A recent analysis of the genetic features of medulloblastoma (MB) suggested classification into distinct subgroups according to gene expression profiles, including the Wingless signaling pathway-activated group (WNT group), the Sonic Hedgehog signaling pathway-activated group (SHH group), group 3, and group 4. To classify MB according to genetic features in practice, we analyzed 74 MBs using representative markers of each group. Based on immunohistochemistries (IHC), cytogenetic alterations, and a CTNNB1 mutation study, the patients were divided into the following three groups: cases showing nuclear β-catenin and/or CTNNB1 mutation and/or monosomy 6 were included in the WNT group (14/74, 18.9%); cases expressing GAB1 were included in the SHH group (15/74, 20.2%); cases that did not show positivity for markers of the WNT or SHH group were included in the non-WNT/SHH group (45/74, 60.6%). Immunoexpression of NPR3 seemed to lack sensitivity for classifying group 3, showing diffuse positivity in only two cases. KCNA1 was not specific to group 4 because it was expressed in all groups. Cases in the WNT group showed a slightly better survival than those in the SHH or non-WNT/SHH group, although additional cases are required for statistical significance. Isochromosome 17q (P = .002) and the large cell/anaplastic variant (P = .002) were demonstrated to be poor prognostic indicators in multivariate analysis. The representative IHC and cytogenetic data facilitated the division of MBs into the WNT and SHH groups; however, more specific markers should be added for the identification of group 3 and group 4 in practice.
Alpha-internexin (INA) is a proneuronal gene-encoding neurofilament interacting protein. INA is overexpressed mostly in oligodendroglial phenotype gliomas, is related to 1p/19q codeletion, and is a favorable prognostic marker. We studied INA expression in oligodendrogliomas (ODGs) and glioblastomas (GBMs) to verify its association with several molecular phenotypes, 1p/19q codeletion, and epidermal growth-factor-receptor (EGFR) amplification. A total of 230 low- and high-grade ODG and GBM cases was analyzed for INA expression by immunohistochemical staining; and 1p/19q and EGFR gene status was examined by fluorescence in-situ hybridization. INA was positive in 80.3% of ODGs and in 34.3% of GBMs. 1p/19q codeletion was detected in 77.0% of ODGs and 5.5% of GBMs. INA and 1p/19q codeletion were strongly correlated (P < 0.001). The specificity of INA expression for 1p/19q codeletion was 70.8%, while sensitivity was 100%; positive predictive value was 72.5%, and negative predictive value was 29.2% in all 228 tumors. INA expression was correlated with better progression-free survival (PFS) and overall survival (OS) (P = 0.001). In conclusion, INA expression has high specificity and sensitivity to predict 1p/19q codeletion, and it is well correlated with PFS of both ODGs and GBMs. Therefore, INA expression could be a simple, reliable, and favorable prognostic and surrogate marker for 1p/19q codeletion and long term survival.
Glioblastoma; Oligodendroglioma; Alpha-internexin, humans; 1p/19q Codeletion; EGFR protein, Human
Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the gastrointestinal tract (GIT). Although interstitial cells of Cajal has been suggested as origin of this tumor, the cytological and ultrastructural features of GISTs are heterogeneous and unclear. A total 10 cases of normal gastrointestinal tissue (control), 13 GISTs of the stomach (8), small intestine (3), mesocolon (1) and liver (1), and 2 gastrointestinal autonomic nervous tumor (GANT) of small intestine were ultrastructurally studied. Normal interstitial cells of Cajal (ICC) were abundantly present around the myenteric plexuses or individually scattered through the wall of GIT. ICC was characterized by slender cytoplasmic processes, well-developed endoplasmic reticulum (ER), mitochondria, Golgi apparatus, caveolae and intermediate filaments. The GISTs and GANTs had overlapping ultrastructures. The most common and important ultrastructural features of GISTs were rich villous cytoplasmic processes, dispersed intermediate filaments and abundant SER, and those of GANTs were neurosecretory granules and skenoid fibers. Compared with ICC, the GISTs and GANTs had remarkably reduced caveolae and gap junctions. Our study suggested that ultrastructural analysis gives much information to investigate lineage differentiation of neoplastic cells and make a differential diagnosis of these tumors from other mesenchymal tumors and between GISTs and GANTs.
