Tumor-infiltrating immune cell subpopulations and programmed death ligand 1 (PD-L1) expression associated with clinicopathological and prognostic parameters in ependymoma.

Ependymomas are biologically and clinically heterogeneous tumors of the central nervous system that have variable clinical outcomes. The status of the tumor immune microenvironment in ependymoma remains unclear. Immune cell subsets and programmed death ligand 1 (PD-L1) expression were measured in 178 classical ependymoma cases by immunohistochemistry using monoclonal antibodies that recognized tumor-infiltrating lymphocyte subsets (TILs; CD3, CD4, CD8, FOXP3, and CD20), tumor-associated macrophages (TAMs; CD68, CD163, AIF1), indoleamine 2,3-dioxygenase (IDO)+ cells and PD-L1-expressing tumor cells. Increases in CD3+ and CD8+ cell numbers were associated with a prolonged PFS. In contrast, increased numbers of FOXP3+ and CD68+ cells and a ratio of CD163/AIF1+ cells were significantly associated with a shorter PFS. An increase in the IDO+ cell number was associated with a significantly longer PFS. To consider the quantities of TILs, TAMs, and IDO+ cells together, the cases were clustered into 2 immune cell subgroups using a k-means clustering analysis. Immune cell subgroup A, which was defined by high CD3+, low CD68+ and high IDO+ cell counts, predicted a favorable PFS compared to subgroup B by univariate and multivariate analyses. We found six ependymoma cases expressing PD-L1. All these cases were supratentorial ependymoma, RELA fusion-positive (ST-RELA). PD-L1 expression showed no prognostic significance. This study showed that the analysis of tumor-infiltrating immune cells could aid in predicting the prognosis of ependymoma patients and in determining therapeutic strategies to target the tumor microenvironment. PD-L1 expression in the ST-RELA subgroup suggests that this marker has a potential added value for future immunotherapy treatments.

Hemangiopericytomas in the Central Nervous System: A Multicenter Study of Korean Cases with Validation of the Usage of STAT6 Immunohistochemistry for Diagnosis of Disease.

BACKGROUND: Hemangiopericytoma (HPC) in the central nervous system (CNS) is a rare disease with distinctive biological/clinical characteristics compared with meningioma. METHODS: Cases of HPCs of the CNS were collected, and clinicopathological records were retrospectively reviewed and analyzed. Immunohistochemistry (IHC) for proliferative markers (Ki-67, PHH3) and STAT6 were performed. RESULTS: A total of 140 cases were collected, with mean follow-up of 77 months (median 58.8 months; range 0.53-540.5 months). 1-, 5-, 10-, and 20-year survival rates were 99.1, 94.0, 74.4, and 61.9 %, respectively. Thirty-nine patients (27.9 %) had recurrent disease. Mean and median times to recurrence were 62.9 and 47.3 months with 1-, 5-, 10-, and 20-year recurrence-free survival rates of 98.3, 78.3, 50.1, and 11.0 %, respectively. Thirteen patients (9.3 %) developed extracranial metastases. No adjuvant radiation therapy, higher histologic grades, failure of gross-total resection, and cases with gamma-knife surgery (GKS) were factors associated with shorter disease-free survival (log-rank test, p = 0.02, 0.00, 0.02, 0.00), among which high histologic grade and cases with GKS were significant in multivariable analysis. Strong nuclear STAT6 expression was noted in HPCs in 62 cases of HPCs (60/62, 96.8 %), whereas diffuse weak positivity was demonstrated in all meningioma cases. CONCLUSIONS: The survival rate in patients with HPC of the CNS is comparable to that of previously reported series. Recurrence remains a critical clinical issue of the disease. Identification of NAB2-STAT6 fusion transcript with surrogate IHC marker is a valuable diagnostic tool in the differential diagnosis of the disease.

Association between the CpG island methylator phenotype and its prognostic significance in primary pulmonary adenocarcinoma.

