Chemotherapy combined with bevacizumab for small cell lung cancer with brain metastases:A case report

BACKGROUND Small cell lung cancer(SCLC)is a common and aggressive subtype of lung cancer.It is characterized by rapid growth and a high mortality rate.Approximately 10%of patients with SCLC present with brain metastases at the time of diagnosis,which is associated with a median survival of 5 mo.This study aimed to summarize the effect of bevacizumab on the progression-free survival(PFS)and overall survival of patients with brain metastasis of SCLC.CASE SUMMARY A 62-year-old man was referred to our hospital in February 2023 because of dizziness and numbness of the right lower extremity without headache or fever for more than four weeks.The patient was diagnosed with limited-stage SCLC.He received 8 cycles of chemotherapy combined with maintenance bevacizumab therapy and achieved a PFS of over 7 mo.CONCLUSION The combination of bevacizumab and irinotecan effectively alleviated brain metastasis in SCLC and prolonged PFS.

Could helical tomotherapy do whole brain radiotherapy and radiosurgery?

Whole brain radiotherapy (WBRT) remains the standard management of breast cancer patients with brain metastases, allowing for symptomatic improvement and good local control in most patients. However, its results remain suboptimal in terms of both efficacy and toxicity. In highly selected breast cancer patients, stereotaxic radiotherapy demonstrates a very good local control with a low toxicity. With the purpose of improving the efficacy/toxicity ratio, we report the association of integrated boost with WBRT in a breast cancer patient with brain metastases. Two and a half years after completion of helical tomotherapy (HT), the patient experienced clinical and radiological complete remission of her brain disease. No delayed toxicity occurred and the patient kept her hair without need of radiosurgical procedure. The HT provided a high dosimetric homogeneity, delivering integrated radiation boosts, and avoiding critical structures involved in long-term neurological toxicity. Further assessment is required and recruitment of breast cancer patients into clinical trials is encouraged.

Precision radiotherapy for brain tumors A 10-year bibliometric analysis

OBJECTIVE： Precision radiotherapy plays an important role in the management of brain tumors. This study aimed to identify global research trends in precision radiotherapy for brain tumors using a bibliometric analysis of the Web of Science. DATA RETRIEVAL： We performed a bibliometric analysis of data retrievals for precision radiotherapy for brain tumors containing the key words cerebral tumor, brain tumor, intensity-modulated radiotherapy, stereotactic body radiation therapy, stereotactic ablative radiotherapy, imaging-guided radiotherapy, dose-guided radiotherapy, stereotactic brachytherapy, and stereotactic radiotherapy using the Web of Science. SELECTION CRITERIA： Inclusion criteria： （a） peer-reviewed articles on precision radiotherapy for brain tumors which were published and indexed in the Web of Science; （b） type of articles： original research articles and reviews; （c） year of publication： 2002-2011. Exclusion criteria： （a） articles that required manual searching or telephone access; （b） Corrected papers or book chapters. MAIN OUTCOME MEASURES： （1） Annual publication output; （2） distribution according to country; （3） distribution according to institution; （4） top cited publications; （5） distribution according to journals; and （6） comparison of study results on precision radiotherapy for brain tumors. RESULTS： The stereotactic radiotherapy, intensity-modulated radiotherapy, and imaging-guided radiotherapy are three major methods of precision radiotherapy for brain tumors. There were 260 research articles addressing precision radiotherapy for brain tumors found within the Web of Science. The USA published the most papers on precision radiotherapy for brain tumors, followed by Germany and France. European Synchrotron Radiation Facility, German Cancer Research Center and Heidelberg University were the most prolific research institutes for publications on precision radiotherapy for brain tumors. Among the top 13 research institutes publishing in this field, seven are in the USA, three are in Germany, two are in France, and there is one institute in India. Research interests including urology and nephrology, clinical neurology, as well as rehabilitation are involved in precision radiotherapy for brain tumors studies. CONCLUSION： Precision radiotherapy for brain tumors remains a highly active area of research and development.

