111Indium (DTPA-octreotide) scintigraphy in patients with cerebral gliomas

Summary Somatostatin receptors (SR) have been identified in vitro in normal brain tissue, in neuro-endocrine tumours and in cerebral gliomas WHO grade 1 or 2 by autoradiography or using somatostatin-gold conjugates. In vivo, SR detection has become possible by scintigraphy applying the somatostatin analogue octreotide, radio-labelled with¹¹¹Indium. It was supposed that expression of SR in cerebral gliomas corresponds to low grade tumour malignancy and that, in vivo, somatostatin receptor scintigraphy (SRS) could refine and improve the WHO grading system for cerebral gliomas.Nineteen patients with cerebral gliomas (grade 2: n=8, grade 3: n=3, grade4: n=8) were examined with¹¹¹In (DTPA-octreotide) to evaluate, whether SRS could improve the pre-operative estimation of tumour biology and the postoperative management. The results of SRS were related with the histological findings and with the in vitro demonstration of somatostatin-binding sites on cultured tumour cells incubated with a somatostatin-gold conjugate.In vivo, none of the patients with glioma grade 2 showed enhanced tracer uptake in the SRS, whereas in vitro SR were detected in cultured tumour tissue in 5 out of 5 cases. Every patient with glioma grade 3 or 4 demonstrated a high focal uptake of¹¹¹In (DTPA-octreotide), as shown by SRS. Three patients with glioma grade 4, additionally examined with 99mTc-DTPA, showed an increased tracer uptake within the tumour area when compared with results of SRS. In vitro, SR were detected on tumour cell surface in 5 out of 6 tissue samples from patients with gliomas grade 3 or 4. One patient harbouring a cerebral abscess presented with a high focal tracer uptake in the SRS but with absence of somatostatinbinding sites in vitro.We concluded, that in glioma patients enhanced tracer uptake in receptor scintigraphy with¹¹¹In (DTPA-octreotide) does not depend on the presence of SR in tumour tissue but on the dysfunction of the blood-brain barrier. Thus, SRS does not improve the preoperative glioma grading or postoperative management in patients with cerebral tumours of glial origin.The article is dedicated to Prof. H. Leonhardt on the occasion of his 75th birthday.     

Cranial neuronavigation with direct integration of (11)C methionine positron emission tomography (PET) data -- results of a pilot study in 32 surgical cases

BACKGROUND: MRI detects small intracranial lesions, but has difficulties in differentiating between tumour, gliosis and edema. (11)C methionine-PET may help to overcome this problem. For its appropriate intra-operative use, it must be integrated into neuronavigation. We present the results of our pilot study with this method. METHOD: 32 patients with 34 intracranial lesions detected by MRI underwent additional (11)C methionine-PET, because the pathophysiological behaviour or the tumour delineation was unclear. All lesions were treated surgically. In 25 patients PET data could be integrated directly into cranial neuronavigation. FINDINGS: (11)C methionine uptake was observed in 27/34 lesions, 26 of them were tumours: 14 malignant and 7 benign gliomas, 3 gliomas without further histological typing, one Ewing sarcoma and one non-Hodgkin lymphoma. Only one (11)C methionine positive lesion was non-tumourous: it was staged as post-irradiation necrosis in a patient operated on for a malignant glioma. 3/7 (11)C-methionine negative lesions were classified as gliosis (n=2) and M. Whipple (n=1), but 4/7 were tumours: 2 astrocytomas WHO(degrees)II, 1 DNT and one astrocytoma WHO(degrees)III. The sensitivity of (11)C methionine-PET was 87%, the specificity 75%, the positive predictive value 96% and the negative predictive value 43%. In all tumourous cases with positive tracer uptake the borderline area of the tumour was better defined by (11)C methionine-PET than by MRI. INTERPRETATION: A positive (11)C methionine-PET is highly suspicious of a tumour, a negative one does not exclude it. (11)C methionine-PET seems to be more sensitive than MRI for differentiating between tumour and edema or gliosis. Simultaneous integration MRI and (11)C methionine-PET into cranial neuronavigation can facilitate cross total tumour removal in glioma surgery.     