Aberrant methylation of promoter CpG islands is one of the most important inactivation mechanisms for tumor suppressor and tumor-related genes. Previous studies using genome-wide DNA methylation microarray analysis have suggested the existence of a CpG island methylator phenotype (CIMP) in lung adenocarcinomas. Although the biological behavior of these tumors varies according to tumor stage, no large-scale study has examined the CIMP in lung adenocarcinoma patients according to tumor stage. Furthermore, there have been no reported results regarding the clinical significance of each of the six CIMP markers. To examine the CIMP in patients with pulmonary adenocarcinoma after a surgical resection, we performed methylation analysis of six genes (CCNA1, ACAN, GFRA1, EDARADD, MGC45800, and p16 (INK4A)) in 230 pulmonary adenocarcinoma cases using the SEQUENOM MassARRAY platform. Fifty-four patients (28 %, 54/191) were in the CIMP-high (CIMP-H) group associated with high nodal stage (P = 0.007), the presence of micropapillary or solid histology (P = 0.003), and the absence of an epidermal growth factor receptor (EGFR) mutation (P = 0.002). By multivariate analysis, CIMP was an independent prognostic marker for overall survival (OS) and disease-specific survival (P = 0.03 and P = 0.43, respectively). In the stage I subgroups alone, CIMP-H patients had lower OS rates than the CIMP-low (CIMP-L) group (P = 0.041). Of the six CIMP markers, ACAN alone was significantly associated with patient survival. CIMP predicted the risk of progression independently of clinicopathological variables and enables the stratification of pulmonary adenocarcinoma patients, particularly among stage I cases.

The impact of postoperative radiation therapy on patterns of failure and survival improvement in patients with intracranial hemangiopericytoma.

Because of the rarity of intracranial hemangiopericytomas (HPCs), the role of postoperative radiation therapy (PORT) in the management of HPC remains unclear. This study therefore analyzed the effects of PORT on patterns of failure and survival improvement in patients with HPC. Fifty-two patients surgically treated for intracranial HPC at our institution between 1992 and 2013 were retrospectively analyzed. Patterns of failure were subdivided into local recurrence, regional metastasis, and distant metastasis. Multivariate Cox proportional hazards models were used to assess factors prognostic of treatment failure and survival, and a time-dependent Cox proportional hazards models were used to investigate the correlations between patterns of failure and death. Of the 52 patients, 45 (87 %) underwent gross total resection, and 39 (75 %) received PORT. PORT significantly lengthened local control (LC) and overall survival (OS), by 14 and 13 months, respectively, independent of the extent of resection. Patients who did and did not receive PORT had 5 year LC rates of 97 and 44 %, respectively (HR .05, P = .002); and 10 year OS rates of 83 and 25 %, respectively (hazard ratio (HR) .20, P = .008). PORT, however, did not show preventive effects on regional and distant metastases. The main patterns of failure were local recurrence in patients who did not receive PORT and distant metastasis in those who received PORT. Regional metastasis was a main immediate cause of death (P < .001), and tended to occur more frequently and earlier in patients not receiving PORT.

Promoter methylation of WNT inhibitory factor-1 and expression pattern of WNT/ß-catenin pathway in human astrocytoma: pathologic and prognostic correlations.

WNT inhibitory factor-1 (WIF1) is an antagonist of the WNT signaling pathway. We investigated the relationship between WIF1 promoter methylation and regulation of the WNT/ß-catenin signaling pathway, tumor grade, and survival in patients with astrocytoma. This study included 86 cases of astrocytoma, comprising 20 diffuse astrocytomas and 66 glioblastomas. In addition, 17 temporal lobectomy specimens from patients with epilepsy were included as controls. The ratio of methylated DNA to total methylated and unmethylated DNA (% methylation) was measured by methylation- and unmethylation-specific PCR. Representative tumor tissue was immunostained for WIF1, ß-catenin, cyclin D1, c-myc, and isocitrate dehydrogenase 1. Levels of WIF1 promoter methylation, mRNA expression, and protein expression in a glioblastoma cell line were compared before and after demethylation treatment. The mean percent methylation of the WIF1 promoter in astrocytomas was higher than that in control brain tissue. WIF1 protein expression was lower in the tumor group with >5% methylation than in the group with <5% methylation. Cytoplasmic ß-catenin staining was more frequently observed in tumors with a low WIF1 protein expression level. Demethylation treatment of a glioblastoma cell line increased WIF1 mRNA and protein expression. Increased WIF1 promoter methylation and decreased WIF1 protein expression were not related to patient survival. In conclusion, WIF1 expression is downregulated by promoter methylation and is an important mechanism of aberrant WNT/ß-catenin pathway activation in astrocytoma pathogenesis.

Frontal transcortical approach in 12 central neurocytomas.

