Biomedical subjects

Sun Ha Paek

Publications and source records attributed to Sun Ha Paek.

25 records · Page 2Linked to original sources

PubMed2003

Clinicopathological study of seven cases of symptomatic supratentorial subependymoma.

Subependymomas are rare, slow-growing tumors, the majority of which are found incidentally at postmortem examination. The authors retrospectively analyzed seven cases of symptomatic supratentorial subependymomas. Five were females and two were males, ranging in age at operation of 6-50 years (median 45). The follow-up period ranged from 1.5 to 8.3 years. Tumors were intraventricularly located as a lobulated mass with cystic changes: four in the frontal horn, two in the trigone, and one in the third ventricle. Moderate to marked enhancement was noted in two tumors of the trigone and in one tumor of the frontal horn on both CT scan and MR imaging. MR spectroscopy of a recurrent subependymoma demonstrated a higher Cho/Cr ratio of 2.66, compared with a Cho/Cr ratio (0.48) of a non-recurrent subependymoma. Angiography, which was performed in four patients, revealed no staining in two and delayed modest staining in two. Radiosurgery was performed in two patients but was ineffective. Five patients with gross total tumor resection showed no evidence of tumor recurrence to the last follow-up. The two subtotally resected trigonal tumors progressed two years after operation. No histological difference except MIB-1 index was noted between recurrent and non-recurrent cases. In conclusion, we suggest that subependymoma could show progressive biological behavior, especially in cases of markedly enhancing, irregularly contoured, large tumors located in the trigone. For symptomatic supratentorial subependymomas, gross total resection is the treatment of choice and radiation has little effect on tumor control.

Adolescent↗

PubMed2003

Linear accelerator radiosurgery for central neurocytoma: a case report.

This study presents a case of central neurocytoma successfully treated with linear accelerator (LINAC)stereotactic radiosurgery. Originally, the tumor in the left lateral ventricle was removed by craniotomy, but a small residual mass was detected in follow-up magnetic resonance imagery 6 months after the operation. A further 6 months later, additional radiographic studies revealed that the residual mass had grown. LINAC radiosurgery was then performed, in which 1750 cGy doses were delivered at the 70% level with 3 isocenters (collimator size, 2 cm). The mass was completely absent over the duration of follow-up, including the final MR imagery examination 51 months after radiosurgery. LINAC radiosurgery is suggested to be a good treatment modality for residual or recurrent central neurocytoma.

Adolescent↗

PubMed2003

Angiographic characteristics of central neurocytoma suggest the origin of tumor.

The authors retrospectively analyzed the angiographic findings performed in 17 cases with central neurocytoma to document the angiographic characteristics and suggested the origin of tumor based on the angiographic findings. Their medical records and radiological investigations were reviewed and cerebral angiographies were thoroughly examined in arterial, capillary, and venous phases. In ten cases, marked or moderate tumor staining was found whereas the staining was either scanty or absent in seven cases. In the ten cases showing marked or moderate tumor staining, the feeding vessels were originated from the ipsilateral carotid and/or vertebro-basilar system. In the venous phase, the ipsilateral thalamostriate vein, tortuous and enlarged, was elevated, and the internal cerebral vein was depressed. Thus, the venous angle of the ipsilateral side was widened at an irregular contour. Based on the characteristic displacement and the increased size of the associated venous system, it is suggested that the central neurocytoma might originate from a neuronal cell mass of the subependymal zone located on the floor of the lateral ventricle around the foramen of Monro rather than from the septum pellucidum.

Adult↗

PubMed2002

Supratentorial primitive neuroectodermal tumors in adults.

A retrospective clinical analysis was made of 12 patients with supratentorial primitive neuroectodermal tumor (PNET) who ranged in age from 20 to 62 years (median 24) and were managed at Seoul National University Hospital between January 1987 and December 1997. Six patients were male and six were female. Most presented with symptoms of increased intracranial pressure and mean duration of symptoms was four months (range: 1-12 months). The tumors were located in the posterior parieto-occipital area in six cases and the mean diameter of mass of these tumors was 5.3 cm. The characteristic magnetic resonance image finding was a large well-demarcated lobulating mass with intratumoral cyst, necrosis, and/or hemorrhage. Calcification was seen in five out of six patients who underwent computed tomography scan. All patients underwent craniotomy and three of them received subsequent operations due to local recurrence. Ten patients received postoperative whole neuraxis radiation therapy and five patients received additional chemotherapy. Mean survival after diagnosis was 86 months. The patients having intratumoral calcifications are all alive and two out of three showing a Ki-67 labelling index greater than 30% died at eight and 20 months after operation, respectively. In conclusion, supratentorial PNET must be included, even in adults, in the differential diagnoses if a tumor has characteristic radiological features. The adult supratentorial PNET seemed similar to that of children in the clinical features and the prognosis. Intratumoral calcifications and the Ki-67 labelling index might be prognostic factors, however, it should be considered that the sample size is too small and not all patients were evaluated.

Adult↗

PubMed2002

Phase II study of chemotherapy with ACNU plus cisplatin followed by cranial irradiation in patients with newly diagnosed glioblastoma multiforme.