Gastrointestinal Neoplasms; Stromal Tumors; Autonomic Pathways; Microscopy, Electron; Immunohistochemistry; Proto-Oncogene Protein c-Kit
Xanthogranulomatous cholecystitis (XGC) is a rare form of chronic cholecystitis that is accompanied by xanthomatous histiocytes and chronic inflammation. A 2-month-old boy presented with a right upper abdominal palpable mass. Cholecystectomy with liver wedge resection was done, under the impression that the mass might be a hepatic tumor or liver abscess. Pathologic examination showed XGC with abscess formation. Most cases of XGC were observed in adult and only a few cases were reported in children. We describe a very rare case of XGC in infancy.
Xanthogranulomatous cholecystitis; Cholecystitis; Infant; Cholecystectomy
The inhibitor of differentiation (ID) genes have been implicated as promoters of tumor progression and metastasis in many human cancers. The current study investigated the expression and functional roles of ID genes in seeding and prognosis of medulloblastoma.
ID gene expression was screened in human medulloblastoma tissues. Knockdown of ID3 gene was performed in medulloblastoma cells in vitro. The expression of metastasis-related genes after ID3 knockdown was assessed. The effect of ID3 knockdown on tumor seeding was observed in an animal model in vivo. The survival of medulloblastoma patients was plotted according to the ID3 expression levels.
Significantly higher ID3 expression was observed in medulloblastoma with cerebrospinal fluid seeding than tumors without seeding. Knockdown of ID3 decreased proliferation, increased apoptosis, and suppressed the migration of D283 medulloblastoma cells in vitro. In a seeding model of medulloblastoma, ID3 knockdown in vivo with shRNA inhibited the growth of primary tumors, prevented the development of leptomeningeal seeding, and prolonged animal survival. High ID3 expression was associated with shorter survival of medulloblastoma patients, especially in Group 4 medulloblastomas.
High ID3 expression is associated with medullolbastoma seeding and is a poor prognostic factor, especially in patients with Group 4 tumors. ID3 may represent the metastatic/ aggressive phenotype of a subgroup of medulloblastoma.
ID3; Medulloblastoma; Seeding; Prognosis; Survival; Group 4
BRAFV600E mutations are involved in the development of melanoma, colon cancer, and papillary thyroid carcinoma. These mutations are also found in primary brain tumors at low to moderate frequencies. In this study, we investigated a series of brain tumors to determine the prevalence and associated clinicopathologic features of BRAFV600E mutations. By direct sequencing, we analyzed 223 brain tumors, including 51 gangliogliomas (GGs), 45 pilocytic astrocytomas (PAs), 12 pleomorphic xanthoastrocytomas (PXAs), 35 glioblastomas (GBs), 28 anaplastic astrocytomas (AAs), 44 oligodendroglial tumors (ODGs), 3 anaplastic oligoastrocytomas, and 5 diffuse astrocytomas. Thirty-six cases (16.1%) exhibited the BRAFV600E mutation, including 66.7% of PXAs, 23.5% of GGs, 15.6% of PAs, and 9.7% of the malignant gliomas; the latter included 14.3% of AAs, 8.6% of GBs, and 4.5% of ODGs. Copy number aberration at the 7q34 (BRAF) locus was found in 73.1% of PAs and 50% of PXAs. 9p Homozygous deletion was found in 66.7% of PXAs, but it was not correlated with the BRAFV600E mutation. Patients' age, sex, histologic grade, and progression-free survival were also not correlated with the BRAFV600E mutation. The BRAFV600E mutation in brain tumors did not have prognostic value but is certainly a diagnostic marker and therapeutic target, not only for pediatric low-grade gliomas but also for malignant gliomas, even though the rate of mutation was not high. These results should be verified in a larger study with more cases and a longer follow-up period to overcome the limitation of small sample size.