BACKGROUND: Central neurocytomas (CN) are rare intraventricular tumors with benign clinical behavior that typically affect young adults. Although a favorable prognosis is generally expected after adequate management, there is no general consensus on the standard of therapy. We evaluated the efficacy and safety of radical surgery for the management of CN. METHODS: Between 1996 and 2010, 12 patients with CN (eight males and four females; range, 18 to 62 years; mean age, 28.5 years) were surgically treated in our institution. The initial goal of therapy was complete resection through a frontal transcortical approach, and repeat surgery was done in cases of residual or recurrent disease. The mean follow-up period was 51.2 months (range, 14-149 months). RESULTS: Complete resection was achieved in all patients either with primary (nine patients, 75 %) or second-look surgery (three patients, 25 %). No mortalities occurred and there were four surgery-related complications (two events of transient hemiparesis, one transient aphasia, and onepostoperative subdural hygroma). All patients were alive with normal activities of daily living at the last follow-up. Two patients (16.6 %) experienced a single recurrence at 26 and 66 months, one of whom underwent redo-surgery. CONCLUSION: For the management of CN, complete resection is feasible, effective, and safe. Repeat surgery may be a viable option in cases of residual or recurrent disease and the use of radiotherapy can be avoided in this young population.

Extrarenal teratoid Wilms' tumor: two cases in unusual locations, one associated with elevated serum AFP.

Teratoid Wilms' tumor is an unusual morphological entity characterized by a classic triphasic malignancy with predominantly heterologous tissue. The authors describe two cases of teratoid Wilms' tumor with an extrarenal site: one in a 13-year-old girl with vaginal spotting (patient 1) and another in a 1-day-old girl with a sacrococcygeal mass (patient 2). The tumors were located in the vagina and coccyx, respectively. Under the initial clinical diagnosis of sarcoma botryoides in patient 1 and teratoma in patient 2, the masses were removed. Microscopically, both tumors were composed of typical triphasic Wilms' tumor tissue with primitive cartilage and skeletal muscle, and squamous and columnar mucinous epithelia. The patient with sacrococcygeal mass (patient 2) had an elevated serum AFP level. The patients were given chemotherapy and have now remained disease free for 7 years 1 month, and 2 years 5 months after surgery, respectively. Familiarity with this rare variant of Wilms' tumor might be important in arriving at a correct diagnosis.

Clinical features of the microform cleft lip and the ultrastructural characteristics of the orbicularis oris muscle.

OBJECTIVE: To clarify the clinical features of the microform cleft lip and to establish the ultrastructural characteristics of the orbicularis muscle. DESIGN: Clinical observations of the characteristic deformities and associated anomalies were made. Muscle biopsies were harvested for histologic and ultrastructural analyses. PATIENTS: Seventy-one consecutive patients with microform cleft lip were included in the study. Muscle biopsies were investigated in 11 patients among them. RESULTS: Nasal deformity, a ridge or a groove from the vermilion to the nostril sill, and interruption of the "white roll" were present in all patients. Lack of a philtral column and a free border notch was observed in over 97% of patients. The orbicularis muscle demonstrated hypoplastic myofibers with nonneurogenic atrophy and focal accumulation of subsarcolemmal mitochondria. CONCLUSION: The typical gross morphology of the microform cleft lip is a surface manifestation of muscular defect, and the disruption of the muscle further extends down to the ultrastructural level. The clinical features, taken together with the ultrastructural defects of the musculature, might help with a more precise delineation of the microform cleft lip, and provide better understanding of cleft lip in general.

Protein Phosphatase Magnesium-Dependent 1δ (PPM1D) Expression as a Prognostic Marker in Adult Supratentorial Diffuse Astrocytic and Oligodendroglial Tumors.

