颅骨及脑组织CT MR显示差异对脑肿瘤放疗剂量学影响的研究

目的:研究颅骨及脑组织CT/MR显示差异对脑瘤放疗剂量学的影响.方法:选取60例接受放疗的脑转移瘤(brain metasta?ses,BM)患者,每例患者均行CT和MR模拟定位,将CT图像和MR图像刚性配准,在CT/MR融合图像上勾画肿瘤靶区、危及器官、颅骨(分别命名为Skull-CT、Skull-MR)、脑组织(分...     

Polymer Delivery of Camptothecin against 9L Gliosarcoma: Release,Distribution, and Efficacy

Camptothecin is a potent antineoplastic agent that has shown efficacy against multiple tumor lines in vitro; unfortunately, systemic toxicity has limited its in vivo efficacy. This is the first study to investigate the release, biodistribution, and efficacy of camptothecin from a biodegradable polyanhydride polymer. Tritiated camptothecin was incorporated into biodegradable polymers that were implanted intracranially in 16 male Fischer 344 rats and the animals were followed up to 21 days post-implant. A concentration of 11–45g of camptothecin-sodium/mg brain tissue was within a 3mm radius of the polymer disc, with levels of 0.1g at the outermost margin of the rat brain, 7mm from the site of implantation. These tissue concentrations are within the therapeutic ranges for human and rat glioma lines tested against camptothecin-sodium in vitro. The in vivo efficacy of camptothecin-sodium was evaluated with male Fischer 344 rats implanted intracranially with 9L gliosarcoma and compared with the efficacy of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). The animals were divided into four groups. Group 1 (control) had a median survival of 17 days. Group 2 (3.8% BCNU polymer) had a median survival of 23 days (P=0.006). Group 3 (20% camptothecin polymer) had a median survival of 25 days (P=0.023). Group 4 (50% camptothecin polymer) had a median survival of 69 days (P<0.001). Drug loadings of 20% and 50% camptothecin released intact camptothecin for up to 1000h in vitro. We conclude that the biodegradable polymer p(CPP:SA) releases camptothecin-sodium, produces tumoricidal tissue levels, results in little or no systemic toxicity, and prolongs survival in a rat glioma model.     

Dense middle cerebral artery computed tomography sign: Confirmation by magnetic resonance (MR) imaging and MR angiography

In acute ischaemic stroke, the dense middle cerebral artery sign on computed tomography indicates occlusion of the middle cerebral artery. A case is described in which the sign was confirmed by magnetic resonance (MR) imaging and MR angiography.     

The Accumulation of Topotecan in 9L Glioma and in Brain Parenchyma with and without Dexamethasone Administration

The accumulation of the topoisomerase I inhibitor topotecan in brain tumor as well as in brain around tumor (BAT) and normal brain following an intravenous bolus of topotecan of 0.5mg/kg was investigated in rats bearing a 9L glioma. Also the influence of dexamethasone (Dex) on the uptake of topotecan was examined. Tumor, BAT and brain tissue as well as whole blood were collected at 1h after an i.v. bolus of topotecan. Concentrations of total topotecan in tumor, BAT and brain were quantified with high-performance liquid chromatography (HPLC) and compared with concentrations in plasma of total topotecan. In brain tumor tissue the mean total topotecan concentration was 96±33ng/g which was 20-fold higher than the accumulation of topotecan in normal brain tissue. In BAT intermediate concentrations of 13±4.9ng/g were reached. Mean total topotecan concentration in plasma was 100±25ng/ml. We did not find an influence of Dex on the uptake of topotecan in either tissue. We conclude that high tissue concentrations of topotecan can be reached in experimental brain tumors in rats. This observation may be useful in the design of clinical studies with topotecan.     

Interobserver variations in gross tumor volume delineation of brain tumors on computed tomography and impact of magnetic resonance imaging.

