• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2023년도 춘계학술발표대회
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• pp.496-498
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• 2023

Brain tumor segmentation problem has challenges in the tumor diversity of location, imbalance, and morphology. Attention mechanisms have recently been used widely to tackle medical segmentation problems efficiently by focusing on essential regions. In contrast, the fusion approaches enhance performance by merging mutual benefits from many models. In this study, we proposed a 3D dual fusion attention network to combine the advantages of fusion approaches and attention mechanisms by residual self-attention and local blocks. Compared to fusion approaches and related works, our proposed method has shown promising results on the BraTS 2018 dataset.

• 대한핵의학회지
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• 제30권4호
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• pp.476-483
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• 1996

임상적으로 뇌종양과 방사선 치료 후 발생한 괴사의 감별은 매우 중요한 문제이다. 그러나 임상 증상이나 방사선학적 소견으로 양자를 감별하는 것은 매우 어렵다. 이에 저자 등은 방사선 치료 후 재발과 괴사를 감별하는데 있어 T1-201 SPECT의 역할을 알아보고자 하였다. 대상은 뇌종양으로 진단 받고 개두술 및 방사선 치료나 감마 나이프 수술을 받은 후 증상의 악화로 내원하여 T1-201 SPECT를 시행한 환자 중 조직학적으로 확진된 20명으로 하였다. T1-201 SPECT는 일단 육안적으로 비정상적 탈륨 섭취 여부를 판별한 다음 비정상적 탈륨 섭취가 있는 경우에 한하여 탈륨 섭취 지수를 구하여 2.5이상인 경우를 종양의 재발로 간주하였으며, 병리조직 소견과 비교하였다. 재수술 또는 조직검사상 20명중 16명이 재발 또는 양성종양의 악성전환으로 나타났으며, T1-201 SPECT 상에서는 18명에서 2.5이상의 높은 탈륨 섭취 지수로 종양 양성이었다. 17예에서 일치를 보였는데 진양성 15예, 진음성 2예였고, 3예에서 불일치를 보였는데 모두 위양성이었다. 조직소견을 기준으로한 예민도, 특이도, 양성 예측율 및 음성 예측율은 각각 100%, 40%, 83%, 100%였다. 결론적으로 뇌종양의 방사선 치료 후 재발과 괴사를 감별하는데 있어 T1-201 SPECT는 높은 예민도와 음성 예측율을 갖는 유용한 검사이다. 상대적으로 낮은 특이도는 조직병리 검사를 시행함에 있어 표본선택오차와 임상가의 검사의뢰 편견이 있을 수 있음을 고려하여 좀 더 많은 수의 환자를 대상으로 한 연구가 있어야 할 것이다.

• 대한수의학회지
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• 제44권1호
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• pp.83-88
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• 2004

Galectin family, endogenous ${\beta}$-galactoside-binding animal lectins, is known for the role in cell differentiation, morphogenesis, apoptosis and tumorigenesis. Galectin-3, one of family member, has been studied for its role in cell differentiation and tumor metastasis, and for its expression on epithelial cells of colon and mast cells but not in brain. Several reports, however, suggest its expression in brain including as a prion binding protein. In this report we explored possibility of galectin-3 expression in brain tissue. With Western blot and RT-PCR with rat brain tissues, we could detect galectin-3 that was not shown by conventional immunohistochemistry. Our results indicated galectin-3 was expressed in brain, and substantiate the previous report on galecin-3 as a prion-related protein in brain.

• Current Optics and Photonics
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• 제3권3호
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• pp.256-262
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• 2019

Extensive tumor resection accompanied by radiotherapy and chemotherapy is the standard of care for malignant gliomas. However, there is a significant obstacle to the complete resection of the tumor due to the difficulty of distinguishing tumor and normal brain tissue with a conventional surgical microscope. Recently, multiple studies have shown the possibility of fluorescence-guided surgery in malignant gliomas. The most used fluorescence dyes for brain tumor surgery are 5-aminolevulinic acid (5-ALA) and indocyanine green (ICG). In this paper, a new fluorescence guided operation system, which can detect both 5-ALA and ICG fluorescent images simultaneously, is presented. This operation system consists of light emitting diodes (LEDs) which emits 410 nm and 740 nm wavelengths. We have performed experiments on rats in order to verify the operation of the newly developed operation system. Oral administration and imaging were performed to observe the fluorescence of 5-ALA and ICG fluorescence in rats. When LEDs at wavelengths of 410 nm and 740 nm were irradiated on rats, 628 nm wavelength with a violet fluorescence color and 825 nm wavelength with a red fluorescence color were expressed in 5-ALA and ICG fluorescent material, respectively, thus we were able to distinguish the tumor tissues easily. Previously, due to the poor resolution of the conventional surgical microscope and the fact that the color of the vein is similar to that of the tumor, the tumor resection margin was not easy to observe, thus increasing the likelihood for cancer recurrence. However, when the tumor is observed through the fluorescence guided operation system, it is possible to easily distinguish the color with the naked eye and it can be completely removed. Therefore, it is expected that surgical removal of cancerous tumors will be possible and surgical applications and surgical microscopes for cancer tumor removal surgery will be promising in the future.

