• Brain Tumor Research and Treatment
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• 제6권2호
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• pp.47-53
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• 2018

Brain tumors represent a diverse spectrum of histology, biology, prognosis, and treatment options. Although MRI remains the gold standard for morphological tumor characterization, positron emission tomography (PET) can play a critical role in evaluating disease status. This article focuses on the use of PET with radiolabeled glucose and amino acid analogs to aid in the diagnosis of tumors and differentiate between recurrent tumors and radiation necrosis. The most widely used tracer is $^{18}F$-fluorodeoxyglucose (FDG). Although the intensity of FDG uptake is clearly associated with tumor grade, the exact role of FDG PET imaging remains debatable. Additionally, high uptake of FDG in normal grey matter limits its use in some low-grade tumors that may not be visualized. Because of their potential to overcome the limitation of FDG PET of brain tumors, $^{11}C$-methionine and $^{18}F$-3,4-dihydroxyphenylalanine (FDOPA) have been proposed. Low accumulation of amino acid tracers in normal brains allows the detection of low-grade gliomas and facilitates more precise tumor delineation. These amino acid tracers have higher sensitivity and specificity for detecting brain tumors and differentiating recurrent tumors from post-therapeutic changes. FDG and amino acid tracers may be complementary, and both may be required for assessment of an individual patient. Additional tracers for brain tumor imaging are currently under development. Combinations of different tracers might provide more in-depth information about tumor characteristics, and current limitations may thus be overcome in the near future. PET with various tracers including FDG, $^{11}C$-methionine, and FDOPA has improved the management of patients with brain tumors. To evaluate the exact value of PET, however, additional prospective large sample studies are needed.

• Journal of Korean Neurosurgical Society
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• 제45권5호
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• pp.275-283
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• 2009

Objective : We retrospectively analyzed survival, local control rate, and incidence of radiation toxicities after radiosurgery for recurrent metastatic brain lesions whose initial metastases were treated with whole-brain radiotherapy. Various radiotherapeutical indices were examined to suggest predictors of radiation-related neurological dysfunction. Methods : In 46 patients, total 100 of recurrent metastases (mean 2.2, ranged 1-10) were treated by CyberKnife radiosurgery at average dose of 23.1 Gy in 1 to 3 fractions. The median prior radiation dose was 32.7 Gy, the median time since radiation was 5.0 months, and the mean tumor volume was $12.4cm^3$. Side effects were expressed in terms of radiation therapy oncology group (RTOG) neurotoxicity criteria. Results : Mass reduction was observed in 30 patients (65%) on MRI. After the salvage treatment, one-year progression-free survival rate was 57% and median survival was 10 months. Age(<60 years) and tumor volume affected survival rate(p=0.03, each). Acute (${\leq}$1 month) toxicity was observed in 22% of patients, subacute and chronic (>6 months) toxicity occurred in 21 %, respectively. Less acute toxicity was observed with small tumors (<$10cm^3$. p=0.03), and less chronic toxicity occurred at lower cumulative doses (<100 Gy, p=0.004). "Radiation toxicity factor" (cumulative dose times tumor volume of <1,000 Gy${\times}cm^3$) was a significant predictor of both acute and chronic CNS toxicities. Conclusion: Salvage CyberKnife radiosurgery is effective for recurrent brain metastases in previously irradiated patients, but careful evaluation is advised in patients with large tumors and high cumulative radiation doses to avoid toxicity.

• Radiation Oncology Journal
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• 제2권2호
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• pp.287-297
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• 1984

The normal intracranial structures are relatively resistant to therapeutic radiation, but may react adversely in a variety of ways, and the damage to nerve tissue may be slow in making its appearance, and once damage has occured the patient recovers slowly and incompletly. Therefore, it is important to consider the possibility of either recurrent tumor or late adverse effect in any patient who has had radiotherapy. The determination o( rnorphological/pathological correlation is very important to the therapeutic radiologist who uses CT scans to define a treatment volume, as well as to the clinician who wishes to explain the patient's clinical state in terms of regress, progression, persistence, or recurrence of tumor or radiation-induced edema or necrosis, The authors are obtained as following results ; 1. The field size(whole CNS, large, intermediate, small field) was variable according to the location and extension of tumor and histopathologic diagnosis, and the tatal tumor dose was 4,000 to 6,000 rads except one of recurred case of 9,100 rads. The duration of follow up CT scan was from 3 months to 5 year 10 months. 2, The histopathologic diagnosis of 9cases were glioblastoma multiforme(3 cases), pineal tumor (3), oligodendroglioma (1), cystic astrocytoma (1), pituitary adenoma (1) and their adverse effects after radiation therapy were brain atrophy (4 cases) , radiation necrosis(2), tumor recurrence with or without calcification (2), radiation·induced infarction (1). 3. The recurrent symptoms after radiation therapy of brain tumor were not always the results of regrowth of neoplasm, but may represent late change of irradiated brain. 4. It must be need that we always consider the accurate treatment planning and proper treatment method to reduce undesirable late adverse effects in treatment of brain tumors.