PURPOSE: (1) To assess the interobserver variability of brain tumor delineation on computed tomography (CT). (2) To assess the impact of the addition of magnetic resonance imaging (MRI) information. METHODS: Nine physicians were asked to delineate the gross tumor volume (GTV) of five patients with supratentorial inoperable brain tumors on CT scans and 2 weeks (or more) later on MRIs. The delineations were performed on a computer screen. During delineation on MRI, the registered CT images (without delineation) were displayed on the screen (MRI+CT). RESULTS: A high interobserver variability in GTV delineation on CT is found: the ratio of the largest to the smallest defined volumes varies for the five patients by factors of resp. 2.8, 1.8, 1.8, 1.9 and 1.7. The interobserver variability is as large on MRI+CT as on CT alone (ratio largest/smallest volume: 2.4, 1.7, 1.9, 2.7 and 1.5). Volumes delineated on MRI+CT (mean: 69.6 cm(3)) are larger than on CT alone (mean: 59.5 cm(3)). Residual volumes (volume delineated on one image modality but not on the other) are >0 for CT alone and for MRI+CT. CONCLUSIONS: A large interobserver variability in GTV delineation of brain tumors is demonstrated. The addition of MRI to CT does not reduce interobserver variability. GTVs delineated on MRI+CT are larger than on CT alone, but some volumes are delineated on CT and not on MRI. Therefore, a combination of the two image modalities is recommended for brain tumor delineation for treatment planning.     

Solitary brainstem metastasis: Comparisons of X-ray computed tomography and magnetic resonance imaging to pathology

A case of a solitary brainstem metastasis from a bronchogenic adenocarcinoma is presented. X-ray computed tomography, magnetic resonance imaging, and specimens obtained at autopsy are compared. T2 weighted magnetic resonance images provided evidence for the diagnosis of a diffusely infiltrating process, whereas T1 weighted images demonstrated a clearly defined, well demarcated tumor. Contrast enhanced computed tomography supported evidence obtained from the TI weighted image. At autopsy, the tumor was a well circumscribed pontine metastasis with surrounding edema. The importance of distinguishing between TI and T2 weighted images is crucial for establishing a correct diagnosis and for instituting proper therapy. In contrast to some reports, we found that the T2 weighted image was misleading in regard to defining the extent of tumor. We conclude that both images must be considered together to provide an accurate diagnostic estimate.     

Metastatic disease of the cavernous sinus: contribution of computed tomography and magnetic resonance imaging to diagnosis

The clinical presentation of metastatic disease to the cavernous sinus includes ophthalmoplegia, pain and sensory deficit along the optic or maxillary branches of the trigeminal nerve. The role of a CT scan and magnetic resonance imaging in the diagnosis is discussed. It was found that magnetic resonance imaging is superior to CT scan in demonstrating the cavernous sinus and pontine borders, especially in lymphomatous involvement of these structures.     

The effects of dexamethasone on transcapillary transport in experimental brain tumors: II. Canine brain tumors

Summary We studied the effect of dexamethasone on transcapillary transport in ten Avian Sarcoma Virus (ASV)-induced canine brain tumors, before and one week after administration of dexamethasone, 2.5 mg/kg/day. A computed tomographic (CT) method was used to measure regional values of K₁ (blood-to-tissue transfer constant), k₂ (tissue-to-blood efflux constant), and V_p (tissue plasma vascular space) of meglumine iothalamate (Conray-60^TM); the values were reconstructed for each 0.8 × 0.8 x 5 mm volume element of the CT data. For all tumors considered together, there was a decrease in the whole tumor K₁ value of meglumine iothalamate from 26 ± 2.2 (SE) before dexamethasone to 24 ± 2.9 l/g/min after dexamethasone. V_p decreased from 7.2 ± 0.7 to 6.7 ± 0.9 ml/100 g, and the size of the tumor extracellular space (V_e) decreased from 0.30 to 0.26 ml/g. These changes were not statistically significant. However, when each tumor was used as its own control, k₁ significantly decreased after dexamethasone in four tumors, significantly increased in two and was unchanged in four. These results suggest that decreased blood-to-tissue transport may be one mechanism underlying resolution of tumor associated cerebral edema in some brain tumors and that the effects of dexamethasone on blood-to-tissue transport in brain tumors are variable from one tumor to the next. Decreased permeability may not be the sole mechanism by which dexamethasone reduces tumor-associated cerebral edema.     