BACKGROUND: Protein phosphatase magnesium-dependent 1δ (PPM1D) is a p53-induced serine/threonine phosphatase, which is overexpressed in various human cancers. A recent study reported that a mutation in the PPM1D gene is associated with poor prognosis in brainstem gliomas. In this study, we evaluated the utility of PPM1D as a prognostic biomarker of adult supratentorial diffuse astrocytic and oligodendroglial tumors. METHODS: To investigate PPM1D protein expression, mRNA expression, and copy number changes, immunohistochemistry, RNAscope in situ hybridization, and fluorescence in situ hybridization were performed in 84 adult supratentorial diffuse gliomas. We further analyzed clinical characteristics and overall survival (OS) according to PPM1D protein expression, and examined its correlation with other glioma biomarkers such as isocitrate dehydrogenase (IDH) mutation, and p53 expression. RESULTS: Forty-six cases (54.8%) were PPM1D-positive. PPM1D expression levels were significantly correlated with PPM1D transcript levels (p= .035), but marginally with PPM1D gene amplification (p=.079). Patients with high-grade gliomas showed a higher frequency of PPM1D expression than those with low-grade gliomas (p <.001). Multivariate analysis demonstrated that PPM1D expression (hazard ratio [HR], 2.58; p=.032), age over 60 years (HR, 2.55; p=.018), and IDH1 mutation (HR, 0.18; p=.002) were significantly independent prognostic factors; p53 expression had no prognostic significance (p=.986). The patients with tumor expressing PPM1D showed a shorter OS (p=.003). Moreover, patients with tumor harboring wild-type IDH1 and PPM1D expression had the worst OS (p<.001). CONCLUSIONS: Our data suggest that a subset of gliomas express PPM1D; PPM1D expression is a significant marker of poor prognosis in adult supratentorial diffuse astrocytic and oligodendroglial tumors.

Postoperative Neurologic Outcome in Patients with Pituitary Apoplexy After Transsphenoidal Surgery.

OBJECTIVE: Pituitary apoplexy can cause severe neuro-ophthalmologic or endocrinologic sequelae, requiring timely treatment. The present study was performed to evaluate postoperative neurologic outcomes and to identify their risk factors in patients who underwent transsphenoidal surgery for pituitary apoplexy. METHODS: Forty-one consecutive patients with pituitary apoplexy who underwent transsphenoidal surgery were reviewed retrospectively. The initial rates of visual acuity (VA) decrease, visual field (VF) defect, and ocular palsy were 34.1%, 46.3%, and 68.3%, respectively. The median maximal diameter and tumoral volume was 2.6 cm (range, 2.0-4.6 cm) and 5.3 cm3 (range, 2.4-38.8 cm3), respectively. Seventeen patients (41.5%) underwent surgery within 7 days. The median follow-up duration was 45 months (range, 12-196 months). RESULTS: At the last follow-up, 62.9% (22/35) of patients had made a full recovery from preoperative neurologic deficits, with partial recovery observed in the remaining patients. The rates of improvement and full recovery from VA decrease were 92.9% and 57.1%, respectively; those from VF defect were 94.7% and 36.8%, respectively; and those from ocular palsy were 100.0% and 96.4%, respectively. On multivariate analysis, initial visual impairment score (≥20) was the only significant risk factor for postoperative neurologic sequelae (P < 0.001; odds ratio, 40.8). Surgical timing was not associated with postoperative neurological recovery (P = 0.733). CONCLUSIONS: Ocular palsy was fully recovered in 96.4% patients with pituitary apoplexy after transsphenoidal surgery. Initial visual impairment status was found to be more strongly associated with postoperative neurologic recovery than surgical timing.

Diagnostic Significance of Cellular Neuroglial Tissue in Ovarian Immature Teratoma.

BACKGROUND: Immature teratoma (IT) is a tumor containing immature neuroectodermal tissue, primarily in the form of neuroepithelial tubules. However, the diagnosis of tumors containing only cellular neuroglial tissue (CNT) without distinct neuroepithelial tubules is often difficult, since the histological characteristics of immature neuroectodermal tissues remain unclear. Here, we examined the significance of CNT and tried to define immature neuroectodermal tissues by comparing the histological features of neuroglial tissues between mature teratoma (MT) and IT. METHODS: The histological features of neuroglial tissue, including the cellularity, border between the neuroglial and adjacent tissues, cellular composition, mitotic index, Ki-67 proliferation rate, presence or absence of tissue necrosis, vascularity, and endothelial hyperplasia, were compared between 91 MT and 35 IT cases. RESULTS: CNTs with a cellularity grade of ≥ 2 were observed in 96% of IT cases and 4% of MT cases (p < .001); however, CNT with a cellularity grade of 3 in MT cases was confined to the histologically distinct granular layer of mature cerebellar tissue. Moreover, CNT in IT exhibited significantly higher rates of Ki-67 proliferation, mitoses, and necrosis than those in MT (p < .001). Furthermore, an infiltrative border of neuroglial tissue and glomeruloid endothelial hyperplasia were significantly more frequent in IT cases than in MT cases (p < .001). CONCLUSIONS: Our results suggest that if CNT with a cellularity grade of ≥ 2 is not a component of cerebellar tissue, such cases should be diagnosed as IT containing immature neuroectodermal tissue, particularly if they exhibit an infiltrative border, mitoses, necrosis, and increased Ki-67 proliferation.

