• Journal of Korean Neurosurgical Society
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• v.62 no.4
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• pp.476-486
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• 2019

Objective : The functional information of $^{11}C$-methionine positron emission tomography (MET-PET) images can be applied for Gamma knife radiosurgery (GKR) and its image quality may affect defining the tumor. This study conducted the phantom-based evaluation for geometric accuracy and functional characteristic of diagnostic MET-PET image co-registered with stereotactic image in Leksell $GammaPlan^{(R)}$ (LGP) and also investigated clinical application of these images in metastatic brain tumors. Methods : Two types of cylindrical acrylic phantoms fabricated in-house were used for this study : the phantom with an array-shaped axial rod insert and the phantom with different sized tube indicators. The phantoms were mounted on the stereotactic frame and scanned using computed tomography (CT), magnetic resonance imaging (MRI), and PET system. Three-dimensional coordinate values on co-registered MET-PET images were compared with those on stereotactic CT image in LGP. MET uptake values of different sized indicators inside phantom were evaluated. We also evaluated the CT and MRI co-registered stereotactic MET-PET images with MR-enhancing volume and PET-metabolic tumor volume (MTV) in 14 metastatic brain tumors. Results : Imaging distortion of MET-PET was maintained stable at less than approximately 3% on mean value. There was no statistical difference in the geometric accuracy according to co-registered reference stereotactic images. In functional characteristic study for MET-PET image, the indicator on the lateral side of the phantom exhibited higher uptake than that on the medial side. This effect decreased as the size of the object increased. In 14 metastatic tumors, the median matching percentage between MR-enhancing volume and PET-MTV was 36.8% on PET/MR fusion images and 39.9% on PET/CT fusion images. Conclusion : The geometric accuracy of the diagnostic MET-PET co-registered with stereotactic MR in LGP is acceptable on phantom-based study. However, the MET-PET images could the limitations in providing exact stereotactic information in clinical study.

• Journal of Korean Neurosurgical Society
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• v.51 no.2
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• pp.98-101
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• 2012

We report a patient who underwent gamma knife radiosurgery to treat recurrent meningioma after microsurgery and thereafter developed secondary malignancy adjacent to the original tumor. A 47-year-old woman had underwent resection of the olfactory groove meningioma. Then radiosurgery was done three times over 4 year period for the recurrent tumor. After 58 months from the initial radiosurgery, she presented with headache and progressive mental dullness. Huge tumor in bifrontal location was revealed in MRI. Subsequent operation and pathological examination confirmed diagnosis of glioblastoma. This case fits the criteria of radiation-induced tumor and the clinical implication of the issue is discussed.

• Journal of Korean Neurosurgical Society
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• v.42 no.3
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• pp.224-227
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• 2007

Chordoid glioma is a rare primary brain tumor of the third ventricle, and was recently characterized as a novel tumor entity. Typical radiological features of chordoid gliomas include; a solid, round-to-ovoid, well-circumscribed, contrast-enhancing mass of the hypothalamus and anterior third ventricle. Despite being classified as WHO grade 2, the third ventricular chordoid glioma has been reported to have a poor clinical outcome because of its anatomical location. The authors report a case of chordoid glioma of the third ventricle in a 48-year-old man with unusual radiological features of cystic component and ill defined circumscription.

• Radiation Oncology Journal
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• v.31 no.4
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• pp.267-272
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• 2013

Although significant advances in the treatment of intrahepatic lesions, it is reported that the prognosis for patients with hepatocellular carcinoma (HCC) who have extrahepatic metastasis remains poor. We report a patient with lung, liver, brain, bone and subcutaneous metastasis from HCC who has survived more than 7 years maintaining relatively good performance status as a result of repeated therapies. A 55-year-old male patient with HCC underwent right lobectomy of the liver and cholecystectomy in September 2006. He received wedge resection for lung metastasis twice (July 2009, January 2011) and Gamma Knife stereotactic radiosurgery for brain metastasis (April 2011). Over the last 3 years, he has developed metastasis in subcutaneous tissues, muscle, and bone with pain. He has undergone 7 courses of radiotherapies for subcutaneous tissues, muscle, and bone metastasis and been prescribed sorafenib and he is still capable of all self-care.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.70-72
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• 2007

In this study, electromagnetic fields emitted from the various environment in the hospital were measured. Measurement spot was patients' head. To monitor how much magnetic fields are emitting from operation room, monitoring device was attached to 19 anesthesiologist and monitoring lasted 8 hours. We also took a measurement from various medical devices. Devices include ESWL, PET, MRI, CT, Gamma knife, X-ray, Angiogram, Echocardiogram, Upper GI and Linear Accelerator. Electromagnetic fields were measured from 10 spots from each of 5 patient waiting room. As a results, there were no places showing risk of high exposure. All the measurement values were below the reference levels for general public exposure to time varying electric and magnetic fields which is issued by ICNIRP.