依据CT及MRI确定区域淋巴结转移的病理对照研究

目的 评估分别依据CT及DWMRI确定胸部肿瘤区域淋巴结转移的诊断效能,寻找更为合理准确的淋巴结勾画方法及界值。方法 2012—2013年共入组43例胸部肿瘤患者(食管癌35例、NSCLC 8例),术前1周完善胸腹强化CT及DWMRI检查,分别依据CT及DWIMR图像确定转移的区域淋巴结,以术后病理为金标准统计并比较两种方法的诊断效能。两种图像结果行χ²检验。结果 CT图像与DWI诊断区域淋巴结转移的敏感性、特异性、准确性、阳性预测值、阴性预测值、约登指数分别为57.1%、96.3%、93.8%、50.0%、97.2%、53.4%和60.0%、98.9%、96.5%、77.8%、97.4%、58.9%,DWMRI诊断的特异性、准确性、阳性预测值优于CT (P=0.005、0.038、0.022)。依据CT诊断的40个淋巴结中20个为假阳性,其中15个(75%)可经DWMRI信息纠正。CT诊断假阴性淋巴结15个,其中3个(20%)可经DWMRI得以分辩。全组35个癌性淋巴结中5个影像学未见明确肿大,余30个中有13个短径<1.0 cm (43.3%)。结论 依据CT判断区域淋巴结转移局限性明显,单以短径≥1.0 cm作为靶区勾画标准可能会漏照较多癌性淋巴结。DWMRI诊断区域淋巴结转移的特异性、准确性及阳性预测值优于CT,可有效排除非癌性肿大淋巴结并分辨部分小的转移性淋巴结。     

Blood-brain barrier and blood volume imaging of cerebral glioma using functional CT: A pictorial review

Five cases of cerebral glioma are presented here that illustrate the benefit of functional CT imaging of blood-brain barrier permeability and cerebral blood volume. Functional CT uses Patlak analysis of a single location dynamic sequence to extract physiological information that is useful clinically in the assessment of cerebral gliomas. Functional CT offers distinct advantages over other functional modalities including clearer delineation of tumour, tumour grading, measurement of tumour activity and monitoring response to therapy.     

头颈部淋巴瘤计算机体层摄影、磁共振成像影像特点及临床病理分析

 【摘要】 目的 探讨头颈部结内型及结外型淋巴瘤的计算机体层摄影（CT）与磁共振成像（MRI）影像特点及临床病理特点。方法 分析46例经手术病理或穿刺活检证实的头颈部淋巴瘤患者临床病理及CT、MRI资料,结合文献复习,评价头颈部淋巴瘤的影像特点及临床、病理特点。结果 46例中38例为非霍奇金淋巴瘤（NHL）,8例为霍奇金淋巴瘤（HL）。结外型21例（45.65 %）,包括原发鼻腔10例、咽环（Waldeyer环）7例、喉部2例、甲状腺及腮腺各1例,其中13例伴发颈部淋巴结转移;结内型25例（54.35 %）,主要累及颈部Ⅱ～Ⅳ区淋巴结。Ann Arbor分期：Ⅰ期14例,Ⅱ期19例,Ⅲ期0例,Ⅳ期13例。根据病变形态分为4型：多发结节型25例,肿块型11例,弥漫肿胀型8例,溃疡坏死型2例。结论 头颈部淋巴瘤的CT、MRI影像表现有一定特点,影像检查对淋巴瘤的诊断、鉴别诊断及观察侵犯范围有一定临床价值。     

The effects of dexamethasone on experimental brain tumors: I. Transcapillary transport and blood flow in RG-2 rat gliomas

Summary Dexamethasone dramatically improves cerebral edema associated with malignant gliomas. Although the pathophysiology of this effect is not clearly understood, many investigators have postulated that tumor capillary permeability is reduced by dexamethasone. We studied blood-to-tissue transport and blood flow in 178 RG-2 transplanted gliomas in a control group and four groups given dexamethasone at doses of 3, 6, 9, and 12 mg/kg for four days.¹⁴C- aminoisobutyric acid (AIB) was used to study blood-to-tissue transport in 31 animals; in an additional 27 animals¹⁴C-AIB and¹³¹I-iodoantipyrine (IAP) were used in double label experiments to study blood-to-tissue transport and blood flow. Regional measurements of the transfer constant (K) of AIB and blood flow (F) were made with quantitative autoradiography. There were significant differences between the control and dexamethasone-treated groups with regard to weight loss and plasma glucose. However, there wasno significant effect of dexamethasone on values of K or F, regardless of the tumor or brain region examined, and regardless of the dose of dexamethasone administered. Analysis of the profiles of the transfer constant of AIB in the brain around tumor showed that the K of AIB decreased within 0.5 mm of the tumor edge in direct relationship to the dexamethasone dose. These results do not support the hypothesis that dexamethasone reduces brain tumor capillary permeability, and suggest that dexamethasone may decrease tumor-associated cerebral edema by effects on bulk flow away from the tumor margin.     