High prevalence of TP53 mutations is associated with poor survival and an EMT signature in gliosarcoma patients.

Gliosarcoma (GS) is a rare variant (2%) of glioblastoma (GBM) that poses clinical genomic challenges because of its poor prognosis and limited genomic information. To gain a comprehensive view of the genomic alterations in GS and to understand the molecular etiology of GS, we applied whole-exome sequencing analyses for 28 GS cases (6 blood-matched fresh-frozen tissues for the discovery set, 22 formalin-fixed paraffin-embedded tissues for the validation set) and copy-number variation microarrays for 5 blood-matched fresh-frozen tissues. TP53 mutations were more prevalent in the GS cases (20/28, 70%) compared to the GBM cases (29/90, 32%), and the GS patients with TP53 mutations showed a significantly shorter survival (multivariate Cox analysis, hazard ratio=23.9, 95% confidence interval, 2.87-199.63, P=0.003). A pathway analysis showed recurrent alterations in MAPK signaling (EGFR, RASGRF2 and TP53), phosphatidylinositol/calcium signaling (CACNA1s, PLCs and ITPRs) and focal adhesion/tight junction (PTEN and PAK3) pathways. Genomic profiling of the matched recurrent GS cases detected the occurrence of TP53 mutations in two recurrent GS cases, which suggests that TP53 mutations play a role in treatment resistance. Functionally, we found that TP53 mutations are associated with the epithelial-mesenchymal transition (EMT) process of sarcomatous components of GS. We provide the first comprehensive genome-wide genetic alternation profiling of GS, which suggests novel prognostic subgroups in GS patients based on their TP53 mutation status and provides new insight in the pathogenesis and targeted treatment of GS.

Giant hypothalamic hamartoma associated with an intracranial cyst in a newborn.

We report the case of a giant hypothalamic hamartoma with a large intracranial cyst in a neonate. On ultrasonography, the lesion presented as a lobulated, mass-like lesion with similar echogenicity to the adjacent brain parenchyma, located anterior to the underdeveloped and compressed left temporal lobe, and presenting as an intracranial cyst in the left cerebral convexity without definite internal echogenicity or septa. The presence of a hypothalamic hamartoma and intracranial neurenteric cyst were confirmed by surgical biopsy. The association of a giant hypothalamic hamartoma and a neurenteric cyst is rare. Due to the rarity of this association, the large size of the intracranial cyst, and the resulting distortion in the regional anatomy, the diagnosis of the solid mass was not made correctly on prenatal high-resolution ultrasonography.

Upfront Stereotactic Radiosurgery for Pineal Parenchymal Tumors in Adults.

OBJECTIVE: Pineal parenchymal tumors (PPTs) in adults are rare, and knowledge regarding their optimal management and treatment outcome is limited. Herein, we present the clinical results of our series of PPTs other than pineoblastomas managed by stereotactic radiosurgery (SRS) at upfront setting. METHODS: Between 1997 and 2014, nine consecutive adult patients with the diagnosis of PPTs, either pineocytoma or pineal parenchymal tumor of intermediate differentiation, were treated with SRS. There were 6 men and 3 women. The median age was 39 years (range, 31-53 years). All of the patients presented with symptoms of hydrocephalus. Endoscopic third ventriculostomy and biopsy was done for initial management. After histologic diagnosis, patients were treated with Gamma Knife with the mean dose of 13.3 Gy (n=3) or fractionated Cyberknife with 32 Gy (n=6). RESULTS: After a mean follow-up of 78.6 months (range, 14-223 months), all patients were alive and all of their tumors were locally controlled except for one instance of cerebrospinal fluid seeding metastasis. On magnetic resonance images, tumor size decreased in all patients, resulting in complete response in 3 patients and partial response in 6. One patient had experienced temporary memory impairment after SRS, which improved spontaneously. CONCLUSION: SRS is effective and safe for PPTs in adults and can be considered as a useful alternative to surgical resection at upfront setting.

Primary histiocytic sarcoma of the central nervous system.

