Kwan Park

Prognostic significance of c-Met expression in glioblastomas

The authors investigated whether expression of c‐Met protein in glioblastomas is associated with overall survival and biologic features representing tumor invasiveness in patients with glioblastomas.

Efficacy of Stereotactic Radiosurgery as a Salvage Treatment for Recurrent Malignant Gliomas

The objective of this prospective cohort study was to determine the efficacy of stereotactic radiosurgery (SRS) as a salvage treatment in patients with recurrent malignant gliomas.

The efficacy of fractionated radiotherapy and stereotactic radiosurgery for pituitary adenomas: long-term results of 125 consecutive patients treated in a single institution.

The objective of this retrospective cohort study was to define the efficacy and safety of fractionated radiotherapy (FRT) and stereotactic radiosurgery (SRS) for the treatment of patients with pituitary adenoma.

Clinical features of peripheral T-cell lymphomas in 78 patients diagnosed according to the Revised European-American Lymphoma (REAL) classification

The aim of this study was to analyse the clinical characteristics and prognostic factors of peripheral T-cell lymphomas (PTCLs) according to the Revised European-American Lymphoma (REAL) classification. From 1994 to 1999, 78 patients were diagnosed with PTCLs, excluding cutaneous T-cell lymphomas and T-cell chronic lymphocytic leukaemia. The distribution of the histological subgroups were: PTCL unspecified (PTCL-U), 40%; angiocentric lymphoma, 32%; anaplastic large cell lymphoma (ALCL), 17%; angioimmunoblastic T-cell lymphoma (AILD), 6%; intestinal T-cell lymphoma, 3%; and panniculitic T-cell lymphoma, 3%. Patients with angiocentric lymphoma presented with favourable prognostic factors, whereas those with AILD presented with unfavourable prognostic factors. Most patients were treated with doxorubicin-containing combination chemotherapy (with or without radiation therapy). The overall complete remission rate was 61.2% (95% Confidence Interval (CI): 48.5-72.8%) and the 5-year probability of failure-free survival was 33.5%. Median survival of all patients was 45 months (range 0-64+ months) and the 5-year probability of survival was 36.2%. In the multivariate analysis, only the International Prognosis Index (IPI) was an independent prognostic factor for overall survival (P<0.01). Taken together, the proportion of angiocentric lymphoma in this study was higher than that in the studies of Western countries. PTCL responds poorly to treatment with low survival rates and the IPI is a useful prognostic factor for PTCL.

Relationship between malignant subtypes of meningioma and clinical outcome

We evaluated the relationship between histological malignant subtypes (WHO grade II or III) of meningioma and clinical outcome. Of 485 patients treated surgically for intracranial meningioma at our hospital between 1994 and 2004, 49 (10%; 18 male, 31 female) had potentially malignant features. The histological tumor subtypes within this group of patients included: atypical (n=23); clear cell (n=3); chordoid (n=5); rhabdoid (n=16); and anaplastic (n=4). Correlations among prognosis, recurrence, and the following factors were analyzed for each histological subtype: the Simpson grade of surgical resection (grades I-III vs. grade IV), tumor location (convexity vs. other), the Ki-67 index, and use of postoperative radiotherapy. The median value of the Ki-67 index was 16.2% (range: 1.0-57.2%). The surgical resections were of Simpson grades I-III and IV in 43 and six of the 49 patients, respectively. Tumors recurred after the initial surgical resection in 14 of the 49 patients. In view of the relatively high proportion of malignant subtypes (10%), we suggest that all meningiomas should be evaluated for malignancy. The extent of surgical resection, the histological subtype, and the Ki-67 index can help to predict the clinical outcome for meningioma patients.

Treatment of atypical meningioma

The aim of this study was to review the outcome after multimodality therapy in atypical meningiomas using the 2000 World Health Organization (WHO) classification system, and to suggest a logical therapeutic approach. Between April 1997 and February 2008, 35 patients with atypical meningiomas were managed in our hospital. All surgical specimens were reviewed according to the 2000 WHO classification system. The median follow-up was 40 months (range: 6-97 months). Radical extirpation surgery (Simpson grade I) was performed in 11 (31%) patients, and there was no tumor recurrence for these patients. For patients who underwent incomplete resection, the median interval to recurrence was increased from 17 months for surgery alone to 39 months for surgery with adjuvant radiation therapy (p=0.138). Age, MIB-l labeling index, and tumor location had no significant effect on either progression-free survival or overall survival. Atypical meningiomas are difficult to manage and have high recurrence and poor survival rates. In our series, complete resection of the tumor is a key determinant for a better outcome. Adjuvant radiation therapy is recommended if incomplete surgical excision is performed.

