【作者】 吴越；

【导师】 魏尔清；

【作者基本信息】 浙江大学 ， 药理学， 2009， 硕士

【摘要】 目的:观察经立体定向放射外科技术(旋转式伽玛刀)治疗后常规脱水治疗无效的继发性顽固性肿瘤周围脑水肿(PTBE)的组织结构及相关分子变化,观察了促肾上腺皮质激素(ACTH)对伽玛刀治疗术后常规脱水治疗无效的顽固性PTBE患者的治疗作用;同时,初步探索伽玛刀治疗术后继发性顽固性PTBE形成机制。方法:收集浙江省人民医院神经外科和伽玛刀治疗中心收治的79例接受伽玛刀治疗后发生继发性PTBE且常规脱水治疗无效的脑肿瘤患者的临床资料,并对其中在接受伽玛刀治疗前曾行肿瘤部分切除术、PTBE治疗过程中出现明显的脱水药物依赖现象,或停药后短期内即出现严重PTBE,或无法耐受长期静脉注射治疗而进行二次开颅手术的16例患者的组织学标本,进行详细的组织学和分子生物学对比研究。HE染色观察接受二次手术的顽固性PTBE患者伽玛刀术前与术后组织病理学变化,透射电镜观察顽固性PTBE患者肿瘤组织及血管超微结构变化,免疫组化法观察顽固性PTBE患者伽玛刀术前与术后肿瘤组织增殖细胞核抗原(PCNA)、血管内皮生长因子(VEGF)及水通道蛋白(AQP)表达,分析上述分子与继发性顽固性PTBE发生的相关性,结合组织结构变化初步探讨伽玛刀治疗术后继发性顽固性PTBE形成机制。观察ACTH对伽玛刀术后发生继发性顽固性PTBE的治疗作用,比较ACTH与地塞米松(DXM)、甲基泼尼松龙(MPD)等临床一线治疗药物对继发性顽固性PTBE患者水肿指数(PTBE-EI)影响的差异,同时检测ACTH治疗对患者血液生化指标的影响,初步评价ACTH作为伽玛刀治疗术后继发性顽固性PTBE治疗替代药物的潜力。结果:1.HE染色光镜下检查发现,伽玛刀治疗术后继发性顽固性PTBE患者中转移性脑肿瘤的病灶明显坏死并伴有炎性细胞浸润,脑膜瘤主要表现为肿瘤间质显著增生;星形细胞瘤的病理变化呈多样性,可见肿瘤坏死、间质增生和囊性病变,血管壁纤维样坏死变性,偶可见血管内血栓形成;海绵状血管瘤均表现为部分管腔闭塞、微小血栓形成和毛细血管增生,偶可见少量瘤内出血。2.透射电镜检查结果表明伽玛刀治疗术后继发性顽固性PTBE患者的肿瘤血管内皮细胞大多变扁平、皱缩,窗孔明显,胞质内吞噬小体数量增多,部分内皮细胞间连接处缝隙增大,偶可见连接中断,部分肿瘤新生血管内皮细胞呈类圆形,胞体内可见数量不等的棒状小体,细胞排列杂乱。3.免疫组化检测表明:16例伽玛刀治疗术后继发性顽固性PTBE患者伽玛刀治疗前PCNA染色阳性13例,其中11例PCNA-PI≥1%,2例PCNA-PI＜1%,其余阴性;伽玛刀治疗后PCNA染色阳性11例,其中4例PCNA-PI≥1%,7例PCNA-PI＜1%,其余阴性;卡方检验结果表明伽玛刀治疗前后PCNA表达无显著差异。16例伽玛刀治疗术后继发性顽固性PTBE患者伽玛刀治疗前VEGF染色阳性9例,其中4例呈低水平的阳性表达,其余阴性;伽玛刀治疗后VEGF染色5例阳性细胞数≥5%,但呈低水平的阳性表达,其余阴性;卡方检验结果表明伽玛刀治疗前后VEGF表达无显著差异。6例星形细胞瘤伽玛刀治疗术后继发性顽固性PTBE患者伽玛刀治疗前AQP-1、AQP-4和AQP-9的表达分别为5.66±0.78,3.89±0.43和1.32±0.20,伽玛刀治疗后分别为4.99±0.57,4.01±0.57和1.66±0.31;伽玛刀治疗前后AQP-1、AQP-4和AQP-9表达无显著差异(P＞0.05,t-test)。4.79例接受伽玛刀治疗后发生继发性PTBE且常规脱水治疗无效的脑肿瘤患者中,39例接受DXM治疗:治疗前PTBE-EI为3.3～4.9(3.17±1.39),治疗后头痛等症状有明显改善,但PTBE-EI增高至5.1～9.8(7.16±1.91)。DXM治疗前后PTBE-EI有显著差异(P＜0.01,t-test),其原因可能与肿瘤病灶伽玛刀治疗后病灶缩小、相应时间放射性脑水肿的出现以及因药物副作用而停药,或减小药物剂量等因素有关。31例(包括14例DXM治疗后停药发生严重PTBE患者)接受MPD治疗:治疗前PTBE-EI为3.8～7.4(5.26±1.93),治疗后降至2.7～5.1(3.88±1.56),MPD治疗前后PTBE-EI有显著差异(P＜0.05,t-test)。但停药两周后又升高至4.1～8.2(6.24±1.76)。46例(包括治疗停药后再次出现严重PTBE的17例DXM患者和6例MPD患者)接受ACTH治疗:治疗前PTBE-EI为4.7～9.6(7.01±1.83),治疗后一月为1.1～2.9(2.07±0.62),治疗前后的PTBE-EI有显著差异(P＜0.05,t-test),三月后可能因病灶缩小PTBE-EI略有升高,为1.7～3.2(2.23±0.90),与治疗前相比仍有显著差异(P＜0.05,t-test)。三组疗效比较:DXM组有效率为20.5%(8/39),分别有14例和17例患者在完全停药后1个月内再次出现严重脑水肿反应而接受MPD和ACTH治疗。MPD组有效率为61.3%(19/31),但12例患者完全停药后再次出现严重脑水肿反应时间较短,仅约2周。ACTH组有效率与MPD组近似,为67.4%(31/46),其中22例(47.8%)患者因病灶基本消失、局部软化灶形成或因水肿基本消退,而无法测算PTBE-EI;9例(19.6%)患者因停药后再次出现严重PTBE给予原剂量ACTH治疗无法耐受进行开颅病灶切除手术;15例(32.6%)出现严重头痛等症状给予ACHT治疗1～2个月后,逐渐减量至临床上症状缓解,或影像学检查脑水肿基本消退后停药。卡方检验结果表明,ACTH疗效强于DXM,差异具有显著性(P＜0.01);ACTH疗效与MPD无显著性差异(P＞0.05)。结论:1.伽玛刀术后继发性顽固性PTBE组织病理变化包括:与立体定向放射外科技术直接相关的血管壁纤维样坏死变性、血栓形成以及肿瘤间质和微小血管增生,导致局部微循环紊乱和受阻;血脑屏障本身的形态结构和功能受损,导致肿瘤病灶及其内皮细胞的基质(基底膜)与血液成分(包括一些血管活性物质)以及浸润的炎性细胞产生直接接触,从而进一步加剧PTBE,这可能是伽玛刀治疗术后继发性顽固性PTBE的形成机制之一。2.伽玛刀治疗术后继发性顽固性PTBE组织PCNA、VEGF、AQP-1、AQP-4以及AQP-9的表达与伽玛刀治疗术前无显著性差异,提示伽玛刀治疗术后继发性顽固性PTBE有其特有的形成机制,与上述分子表达相关性甚小,不同于一般肿瘤源性脑水肿的形成机制。3.ACTH可迅速降低患者的PTBE-EI,疗效显著,并且治疗剂量的外源性ACTH对垂体日常内源性ACTH的分泌及其生理作用,并无太大的干扰和影响,提示可作为治疗伽玛刀治疗术后继发性顽固性PTBE的替代药物。更多还原