Various energy devices had been used in thyroid surgery. Aim of study is to develop canine model for recurrent laryngeal nerve injury by harmonic scalpel and to evaluate feasibility of using this model for evaluating the safety use of harmonic scalpel during thyroid surgery. Nine dogs were divided into 3 groups according to distance between harmonic scalpel application and recurrent laryngeal nerve; group 1 (1 mm), 2 (2 mm), and 3 (3 mm). Vocal cord function was assessed pre- and postoperatively using video laryngoscopy. Harmonic scalpel was applied adjacent to left recurrent laryngeal nerve and, two weeks later, right recurrent laryngeal nerve at assigned distances. Recurrent laryngeal nerves were evaluated for subacute and acute morphologic changes. Laryngoscopy demonstrated 3 abnormal vocal cords in group 1, 1 in group 2, and no in group 3 (P=0.020). Subacute histologic changes were observed in nerves with abnormal function. Acute histologic changes were observed 5/8 (62.5%) in group 1, 1/7 (14.3%) in group 2, and not in group 3. We developed canine model for recurrent laryngeal injury. The functional outcomes matched with the histologic changes. These warrant further study to determine the safety margin for energy device in vicinity of recurrent laryngeal nerve.
Recurrent laryngeal nerve; canine model; harmonic scalpel; safety margin; nerve damage; ultrasonic shears
The 5-aminolevulinic acid (5-ALA)-induced tumor fluorescence is a useful intraoperative marker for the diagnosis and the detection of various malignancies, but its use in meningioma is only reported infrequently. In meningioma, a complete resection of the tumor mass is crucial for the prevention of recurrence and postoperative morbidities. Deep sylvian meningioma is a rare type of meningioma where complete tumor removal is complicated by its deep anatomical location and close involvement with the middle cerebral artery. From our experience, 5-ALA-mediated fluorescence facilitated a safe excision whilst preserving critical neurovascular structures. To our best knowledge, this is first report from use of 5-ALA in a deep sylvian meningioma.
5-aminolevulinic acid; Resection; Deep sylvian meningioma; Meningioma without dural attachment
Paragonimiasis is caused by ingesting crustaceans, which are the intermediate hosts of Paragonimus. The involvement of the brain was a common presentation in Korea decades ago, but it becomes much less frequent in domestic medical practices. We observed a rare case of cerebral paragonimiasis manifesting with intracerebral hemorrhage. A 10-yr-old girl presented with sudden-onset dysarthria, right facial palsy and clumsiness of the right hand. Brain imaging showed acute intracerebral hemorrhage in the left frontal area. An occult vascular malformation or small arteriovenous malformation compressed by the hematoma was initially suspected. The lesion progressed for over 2 months until a delayed surgery was undertaken. Pathologic examination was consistent with cerebral paragonimiasis. After chemotherapy with praziquantel, the patient was monitored without neurological deficits or seizure attacks for 6 months. This case alerts practicing clinicians to the domestic transmission of a forgotten parasitic disease due to environmental changes.
Cerebral Paragonimiasis; Intracerebral Hemorrhage; Diagnosis
To evaluate the mechanism of the development of therapeutic resistance after temozolomide treatment, we focused on changes in O6-methylguanine DNA methyltransferase (MGMT) and mismatch repair (MMR) between initial and recurrent glioblastomas. Tissue samples obtained from 24 paired histologically confirmed initial and recurrent adult glioblastoma patients who were initially treated with temozolomide were used for MGMT and MMR gene promoter methylation status and protein expression analysis using methylation-specific multiplex ligation probe amplification (MS-MLPA), methylation-specific polymerase chain reaction (MSP), and immunohistochemical staining. There was a significant decrease in the methylation ratio of the MGMT promoter determined by MS-MLPA, which was not detectable with MSP, and MGMT protein expression changes were not remarkable. However, there was no epigenetic variability in MMR genes, and a relatively homogeneous expression of MMR proteins was observed in initial and recurrent tumors. We conclude that the development of reduced methylation in the MGMT promoter is one of the mechanisms for acquiring therapeutic resistance after temozolomide treatment in glioblastomas.