• Journal of Korean Neurosurgical Society
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• 제64권6호
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• pp.983-994
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• 2021

Objective : The effectiveness of gamma knife radiosurgery (GKR) in the treatment of brain metastases is well established. The aim of this study was to evaluate the efficacy and safety of maximizing the radiation dose in GKR and the factors influencing tumor control in cases of small and medium-sized brain metastases from non-small cell lung cancer (NSCLC). Methods : We analyzed 230 metastatic brain tumors less than 5 mL in volume in 146 patients with NSCLC who underwent GKR. The patients had no previous radiation therapy for brain metastases. The pathologies of the tumors were adenocarcinoma (n=207), squamous cell carcinoma (n=18), and others (n=5). The radiation doses were classified as 18, 20, 22, and 24 Gy, and based on the tumor volume, the tumors were categorized as follows : small-sized (less than 1 mL) and medium-sized (1-3 and 3-5 mL). The progression-free survival (PFS) of the individual 230 tumors and 146 brain metastases was evaluated after GKR depending on the pathology, Eastern Cooperative Oncology Group (ECOG) performance score (PS), tumor volume, radiation dose, and anti-cancer regimens. The radiotoxicity after GKR was also evaluated. Results : After GKR, the restricted mean PFS of individual 230 tumors at 24 months was 15.6 months (14.0-17.1). In small-sized tumors, as the dose of radiation increased, the tumor control rates tended to increase (p=0.072). In medium-sized tumors, there was no statistically difference in PFS with an increase of radiation dose (p=0.783). On univariate analyses, a statistically significant increase in PFS was associated with adenocarcinomas (p=0.001), tumors with ECOG PS 0 (p=0.005), small-sized tumors (p=0.003), radiation dose of 24 Gy (p=0.014), synchronous lesions (p=0.002), and targeted therapy (p=0.004). On multivariate analyses, an improved PFS was seen with targeted therapy (hazard ratio, 0.356; 95% confidence interval, 0.150-0.842; p=0.019). After GKR, the restricted mean PFS of brain at 24 months was 9.8 months (8.5-11.1) in 146 patients, and the pattern of recurrence was mostly distant within the brain (66.4%). The small and medium-sized tumors treated with GKR showed radiotoxicitiy in five out of 230 tumors (2.2%), which were controlled with medical treatment. Conclusion : The small-sized tumors were effectively controlled without symptomatic radiation necrosis as the radiation dose was increased up to 24 Gy. The medium-sized tumors showed potential for symptomatic radiation necrosis without signifcant tumor control rate, when greater than 18 Gy. GKR combined targeted therapy improved the tumor control of GKR-treated tumors.

• Journal of Korean Neurosurgical Society
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• 제30권sup2호
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• pp.189-196
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• 2001