【Abstract】 Objective:We investigated the secondary peritumoral brain edema(PTBE) afterγ-radiotherapy,which had been unaffected by the routine dehydrate therapy.The therapeutic effect of adrenocorticortropic hormone(ACTH) in treating the secondary PTBE was observed to evaluate the possibility whether ACTH can be used as a substitute dehydration instead of conventional treatments of PTBE.The changes in biomolecules and histological structures were also investigated to explore the mechanisms of PTBE.Methods:A total of 79 patients suffered from brain tumors with stubborn PTBE afterγ-radiotherapy were studied in this series,who were admitted inγ-radiotherapy Center, Zhejiang Provincial People’s Hospital.Among them,brain tumors were partially removed in 16 patients beforeγ-radiotherapy for the tumor volume adaptation ofγ-radiotherapy.Craniatomy was re-performed afterγ-radiotherapy because of dehydrate therapy dependence and intolerable intravenous transfusion during the treatment of stubborn PTBE.Biological molecules and histological changes in these tumor samples were observed comparably.The pathological observations of patients with stubborn PTBE before and afterγ-radiotherapy were investigated by HE staining.The fine structure of tumors and the tumoral vessels were observed by transmission electric microscopy.The expression of proliferating cell nuclear antigen(PCNA),vascular endothelial growth factor(VEGF) and aquaporins(AQP) were immunohistochemically stained.The results of these observations were analyzed to reveal the correlation to the PTBE and its possible mechanisms.The therapeutic effect of ACTH on secondary stubborn PTBE was investigated and compared with those of dexamethasone(DXM) and methylprednisolone(MPD) using PTBE-EI as the indicator.The dynamics of anterior pituitary hormones(APHs),thyroid function(TF) and genital hormones(GnH) in patients with stubborn PTBE during the ACTH therapy were also detected to evaluate the usefulness of ACTH as a substitute dehydration.RESULTS:1.By light microscopy,the main pathological changes in brain samples from metastasis patients with stubborn PTBE afterγ-radiotherapy were necrosis and infiltration of inflammatory cells.Tumor interstitial hyperplasia was observed obviously in meningioma patients.Necrosis,interstitial hyperplasia,cystic formation,fibrinoid necrosis and occasionally thrombosis in small vessel were more common in glioma samples.In cavernous angioma,embolism,thrombosis and capillary hyperplasia were presented.2.Under