Ca2+ signaling is an important determining factor in many cellular processes, especially in cancer cell proliferation, motility and invasion. Glioblastoma is the deadliest brain cancer with its average survival time of less than a year, with the most prominent cellular feature being the ability of these cells to migrate to and invade the neighboring tissue. We hypothesized that disturbing the Ca2+ signaling pathway would decrease the propensity for these cells to migrate. Thus, we investigated the detailed Ca2+ signaling pathway of the glioblastoma cells in response to various receptor tyrosine kinases (RTK) and G-protein coupled receptor (GPCR) agonists. Here we report that caffeine, which is a well-known activator of ryanodine receptors (RyRs), paradoxically inhibits inositol-1, 4, 5-triphospate receptor(IP3R)-mediated Ca2+ increase by selectively targeting IP3R subtype 3(IP3R3), whose mRNA expression is significantly increased in glioblastoma cells. Consequently, by inhibiting IP3R3-mediated Ca2+ release, caffeine was found to inhibit the invasion and migration of various glioblastoma cell lines in scrape motility, Matrigel invasion, soft agar, and brain slice implantation assays. In a mouse xenograft model of glioblastoma, caffeine intake via drinking water greatly increased mean survival duration of subject animals. These findings propose IP3R3 as a novel target for glioblastoma treatment and that caffeine may be a useful adjunct therapy that slows glioblastoma invasion and migration by selectively targeting IP3R3.
Pseudoprogression is a major diagnostic dilemma in current treatment protocols for malignant gliomas that involve concurrent chemoradiotherapy. We hypothesized that methylation-specific multiplex ligation probe amplification (MS-MLPA), an assay that permits semiquantitative evaluation of promoter methylation, may be used to diagnose pseudoprogression based on the quantification of the methylation status of the O6-methylguanine DNA methyltransferase (MGMT) promoter. We examined the methylation ratio of the MGMT promoter with MS-MLPA in 48 samples from glioblastoma patients. The results were compared with those from methylation-specific polymerase chain reaction (MSP), and protein levels were confirmed by immunohistochemical staining. We then evaluated the correlation between those molecular signatures and clinical outcomes. With regard to radiological progression after chemoradiotherapy, the diagnostic accuracy of the MS-MLPA method was 80% (using a cut-off value of 0.2). These results are better than those obtained with MSP (diagnostic accuracy of 68%). Combining the MS-MLPA and MSP methods resulted in a diagnostic accuracy of 93% for the identification of pseudoprogression among patients to whom these results were coherent. These results demonstrate that MS-MLPA is a useful method to predict radiological progression vs pseudoprogression in glioblastoma patients and that the interpretation of these results in combination with MSP results will provide good practical guidelines for clinical decision making in glioblastoma treatment.
glioblastoma; MS-MLPA; MGMT; pseudoprogression
The authors report a case of atypical extraventricular neurocytoma (EVN) transformed from EVN which had been initially diagnosed as an oligodendroglioma 15 years ago. An 8-year-old boy underwent a surgical resection for a right frontal mass which was initially diagnosed as oligodendroglioma. When the tumor recurred 15 years later, a secondary operation was performed, followed by salvage gamma knife treatment. The recurrent tumor was diagnosed as an atypical EVN. The initial specimen was reviewed and immunohistochemistry revealed a strong positivity for synaptophysin. The diagnosis of the initial tumor was revised as an EVN. The patient maintained a stable disease state for 15 years after the first operation, and was followed up for one year without any complications or disease progression after the second operation. We diagnosed an atypical extraventricular neurocytoma transformed from EVN which had been initially diagnosed as an oligodendroglioma 15 years earlier. We emphasize that EVN should be included in the differential diagnosis of oligodendroglioma.
Atypical extraventricular neurocytoma; Differential diagnosis; Oligodendroglioma; Recurrence
The aim of this study was to evaluate the effect of early motor balance and coordination training on functional recovery and brain plasticity in an ischemic rat stroke model, compared with simple locomotor exercise. Adult male Sprague-Dawley rats with cortical infarcts were trained under one of four conditions: nontrained control, treadmill training, motor training on the Rota-rod, or both Rota-rod and treadmill training. All types of training were performed from post-operation day 1 to 14. Neurological and behavioral performance was evaluated by Menzies' scale, the prehensile test, and the limb placement test, at post-operation day 1, 7, and 14. Both Rota-rod and treadmill training increased the expression of synaptophysin in subcortical regions of the ischemic hemisphere including the hippocampus, dentate gyrus, and thalamus, but did not affect levels of brain-derived neurotrophic factor or tyrosin kinase receptor B. The Rota-rod training also improved Menzies' scale and limb placement test scores, whereas the simple treadmill training did neither. The control group showed significant change only in Menzies' scale score. This study suggests that early motor balance and coordination training may induce plastic changes in subcortical regions of the ischemic hemisphere after stroke accompanied with the recovery of sensorimotor performance.