Therapeutic Effect of First-line Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor (EGFR-TKI)Combined with Whole Brain Radiotherapy on Patients with EGFR Mutation-positive Lung Adenocarcinoma and Brain Metastases

This study compared the therapeutic effect of first-line epidermal growth factor receptor tyrosine kinase inhibitor(EGFR-TKI)with that of EGFR-TKI plus whole brain radiotherapy(WBRT)on patients with EGFR mutation-positive lung adenocarcinoma and brain metastases.A total of 139 patients with lung adenocarcinoma and brain metastases treated with first-line EGFR-TK1therapy from September 2008 to December 2017 were enrolled in this study.The study endpoints were intracranial time to progression(TTP)and overall survival(OS).The effects of clinical pathological parameters and EGFR gene status on the study endpoints were compared.The results showed that the intracranial TTP was significantly longer in EGFR-TKI plus WBRT group than in EGFR-TKI group (median 30.0 vs.18.2 months,χ2=10.824,P=0.001),but no significant difference in the OS was noted between the two groups (median 48.0 vs.41.1 months,χ2=0.012, P=0.912).Also,there was no statistically significant difference in the OS between patients treated with early and late radiotherapy (P=0.849)and between those with asymptomatic and those with symptomatic intracranial metastases (P=0.189).The OS and intracranial TTP of patients with intracranial oligometastases (≤3metastatic sites)were not significantly different from those of patients with multiple intracranial metastases (P=0.104 and P=0.357,respectively),and exon 19 and exon 21 mutations didn't show significant effects on the OS and intracranial TTP of patients (P=0.418 and P=0.386,respectively).In conclusion,there was no statistically significant difference in the OS between the EGFR-TKI alone group and EGFR-TK1 plus WBRT group.However, simultaneous use of WBRT was found to significantly prolong intracranial TTP and improve cerebral symptoms,and thus EGFR-TKI and WBRT combined may be clinically beneficial for patients with EGFR mutation-positive lung adenocarcinoma and brain metastases.

Radiotherapy for multiple brain metastases from hepatocellular carcinomas

A 78-year-old man with liver cirrhosis was foundto have multiple hepatocellular carcinomas (HCCs)and underwent 3 sessions of transcatheter arterialchemoembolization. Fourteen months after diagnosis,the patient presented with left hemiparesis. Contrast-enhanced magnetic resonance imaging showed multiplemetastases with ring-shaped enhancement in thecerebrum and cerebellum. There were no metastases toother organs. The metastatic lesions almost completelydisappeared after whole-brain radiotherapy with atotal dose of 50 Gy. Neurologic symptoms decreased,and the patient's quality of life improved. The patientunderwent 2 more sessions of transcatheter arterialchemoembolization. Twelve months after the diagnosisof brain metastasis, the patient remains alive. Thepresent case indicates that radiotherapy can improvequality of life and prolong survival in some patients withbrain metastases from HCCs.

A CLINICAL STUDY FOR EVALUATING EARLY RADIOTHERAPY EFFECT IN PATIENTS WITH BRAIN TUMOR USING ^(99)Tc^m-HL91 SPECT

Objective： The purpose of this study was to evaluate the early radiotherapy effect using ^99Tc^m-HL91 SPECT in patients with brain tumors. Methods： Twenty-one patients with brain tumors who were treated by radiotherapy were studied. KPS grade, tumor size on ^99Tc^m-HL91 SPECT, tumor size on MRI, and ratio of T/N （tumor counts/sec over normal brain tissue counts/sec） were investigated before ,during and after radiotherapy. Results： The average tumor size on ^99Tc^m-HL91 SPECT and MRI was 11.34±5.88 cm^2, 9.46±5.66 cm^2, respectively before radiotherapy. The tumor size on ^99Tc^m-HL91 SPECT was not in accordance with to that on MRI （P〈0.05）. KPS grade, tumor size on ^99Tc^m-HL91 SPECT and ratio of T/N had significance differences before, during and after radiotherapy （P〈0.05）, but the tumor size on MRI imaging had no significance differences before, during and after radiotherapy （P〉0.05）. The rate of symptom improvement was 80% during radiotherapy and 100% after radiotherapy. The rates of imaging remission based on the brain tumor size on ^99Tc^m-HL91 SPECT, MRI and T/N were 75%, 15%, and 80%, respectively during radiotherapy. The agreement rates between imaging remission diagnosed by those three methods and symptom improvement were 70%, 40%, and 60% respectively during radiotherapy. The rates of imaging remission based on the brain tumor sizes on ^99Tc^m-HL91 SPECT, MRI and T/N were 100%, 25%, and 95% respectively after radiotherapy. The agreement rates between imaging remission diagnosed by those three methods and symptoms improvement were 100%, 20%, and 95% respectively after radiotherapy. Conclusion： The tumor size on ^99Tc^m-HL91 SPECT is a valuable tool for evaluating early radiotherapy effect of brain tumor in process of radiotherapy. T/N is not a feasible method in evaluating radiotherapy effect of brain tumor because it may show elevation unrelated to the curative effect during radiotherapy.