三磷酸腺苷结合盒转运体成员2在人脑胶质瘤中的表达及其与神经巢蛋白表达的关系

目的 探讨三磷酸腺苷结合盒转运体成员2(ABCG2)在人脑胶质瘤组织中的表达及其与胶质瘤分级和神经巢蛋白(nestin)表达的关系.方法 实时荧光定量聚合酶链反应(PCR)检测ABCG2在52例不同病理级别胶质瘤中的mRNA表达;免疫组织化学SABC法检测ABCG2和nestin的蛋白表达.结果 ABCG2在脑胶质瘤中的mRNA表达与正常脑组织比较呈过表达(P<0.05),且随着病理级别的升高而增加(P<0.05);免疫组织化学显示ABCG2在52例胶质瘤中的阳性表达率为32.7%(17/52),并与病理级别明显相关(x2=4.62,P<0.05),主要呈亲血管分布;ABCG2的表达与nestin的表达明显相关(x2=7.60,P<0.05).结论 ABCG2在人脑胶质瘤中的表达随着病理级别的升高而逐渐增加,且与nestin的表达呈正相关;脑肿瘤干细胞可能与神经干细胞具有一定的同源性.     

The striate sign: peritumoural perfusion pattern of infiltrative primary and recurrent gliomas

MR perfusion depicts angiogenesis as a key factor for growth and malignancy in gliomas by means of increased regional cerebral blood volume (rCBV). The rCBV increase is not limited to the tumour area, but may also produce a stripe-like pattern of peritumoural rCBV increase that we defined as the “striate sign”. We evaluated if prior radiochemotherapy influences perfusion values and pattern in and adjacent to malignant gliomas comparing rCBV of treated recurrent gliomas with untreated gliomas. Ninety-three patients with primary or recurrent WHO grades II–IV glial tumours underwent T2*-weighted dynamic susceptibility-weighted contrast-enhanced (DSC)-MRI. Differences of normalised rCBV and rCBV_max were evaluated using Kruskal−Wallis analysis with post hoc tests. The number of cases showing a hot spot of rCBV (rCBV_max) and/or a peritumoural striate pattern of rCBV increase (striate sign) was assessed and evaluated by Fisher’s exact test. Significance level was determined as p < 0.05. Normalised rCBV, rCBV_max and number of cases with the striate sign were significantly lower in recurrent (rCBV = 3.24 ± 1.22, rCBV_max = 5.05 ± 2.27 and striate sign = 10/24) compared to primary WHO grade IV tumours (rCBV = 4.44 ± 1.39, rCBV_max = 7.31 ± 3.0 and striate sign = 17/21, respectively). There were fewer cases with a striate sign in treated recurrent WHO grade III tumours than in untreated malignant transformed WHO grade II tumours. The pattern and degree of rCBV increase in and around gliomas differ between untreated and previously treated tumours. These differences might be due to post-therapeutic changes of the tumour-associated microvasculature by radiochemotherapy. Spectroscopic and susceptibility-weighted MR imaging may provide further insights into the tumour biology.     

Cellular immunity and complement levels in hosts with brain tumours

Summary As a major defence mechanism against cancer, host immunological surveillance is composed of a cellular immunity as well as humoral immunity including antibody and a complement system. In the course of the progress of brain tumours alone, serum complement level (CH 50) as a humoral immunological factor and the tuberculin skin reactivity as an index of cellular immune activity, were serially measured in brain tumour patients. One hundred and fifty-seven cases of brain tumours, including 75 cases of glioma, 25 benign tumours, and 42 metastatic tumours, were examined. Most cases of benign tumour belong to stage I oder II, in which both tuberculin reaction and complement are active. Many cases of glioblastoma and metastatic tumour belong to stage III; that is, they show negative tuberculin reaction and increased complement activity. The relation of immunological response to the tumour size and the clinical severity in patients with gliomas is revealed by the fact that complement titres rise in accordance with the degree of progress of the tumour and a negative tendency in the tuberculin reaction runs parallel to this. All cases of glioma, even in the terminal stages, remain in stage III. On the other hand, cases of metastatic tumour progress to stage IV and V, in which the tuberculin reaction is negative and complement titres decrease. The combined results of elevated complement level and depressed status of tuberculin reaction in patients with gliomas may be explained by the concept that complement activity rises to compensate for depressed cell-mediated immunity, in order to preserve the activity of the biophylaxis mechanism against cancer.     