Stroke; Motor Skills; Neuronal Plasticity; Synaptophysin
A seventeen-year-old female patient was admitted with sudden-onset of headache and vomiting. Brain magnetic resonance imaging demonstrated a heterogeneously enhancing tumour in the left lateral ventricle. The tumour was removed and confirmed as a central neurocytoma (CN). For the residual tumour in the left lateral ventricle, gamma knife stereotactic radiosurgery was done at fifteen months after the initial surgery. Tumour recurred in the 4th ventricle at 5 yr after initial surgery. The tumour was removed and proved as a CN. In vitro primary culture was done with both tumours obtained from the left lateral ventricle and the 4th ventricle, respectively. Nestin, a neuronal stem cell marker was expressed in reverse Transcriptase-Polymerase Chain Reaction of both tumors. Both tumours showed different morphology and phenotypes of neuron and glia depending on the culture condition. When cultured in insulin, transferrin selenium and fibronectin media with basic fibroblast growth factors, tumour cells showed neuronal morphology and phenotypes. When cultured in the Dulbeco's Modified Essential Media with 20% fetal bovine serum, tumors cells showed glial morphology and phenotypes. It is suggested that CN has the characteristics of neuronal stem cells and potential to differentiate into mature neuron and glial cells depending on the environmental cue.
Neurocytoma; Cell Culture Techniques; Neuronal Stem Cells
We analyzed the methylation status of the O6-methylguanine-DNA methyltransferase (MGMT) gene promoter in World Health Organization (WHO) grade III gliomas in association with other molecular markers to evaluate their prevalence.
The samples of a total of 36 newly WHO grade III glioma patients including 19 anaplastic oligodendrogliomas (AO), 7 anaplastic oligoastrocytomas (AOA), and 10 anaplastic astrocytomas (AA) were analyzed. The methylation status of the MGMT gene promoter was confirmed by methylation-specific polymerase chain reaction. The 1p/19q chromosomal deletion status and EGFR amplification were assessed by Fluorescence In-Situ Hybridization. MGMT, EGFR, EGFRvIII, and p53 expression were analyzed by immunohistochemical staining.
The MGMT gene promoter was methylated in 32 (88.9%) and unmethylated in 4 (11.2%). Among them, all of the AO and AOA had methylated MGMT gene promoter without exception. Significant associations between MGMT gene promoter hypermethylation and 1p/19q deletion was observed (p = 0.003). Other molecular markers failed to show significant associations between MGMT gene promoter statuses.
There was extensive epigenetic silencing of MGMT gene in high grade gliomas with oligodendroglial component. Together with frequent 1p/19q co-deletion in oligodendroglial tumors, this may add plausible explanations supporting the relative favorable prognosis in oligodendroglial tumors compared with pure astrocytic tumors.
MGMT gene promoter; Methylation; 1p/19q; Oligodendroglioma; Methylation-specific PCR
Primary ovarian choriocarcinoma arising from a germ cell is an extremely rare occurrence, especially in postmenopausal women, and the prognosis is poor. Non-gestational choriocarcinoma of the ovary (NGCO) accounts for 0.6% or less of all ovarian neoplasms. It is important to distinguish gestational choriocarcinomas of the ovary (GCO) from other carcinomas because of the poor prognosis of NGCO. We describe a case of NGCO with lung metastasis in a 55 year old woman, which we present together with a brief review of the literature.
Nongestational choriocarcinoma; Ovary; Postmenopause
In this study, we investigated the clinical characteristics and treatment results of osteosarcoma during the past 7 years, and evaluated the role of high dose chemotherapy (HDCT) with autologous stem cell transplantation (ASCT).
Materials and Methods
We retrospectively analyzed the clinical data of patients who were diagnosed as osteosarcoma at our center from January, 2000 to December, 2007.
The 5-year overall survival and event-free survival of the patients were 72.6% and 55.9%, respectively. Seventeen (41.5%) patients showed disease progression during treatment or relapse after the end of treatment. The patients who had metastasis at diagnosis or who had a lower grade of necrosis after neoadjuvant chemotherapy showed decreased overall and event-free survival. Four patients received ASCT after HDCT, and 3 of them are alive without disease.
