• Journal of Korean Neurosurgical Society
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• v.30 no.6
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• pp.755-760
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• 2001

Objective : To determine the feasibility of translabyrinthine approach in the vestibular schwannoma patients, the authors reviewed eighteen consecutive cases, focusing at their functional outcome and operative complications. Materials and Method : To evaluate the functional outcome, we reviewed preoperative radiological findings such as size of tumors and location of jugular bulb as well as the preoperative neurological status including audiometric analysis and cranial nerve function in 18 patients, diagnosed as vestibular schwannoma. Also the surgical outcome was evaluated according to the functional preservation of facial nerve and incidence of the surgical complication as well as the extent of surgical resection. Results : The age of patients ranged from 21 to 62 years, with a mean of 50 years. Of 18 patients operated in our center by the translabyrinthine approach, wide exposure with total removal of the mass was possible in 16 cases (88.8%). The facial nerve was anatomically preserved in 88.8%. At six-month follow-up, facial nerve function was good(Grade I-II) in 15 patients(83%) and acceptable(I-IV) in all patients. Although the jugular bulb was highly placed is five patients, gross total resection was possible without facial nerve injury in all patients by the translabyrinthine approach. One patient experienced CSF leakage after surgery, but there was no patient with disabling deficit. Conclusion : Use of the translabyrinthine approach for removal of vestibular schwannomas resulted in good anatomical and functional preservation of the facial nerve, with minimal incidence of morbidity and no mortality. In cases of high jugular bulb impacted into mastoid bone, total removal was possible by displacing the jugular bulb with Surgicel cellulose and placement of bone wax.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.5019-5024
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• 2015

Background: The purpose of this study was to assess the dosimetric and clinical feasibility of volumetric modulated arc based hypofractionated stereotactic radiotherapy (RapidArc) treatment for large acoustic schwannoma (AS >10cc). Materials and Methods: Ten AS patients were immobilized using BrainLab mask. They were subject to multimodality imaging (magnetic resonance and computed tomography) to contour target and organs at risk (brainstem and cochlea). Volumetric modulated arc therapy (VMAT) based stereotactic plans were optimized in Eclipse (V11) treatment planning system (TPS) using progressive resolution optimizer-III and final dose calculations were performed using analytical anisotropic algorithm with 1.5 mm grid resolution. All AS presented in this study were treated with VMAT based HSRT to a total dose of 25Gy in 5 fractions (5fractions/week). VMAT plan contains 2-4 non-coplanar arcs. Treatment planning was performed to achieve at least 99% of PTV volume (D99) receives 100% of prescription dose (25Gy), while dose to OAR's were kept below the tolerance limits. Dose-volume histograms (DVH) were analyzed to assess plan quality. Treatments were delivered using upgraded 6 MV un-flattened photon beam (FFF) from Clinac-iX machine. Extensive pretreatment quality assurance measurements were carried out to report on quality of delivery. Point dosimetry was performed using three different detectors, which includes CC13 ion-chamber, Exradin A14 ion-chamber and Exradin W1 plastic scintillator detector (PSD) which have measuring volume of $0.13cm^3$, $0.009cm^3$ and $0.002cm^3$ respectively. Results: Average PTV volume of AS was 11.3cc (${\pm}4.8$), and located in eloquent areas. VMAT plans provided complete PTV coverage with average conformity index of 1.06 (${\pm}0.05$). OAR's dose were kept below tolerance limit recommend by American Association of Physicist in Medicine task group-101(brainstem $V_{0.5cc}$ < 23Gy, cochlea maximum < 25Gy and Optic pathway <25Gy). PSD resulted in superior dosimetric accuracy compared with other two detectors (p=0.021 for PSD.