Histiocytic sarcoma is a type of lymphoma that rarely involves the central nervous system (CNS). Its rarity can easily lead to a misdiagnosis. We describe a patient with primary CNS histocytic sarcoma involving the cerebral hemisphere and spinal cord, who had been initially misdiagnosed as demyelinating disease. Two biopsies were necessary before a correct diagnosis was made. A histologic examination showed bizarre shaped histiocytes with larger nuclei and nuclear atypia. The cells were positive for CD68, CD163, and S-100 protein. As a resection was not feasible due to multifocality, he was treated with highdose methotrexate, but showed no response. As a result, he was switched to high dose cytarabine; but again, showed no response. The patient died 2 months from the start of chemotherapy and 8 months from the onset of symptoms. Since few patients with this condition have been described and histopathology is difficult to diagnose, suspicion of the disease is essential.

Chondromyxoid fibroma of the sternum.

Primary chondromyxoid fibroma (CMF) of the sternum is quite rare with only four cases documented in the literature. We present a new case of CMF arising from the sternum of a 47-year-old man and compare it with the previous cases.

MR imaging and histopathologic findings of a case of cerebral ganglioneurocytoma.

We report a case of ganglioneurocytoma manifesting as a complex partial seizure in a young adult male. MR images depicted a well-marginated cystic mass with a heterogeneous solid portion abutting the dura in the parietal lobe. The solid portion showed minimal heterogeneous enhancement, and pressure erosion of the overlying calvarium had occurred. Following gross total resection, the clinical outcome was satisfactory, with no further seizures, and during the five-year follow-up period, the tumor did not recur.

Nested PCR for diagnosis of tuberculous lymphadenitis and PCR-SSCP for identification of rifampicin resistance in fine-needle aspirates.

An accurate diagnosis of tuberculosis and multidrug resistance is important for the control of tuberculosis, which remains a major public health problem. Fine-needle aspiration (FNA) has provided an alternative tool for bacterial examination. This study was performed to investigate the usefulness of one-step polymerase chain reaction (PCR) and PCR-SSCP as a routine test for the detection of Mycobacterium tuberculosis and rifampicin-resistant strain in FNA. Ziehl-Neelsen stain (Z-N) and PCR were processed using the aspirates of tuberculous lymphadenitis for the detection of M. tuberculosis. PCR-SSCP was done for the identification of rpoB mutation. M. tuberculosis was detected in 49/63 (77.8%) by PCR and 25/63 (39.7%) by Z-N. There were 26 cases with PCR(+)/Z-N(-) and two cases with PCR(-)/Z-N(+). Twelve cases showed negativity against both. In 7/22 (31.8%), rpoB mutation was observed. In conclusion, PCR is more sensitive in the detection of M. tuberculosis in FNA than Z-N. PCR-SSCP could also be used in FNA in the prediction of multidrug resistance.

Intramedullary spinal cysticercosis: a case report and review of literature.

To report a case of spinal intramedullary cysticercosis in thoracic spine. A 47-year old man living in Korea referred to our hospital with both feet tingling sensation for about a year. Laboratory evaluations, including serologic tests were not helpful. Magnetic resonance imaging revealed a 1.7 cm intramedullary mass at T10-11 level, which believed to be a tumor instead, rather than a cysticercosis preoperatively. Successful operation was done with a histopathological result confirmed it as cysticercosis. Even though the prevalence of intramedullary spinal cysticercosis is extremely rare, and radiologic exams mimic other common tumors like ependymoma or astrocytoma, the disease should be considered as differential diagnosis.

Treatment outcome of radiation therapy for intracranial germinoma: adaptive radiation field in relation to response to chemotherapy.

AIM: To determine the optimal radiotherapy (RT) target volume in correlation with tumor response to chemotherapy in patients with intracranial germinoma. PATIENTS AND METHODS: Seventy-two patients received chemotherapy followed by RT. The RT field was tailored to chemotherapy response. RESULTS: Five-year recurrence-free survival (RFS) was 87% and overall survival was 97%. RT field was significantly associated with RFS, with 5-year RFS rates of 95%, 91%, and 62% in those who received craniospinal irradiation, whole-brain/whole-ventricle RT, and focal RT, respectively (p=0.01). In the complete-response group after chemotherapy, 5-year RFS rates were 100% after whole-brain RT/whole-ventricle RT and 70% after focal RT (p=0.04). In the partial-response group, 5-year RFS rates after craniospinal irradiation, whole-brain RT, and focal RT were 100%, 85%, and 33%, respectively (p<0.01). CONCLUSION: Regardless of response, those treated with focal RT had an excessively high relapse rate. Whole-brain/whole-ventricle RT could be applied to patients who show a complete response to chemotherapy, but the optimal strategy for patients with partial response needs further investigation.