목 적 : 교모세포종은 흔한 원발성 뇌종양이며 생물학적 특성상 빠른 성장률을 보이는 것 외에 침습성이 강하여 종양과 인접한 부분을 파괴 시킬 뿐 아니라 직접접촉하지 않는 부분의 파괴도 일어나게 되어 치료 예후가 매우 불량한 것으로 되어 있다. 광역학치료는 광감각제를 이용하며 광감각제는 적절한 파장의 광원에 노출되면 세포 내에서 산소독성 물질을 생성하여 세포괴사를 유도하는 것이 주 살해작용의 기전이다. 본 실험에서는 사람의 신경교종 세포주인 U87 세포를 이용하여 실험관 내에서 광감각제 photofrin을 이용한 광역학치료가 종양의 침습성에 미치는 영향을 알아보고 동시에 이를 뇌종양치료의 새로운 방법으로 사용될 수 있는지의 여부를 알아보고자 하였다. 재료 및 방법 : 교모세포종 세포주인 U87 세포를 여러 농도의 photofrin으로 처리한 후 632nm $100mJ/cm^2$의 고정된 광선조건에서 본 실험을 시행 하였으며 Microculture tetrazolium(MTT) assay를 이용하여 세포 살해능력을 측정하고 침습성은 matrigel artificial basement membrane assay 및 tumor spheroid fetal rat brain aggregate(FRBA) confrontation assay를 이용하여 측정하였다. 결 과 : MTT assay를 이용하여 측정한 광역학 치료의 세포살해능력은 $100mJ/cm^2$의 광선 세기에서 광감각제인 photofrin의 농도에 비례하여 세포 살해 능력을 보였다. Matrigel artificial basement membrane assay 를 이용한 종양 침습성 검사에서 광역학치료가 종양침습의 억제효과를 나타냄을 알 수 있었으며 특히 세포 살해능력을 별로 보이지 않았던 photofrin 농도 2.5ug/ml에서 뚜렷한 침습억제효과를 나타내고 있었다(p<0.05). tumor spheroid fetal rat brain aggregate(FRBA) confrontation assay에서는 brain aggregate의 파괴와 종양의 침습을 관찰할 수 있었는데 파괴의 모양은 생체내에서 보이는 것과 비슷 하였다. 또한 그 정도와 범위는 처리된 Photofrin의 농도에 비례하여 종양침습이 억제됨을 알 수 있었다. 결 론 : 이러한 결과를 종합해 보았을 때 PDT는 종양세포의 침습성에 중요한 역할을 함을 알 수 있었으며 PDT 는 세포 살해능력뿐 아니라 침습성에도 영향을 미침으로써 종양 치료에 유용한 방법으로 사용될 수 있을 것으로 사료된다.

• Radiation Oncology Journal
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• 제21권1호
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• pp.10-18
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• 2003

목적 : 양성 뇌종양에 대하여 분할 정위 방사선치료를 시행한 후의 임상 경과 및 방사선 반응 등을 추적하여 그 효과를 평가하고자 하였다. 대상 및 방법 : 1996년 3월부터 2002년 3월까지 양성 뇌종양으로 진단 받고 분할 정위 방사선치료를 받았던 36례를 대상으로 분석을 하였다. 대상 환자의 종양은 뇌하수체 선종 12례, 두개인두종 5례, 수막종 10례, 청신경초종 9례 이었다. 방사선치료는 종양의 위치, 종류, 크기에 따라 5~10회 분할 치료로 85~90%의 등선량 곡선에 25~35 Gy까지 조사하였다. 임상 추적관찰 기간은 2~74개월(중앙값 31개월)이었고, 방사선 추적 관찰 기간은 4~56개월(중앙값 21개 월)이었다. 결과 : 임상 증상이 있었던 35례 중 분할 정위 방사선치료 후 임상 증상의 호전은 13례(37.1%)에서 보였으며, 16례 (45.7%)에서 증상의 변화가 없었고 증상의 악화는 6례(17.2%)에서 관찰되었다. 뇌신경장애를 동반한 28례 중 7례(25%)에서 증상 개선을 보였다. 추적 방사선 검사를 시행한 33례 중 17례(51.5%)에서 종양 크기의 감소를 보였으며, 그 중 7례(21.2%, 뇌하수체 선종-2, 두개인두종-3, 수막종-1, 청신경초종-1)는 종양의 완전 소실을 보였다. 13례(39.4%)에서 종양 크기의 변화가 없었고, 3례(9.1%)는 종양 크기의 진행을 나타내었다. 급성 부작용은 11례(30.6%)에서 관찰되었다 결론 : 양성 뇌종양의 분할 정위 방사선치료는 심각한 부작용 없이 시행할 수 있는 안전하고 효과적인 치료법이었다. 그러나, 정확한 역할에 대해서는 좀 더 많은 환자와 장기간의 추적관찰이 필요할 것으로 사료되었다.