Prognostic value of perfusion-weighted imaging in brain glioma: a prospective study

Summary Object. Biopsy targeting based on MR imaging alone may fail to identify malignant areas in brain gliomas. Considering the differences in relative Cerebral Blood Volume (rCBV) ratios reported among tumour grades, we evaluated whether perfusion-weighted MR imaging (PWI) could usefully implement the routine preoperative imaging by detecting those areas bearing a higher yield for malignancy to guide the stereotactic biopsy or the surgical removal. Clinical material and methods. We studied a series of 55 consecutive patients with newly diagnosed brain glioma using both conventional MR imaging and PWI in the preoperative assessment. The pathological diagnosis was established by stereotactic biopsy in 29 cases and by craniotomy in 24 cases. We evaluated the patient survival to detect undergrading. Discussion. Independent from contrast-enhancement, perfusion-weighted MR imaging improved the target selection in stereotactic biopsy guidance and the removal of malignant areas in tumours amenable to surgery. Particularly sensitive to the perfused part of the tumour as to small regional changes, rCBV maps allowed a better detection of malignant areas. The rCBV ratios correlated significantly to the tumour grade and the final outcome (p < 0.01). Conclusions. We found PWI valuable in the preoperative assessment of brain gliomas, discriminating high from low-grade gliomas. PWI can easily be performed on widely available MR imaging systems as part of the routine imaging of gliomas.     

Emerging molecular mechanisms of brain tumour oedema

A common property of brain tumours is their ability to cause oedema in the surrounding brain. Oedema forms as a result of a leaky blood-tumour barrier and persists when the brain fails to clear the excess fluid. It is a significant source of morbidity and mortality. The principal anatomical component of the blood-brain barrier is the endothelial tight junction which opens in glioma microvessels. Multiple tight junction proteins have recently been identified, such as occludin, claudin, ZO-1, ZO-2 and ZO-3. We propose a model to explain tight junction opening in gliomas based on vascular endothelial growth factor secretion and loss of tight junction inducing factor production by tumour cells. The level of expression of the water channel aquaporin-4 in peritumoural astrocytes may determine the rate of oedema fluid clearance. The identification of the molecular mechanisms of brain tumour oedema may allow the design of novel anti-oedema medications.     

Positron emission tomography with injection of methionine as a prognostic factor in glioma.

OBJECT: Positron emission tomography with L-[methyl-11C]methionine (MET-PET) provides information on the metabolism of gliomas. The aim of this study was to determine the predictive value of MET-PET in the treatment of patients with gliomas. METHODS: Since 1992, 85 patients with a World Health Organization (WHO) classification-verified glioma underwent PET studies in which MET was injected before (74 cases) or after treatment (11 cases). Analysis of PET data was conducted by the same investigator using two scales: a qualitative visual grading scale and a quantitative scale (ratio between tumor uptake and normal brain uptake, classified on a seven-level scale). Uptake of MET was present in 98% of gliomas. The investigator judged this uptake to be moderate to very high based on visual inspection (qualitative scale). For all grades of gliomas, a visual grade of 3 was statistically associated with a shorter patient survival period (p < 0.005). The tumor/normal brain uptake ratio was significantly influenced by the histological grade of the tumor. A statistically poor outcome was demonstrated when this ratio was higher than a threshold of 2.2 for a WHO Grade II tumor and 2.8 for WHO Grade III tumor. For Grade II and III tumors, oligodendrogliomas had a higher uptake of MET than astrocytomas. CONCLUSIONS: Uptake of MET was present in 98% of the gliomas studied. A high uptake is statistically associated with a poor survival time. The intensity of MET uptake represents a prognostic factor for WHO Grade II and III tumors considered separately.     

