放射外科治疗后星形胶质细胞瘤的病理、超微结构对比研究

  本文关键词：放射外科治疗后星形胶质细胞瘤的病理、超微结构对比研究，由笔耕文化传播整理发布。

        目的观察放射外科治疗后星形胶质细胞瘤的病理组织学、超微结构变化,探讨放射治疗的生物学机制,探寻胶质瘤综合治疗的新方法。方法回顾性对比分析25例原发脑星形胶质瘤(放射治疗前)与25例放射外科治疗后脑星形胶质瘤的常规病理、免疫组化和放射治疗前后各8例星形胶质瘤患者不同部位(肿瘤中心、肿瘤边缘、瘤周水肿脑组织)电镜超微结构改变,并就对其结果进行统计分析客观评判。结果1.病理(光学显微镜)1)对照组:根据肿瘤细胞形态多形性,核分裂像,瘤细胞密度,血管内皮增生程度以及瘤组织坏死情况,光镜下将星形胶质细胞瘤分为高级别和低级别胶质瘤。低级别胶质瘤分化较好,瘤细胞之间可见红染的原纤维性背景,包括纤维型、原浆型、肥胖型和混合细胞等亚型。高级别胶质瘤主要包括间变性星形细胞瘤和胶质母细胞瘤,前者主要表现为瘤细胞密度增加,核异型性明显,核深染可见核分裂像,血管内皮细胞增生;后者主要表现为瘤细胞密集,有明显异型性,可见异型的单核或多核瘤巨细胞,出血坏死明显。2)治疗组:(1)放射治疗后低级别胶质瘤:可见瘤细胞呈点状或灶状坏死。微血管壁肿胀,管腔变窄,管壁呈透明样变性。(2)放射治疗后高级别胶质瘤:肿瘤细胞多成片状坏死,并见多个出血灶。有的微血管管腔闭塞,管壁透明样变性,周围有炎细胞浸润,呈套袖样改变。放射治疗后坏死面积与程度,与胶质瘤的分级呈正相关(P＜0.05)。2.电子显微镜1)对照组:(1)肿瘤中心:低级别胶质细胞瘤瘤细胞核异型性不大,核膜、胞膜完整,胞浆均匀,细胞器明显较多,肿胀不明显,血管内皮细胞无肿胀,基膜结构完整;高级别胶质瘤瘤细胞核大小和形状不一致,核不规则伴分裂,核周质内见胶质丝,细胞小器稀少,胞浆内线粒体轻度肿胀、内质网扩张,可见部分毛细血管的外形轮廓基本正常,一些内皮细胞间的紧密连接仍呈关闭状态,内皮细胞有线粒体肿胀,内质网扩张,基底膜厚薄不均。(2)肿瘤边缘:瘤细胞形态与中心相似,毛细血管内皮的变化与瘤体中内皮的变化无明显差异,但内皮基膜厚薄不均,胶质膜局部缺损,内皮外周组织间有渗出液。(3)瘤周水肿脑组织:可见瘤细胞。毛细血管内皮细胞无肿胀,无内皮孔,腔面无绒毛样突起;胞质内胞饮泡少,有线粒体和粗面内质网,紧密连接无增长,细胞间连接无明显弯曲,内皮基膜厚薄均匀、完整,胶质膜无缺损。2)治疗组:(1)肿瘤中心:治疗组中均见到肿瘤细胞的坏死,表现为包膜不完整或消失,胞浆内线粒体肿胀、内质网扩张呈空泡样改变,胞核内染色质浓聚,常染色体减少或消失,甚至有的出现细胞核碎裂溶解。血管内皮细胞崩解、脱落,血管壁各层细胞结构消失,基底膜断裂或皱缩,有较多的片状出血灶。部分标本发现凋亡细胞。(2)肿瘤边缘:肿瘤细胞变化与中心相似,但完整的瘤细胞较多,主要表现为细胞器的肿胀。瘤细胞胞浆线粒体、高尔基体明显肿胀,胞浆中可见大量空泡,细胞膜不完整或消失,细胞核极不规则,呈锯齿状凹陷,形成胞浆假包含体,异染色质趋边浓染。部分位于肿瘤边缘区域的瘤细胞胞浆中可见少量空泡,细胞核完整,但核间隙增宽。有捌亡细胞出现。(3)瘤周水肿脑组织:有瘤细胞存在,变化较轻,可见神经元部分细胞肿胀,核异染色质增多,呈斑块状分布,核缘弯曲,核周间隙增宽,核仁易见,胞质内脂褐素明显增多。线粒体肿胀,高尔基体、粗面内质网及糖原颗粒减少,胶质细胞核异染色质增多,胞质内有单个或多个空泡,部分髓鞘呈脱髓鞘改变。3.免疫组织化学(1)对照组中高级别星形胶质细胞瘤Ki-67、VEGF、MVD明显高于低级别星形胶质细胞瘤,与肿瘤的分级呈显著正相关。对照组中Ki-67与VEGF的表达、MVD呈正相关。VEGF与MVD无显著相关性。(2)治疗组中高级别星形胶质细胞瘤Ki-67、VEGF、MVD明显高于低级别星形胶质细胞瘤,与肿瘤的分级呈显著正相关。治疗组中Ki-67与VEGF的表达、MVD呈正相关。VEGF与MVD呈显著正关性。(3)治疗组与对照组同级别的胶质瘤比较Ki-67与MVD存在明显性差异,提示放射治疗后Ki-67、MVD降低;而放射治疗前后VEGF表达的变化无统计学意义。结论1.接受放射外科治疗肿瘤细胞均呈现不同程度的变性、坏死改变,在肿瘤中心、高级别肿瘤其变性、坏死改变更为明显。提示放射治疗根据治疗剂量不同可直接诱导肿瘤细胞变性、坏死,治愈和控制肿瘤。2.放射治疗可诱导细胞凋亡,促进细胞凋亡可能是提高胶质瘤远期治疗效果的重要治疗手段,具有很高的潜在临床意义。3.微血管内皮细胞对射线的敏感程度较高,管壁呈透明样变性,管壁明显增厚,管腔狭窄,甚至闭塞,血管周围有明显的肿瘤细胞的坏死和炎性细胞的浸润,放射治疗导致微血管损伤是放射治疗晚反应组织的主要作用之一。4.电离辐射导致血脑屏障三层超微结构的破坏,通透性增加,为胶质瘤放疗后联合化疗以及生物治疗等综合治疗提供了重要理论依据。5.放射性脑病及顽固性脑水肿是肿瘤细胞坏死、神经胶质细胞的损伤、微血管透明变性、血脑屏障破坏以及髓鞘不同程度的损伤共同作用的结果。6.推荐针对不同胶质瘤采用个体化综合治疗措施:①立体定向放射治疗代替传统放射治疗;②恶性胶质瘤,扩大野适形放射治疗+放射外科/低分次立体定向放射治疗;③恶性胶质瘤放射治疗联合抗肿瘤化疗;④恶性胶质瘤放化疗联合VEGF靶向治疗;⑤低级别复发、残留胶质瘤,单次大剂量放射外科/低分次立体定向放射治疗;⑥有占位效应、诊断不明确的脑原发占位病变,宜开颅手术治疗。

    ObjectiveTo study the radiobiological mechanism of radiotherapy on brain gliomas via observation of the histopathological change and ultrastracture features of human gliomas treated with stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT). And we also collect data to explore the new therapeutics for the integrated management of gliomas.MethodsA comparative, retrospective study of pathological change and immunohistochemistry of 25 glioma specimens without radiotherapy and 25 cases with SRS and SRT, and the ultrastructure of 8 glioma specimens without radiotherapy and 8 with SRS and SRT, were carried out. All the specimens were