Analyzing Planning Techniques for Whole Brain Radiotherapy

Aims: This study compares data between the Field in Field planning and Wedge planning techniques to figure out which technique has better dose coverage and distribution for PTV, and, if using FiF technique for whole brain treatment, how many beams will have better plan. Methods: 56 patients, who need to radiate whole brain with 30 Gy/10 fractions, have been selected for this study. Four plans have been made for each patient (FiF1—one subfield per field plan, FiF2—two subfields per field plan, FiF3—three subfields per field plan, and a Wedge plan). Results: The results of Field in Field plans including Compare dose distribution on the transverse CT slice, plan evaluation using DVH, number MU of plan, Dmax, HI, HTCI, DmaxPTV, DmeanPTV. Volume of PTV with the dose over 105% prescribed dose, dose of organ at risk, and Quality Assurance (QA) plan, are better than those of Wedge plan. Conclusions: Plans using Field in Field technique has better coverage, is more homogeneous in dose distribution than plan using Wedge technique. When using Field in Field technique for whole brain radiotherapy, using three subfields per field has better result than two subfields per field and one subfield per field.

The effects of three-dimensional conformal radiotherapy combined with whole brain irradiation on brain metastases

观察三维的保角的放射疗法的最近治疗学的效果和毒性的目的与大脑转移为病人与整个大脑照耀结合了。33 个盒子其剂量是 36 40 Gy (18 20 f ) 起初被整个大脑照耀对待的方法。然后三维的保角的放射疗法与 20 25 Gy 的全部的剂量被加到焦点，其 fractionated 剂量是 2 5 Gy/time， 5 时间 / 星期或 3 时间 / 星期。在在放射疗法以后的 1 个月以内的结果根据大脑的成像，所有病人的 CR 是 45.5% ， PR 36.4% ， NC 15.1% ，和 PD 3% 。为有在放射前的神经症状的 32 个盒子，症状的 CR 是 40.6% 并且 PR 59.4% 。所有病人在 KPS 等级获得了不同增加。在后续时期底，有有直到 9.3 个月的吝啬的幸存时间的 22 死亡。与整个大脑照耀相结合的结论三维的保角的放射疗法不能仅仅有效地控制大脑转移并且改进生活质量，而且趋于延长幸存时间。

Efficacy of Temozolomide Combined with Whole Brain Radiotherapy in the Treatment of Cerebral Metastases from Lung Cancer

[Objectives] To observe the clinical efficacy,adverse reaction and survival time of temozolomide combined with whole brain radiotherapy in the treatment of lung cancer. [Methods] A total of 43 patients with lung cancer and cerebral metastases were reviewed and analyzed. Three-dimensional conformal radiotherapy(3D-CRT) technique was used to perform whole brain radiotherapy,one time a day and5 times a week. At the same time of radiotherapy,temozolomide chemotherapy was performed,150 mg/( m2·d),continuous oral administration of 5 d,every 28 days were a cycle( those patients who continue receiving temozolomide chemotherapy did not receive other related antitumor therapy,such as systemic chemotherapy and molecular targeted therapy,etc.),and drugs were administered for 4-6 cycles according to tolerance of patients. Kaplan-Meier method was used to calculate the survival rate. [Results]The objective response rate of 43 patients was79. 0%(34/43),in which CR was 6/43,PR was 28/43,and 9 cases had PD. By December 31,2016,7 patients in 43 cases died,one patient died of cerebral hernia due to intracranial lesions and 6 patients died of failure of other important organs due to metastasis. The OS and PFS of the whole group of patients in one year were 49. 1% and 56. 9% respectively. The adverse reactions were mild and the patients could tolerate such treatment. [Conclusions] Temozolomide combined with whole brain radiotherapy in the treatment of lung cancer with cerebral metastases has excellent clinical efficacy,while patients can tolerate such treatment.