Fronto-mesial WHO grade II and III gliomas: specific aspects of tumours arising from the anterior cingulate gyrus

A total 17 fronto-mesial grade II and III gliomas among a total of 64 frontal grade II and III gliomas underwent surgical resection between January 2003 and June 2007. Eleven fronto-mesial gliomas originated from the anterior cingulate gyrus, while the others originated from the genu of the corpus callosum. None of the grade II or III gliomas originated from the gyrus rectus. Anterior cingulate gliomas exhibited distinct features with regard to presenting symptoms, MRI, histopathology and prognosis. Epilepsy was the dominant presenting symptom of anterior cingulate tumours. Five of the 11 gliomas had a sharp border on MRI. Four of the 11 were histopathologically classified as WHO grade II and seven as WHO grade III and an oligodendrocytic component was apparent in eight of the 11 specimens. Comparison of the post-operative survival with the entire set of frontal gliomas showed a trend that anterior cingulate tumours had a more favourable prognosis.     

人脑胶质瘤血管生成素-2表达及其与管生成和脑水肿的关系

目的 研究血管生成素.2(Ang-2)基因在人脑胶质瘤表达及其与胶质瘤血管生成及瘤周水肿的关系。方法 用半定量逆转录-聚合酶链反应(RT-PCR)、免疫组织化学方法测定42例人脑胶质瘤和8例正常脑组织中Ang-2 mRNA及其蛋白表达情况。用免疫组织化学方法检测肿瘤微血管密度(MVD)。结果 正常脑组织中无或弱表达Ang-2。42例胶质瘤组织中均有Ang-2 mRNA表达,不同级别间Ang-2 mRNA的表达差异有显著性(P<0.05)。随着脑胶质瘤恶性程度的增加,Ang-2 mRNA的表达增高(r=0.894,P<0.01)。免疫组织化学结果显示,胶质瘤细胞及肿瘤血管内皮细胞中均有Ang-2蛋白表达。Ang-2 mRNA表达与MVD、脑水肿指数(EI)显著相关(分别为r=0.853,P<0.01;r=0.784,P<0.01)。结论 Ang-2可能参与胶质瘤血管生成,对胶质瘤瘤周脑水肿及恶性进展有促进作用。     

Proteomic analysis of gliomas

Primary malignant brain tumours (anaplastic glioma and glioblastoma) display heterogenous histopathology and diverse genetic abnormalities. These tumours remain incurable with no significant improvement in median survival times in the last 20 years, despite significant technological advances in surgery and radiotherapy, and mechanistic insights into their aetiology. Recent clinical trials suggest molecular characterization of tumours is essential in guiding both therapy and predicting prognosis. Genetic insight into tumour biology and increasingly proteomic technology has opened new avenues for novel applied clinical research. Protein expression in human malignant glioma and matched normal brain tissues can now be reliably analysed using quantitative proteomic techniques, the most accessible of which is two-dimensional gel electrophoresis (2DGE) and matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry from which differentially expressed proteins can be identified and characterized. The potential of using differential proteomic profiling in gliomas to identify prognostic markers and to gain insight into tumour biology is currently being investigated. The current status of proteomic technology, its application to gliomas and the utility of such translational studies is reviewed.     

Production of Urokinase-Type Plasminogen Activator (u-PA) and Plasminogen Activator Inhibitor-1 (PAI-1) in Human Brain Tumours

Summary We investigated the role of plasminogen activators (PAs) and their inhibitor (plasminogen activator inhibitor-1, PAI-1) in human brain tumours. The amounts of urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1), and the activity of u-PA and t-PA were determined by enzyme-linked immunosorbent assay (ELISA), and u-PA and PAI-1 were immunolocalized using monoclonal antibodies in human brain tumours and normal brain tissues. The tissues were surgically removed from 64 patients; normal brain tissue (5 cases), low-grade glioma (4 cases), high-grade glioma (17 cases), metastatic tumour (9 cases), meningioma (benign 12 cases, malignant 6 cases), acoustic schwannoma (11 cases). u-PA activity and u-PA and PAI-1 antigen levels were significantly elevated in malignant brain tumours (malignant meningiomas, high-grade gliomas, and metastatic tumours) and acoustic schwannomas but very low in benign meningiomas, low-grade gliomas and normal brain. There was no difference in t-PA antigen levels among normal and malignant tissues, however levels of t-PA activity were markedly decreased in metastastic tumours. All malignant brain tumour tissues showed positive immunostaining for u-PA and PAI-1, however, some tumour cells showed negative intensity while others showed strong intensity for these antibodies. This contrasts to the homogeneous staining pattern found in acoustic schwannoma. These findings indicate that malignancy in human brain tumours is associated with elevated levels of u-PA and PAI-1 and that an imbalance between these proteins in a micro-enviroment contributes (ascribes) to tumour cell invasion.     