taken from their tumor center, tumor margin and peripheral edema brain tissues in each case. And the findings were statistically analyzed as to get an objective assessment.Results1. Traditional pathological observation1) Control groupAccording to the multiformity of tumor cells, the nuclear fission, the density of tumor cells, vascular endothelial proliferation and the extent of tumor necrosis, gliomas are divided into LGG and HGG group under optical microscope. The LGG is well differentiated, including subtypes of fibrillary, protoplasmic, gemistocytic and mixed astrocytoma. The HGG includes anaplastic astrocytoma and glioblastoma. The former was mainly expressed in significant increase of tumor cell density, nuclear atypia, deeply stained nuclear, mitotic nuclear, vascular endothelial cell proliferation. In glioblastoma, there was tumor cell congeries, obvious unclear atypia, different types of single-core or multi-core giant tumor cell as well as substantial necrosis and blooding. 2) Treatment groupSimilar radiation injury characteristics with different degrees were observed in all cases of the study. The structure of tumor cells at the tumor center disappeared. Whereas lots of cell fragments remained at the edge of the center areas. Some tumor cells died and hyperemia as well as hyaline degeneration could be seen. The structure of blood vessels looked like coats of onions. Swelled cells, enlarged cells, puffed endocylema and hyaline degeneration of the vessel wall can also be found. The walls of blood vessel were thickened and lumen narrowed. Some inflammatory cell infiltrated. Some small blood vessels around the brain tumor tissues dilated and became hyperemia.The square and extent of tumor necrosis and liquation were positively correlated with the tumor grade significantly (P<0.05).2. Electron microscopic observation1) Control group①Central tumor: In the tissue of LGG, tumor cells were observed with uniform nuclear atypia, vascular endothelial cells evenly. There are great many organelles without edema. And vessel endothelial cell without edema yet with integrated basement membrane were also easy found. In the tissue of HGG, tumor cells with large, irregular, multiform nuclear, mild swelling of mitochondria in the cytoplasm and expansion in endoplasmic reticulum were observed. The normal appearance of capillaries exist, the tight junctions between endothelial cell are still closed, mitochondria and endoplasmic reticulum expansion, the thickness of basement membrane is uneven.②Tumor edge: The morphology of tumor cells is similar to that in tumor center. And there was no significant difference between vascular endothelial cells in tumor edge and in tumor center. Yet there were apertures or openings on colloidal membrane of vascular endothelial cells as well as the extra-membrane extravasate in the tumor edge.