Detection of liver metastases from endocrine tumors: a prospective comparison of somatostatin receptor scintigraphy, computed tomography, and magnetic resonance imaging.

PURPOSE: To compare the respective sensitivity of somatostatin receptor scintigraphy (SRS), computed tomography (CT), and magnetic resonance imaging (MRI) in the detection of liver metastases from well-differentiated gastroenteropancreatic endocrine tumor (WDGEP ET) patients. To define predictive factors for "high-sensitivity SRS." PATIENTS AND METHODS: Sixty-four patients with WDGEP ET underwent SRS with abdominal single-photon emission computed tomography (SPECT), spiral CT, and 1.5-T MRI within a 15-day interval, the order of which was randomized. Two readers analyzed images of each modality, blindly and independently. RESULTS: Hepatic metastases were present in 40 of the 64 patients and confirmed by pathology after liver biopsy or surgery in 32 and eight patients, respectively. SRS, CT, and MRI detected a total of 204, 325, and 394 metastases, respectively. The number of detected metastases was significantly higher with MRI than with CT (P = .02) and SRS (P < 10(-4)) and higher with CT than with SRS (P < 10(-4)). SRS was negative in seven patients with a positive CT and/or MRI. More lesions were detected in 10 patients by SPECT compared with static views. The median metastasis size was significantly correlated (P = .04) with the sensitivity of SRS. CONCLUSION: MRI seems to have an edge over CT and SRS for the detection of liver metastases from endocrine tumors. We recommend the systematic performance of liver MRI at WDGEP ET initial staging and before major therapeutic events. The low performance of SRS was mainly explained by the impact of the metastasis size on the detection capacity of SRS.     

下咽癌颈部及咽后淋巴结转移的CT/MRI分析

背景与目的:下咽癌早期即可出现区域淋巴结转移,然而关于下咽癌区域淋巴结尤其是咽后淋巴结转移的报道少见。本研究旨在通过对下咽癌CT/MRI扫描结果的分析,探讨下咽癌区域淋巴结特别是咽后淋巴结转移的特性,为临床治疗提供参考。方法:回顾性分析2000年8月至2009年3月我院病理证实的88例下咽癌区域淋巴结转移的CT/MRI结果。对其局部分期、各区域淋巴结转移的相互关系采用χ2检验和Logistic多因素分析研究。结果:下咽癌的区域淋巴结转移率为73.9%,Ⅱa、Ⅱb、Ⅲ区淋巴结转移发生率最高,分别为61.4%、44.3%及37.5%。Ⅰ、Ⅳ、Ⅴ、Ⅵ区及咽后淋巴结转移都较少,并且均合并Ⅱ、Ⅲ区淋巴结转移。单因素分析显示Ⅰb、Ⅲ区淋巴结转移与Ⅳ区淋巴结转移,Ⅱb区、双侧颈部淋巴结转移与咽后淋巴结转移的关系有统计学意义。多因素分析结果显示Ⅳ区淋巴结转移与Ⅵ区淋巴结转移,双侧颈部淋巴结转移与咽后淋巴结转移的关系有统计学意义。结论:下咽癌区域淋巴结转移途径遵循一定的规律,跳跃性转移少见,以Ⅱ、Ⅲ区转移最常见。双侧颈部淋巴结可能是咽后淋巴结转移的危险因素。     

Simultaneous positron emission tomography and magnetic resonance imaging for the detection and characterisation of liver lesions in patients with colorectal cancer: A pictorial review