• Archives of Plastic Surgery
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• v.42 no.6
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• pp.800-802
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• 2015

• Journal of Chest Surgery
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• v.38 no.3 s.248
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• pp.249-252
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• 2005

Neurogenic tumors of the brachial plexus region are relatively rare. We report a recent experience of schwannoma of the right brachial plexus in the inferior trunk, which was successfully treated by microsurgical resection. A 38-year- old man presented a dysesthetic pain in the supraclavicular area and the right forearm of C6, 7 dermatome. Rubbery hard mass was palpated in the right supraclavicular area and magnetic resonance imaging showed a well circumscribed, well enhanced ovoid mass with cystic degeneration on the right brachial plexus portion. The patient underwent complete removal of the mass through the anterior cervicothoracic (modified Dartevelle) approach. At the postoperative 3 months, there is no neurologic deficit.

• The Korean Journal of Pain
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• v.18 no.2
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• pp.255-258
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• 2005

Many patients with intractable chest pain visit pain clinics, two of which, with rare cases of an intraspinal tumor and malignant mesothelioma were experiences at our clinic. A 37-year old female patient presented with exacerbating chest pain, but without neurological manifestations, of 15-months duration. Her laboratory findings, such as blood tests, chest X-ray, EKG, abdominal ultrasonography and chest CT, were normal. MRI revealed an intradural extramedullary schwannoma at the T 5 and 6 levels of the thoracic spine. She completely recovered following a laminectomy, with removal of the tumor. The other case was a 65-year old male patient, who presented with chest and back pain in the thoracic area of 6 months duration. He had no cough and dyspnea, and was initially misdiagnosed with intercostal neuralgia; therefore, pain control medication was administered, but all trials were ineffective. Finally, chest CT revealed a malignant mesothelioma, with multiple spine metastases. In conclusion, patients with intractable chest pain should be re-examined both clinically and radiographically.

• Journal of Korean Neurosurgical Society
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• v.42 no.6
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• pp.450-454
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• 2007

Objective : The aim of this study was to identify the anatomical location and course of the facial nerve (FN) and their relationship to the tumor size in surgically treated vestibular schwannomas. Methods : A retrospective study was conducted on 163 patients who had been treated by the microsurgical resection for a newly diagnosed vestibular schwannoma between 1995 and 2005 (mean age of 46.1 years; 108 females and 55 males). Surgery was carried out via retrosigmoid approach in all patients with the electromyographic monitoring for the FN function. The anatomical location and course of the FN along the tumor surface were verified in each patient during the microsurgery, and were classified into 4 groups : 1) the FN displaced along the ventral and superior surface of the tumor (VS); 2) the ventral and central (VC); 3) the ventral and inferior (VI); and 4) the dorsal (Do). Results : The FN displacement was identified as the followings : VS in 91 patients (55.8%); VC in 57 (35.0%); VI in 14 (8.6%); and Do in 1 (0.6%). In the subgroup with tumors less than 2 cm in diameter (n=23), the FN was displaced along the ventral and central surface of the tumor in the majority (65.2%), whereas, in the patients with tumors larger than 2cm (n=140), it was displaced along the ventral and superior surface most frequently (59.3%). Conclusion : The FN can be displaced variably in vestibular schwannomas, and most frequently along the ventral and superior surface of the tumor, especially in large ones.

• Journal of Korean Neurosurgical Society
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• v.42 no.3
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• pp.159-167
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• 2007

Vestibular schwannoma (VS) is a benign tumor typically originated in the schwann cell of vestibular nerve and usually accompany hearing symptom. Microsurgical removal and radiosurgery have a great role for the treatment of VS. Recently radiosurgery has been considered as an alternative or primary treatment for VS with the tremendous increase of patients who were treated with gamma knife radiosurgery (GKS) though microsurgery still takes the premier. By many published results, it is proved that GKS is a effective and noninvasive technique for VS, especially small sized tumors with satisfactory tumor control rate. The authors assumed that GKS can be expected to achieve satisfactory tumor control rate for small VS under 5cc in volume. A major interest regarding radiosurgery nowadays is to determine the optimal radiation dose for hearing preservation to improve the quality of life of patients. The more high radiation dose are used for effective tumor growth control, the more radiation-related complications like as hearing deficit, the impairment of other cranial nerve function are increased. Since 1990's the mean radiation dose for tumor margin was more than 18 Gy, but there were high complication rate in spite of good tumor growth control. After the year of 2000, under the influence of advanced neuro-imaging techniques and radiosurgical planning system which enable clinicians to do more precise planning, marginal dose for VS has been decreased to 12-13 Gy and the radiation-related complications has been reduced. But because there may be a unexpected radiation induced complications as time goes by after the latency period, optimal radiation dose for VS should be established on the basis of more long term follow-up observation.