③Peripheral edema cortex: The tumor cells can also be observed. The capillary endothelial cells are not swelling. In cytoplasm small pinocytic vesicles, mitochondria and rough endoplasmic reticulum are existed, the thickness of basement membrane is even and integrity.2) Treatment group①Central tumor: The tumor necrosis could be found in the center of all the specimen tissues. It was revealed as follows: the cellular membrane was incomplete or disappeared, chondriosomes of astrocytes swelled, cristae decreased or disappeard, and expansion of endoplasmic reticulum was vacuolated. In cellular nucleus, the chromatin was concentrated, autosomel was reduced or disappeared, and even some cellular nucleus were disrupted and dissolved. Some of vascular endothelial cells were disrupted and shedding. The structure of vessel wall was disappeared. The basement membrane was ruptured and a larger number of hemorrhagic foci were appeared. And the apoptosis cells could be found in some tissues. ②Tumor edge: The appearances of tumor cells in tumor edge were similar with that in the central field, yet more tumor cells were shown completed. The swelling organelle was the primary features. The cellular membrane was incomplete or disappeared. The chondriosomes, golgiosome of astrocytes were swelled obviously and expansion of endoplasmic reticulum was often vacuolated. The cellular nucleus was irregular and appeared serrate depression. The pseudo inclusion bodies could be found. And heterochromatin was concentrated peripherally. Only a little of vacuoles appeared in the peripheral enchylema in some specimens. Their cellular nucleus was revealed completely with the increased nucleus gap. And the apoptosis cells could also be found in some tissues.③Peripheral edema cortex: Some tumor cells could be found in most cases. But they varied much less in appearance. We could find some of the neuron cells were swelling, heterochromatin were increased and collected. The nucleus margin was abnormal, the nucleus gap was increased, and nucleolus could be revealed easily. And the lipofuscin was also increased. The hondriosomes of astrocytes were swelling, golgi apparatus, rough endoplasmic reticulum and glycogen granules reduced. The heterochromatin in glial cell nucleus was increased. There were single or multiple vacuoles also. And some of myelin was demyelinated.3. Immunohistochemistry examination1) Control group: The expression of Ki-67, VEGF protein and the MVD in HGG group were significant higher than those in LGG. And they were positively correlated with the glioma grade. And the Ki-67 protein expression was positively correlated with the VEGF protein expression and the MVD. Yet the VEGF protein expression was not significantly correlated with the MVD.2) Treatment group: The expression of Ki-67, VEGF protein and the MVD in HGG group were significant higher than those in LGG. And they were positively correlated with the glioma grade. And the Ki-67 protein expression was positively correlated with the VEGF protein expression and the MVD. The