PURPOSE: To evaluate the efficacy and toxicity of chemotherapy with ACNU (1-(4-amino-2-methyl-5-pyrimidinyl)-methyl-(2-chloroethyl)-3-nitrosourea) plus cisplatin followed by cranial irradiation in patients with newly diagnosed glioblastoma multiforme. PATIENTS AND METHODS: Between August 1999 and July 2001, previously untreated 30 patients with histologically confirmed glioblastoma multiforme were treated. Chemotherapy consisting of up to 2 cycles of 72 h of continuous intravenous infusion of ACNU (40 mg/m2/day) and cisplatin (40 mg/m2/d) was given over a 6-week period. Radiation was begun 6 weeks after the second cycle of chemotherapy. RESULTS: Median age was 48 years (range 18-66 years) and 22 patients with residual measurable disease after surgery were eligible for response analysis. One (5%) had a complete response (CR), 36% partial response (PR), 14% stable disease (SD), and 45% progressive disease (PD) after chemotherapy. After additional radiation, 22% had CR, 22% PR, 16% SD, and 42% PD. Grades III and IV leukopenia and thrombocytopenia occurred in 18 cycles (36%) and 15 cycles (30%), respectively. No fatal complications occurred. Median time to progression was 5.9 months (95% CI 5.1-6.8 months) and median overall survival was 14.9 months (95% CI 9.1-20.7 months). CONCLUSIONS: Preradiation chemotherapy with ACNU plus cisplatin is effective and feasible in patients with gliobiastoma multiforme.

Adolescent↗

PubMed2002

Correlation of clinical and biological parameters with peritumoral edema in meningioma.

Peritumoral edema (PTE) in meningioma occurs variably and can adversely affect the clinical course. Moreover, the etiology of PTE in meningioma is not well documented. To examine possible correlations with PTE, the authors investigated the clinical parameters and the expressions of vascular endothelial growth factor (VEGF), matrix metalloproteinases (MMPs), and their inhibitors (TIMPs) in 20 meningiomas. The estimation of tumor volume (V(T)) and edema volume (V(E)) was done using Osiris software with magnetic resonance images and the edema index (EI) was calculated. The expression of VEGF, MMP, and TIMP were estimated in all 20 meningiomas by immunohistochemical staining, Western blotting, zymography, and laser densitometry. Tumor location was closely related with PTE. Meningiomas of the frontal lobe or the frontotemporal base had large PTEs, whereas those of the occipitoparietal lobe, posterior fossa or petroclivus were small. The level of VEGF expression bore correlation with the extent of PTE but not with histologic malignancy. MMP-2 and -9 were detected in 100% of meningiomas by zymography. The levels of MMP-9 were significantly elevated in moderate to severe edema (EI > 1.0) group (p < 0.05) whereas those of MMP-2 were elevated in minimal to mild edema (EI < 1.0) group. TIMP-1 and -2 were detected in 19 (95%) and 12 (60%) of meningiomas respectively and their presence had no significant correlations statistically with PTE between two groups (p = 0.190 and 0.089, respectively). Meningiomas with severe PTE expressed high levels of VEGF and MMP-9 and low levels of MMP-2. The expressions of MMP-2, -9, and TIMPs as well as VEGF in meningioma suggests that they are strongly related with the presence of PTE in meiningiomas, and that they might play the important role in the formation of PTE in meningiomas.

Adolescent↗

PubMed2002

Aggressive vestibular schwannomas with postoperative rapid growth: clinicopathological analysis of 15 cases.

OBJECTIVE: Vestibular schwannomas (VSs) are known to be relatively slow-growing tumors. Some VSs, however, rapidly regrow or recur after surgical resection. Our objective was to investigate the clinicopathological characteristics of these tumors and to elucidate factors that can predict rapid regrowth or recurrence after surgical resection. METHODS: Between 1978 and 2000, 29 patients with VS underwent reoperation for regrowth or recurrence at the Department of Neurosurgery in Seoul National University Hospital. Among these patients, 15 experienced rapid VS regrowth or recurrence (annual growth rate, >15 mm/yr). The clinical, radiological, operative, and pathological findings were reviewed. For a comparison of the morphology and proliferative activity, 15 cases of VS were randomly selected as a control group from among the consecutive operative cases with tumor size larger than 4 cm treated between 1991 and 1999. Pathological parameters consisting of cellularity, pleomorphism, mitosis, necrosis, invasion to adjacent tissue, and microvascular proliferation were analyzed. Proliferative indices (e.g., Ki-67 index) also were evaluated. Statistical analyses were performed using Fisher's exact test and the analysis of variance test. RESULTS: The differences in clinical features between the aggressive VS group and the control VS group were nonspecific. The mean ages at diagnosis were 40.6 years (range, 21-63 yr) and 49.7 years (range, 35-67 yr) (P = 0.438), and the male-to-female ratios were 7:7 and 5:10 (P = 0.462), respectively. The clinical symptoms and signs were similar between the two groups. Radiologically, aggressive tumors at initial presentation had more lobulating contours than those in the control group (7 of 13 cases versus 3 of 15 cases; P = 0.001). In pathological findings, cellularity and pleomorphism were significantly higher than those in the control group (P = 0.001). However, mitosis, necrosis, invasion to adjacent tissue, and microvascular proliferation were not different between the two groups. The proliferative index (Ki-67 index) was higher in the aggressive group than in the control group (2.28 [range, 0.1-8.6] versus 0.59 [range, 0-1.5]; P = 0.034). CONCLUSION: VSs presenting with lobulating contour, high proliferative index (Ki-67 index), and high cellularity or pleomorphism require frequent radiological investigation during follow-up to facilitate early detection of regrowth or recurrence.

Adult↗