optic gliomas in children. However, long-term follow-up is required for further evaluation of efficacy and potential side effects.

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.

Intraventricular atypical meningiomas.

A rare case of intraventricular meningioma that arose in the atrium of the left lateral ventricle was identified in a 51-year-old woman. Gross total removal was performed by transcortical approach. Histopathological findings showed meningothelial meningioma with a focal atypical area which had 8% of Ki-67 labeling index (LI). A large recurrence extending into the ipsilateral quadrigeminal cistern and opposite medial occipital lobe developed approximately 41 months after the first operation. The specimens obtained from the second resection showed atypical meningioma with 20% of Ki-67 LI but there were no anaplastic area. The patient underwent fractionated stereotactic radiotherapy. However, multiple local distant metastases were found in the occipital and cerebellar cortex suggesting cerebrospinal fluid dissemination apparently 24 months after the second operation. This report presents chronological progression of a rare intraventricular atypical meningioma with more aggressive transformation.

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.

Comparison of beam data using diode and ion chamber in small field of CyberKnife

Ion chamber, diode detector and film are used for measuring small field of SRS. The diode detector is recommended to measure the beam from CyberKnife recently. In this study, various detectors had been used to measure the beam data and compared that for each CyberKnife of domestic and foreign departments.