The patients who relapsed or had refractory osteosarcoma or who had metastasis at diagnosis or a lower grade of necrosis after neoadjuvant chemotherapy showed poor prognosis. HDCT with ASCT could be an alternative treatment option for these patients.
Osteosarcoma; Autologous stem cell transplantation; High dose chemotherapy; Pediatrics
Centronuclear myopathies are clinically and genetically heterogenous diseases with common histological findings, namely, centrally located nuclei in muscle fibers with a predominance and hypotrophy of type 1 fibers. We describe two cases from one family with autosomal dominant centronuclear myopathy with unusual clinical features that had initially suggested distal myopathy. Clinically, the patients presented with muscle weakness and atrophy localized mainly to the posterior compartment of the distal lower extremities. Magnetic resonance imaging revealed predominant atrophy and fatty changes of bilateral gastrocnemius and soleus muscles. This report demonstrates the expanding clinical heterogeneity of autosomal dominant centronuclear myopathy.
Myopathies, Structural, Congenital; Autosomal Dominant Inheritance; Distal Myopathies
To evaluate the usefulness of dynamic susceptibility contrast (DSC) enhanced perfusion MR imaging in predicting major genetic alterations in glioblastomas.
Materials and Methods
Twenty-five patients (M:F = 13∶12, mean age: 52.1±15.2 years) with pathologically proven glioblastoma who underwent DSC MR imaging before surgery were included. On DSC MR imaging, the normalized relative tumor blood volume (nTBV) of the enhancing solid portion of each tumor was calculated by using dedicated software (Nordic TumorEX, NordicNeuroLab, Bergen, Norway) that enabled semi-automatic segmentation for each tumor. Five major glioblastoma genetic alterations (epidermal growth factor receptor (EGFR), phosphatase and tensin homologue (PTEN), Ki-67, O6-methylguanine-DNA methyltransferase (MGMT) and p53) were confirmed by immunohistochemistry and analyzed for correlation with the nTBV of each tumor. Statistical analysis was performed using the unpaired Student t test, ROC (receiver operating characteristic) curve analysis and Pearson correlation analysis.
The nTBVs of the MGMT methylation-negative group (mean 9.5±7.5) were significantly higher than those of the MGMT methylation-positive group (mean 5.4±1.8) (p = .046). In the analysis of EGFR expression-positive group, the nTBVs of the subgroup with loss of PTEN gene expression (mean: 10.3±8.1) were also significantly higher than those of the subgroup without loss of PTEN gene expression (mean: 5.6±2.3) (p = .046). Ki-67 labeling index indicated significant positive correlation with the nTBV of the tumor (p = .01).
We found that glioblastomas with aggressive genetic alterations tended to have a high nTBV in the present study. Thus, we believe that DSC-enhanced perfusion MR imaging could be helpful in predicting genetic alterations that are crucial in predicting the prognosis of and selecting tailored treatment for glioblastoma patients.
To compare the reproducibilities of manual and semiautomatic segmentation method for the measurement of normalized cerebral blood volume (nCBV) using dynamic susceptibility contrast-enhanced (DSC) perfusion MR imaging in glioblastomas.
Materials and Methods
Twenty-two patients (11 male, 11 female; 27 tumors) with histologically confirmed glioblastoma (WHO grade IV) were examined with conventional MR imaging and DSC imaging at 3T before surgery or biopsy. Then nCBV (means and standard deviations) in each mass was measured using two DSC MR perfusion analysis methods including manual and semiautomatic segmentation method, in which contrast-enhanced (CE)-T1WI and T2WI were used as structural imaging. Intraobserver and interobserver reproducibility were assessed according to each perfusion analysis method or each structural imaging. Interclass correlation coefficient (ICC), Bland-Altman plot, and coefficient of variation (CV) were used to evaluate reproducibility.
Intraobserver reproducibilities on CE-T1WI and T2WI were ICC of 0.74–0.89 and CV of 20.39–36.83% in manual segmentation method, and ICC of 0.95–0.99 and CV of 8.53–16.19% in semiautomatic segmentation method, repectively. Interobserver reproducibilites on CE-T1WI and T2WI were ICC of 0.86–0.94 and CV of 19.67–35.15% in manual segmentation method, and ICC of 0.74–1.0 and CV of 5.48–49.38% in semiautomatic segmentation method, respectively. Bland-Altman plots showed a good correlation with ICC or CV in each method. The semiautomatic segmentation method showed higher intraobserver and interobserver reproducibilities at CE-T1WI-based study than other methods.