Treatment of patients with multiple brain metastases by isolated radiosurgery:Toxicity and survival

BACKGROUND Radiosurgery for multiple brain metastases has been more reported recently without using whole-brain radiotherapy.Nevertheless,the sparsity of the data still claims more information about toxicity and survival and their association with both dosimetric and geometric aspects of this treatment.AIM To assess the toxicity and survival outcome of radiosurgery in patients with multiple(four or more lesions)brain metastases.METHODS In a single institution,data were collected retrospectively from patients who underwent radiosurgery to treat brain metastases from diverse primary sites.Patients with 4-21 brain metastases were treated with a single fraction with a dose of 18 Gy or 20 Gy.The clinical variables collected were relevant to toxicity,survival,treatment response,planning,and dosimetric variables.The Spearman’s rank correlation coefficients,Mann-Whitney test,Kruskal-Wallis test,and Log-RESULTS From August 2017 to February 2020,55 patients were evaluated.Headache was the most common complaint(38.2%).The median overall survival(OS)for patients with karnofsky performance status(KPS)>70 was 8.9 mo,and this was 3.6 mo for those with KPS≤70(P=0.047).Patients with treated lesions had a median progression-free survival of 7.6 mo.There were no differences in OS(19.7 vs 9.5 mo)or progression-free survival(10.6 vs 6.3 mo)based on prior irradiation.There was no correlation found between reported toxicities and planning,dosimetric,and geometric variables,implying that no additional significant toxicity risks appear to be added to the treatment of multiple(four or more)lesions.CONCLUSION No associations were found between the evaluated toxicities and the planning dosimetric parameters,and no differences in survival rates were detected based on previous treatment status.

基于体素的分析方法比较IMRT与VMAT技术在晚期鼻咽癌患者大脑中的剂量差异

目的:定位晚期鼻咽癌患者放疗过程中大脑受照射的确切位置,分析IMRT和VMAT技术在晚期鼻咽癌患者的脑内剂量分布差异。方法:使用蒙特利尔神经学研究所空间中的CT脑模板,采用基于体素的分析方法对脑内的剂量分布进行分析。结果:对于晚期鼻咽癌患者,VMAT计划在保护脑内正常组织方面并没有表现出优势,相反,IMRT计划更加出色,IMRT计划表现出优势的区域包括脑干、小脑后叶、小脑前叶、颞叶、枕叶、边缘叶以及叶下回的部分区域。结论:对晚期鼻咽癌患者,VMAT在保护正常脑组织方面显示出劣势,提示IMRT方法对正常脑组织的保护可能更有优势。

伽玛刀立体定向放射治疗肺癌脑转移瘤患者预后不良的影响因素

目的:分析伽玛刀立体定向放射治疗肺癌脑转移瘤患者预后不良的影响因素。方法:回顾性分析2022年1月至2023年1月在该院接受伽马刀立体定向放射治疗的121例肺癌脑转移瘤患者的临床资料。统计伽玛刀立体定向放射治疗肺癌脑转移瘤患者的预后情况,采用Logistic回归分析伽玛刀立体定向放射治疗肺癌脑转移瘤患者预后不良的影响因素。结果:121例伽马刀立体定向放射治疗肺癌脑转移瘤患者预后不良40例,设为预后不良组,预后良好81例,设为预后良好组;预后不良组脑转移瘤最大直径≥3 cm、血清鳞状细胞癌抗原(SCC-Ag)≥3.80 ng/mL、血清细胞角蛋白19片段(CYFRA21-1)≥7.52 ng/mL、血清神经元特异性烯醇化酶(NSE)≥50.81μg/L占比均高于预后良好组,差异有统计学意义(P<0.05);Logistic回归分析结果显示,血清SCC-Ag≥3.80 ng/mL、血清NSE≥50.81μg/L均为伽玛刀立体定向放射治疗肺癌脑转移瘤患者预后不良的危险因素(OR>1,P<0.05)。结论:血清SCC-Ag≥3.80 ng/mL、血清NSE≥50.81μg/L均为伽玛刀立体定向放射治疗肺癌脑转移瘤患者预后不良的危险因素。

大体积脑转移瘤大分割后程缩野放疗的剂量学及临床疗效分析

目的探讨大分割后程缩野放疗对大体积脑转移瘤患者的剂量学及其临床疗效分析。方法收集20例病灶体积6~20 cm^(3)、病灶数目1~4个且行大分割后程缩野放疗的脑转移瘤患者资料。脑部病灶处方剂量为52.5 Gy/3.5 Gy/15 f。治疗10次后复查颅脑增强MRI评估疗效、若肿瘤退缩明显重新勾画靶区完成后程放疗。评估不缩野放疗计划(Plan1)和后程缩野放疗计划下(Plan2)脑组织及其他危及器官剂量学参数变化、后程计划缩瘤率、近期疗效(疗后2~3个月评估近期疗效)。结果后程缩野放疗中脑组织及危及器官的辐射剂量都有下降。且后程缩野时平均缩瘤率为41.76%,3个月ORR为90.5%,6个月LCR为100%。结论大分割后程缩野放疗缩瘤率高,能有效减少正常组织剂量学参数值,对大体积病灶局部控制率好,近期疗效佳。