the transmission electric microscope,endothelia often showed thin and flat appearance,increased numbers of pinocytotic vesicles and surface infoldings.Widely separation,even disconnecting between endothelial cells was also detected in patients with stubborn PTBE afterγ-radiotherapy.Weibel-Palade body was often detected in plasma of round proliferated endothelium.3.In immunohistochemical studies,PCNA immunohistochemical stain was positive in 13 of 16 patients beforeγ-radiotherapy.Proliferating cell ratio above 1%happened in 11 patients,below 1%in 2 patients and negative in another 3 patients.Afterγ-radiotherapy, 11 patients were positive.Proliferating cell ratio above 1%happened in 4 of 11 patients, below 1%in 7 patients and negative in another 5 patients.Immunohistochemical staining for VEGF showed that VEGF protein was positive beforeγ-radiotherapy in 9 patients,among them,4 patients were weakly expressed.Another 7 patients were negative.Afterγ-radiotherapy,VEGF was weakly expressed in 5 patients and negative in other 11 patientss.There was no statistically significant difference in the PCNA and VEGF expressions in the patients with stubborn PTBE before and afterγ-radiotherapy.AQP-1,AQP-4 and AQP-9 expressions were 5.66±0.78,3.89±0.43 and 1.32±0.20 in 6 patients of star-shaped cell tumor beforeγ-radiotherapy,and 4.99±0.57,4.01±0.57 and 1.66±0.31,respectively afterγ-radiotherapy in patients with refractory PTBE induced byγ-radiotherapy.There were no significant differences in AQP-1, AQP-4 and AQP-9 expressions before and afterγ-radiotherapy(P＞0.05,t-test).4.In 79 patients with refractory PTBE induced byγ-radiotherapy and resistance to conventional dehydration,39 patients received DXM treatment.Their pre-treatment PTBE-EI was 3.3～4.9(3.17±1.39).After treatment,headache and other symptoms were significantly improved,but PTBE-EI increased to 5.1～9.8(7.16±1.91). PTBE-EI was significantly increased(P＜0.01,t-test) after DXM treatment;the reason might be related to reduced tumor size,corresponding time of the appearance of radiation-induced cerebral edema,and decrease of the drug dose because of adverse after theγ-radiotherapy.In 31 patients(including 17 patients with serious PTBE after withdrawal of DXM treatment) received MPD treatment,their pre-treatment PTBE-EI was 3.8～7.4(5.26±1.93),and 2.7～5.1(3.88±1.56) after treatment.PTBE-EI was significantly decreased (P＜0.05,t-test) after MPD treatment.However,PTBE-EI was increased to 4.1～8.2 (6.24±1.76) two weeks after drug withdrawal.In 46 patients(including 17 patients with DXM treatment and 6 patients with MPD treatment and occurred serious PTBE) received ACTH treatment,their pre-treatment PTBE-EI was 