白细胞介素6、信号传导和转录活化因子3和血管内皮生长因子在人脑胶质瘤中的表达及相关性研究

目的研究人脑不同级别胶质瘤中白细胞介素（IL）-6，信号传导和转录活化因子3（STAT3）和血管内皮生长因子（VEGF）的表达，探讨IL-6、STAT3和VEGF与肿瘤病理级别和侵袭性的关系。方法采用免疫组织化学法，检测70例人脑胶质瘤，10例脑膜瘤和5例正常脑组织中IL-6、STAT3和VEGF的表达。结果胶质瘤中IL-6、STAT3和VEGF的表达水平在高级别组（Ⅲ、Ⅳ级）明显高于低级别组（Ⅰ、Ⅱ级），两组间差异有统计学意义（P〈0．01），STAT3的表达与IL-6和VEGF的表达均呈正相关（P〈0．01）。结论IL-6、STAT3和VEGF的表达与胶质瘤的恶性程度有密切关系；且三者协同在胶质瘤发生、发展过程中起重要作用。三者的相关性证实VEGF基因由STAT3蛋白调节，而STAT3又由IL-6刺激活化。     

Expression of cALLa/NEP on gliomas: A possible marker of malignancy

Summary First described on pre-B leukemia cells, the common acute lymphoblastic leukemia antigen (cALLa) is also expressed on glioma cellsin vitro. Its identity to neutral endopeptidase (NEP) (E.C.3.24.11) was corroborated by our finding that cALLa positive glioma cells had NEP activity. To study cALLa/NEP distribution on glial tumours in vivo, we examined 76 brain tumour biopsies by immunostaining techniques on frozen tissue sections using anticALLa (FAH99) and anti-NEP (135 A 3) monoclonal antibodies. We found that 96% of grade 4 gliomas (25/26) expressed NEP. Whereas only 45% (4/9) of grade 3 or anaplastic astrocytomas did. In low grade gliomas, we found 2 positive tumours out of 21 tested (10%). Double immunostaining procedures revealed that NEP was co-expressed with GFAP. However no NEP could be detected on non-glial brain tumours nor on reactive astrocytes. These results suggest that cALLa/NEP expression could be linked to malignant progression of gliomas.     

Heme oxygenase (HO) isoforms in experimental C6 glioma: an immunocytochemical study.

Abstract Because of their potential to regulate tumoural blood flow and interactions with nitric oxide the expression of the type 1 and 2 isoforms of heme oxygenase (HO-1 and HO-2) were evaluated in implanted C6 striatal gliomas. Immunocytochemistry using antibodies specific for HO-1 and HO-2 were used in 20 C6 glioma tumours. The bulk of the tumour parenchyma and endothelium was negative for both HO isoforms. Isolated, but weak staining for HO-1 was seen in most tumours with focally increased expression in perinecrotic regions. Cells morphologically resembling macrophages stained with both HO-1 and HO-2, but were not numerous. These findings suggest that carbon monoxide, unlike nitric oxide, does not have a major role in regulating tumoural blood flow in this experimental glioma model. These findings once again demonstrate the differences between human malignant glioma and experimental implantation glioma models.     

人脑胶质瘤中连接蛋白基因表达及其临床意义

目的探讨人脑胶质瘤连接蛋白(Cx)43、32基因表达及其临床意义。方法对8例正常脑组织和50例人脑胶质瘤采用Northern印迹和免疫组织化学法检测。结果人脑胶质瘤Cx43mRNA及其蛋白表达阳性率分别为54％、52％，Cx32仅在1例低恶度少枝胶质细胞瘤及1例混合性星形一少枝胶质细胞瘤中表达。Cx43mRNA及其蛋白表达水平随肿瘤恶性程度升高而下降。结论Cx基因在人脑胶质瘤中表达可下降或缺失，与肿瘤的病理类型及恶性程度呈负相关，可作为某些肿瘤的病理诊断参考指标之一。     