• Journal of Korean Neurosurgical Society
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• 제50권6호
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• pp.538-541
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• 2011

Objective : We evaluated a modified trans-middle temporal gyrus (MTG) approach with good postoperative visual preservation for patients with trigonal tumors. Methods : Three patients with a trigonal tumor were treated via the modified trans-MTG approach guided by a neuro-navigator. Modified trans-MTG approach involve the incision at the MTG within 5 mm to the superior temporal sulcus. This approach makes a proper trajectory to the trigone but also reduces the retraction injury of MTG as little as possible to prevent postoperative visual field defect. Preoperative and postoperative visual field examination using perimetry was performed to evaluate the visual field. Results : Three patients underwent surgery for lymphoma in the right trigone, meningioma in the left trigone, and focal enhancing nodule in the right paratrigonal area, respectively. In case of lymphoma, preoperative examination showed a left homonymous hemianopsia : one week later after surgery, a visual field examination was performed and revealed improvement of the visual field defect. In case of the meningioma, the preoperative examination showed no visual field defect : one month later, the visual field had no defect. In case of the enhancing nodule, preoperative visual field testing revealed a partial left homonymous hemianopsia. Visual examination within one month after surgery showed no visual field defect. All three patients treated with the modified trans-MTG approach showed no visual deterioration after surgery. Conclusion : The modified trans-MTG approach provides a safe and useful technique for trigonal tumors without postoperative visual field deterioration and affords adequate exposure of the trigonal tumor with a short trajectory.

• Journal of Korean Neurosurgical Society
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• 제61권3호
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• pp.363-375
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• 2018

Intraoperative monitoring (IOM) utilizes electrophysiological techniques as a surrogate test and evaluation of nervous function while a patient is under general anesthesia. They are increasingly used for procedures, both surgical and endovascular, to avoid injury during an operation, examine neurological tissue to guide the surgery, or to test electrophysiological function to allow for more complete resection or corrections. The application of IOM during pediatric brain tumor resections encompasses a unique set of technical issues. First, obtaining stable and reliable responses in children of different ages requires detailed understanding of normal age-adjusted brain-spine development. Neurophysiology, anatomy, and anthropometry of children are different from those of adults. Second, monitoring of the brain may include risk to eloquent functions and cranial nerve functions that are difficult with the usual neurophysiological techniques. Third, interpretation of signal change requires unique sets of normative values specific for children of that age. Fourth, tumor resection involves multiple considerations including defining tumor type, size, location, pathophysiology that might require maximal removal of lesion or minimal intervention. IOM techniques can be divided into monitoring and mapping. Mapping involves identification of specific neural structures to avoid or minimize injury. Monitoring is continuous acquisition of neural signals to determine the integrity of the full longitudinal path of the neural system of interest. Motor evoked potentials and somatosensory evoked potentials are representative methodologies for monitoring. Free-running electromyography is also used to monitor irritation or damage to the motor nerves in the lower motor neuron level : cranial nerves, roots, and peripheral nerves. For the surgery of infratentorial tumors, in addition to free-running electromyography of the bulbar muscles, brainstem auditory evoked potentials or corticobulbar motor evoked potentials could be combined to prevent injury of the cranial nerves or nucleus. IOM for cerebral tumors can adopt direct cortical stimulation or direct subcortical stimulation to map the corticospinal pathways in the vicinity of lesion. IOM is a diagnostic as well as interventional tool for neurosurgery. To prove clinical evidence of it is not simple. Randomized controlled prospective studies may not be possible due to ethical reasons. However, prospective longitudinal studies confirming prognostic value of IOM are available. Furthermore, oncological outcome has also been shown to be superior in some brain tumors, with IOM. New methodologies of IOM are being developed and clinically applied. This review establishes a composite view of techniques used today, noting differences between adult and pediatric monitoring.

• Molecules and Cells
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• 제43권6호
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• pp.539-550
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• 2020

Glioblastoma multiforme (GBM) is a fatal malignant tumor that is characterized by diffusive growth of tumor cells into the surrounding brain parenchyma. However, the diffusive nature of GBM and its relationship with the tumor microenvironment (TME) is still unknown. Here, we investigated the interactions of GBM with the surrounding microenvironment in orthotopic xenograft animal models using two human glioma cell lines, U87 and LN229. The GBM cells in our model showed different features on the aspects of cell growth rate during their development, dispersive nature of glioma tumor cells along blood vessels, and invasion into the brain parenchyma. Our results indicated that these differences in the two models are in part due to differences in the expression of CXCR4 and STAT3, both of which play an important role in tumor progression. In addition, the GBM shows considerable accumulation of resident microglia and peripheral macrophages, but polarizes differently into tumor-supporting cells. These results suggest that the intrinsic factors of GBM and their interaction with the TME determine the diffusive nature and probably the responsiveness to non-cancer cells in the TME.