4.7～9.6(7.01±1.83),1.1～2.9(2.07±0.62) one month after treatment, and 1.7～3.2(2.23±0.90) three months later.PTBE-EI was significantly decreased(P＜0.05,t-test) after ACTH treatment.In comparison of efficacies of three treatment groups,DXM response rate was 20.5% (8/39),in which 14 patients and 17 patients had received MPD and ACTH treatments because of the serious PTBE within 1 month after stopping DXM treatment.MPD response rate was 61.3%(19/31),but serious PTBE occurred again in 12 patients after MPD withdrawal only about 2 weeks later.ACTH response rate was 67.4%(31/46), which was similar to MPD group.In ACTH group,PTBE-EI in 22 patients(47.8%) was not dissipated because of lesions,disappeared edema or partial softening foci formation; 9 patients(19.6%) received craniotomy excision surgery due to the severe PTBE after ACTH treatment withdrawal,or could not be tolerated;15 patients(32.6%) received ACHT treatment 1 to 2 months later because of the severe headache and other symptoms,till to a gradual reduction and attenuation of the clinical symptoms,or basically dissipated in imaging studies of brain edema after the withdrawal.Chi-square test results showed that ACTH effect was significantly more effective than DXM(P＜0.01),and was as effective as MPD(P＞0.05).Conclusion:1.The pathological changes in brain samples from patients with refractory PTBE induced byγ-radiotherapy include the vessel wall fibrinoid necrosis and degeneration, thrombosis,and tumor interstitial and small blood vessel proliferation.This is directly related to stereotactic radiosurgery technology and leads to local micro-circulation disorders and obstructed.Blood-brain barrier structure and function are damaged,which leads to tumor and endothelial cell matrix(basement membrane) and blood components (including some vasoactive substances) as well as infiltration of inflammatory cells in direct contact,thus further exacerbating PTBE.This may be one of the possible mechanisms of the formation of refractory PTBE induced byγ-radiotherapy.2.There is no significant difference between pre- and post-γ-radiotherapy in PCNA, VEGF,AQP-1,AQP-4 and AQP-9 expressions in brain samples from patients with refractory PTBE induced byγ-radiotherapy.This suggests that the formation mechanism of refractory PTBE induced byγ-radiotherapy is different from the primary tumor-induced cerebral edema.3.ACTH can rapidly reduce the patient’s PTBE-EI.Therefore,and the therapeutic dose of exogenous ACTH on the pituitary gland the daily endogenous secretion of ACTH and its physiological role,is not too much interference and influence,ACTH may be used as the alternative medicine in the treatment of refractory PTBE induced byγ-radiotherapy.更多还原