• 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.

• Journal of Korean Neurosurgical Society
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• 제61권3호
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• pp.393-401
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• 2018

The prognosis of brain tumors in children has improved for last a few decades. However, the prognosis remains dismal in patients with recurrent brain tumors. The outcome for infants and young children in whom the use of radiotherapy (RT) is very limited because of unacceptable long-term adverse effect of RT remains poor. The prognosis is also not satisfactory when a large residual tumor remains after surgery or when leptomeningeal seeding is present at diagnosis. In this context, a strategy using high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT) has been explored to improve the prognosis of recurrent or high-risk brain tumors. This strategy is based on the hypothesis that chemotherapy dose escalation might result in improvement in survival rates. Recently, the efficacy of tandem HDCT/auto-SCT has been evaluated in further improving the outcome. This strategy is based on the hypothesis that further dose escalation might result in further improvement in survival rates. At present, the number of studies employing tandem HDCT/auto-SCT for brain tumors is limited. However, results of these pilot studies suggest that tandem HDCT/auto-SCT may further improve the outcome. In this review, we will summarize our single center experience with tandem HDCT/auto-SCT for recurrent or high-risk brain tumors.

• 대한핵의학회지
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• 제26권2호
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• pp.360-364
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• 1992

Treatment for the brain tumors consist of surgery, chemotherapy, and a variety of methods of irradiation. Therapy is aimed to destroy the tumor, but necrosis and edema occur concurrently. Conventional structural imaging techniques such as CT or MRI are unable to reliably distinguish persistent and recurrent tumor from necrosis or edema. T1-201 has been shown to be useful in the evaluation of the myocardial viability by comparing the early uptake and redistribution image. The aim of this study is to evaluate the clinical usefulness of the early uptake and delayed washout images of the T1-201 brain SPECT in the brain tumors. In the pathologically diagnosed various brain tumor patients, brain SPECT was done with rotating gamma camera 15 minutes and 3 hours after T1-201 injection, and the T1-201 uptake in the tumor was compared with the skull and scalp activity. In the glioblastoma multiforme, meningioma and metastatic tumor, the T1-201 uptake was higher than low grade glioma in both 15 minute and 3 hour images (p<0.02). In the low grade glioma,3 hour T1-201 uptake was significantly lower than 15 minute uptake (p<0.05) but in the glioblastoma, meningioma and metastatic tumor there was no significant difference. There was no significant difference in the T1-201 uptake among the glioblastoma, meningioma and metastatic tumors. In one matastatic tumor, T1-201 uptake was decreased after radiation therapy. T1-201 brain SPECT could distinguish the benign and malignancy, and seems to be useful in the follow-up after treatment. But one of the early or delayed SPECT seems not to be necessary for these purposes.

• Journal of Korean Neurosurgical Society
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• 제54권3호
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• pp.175-182
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• 2013

Objective : Intracavitary injection of beta-emitting radiation source for control of cystic tumors has been tried with a benefit of localized internal radiation. The authors treated cystic brain tumor patients with Holmium-166-chitosan complex (Ho-166-chico), composed of a beta-emitting radionuclide Holmium-166 and biodegradable chit polymer, and evaluated the safety and effective measurement for response. Methods : Twenty-two patients with recurrent cystic brain tumor and/or located in a deep or eloquent area were enrolled in this pilot study. The cyst volume and wall thickness were determined on CT or MRI to assess radiological response. The activity of Ho-166-chico injected via Ommaya reservoir was prescribed to be 10-25 Gy to the cyst wall in a depth of 4 mm. Results : There was neither complications related to systemic absorption nor leakage of Ho-166-chico in all 22 patients. But, two cases of oculomotor paresis were observed in patients with recurrent craniopharyngioma. Radiological response was seen in 14 of 20 available follow-up images (70%). Seven patients of 'evident' radiological response experienced more than 25% decrease of both cyst volume and wall thickness. Another 7 patients with 'suggestive' response showed decrease of cyst volume without definitive change of the wall thickness or vice versa. All patients with benign tumors or low grade gliomas experienced symptomatic improvement. Conclusion : Ho-166-chico intracavitary radiation therapy for cystic tumor is a safe method of palliation without serious complications. The determination of both minimal effective dosage and time interval of repeated injection through phase 1 trial could improve the results in the future.