• The Journal of Internal Korean Medicine
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• v.37 no.5
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• pp.893-902
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• 2016

Objective: To describe the effects of traditional Korean medicine on dizziness and gait disturbance arising after removal of a vestibular schwannoma. Methods: The patient was treated using Korean medical treatments, such as herbal medicines (Jaeumkunbi-tang-gagambang and Yookmijihwang-Insamyangyoung-tang-gagambang), acupuncture, and moxibustion. We measured the state and progress of this case with the Korean Vestibular Disorder Activities of Daily Living Scale (K-VADL), Berg Balance Scale (BBS), and a visual analogue scale (VAS). Results: After treatment, the K-VADL score decreased from 167 to 74 and the VAS score decreased from 10 to 5.7, while the BBS score increased from 3 to 42. Conclusion: Jaeumkunbi-tang-gagambang (滋陰健脾湯) and Yookmijihwang-Insamyangyoung-tang-gagambang(六味地黃湯 合 人蔘養榮湯 加減方) appear to be effective for controlling dizziness and gait disturbances occurring after removal of vestibular schwannomas.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3271-3276
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• 2016

Background: Intracranial nonvestibular schwannomas arising from various cranial nerves excluding CN VIII are uncommon. Recently, stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (SRT) have been widely reported as effective treatment modalities for nonvestibular schwannomas. The purpose of this study was to study the long term clinical outcome for nonvestibular schwannomas treated with both X-Knife and CyberKnife (CK) radiosurgery at one institution. Materials and Methods: From 2004 to 2013, fifty-two nonvestibular schwannoma patients were included in this study, 33 patients (63%) were treated with CK, and 19 (37%) were treated with X-Knife. The majority of the tumors were jugular foramen schwannomas (38%) and trigeminal schwannomas (27%). HSRT was given for 45 patients (86%), whereas CSRT was for 6 (12%) and SRS for 1 (2%). Results: The median pretreatment volume was $9.4cm^3$ (range, $0.57-52cm^3$). With the median follow up time of 36 months (range, 3-135), the 3 and 5 year progression free survival was 94 % and 88%, respectively. Tumor size was decreased in 13 (25%), stable in 29 (56%), and increased in 10 (19%). Among the latter, 3 (30%) required additional treatment because of neurologic deterioration. No patient was found to develop any new cranial nerve deficit after SRS/SRT. Conclusions: These data confirmed that SRS/SRT provide high tumor control rates with low complications. Large volume tumors and cystic expansion after radiation should be carefully followed up with neurological examination and MRI, because it may frequently cause neurological deterioration requiring further surgery.

• Journal of Chest Surgery
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• v.40 no.10
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• pp.715-718
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• 2007

Neurogenic tumors of the brachial plexus are rare. An malignant schwannoma originates from the schwan cells or nerve sheath cells. Occasionally, schwannomas are associated with Von Rechlinghausen's disease, but this is rare. We were recently presented with a thirty-five year old female patient with a history of pulmonary tuberculosis about ten years prior. The patient also presented with a mass that has been slowly growing for one year. Onset of pain occurred six months after the tumor began to grow. The mass was $5{\times}7cm$ in size. The patient underwent on bloc resection of the tumor as the mass recurred twice in spite of postoperative radiotherapy.