不同剂量脑立体定向放疗联合PD-1/PD-L1抑制剂治疗非小细胞肺癌脑转移的疗效及安全性

目的不同剂量脑立体定向放疗联合PD-1/PD-L1抑制剂治疗非小细胞肺癌脑转移的疗效及安全性。方法选取50例非小细胞肺癌脑转移患者作为研究对象,根据患者脑立体定向放疗分割剂量分为A组(n=15)、B组(n=15)和C组(n=20),患者均接受脑立体定向放疗联合生存PD-1/PD-L1抑制剂治疗,A组脑立体定向放疗剂量为4 Gy/f,12 f,B组为5 Gy/f,8 f组,C组为7 Gy/f,5 f。对比三组患者治疗后临床疗效、不良反应发生率以及生存情况;对比三组患者治疗前后KPS评分。结果三组患者临床总有效率比较差异具有统计学意义(P<0.05);C组临床总有效率比较显著高于A组和B组(P<0.05);三组患者不良反应总发生率对比差异无统计学意义(P>0.05);A组、B组和C组患者中位生存期分别为2.70个月、2.40个月和6.60个月。Log-rank检验结果提示,三组患者中位生存期比较,差异具有统计学意义(P<0.05);治疗后,三组患者的KPS评分均显著升高,组间比较差异显著,且C组患者较A组和B组显著更高(P<0.05)。结论对于非小细胞肺癌脑转移患者,7 Gy/f,5 f分割剂量相比于4 Gy/f,12 f和5 Gy/f,8 f联合PD-1/PD-L1抑制剂改善患者的临床疗效更明显,延长生存时间和生存质量更为明显。

联合免疫检查点抑制剂治疗驱动基因阴性非小细胞肺癌脑转移的研究进展

非小细胞肺癌(non-small cell lung cancer,NSCLC)是肺癌中最常见的组织学类型,约66%的患者在确诊时就被发现伴有远处转移。脑转移是最常见的转移部位之一,约13%的患者在初诊时即发现颅内受累,严重影响生活质量,预后不佳。驱动基因阳性的NSCLC脑转移患者靶向治疗可以达到较好的颅内控制率,但驱动基因阴性的患者治疗手段较为局限。近年来,随着免疫治疗的兴起,免疫检查点抑制剂(immune checkpoint inhibitors,ICIs)被广泛运用于临床,ICIs联合放疗的治疗模式为驱动基因阴性NSCLC脑转移患者的治疗带来了新希望。本文就放疗联合免疫治疗在敏感驱动基因阴性NSCLC脑转移患者中的临床研究进展进行综述,以期为临床治疗方案的选择提供参考。

儿童毛细胞型星形细胞瘤术后综合治疗研究进展

毛细胞型星形细胞瘤(PA)是最常见的儿童低级别脑肿瘤,常见于视神经、视交叉、下丘脑、脑干、小脑和大脑等部位。PA往往边界清楚、生长缓慢,属于WHO I级肿瘤,手术切除是治疗的首选方案。然而,由于视神经、视交叉、下丘脑或脑干等处神经功能的重要性,手术不一定能做到全切。目前临床对于儿童PA术后的治疗方案尚无定论,国内外对于儿童PA术后的主要治疗方式包括放疗、化疗、靶向治疗和随访观察。随着影像学和放射技术的进步,除了传统分次放疗,还包括适形放疗、立体定向放射治疗和质子治疗。但目前多数学者尚不推荐将放疗作为儿童PA术后的一线治疗选择。以长春新碱联合卡铂的化疗方案是进展性PA的首选,伊立替康-贝伐单抗可作为二线治疗用药。靶向治疗的发展如火如荼,以丝裂原活化蛋白激酶(MEK)抑制剂为首的靶向药物因其更少的毒副反应和良好的疗效而有望在未来成为儿童PA术后的一线用药,但目前尚缺乏高级别的临床证据。随访观察是儿童PA术后的选择之一,有学者提出儿童PA的分层治疗方案,推荐低风险层患者于术后随访观察。该文对儿童PA术后综合治疗进展作综述报道。