• Journal of Korean Neurosurgical Society
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• 제41권6호
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• pp.425-428
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• 2007

Hemangiopericytoma [HPC] is a rare tumor with uncommon location in the central nervous system. We report a rare case of sellar and suprasellar HPC mimicking pituitary adenoma in a patient initially seen with the symptoms of bitemporal hemianopsia, headache, and panhypopituitarism. Magnetic resonance imaging of the brain revealed a contrast-enhancing soft tissue mass arising from the pituitary fossa, with apparent compression of the chiasm and involving the cavernous sinus. Subtotal resection of the tumor was achieved via a pterional approach. Histopathological examination identified the tumor as a HPC. Nine years later, the tumor recurred. To our knowledge, this is the first reported case of sellar and suprasellar HPC in Korea.

• 대한두경부종양학회지
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• 제18권2호
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• pp.219-222
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• 2002

Malignant glomus tumor is a very rare disease originating from the paraganglia system through the body. Glomus tumor, also known as paraganglioma, usually are considered benign, and arises in a variety of head and neck locations, most of which include the carotid body, the vagus nerve, and the jugulotympanic area. The most widely accepted management of benign glomus tumor is surgical extiration. Here, we report a case of recurrent laryngeal glomus tumor which is proven malignant and metastatic to the brain and the lungs. We have treated the patient with combination chemotherapy and radiation to the brain, the result of which is partial response in terms of decreased size of metastatic lung lesions.

• 대한핵의학회지
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• 제26권1호
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• pp.14-25
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• 1992

Thallium-201 $(^{201}T1)$ SPECT studies were performed on a normal volunteer and 12 patients with intracerebral lesions: 3 patients with gliomas, 3 patients with meningiomas, 1 patient each with metastatic tumor, brain abscess, and cerebral infarction, and 3 postirradiation patients. (2 with metastatic tumors, 1 with lymphoma). A $^{201}T1$ index, based on the ratio of $^{201}T1$ uptake in the brain lesion versus the homologous contralateral brain, was calculated and compared with tumor histology and CT/MRI findings. The SPECT $^{201}T1$ scan showed minimal uptake of tracer in a normal brain. There was substantial uptake of $^{201}T1$ in high-grade gliomas (index>1.5) with little uptake in low-grade lesions. A previously irradiated patient with recurrent astrocytoma, in whom MRI study was unable to distinguish tumor recurrence from necrosis, showed the lesions with high $^{201}T1$ indices in both hemispheric regions (2.50/1.93), suggesting tumor recurrence. Two meningiomas and a metastatic tumor showed varying degrees of $^{201}T1$ uptake (index $1.71\sim8.15$), revealing that $^{201}T1$ uptake is not exclusive to high-grade gliomas. In 2 postirradiation patients with metastatic tumors, no abnormal $^{201}T1$ uptake was found in the cerebral lesions, shortly after the initiation of radiation therapy or despite the persistence of enhancing lesions-though improved-on MR images, suggesting that $^{201}T1$ uptake may reflect the metabolic and possibly clonogenic activities of tumors and the brain $^{201}T1$ SPECT imaging might be valuable for the evaluation of tumor responsiveness to the therapy and for early detection of tumor recurrence. A patient with brain abscess on antibiotic treatment, showig increased uptake of $^{201}T1$ in the resolving lesions (index 2.87/1.52) is discussed. In a patient with cerebral infarction, there was no abnormal uptake of $^{201}T1$ in infarcted tissue. When using a threshold index of 1.5, correlation rate between $^{201}T1$ uptake and contrast enhancement of the cerebral lesions on CT/MRI was 73% (8/11). In conclusion, the brain $^{201}T1$ SPECT imaging may be useful for assessment of tumor response to the therapy and to predict low-or high-grade lesions.