STAT3和Cyclin D1在人脑胶质瘤中的表达及其意义

目的 探讨信号转导及转录激活因子3(STAT3)和细胞周期蛋白D1(Cyclin D1)表达与脑胶质瘤生物学行为的关系及意义.方法 用逆转录-聚合酶链反应(RT-PCR)和Western blot方法检测并比较68例不同级别胶质瘤和10例正常脑组织中STAT3和Cyclin D1的表达,并对两者表达做相关分析.结果 RT-PCR检测胶质瘤组织STAT3、Cyclin D1的mRNA表达量(2.23±0.32、2.18±0.26)均明显高于正常脑组织(0.53±0.14、0.48±0.11),Western blot检测胶质瘤组织STAT3、Cyclin D1的蛋白表达量(42.3±2.6)%、(45.4±1.8)%均明显高于正常脑组织(9.8±1.1)%、(10.4±0.9)%,其差异均有统计学意义(P＜0.05),STAT3和Cyclin D1的表达与胶质瘤级别呈正相关.结论 STAT3可能通过激活其下游靶基因Cyclin D1,引起胶质瘤细胞异常增殖和分化失控.     

Evaluation of brain tumour laser surgery

Summary A surgical carbon dioxide laser unit (laser) has been used since 1977 in twentyfive cases of various brain tumours, including ten meningiomas (four sphenoid ridge, two parasagittal, two falx, one olfactory, one posterior fossa), eleven gliomas (seven glioblastoma, four astrocytoma), two metastatic brain tumours, one haemangioblastoma, and one arteriovenous malformation (AVM).The criteria for laser use, as based on evaluation and location of meningioma, were: grade 1, convenient but adjuvant; grade 2, also necessary; grade 3, indispensable. The laser is obligatory in sphenoid ridge meningioma in order to peel the tumour away from the internal carotid artery, middle cerebral artery, cavernous sinus etc. The grade of necessity for laser use is therefore either 2 or 3. In convexity or parasagittal meningioma, on the other hand, the necessity grade is either 1 or 2.In the glioma group hemorrhage in seven cases of glioblastoma was easily laser-controlled, and the tumours were wasted away in a short time through vaporization, with minimum mechanical effect on adjacent tissue. The laser is therefore very useful in cases of glioma, especially glioblastoma, considering the shortened operating time, decreased blood loss, and extended area of tumour resection.Laser surgery is proposed as being most appropriate, mainly for its vaporizing and coagulating functions, in cases of brain tumour involving the elderly and poor risk cases.     

The impact of fluorescence guidance on spinal intradural tumour surgery

Purpose

5-Aminolevulinic acid (5-ALA)-based fluorescence-guided surgery was shown to be beneficial for cerebral malignant gliomas. Extension of this technique for resection of meningiomas and cerebral metastasis has been recently evaluated. Aim of the present study is to evaluate the impact of fluorescence-guided surgery in spinal tumor surgery.

Methods

Twenty-six patients with intradural spinal tumors were included in the study. 5-ALA was administered orally prior to the induction of anesthesia. Intraoperative, 440 nm fluorescence was applied after exploration of the tumor and, if positive, periodically during and at the end of resection to detect tumor-infiltrated sites.

Results

Tumors of WHO grade III and IV were found in five patients. In detail intra- or perimedullary metastasis of malignant cerebral gliomas was found including glioblastoma WHO grade IV (n = 2), anaplastic astrocytoma WHO grade III (n = 1), anaplastic oligoastrocytoma WHO grade III (n = 1). In addition, one patient suffered from a spinal drop metastasis of a cerebellar medulloblastoma WHO grade IV. Tumors of WHO grade I were diagnosed in 18 patients: Eight cases of meningioma (two recurrences), six cases of neurinoma, one neurofibroma, two ependymoma and one plexus papilloma. At least, benign pathologies were histologically proven in three patients. All four spinal metastasis of malignant glioma (100 %), seven of eight meningiomas (87.5 %) and one of two ependymoma (50 %) were found to be ALA-positive.

Conclusion

The present study demonstrates that spinal intramedullary gliomas and the majority of spinal intradural meningiomas are 5-ALA positive. As a surgical consequence, especially in intramedullary gliomas, the use of 5-ALA fluorescence seems to be beneficial.