High-dose methotrexate and zanubrutinib combination therapy for primary central nervous system lymphoma

In this editorial I comment on the article,published in the current issue of the World Journal of Clinical Oncology.Primary central nervous system lymphoma(PCNSL)is a disease of elderly and immunocompromised patients.The authors reported clinical results of 19 patients with PCNSL treated with zanubrutinib/high dose methotrexate(HD-MTX)until disease progression.They demonstrated that the combination of zanubrutinib with HD-MTX led to a marked clinical response and tolerability among these patients.They also observed that cerebrospinal fluid liquid biopsy to detect circulating tumor DNA may be a good option for evaluating treatment response and tumor burden in patients with PCNSL.PCNSL is a challenging disease for treatment as these patients present with different neurological states and comorbidities.Treatment has evolved over the years from whole brain radiotherapy to HD-MTX followed by autologous stem cell transplant.Gradually,treatment of patients with PCNSL is going to become individualized.

CT与MRI结合评估脑胶质瘤分级的价值及指导放化疗的作用探究

目的分析CT与磁共振成像(MRI)结合评估脑胶质瘤分级的价值,并探究其指导放化疗的作用。方法选择2020年5月至2022年5月医院收治的86例脑胶质瘤患者,所有患者入院时均接受CT及MRI检查,以组织病理检查为基准,分析CT与MRI单独及联合评估脑胶质瘤分级与组织病理检查结果的一致性。结果经组织病理检查结果显示,86例脑胶质瘤患者中脑胶质瘤Ⅰ级9例(10.47%),Ⅱ级29例(33.72%),Ⅲ级21例(24.42%),Ⅳ级27例(31.40%);CT、MRI单独评估脑胶质瘤分级结果与组织病理检查结果一致性理想(Kappa=0.709、0.743,P<0.05);CT与MRI联合评估脑胶质瘤分级结果与组织病理检查结果一致性极好(Kappa=0.823,P<0.05);CT-MRI融合图像组GTV、临床靶区、计划靶区体积小于CT图像组(P<0.05);CT-MRI融合图像组靶区受照最大剂量、平均剂量低于CT图像组(P<0.05);CT-MRI融合图像组脑干、视神经、视交叉、垂体、晶体、眼球最大受照剂量及最小受照剂量均低于CT图像组(P<0.05);随访1年,CT图像组复发率(32.56%)与CT-MRI融合图像组复发率(37.21%)比较,差异不显著(P>0.05)。结论CT与MRI结合评估脑胶质瘤分级与组织病理检查一致性极好,具有较高临床应用价值,且在放化疗指导中具有重要作用,能够降低正常组织放疗照射剂量,保护正常组织。

Fraxion系统与热塑膜固定在脑恶性肿瘤放疗中的摆位误差比较

目的评估Fraxion系统与热塑膜在脑恶性肿瘤放疗体位固定中的摆位准确性。方法选取2018年1月至2022年9月在我院肿瘤内科接受头部放疗固定的脑恶性肿瘤患者92例(采用Fraxion系统32例,热塑膜60例)为研究对象。将锥形束容积断层成像技术图像与计划电子计算机断层扫描图像匹配后获得线性摆位误差、3D矢量位移;根据外扩边界(Margin of Planning Target Volume,MPTV)公式计算出计划靶区MPTV,比较Fraxion系统组和热塑膜组的摆位准确性。结果Fraxion系统组和热塑膜组的摆位误差在左右方向(X轴)分别为(0.79±0.45)mm和(1.60±1.00)mm,在头脚方向(Y轴)分别为(0.82±0.46)mm和(1.77±1.07)mm,在前后方向(Z轴)分别为(0.62±0.37)mm和(1.88±1.05)mm;3D矢量位移分别为(1.42±0.45)mm和(3.13±1.62)mm。Fraxion系统组的线性摆位误差、3D矢量位移均小于热塑膜组,差异具有统计学意义(P<0.001)。Fraxion系统组和热塑膜组在X轴、Y轴、Z轴方向的MPTV分别为0.64、0.66、0.52 mm和1.08、1.12、2.64 mm。结论Fraxion系统在脑恶性肿瘤放疗定位中摆位准确性优于热塑膜固定,可精准定位靶区。