Clinical Features and Long-term Results of Spontaneous Intracranial Hypotension

OBJECTIVE:Although spontaneous intracranial hypotension (SIH) is an increasingly recognized syndrome, the long-term outcomes have not been established. We conducted a long-term follow-up study to clarify the clinical features and long-term outcomes of patients with this disorder. METHODS:We performed a retrospective study in 13 consecutive patients with SIH treated between 1998 and 2003. The diagnosis of intracranial hypotension was made on the basis of clinical symptoms, lumbar puncture, radiological studies (e.g. brain magnetic resonance imaging, spine magnetic resonance imaging, computed tomographic myelography) and radionuclide cisternography. We collected follow-up clinical information of the patients by telephone or by examination at an outpatient clinic. RESULTS:All patients were treated by nonsurgical conservative treatments, such as absolute bed rest, intravenous hydration and repetitive epidural blood patch (5 patients). The mean duration of follow up was 51.4 months (range, 15–80 mo). Among 13 patients included in this study, only one patient (7.7%) developed recurrent SIH, and the other patients improved from orthostatic headache. Although 7 of 13 patients had complete resolution of headache at a minimum of 2 years follow-up, 4 patients had mild headache and 2 patients continued to have moderate headache at the final examination. CONCLUSION:In this series, the outcome of SIH after conservative treatment was not as satisfactory as that reported in previous studies. We conclude that periodic follow-up examinations must be performed and a more effective treatment modality developed to achieve complete resolution of SIH.

Gamma knife surgery for brain metastases in patients harboring four or more lesions: survival and prognostic factors.

OBJECT This study was performed to evaluate the role of gamma knife surgery (GKS) in patients with a large number (four or more) of metastatic brain lesions. METHODS The authors retrospectively reviewed the outcome in 130 patients who underwent GKS for metastatic lesions. Eighty-four patients presented with one to three lesions (Group A) and 46 presented with four or more lesions (Group B). The overall median survival time after GKS was 35 weeks. The median survival time in Group A (48 weeks) was significantly longer (p = 0.005) than the survival time in Group B (26 weeks). The recursive partitioning analysis (RPA) class was the only significant prognostic factor identified in multivariate analysis. The median survival for patients in RPA Classes I, II, and III was 72, 48, and 19 weeks, respectively, in Group A and 36 and 13 weeks for Classes II and III in Group B. The number of lesions, tumor volume, whole brain radiotherapy, primary tumor site, age, and sex did not affect survival significantly. CONCLUSIONS It is suggested that GKS provides an increase in survival time even in patients with a large number (four or more) of metastatic lesions. Concerning the selection of patients for GKS, RPA class should be considered as the most important factor and multiplicity of the lesions alone should not be a reason for withholding GKS.

Outcome of repeated radiosurgery for recurrent metastatic brain tumors.

OBJECTIVE We investigated the outcome of repeated gamma knife radiosurgery (GKS) for local or remote recurrence after initial radiosurgery. MATERIAL AND METHODS We retrospectively reviewed 204 patients who were treated with GKS. Among them 43 patients (21%) underwent GKS more than once. The second GKS was given for recurrence at the previously treated sites in 16 patients, new lesions at remote sites in 13, and both local recurrence and new lesions in 14. RESULTS The median survival from the first GKS was 36 (7-190) weeks in all patients and 68 (16-156) weeks in 43 patients with repeated GKS. The median time from the first GKS to the second was 37 weeks. The median survival from the second radiosurgical intervention was 32 (7-132) weeks. Local control rate at 6 months after salvage GKS was 90.7%. RPA class was the commonly dominant prognostic factor in both initial and salvage GKS. CONCLUSION Recurrence is common for patients with metastatic brain tumors after initial radiosurgery. Local control and survival time after salvage treatment are comparable with those after initial radiosurgery. GKS as a salvage treatment may provide additional survival benefit in selected patients.

Gamma Knife Radiosurgery for Ten or More Brain Metastases

OBJECTIVE This study was performed to assess the efficacy of GKS in patients with ten or more brain metastases. METHODS From Aug 2002 to Dec 2007, twenty-six patients (13 men and 13 women) with ten or more cerebral metastatic lesions underwent GKS. The mean age was 55 years (32-80). All patients had Karnofsky performance status (KPS) score of 70 or better. According to recursive partitioning analysis (RPA) classification, 3 patients belonged to class I and 23 to class II. The location of primary tumor was lung (21), breast (3) and unknown (2). The mean number of the lesions per patient was 16.6 (10-37). The mean cumulated volume was 10.9 cc (1.0-42.2). The median marginal dose was 15 Gy (9-23). Overall survival and the prognostic factors for the survival were retrospectively analyzed by using Kaplan Meier method and univariate analysis. RESULTS Overall median survival from GKS was 34 weeks (8-199). Local control was possible for 79.5% of the lesions and control of all the lesions was possible in at least 14 patients (53.8%) until 6 months after GKS. New lesions appeared in 7 (26.9%) patients during the same period. At the last follow-up, 18 patients died; 6 (33.3%) from systemic causes, 10 (55.6%) from neurological causes, and 2 (11.1%) from unknown causes. Synchronous onset in non-small cell lung cancer (p=0.007), high KPS score (>/=80, p=0.029), and controlled primary disease (p=0.020) were favorable prognostic factors in univariate analysis. CONCLUSION In carefully selected patients, GKS may be a treatment option for ten or more brain metastases.