VEGF protein expression was also positively correlated with the MVD.3) Deference between the gliomas with and without SRS/SRT: The Ki-67 protein expression and the MVD in treatment group were significant lower than those of the control group in both LGG and HGG. Yet there was no significant difference of expression of VEGF between treatment group and control group.ConclusionThe radiotherapy plays an important role in the suppression and destruction of the glioma cells directly. Both degeneration and necrosis of glioma cells were found in the pathological and ultrastracture observation. The radiation efficacy not only depends on the intensity of radiation, the time of fraction, the way of irradiation, but also on the tumor grade and the proliferation phase in the cell cycle.Radiotherapy can also induce apoptosis. How to promote or induce tumor apoptosis is great important in clinical application which would improve the long-term outcome of gliomas.Microvascular endothelial cells have high sensitivity to SRS and SRT. After irradiation, the endothelial cells underwent swelling, loss, compensatory proliferation and increasing of fibrous stroma was observed. The fibrous thickening of the vascular walls was observed, following with marked lymphocyte infiltration and hemorrhages. The radiation injury of microvascular endothelial cells is one of the major radiotherapeutic radiobiological mechanisms of SRS and SRT.Ionizing radiation induced the destruction of ultrastructure in blood-brain barrier and increased permeability. It provided a theoretical basis to the comprehensive treatment of radiotherapy combined chemotherapy and biotherapy.Stubborn brain radiation necrosis and brain edema is the common result of the necrosis of tumor cells, the injury of glial cells, angiohyalinosis, the destroied blood-brain barrier and the myelin of different cellular necrosis.Seeking for personalized unique therapeutics for different glioma patients is promoted up to date.①To promote substitute traditional radiotherapy for SRT.②The extended-field conformal radiotherapy combined with SRS or hypofractionated SRT are recommended for the malignant gliomas.③The combination therapy of radiotherapy and chemotherapy are also promoted for the malignant gliomas.④The VEGF targeted therapy is also recommended with the combination of radiotherapy and chemotherapy.⑤The high single dose SRS and hypofractionated SRT are suitable for both postoperative residual LGG and recurrent LGG.⑥The primary undiagnosed cerebral tumors with mass effects are feasible for direct operation as to get the diagnosis and decompression.

放射外科治疗后星形胶质细胞瘤的病理、超微结构对比研究

1 放射外科治疗后星形胶质细胞瘤的病理、超微结构对比研究5-39    1.1 英汉缩略词对照表5-6    1.2 中文摘要6-9    1.3 英文摘要9-12    1.4 引言13-14    1.5 材料与方法14-16    1.6 结果16-19    1.7 讨论19-25    1.8 结论25-26    1.9 参考文献26-29    1.10 附图29-392 立体定向放射治疗后星形胶质细胞瘤的超显微结构变化(综述1)39-483 电子显微镜技术在脑胶质瘤研究中的应用(综述2)48-544 致谢54

  本文关键词：放射外科治疗后星形胶质细胞瘤的病理、超微结构对比研究，由笔耕文化传播整理发布。