The best reproducibility was found using the semiautomatic segmentation method based on CE-T1WI for structural imaging in the measurement of the nCBV of glioblastomas.
The purpose of this study was to differentiate true progression from pseudoprogression of glioblastomas treated with concurrent chemoradiotherapy (CCRT) with temozolomide (TMZ) by using histogram analysis of apparent diffusion coefficient (ADC) and normalized cerebral blood volume (nCBV) maps.
Materials and Methods
Twenty patients with histopathologically proven glioblastoma who had received CCRT with TMZ underwent perfusion-weighted imaging and diffusion-weighted imaging (b = 0, 1000 sec/mm2). The corresponding nCBV and ADC maps for the newly visible, entirely enhancing lesions were calculated after the completion of CCRT with TMZ. Two observers independently measured the histogram parameters of the nCBV and ADC maps. The histogram parameters between the true progression group (n = 10) and the pseudoprogression group (n = 10) were compared by use of an unpaired Student's t test and subsequent multivariable stepwise logistic regression analysis to determine the best predictors for the differential diagnosis between the two groups. Receiver operating characteristic analysis was employed to determine the best cutoff values for the histogram parameters that proved to be significant predictors for differentiating true progression from pseudoprogression. Intraclass correlation coefficient was used to determine the level of inter-observer reliability for the histogram parameters.
The 5th percentile value (C5) of the cumulative ADC histograms was a significant predictor for the differential diagnosis between true progression and pseudoprogression (p = 0.044 for observer 1; p = 0.011 for observer 2). Optimal cutoff values of 892 × 10-6 mm2/sec for observer 1 and 907 × 10-6 mm2/sec for observer 2 could help differentiate between the two groups with a sensitivity of 90% and 80%, respectively, a specificity of 90% and 80%, respectively, and an area under the curve of 0.880 and 0.840, respectively. There was no other significant differentiating parameter on the nCBV histograms. Inter-observer reliability was excellent or good for all histogram parameters (intraclass correlation coefficient range: 0.70-0.99).
The C5 of the cumulative ADC histogram can be a promising parameter for the differentiation of true progression from pseudoprogression of newly visible, entirely enhancing lesions after CCRT with TMZ for glioblastomas.
Apparent diffusion coefficient; Cerebral blood volume; Glioblastoma multiforme; Histogram analysis; Pseudoprogression
Glioma grading assumes significant importance in that low- and high-grade gliomas display different prognoses and are treated with dissimilar therapeutic strategies. The objective of our study was to retrospectively assess the usefulness of a cumulative normalized cerebral blood volume (nCBV) histogram for glioma grading based on 3 T MRI.
From February 2010 to April 2012, 63 patients with astrocytic tumors underwent 3 T MRI with dynamic susceptibility contrast perfusion-weighted imaging. Regions of interest containing the entire tumor volume were drawn on every section of the co-registered relative CBV (rCBV) maps and T2-weighted images. The percentile values from the cumulative nCBV histograms and the other histogram parameters were correlated with tumor grades. Cochran’s Q test and the McNemar test were used to compare the diagnostic accuracies of the histogram parameters after the receiver operating characteristic curve analysis. Using the parameter offering the highest diagnostic accuracy, a validation process was performed with an independent test set of nine patients.
The 99th percentile of the cumulative nCBV histogram (nCBV C99), mean and peak height differed significantly between low- and high-grade gliomas (P = <0.001, 0.014 and <0.001, respectively) and between grade III and IV gliomas (P = <0.001, 0.001 and <0.001, respectively). The diagnostic accuracy of nCBV C99 was significantly higher than that of the mean nCBV (P = 0.016) in distinguishing high- from low-grade gliomas and was comparable to that of the peak height (P = 1.000). Validation using the two cutoff values of nCBV C99 achieved a diagnostic accuracy of 66.7% (6/9) for the separation of all three glioma grades.
Cumulative histogram analysis of nCBV using 3 T MRI can be a useful method for preoperative glioma grading. The nCBV C99 value is helpful in distinguishing high- from low-grade gliomas and grade IV from III gliomas.