• Journal of Korean Neurosurgical Society
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• v.39 no.2
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• pp.148-151
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• 2006

Dermatofibrosarcoma protuberans[DFSP] is an uncommon fibrohistiocytic tumor characterized by aggressive local invasion and consequent local recurrence rather than distant metastasis. We present a case of a 51-year-old male patient with a typical cutaneous DFSP, which showed local recurrences and distant metastasis to the central nervous system[CNS] and the lung after 15 years from the initial diagnosis. CNS metastatic lesions recurred in 5 months after surgical resection of the first CNS lesion. These metastatic tumors were treated by open surgery and gamma-knife radiosurgery. Despite continuous medication of oral chemotherapeutic agent, the patient died during 1-year follow-up period.

• Journal of Korean Neurosurgical Society
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• v.46 no.2
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• pp.152-155
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• 2009

A 43-year-old woman presented with dizziness, ataxia and right hearing difficulty. Her magnetic resonance images demonstrated an inhomogeneously contrast-enhanced large tumor growing into right cavernous sinus and Meckel's cave located totally within intradural retroclival region. She underwent retromastoid suboccipital craniotomy to resect the tumor mass and adjuvant gamma knife radiosurgery for remnant tumor at 1 month after operation. Adjuvant radiosurgery after surgical excision seems to be effective for the treatment of intradural extraosseous chordomas.

• Journal of Korean Neurosurgical Society
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• v.60 no.3
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• pp.294-300
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• 2017

Hypothalamic hamartoma (HH) is a benign indolent lesion despite the presentation of refractory epilepsy. Behavioral disturbances and endocrine problems are additional critical symptoms that arise along with HHs. Due to its nature of generating epileptiform discharge and spreading to cortical region, various management strategies have been proposed and combined. Surgical approaches with open craniotomy or endoscopy, stereotactic approaches with radiosurgery and gamma knife surgery or radiofrequency thermos-coagulation, and laser ablation have been introduced. Topographical dimension and the surgeon's preference are key factors for treatment modalities. Endoscopic disconnection has been one of the most favorable options performed in treating HHs. Here we discuss presurgical evaluation, patient selection, surgical procedures, and complications.

• Journal of Korean Neurosurgical Society
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• v.38 no.1
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• pp.65-67
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• 2005

Intracranial chloroma may occur in leukemia, although they are rare. A 23-year-old female complained diplopia. Brain magnetic resonance MR imaging showed tumors in the both cavernous sinus, both tentorial and anterior falx. Gamma-Knife radiosurgery was performed with maximal dose; 20Gy, marginal dose; 10Gy. Peripheral blood smear revealed leukemia, and bone marrow aspiration biopsy showed acute lymphocytic leukemia. Two weeks later, MR image for the stereotactic biopsy noticed markedly decreased tumor size. Biopsy result was lymphocytic leukemia. She received conventional radiation therapy, chemotherapy, and bone marrow transplantation. Brain involvement by acute lymphocytic leukemia is very rare. Even though chloroma are sensitive to radiation therapy, prognosis is poor because of the gravity of the underlying disease and association with impending blast transformation. The authors reports a intracranial chloroma by acute lymphocytic leukemia.

• Journal of Korean Neurosurgical Society
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• v.60 no.1
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• pp.98-101
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• 2017

We report a case of primary intracranial malignant melanoma (PIMM) with extracranial metastases. The patient was an 82-year-old woman diagnosed with PIMM under the left cerebellar tentorium. We performed a tumor resection followed by gamma knife surgery. An magnetic resonance imaging at 11 months after surgery showed a local intracranial recurrence. At 12 months, vertebral metastasis was suspected, and 2-[fluorine-18]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT) showed multiple extracranial metastases. She died at 13 months after surgery. Although extracranial metastases of PIMM are extremely rare, we should carefully follow up extracranial metastases together with intracranial ones, especially by FDG-PET/CT, even at an early asymptomatic stage.