Patients with colorectal cancer undergo frequent diagnostic imaging to stage the extent of metastatic disease and assess response to treatment. Imaging is typically via diagnostic contrast‐enhanced CT or combined FDG‐PET/CT. However, recent research has demonstrated promising benefits of combined FDG‐PET/MRI in oncologic imaging due to the superior soft‐tissue contrast of MRI. The extent of both intrahepatic and extrahepatic disease is important in establishing treatment options for colorectal cancer patients, and FDG‐PET/CT and dedicated liver imaging are often both required. FDG‐PET/MRI offers the advantage of a single examination which can be completed within a similar duration as dedicated liver MRI imaging. This improves patient convenience and anatomical co‐registration between PET and MRI imaging and provides a potential cost benefit. The diagnostic benefits of FDG‐PET/MRI include the simultaneous characterisation of focal liver lesions, exclusion of extrahepatic disease, the detection of additional hepatic metastases and extrahepatic disease, and the multi‐parametric assessment of treatment response. This pictorial review highlights examples of these benefits.     

Optimal size criteria of malignant lymph nodes in the treatment planning of radiotherapy for esophageal cancer: Evaluation by computed tomography and magnetic resonance imaging

To determine the optimal size criterion for detection of lymph node metastases from esophageal cancer for radiotherapy by computed tomography (CT) and magnetic resonance (MR) imaging.

In 58 patients with esophageal cancer treated with subtotal esophagectomy and radical lymph node dissection the preoperative Mr (n = 58) images and CT scans (n = 41) were reviewed. The relationship of the CT and MR findings for the neck and mediastinum to the surgical and histopathological results was examined. Five size criteria on malignant lymph nodes were used to construct receiver operating characteritic (ROC) curves for CT and MR, and their detectabilities were evaluated.

The specificities of both modalities at the cutoff of 3 mm short-axis diameter were lower than those at the cutoff of 5 mm or more. In contrast, the sensitivities apparently decreased at teh cutoff of 10 mm or more. The analysis of the ROC curves showed that the optimal size criterion for malignant lymph nodes was 5 mm for both CT and MR. When the criterion of 5 mm was used, the sensitivity, specificity, and accuracy for CT was 68, 92, adn 87%, respectively, and the respective values for MR were 70, 93, and 89%. Although there was no significant difference between the two ROC curves, MR was useful in distinguishing lymph nodes from vascular structures because of the flow void.

There was no significant between CT and MR in the detection of malignant lymph nodes from esophageal cancer. The optimal size criterion for both CT and MR in the detection of cervical and mediastinal lymph node metastases is 5 mm for short-axis diameter. These result suggest that all regional lymph nodes of 5 mm or more on CT or MR should be regarded as part of the gross tumor volume in the treatment planning of radiotherapy for esophageal cancer.     

螺旋CT与MRI评价鼻咽癌颅底侵犯

背景与目的：随着螺旋CT与MRI的普遍应用,研究哪种方法对鼻咽癌发生颅底侵犯的诊断更有价值,是临床上亟待解决的问题。本研究拟探讨用CT与MRI诊断鼻咽癌颅底侵犯的价值。方法：选取1993年8月--2001年9月经病理证实为鼻咽癌的患者6l例,全组患者治疗前均行螺旋CT及MRI检查。此外,螺旋CT薄层扫描三维重建8例。CT扫描采用Elscient CT Twin Flash,常规横断面平扫,部分加冠状面扫描,13例加增强扫描。MRI扫描采用Philips T5-Ⅱ型0.5 Tesla超导成像系统,标准头部正交线圈。常规SE序列,扫描方向为横断面、矢状面和冠状面,扫描范围由鞍上池至第二颈椎下缘水平,6l例中55例患者进行增强扫描。结果：CT发现颅底骨质侵犯17例,MRI扫描发现颅底侵犯26例,其中6例MRI扫描发现斜坡、翼突基底部和蝶骨基底部早期的骨髓浸润,而CT检查未见有这些部位的骨质破坏,另外3例MRI见肿瘤沿三叉神经向颅内侵犯,而CT未见明确的卵圆孔破坏。结论：CT与MRI均可显示鼻咽癌通过破坏骨质侵犯颅底,也可以通过自然孔道进入颅内。MRI较CT对颅底骨质破坏的检出更敏感,MRI可以发现肿瘤沿三叉神经向颅内侵犯,而卵圆孔没有骨质破坏。MRI较CT可以更准确地界定肿瘤的侵犯范围;螺旋CT薄层三维重建,可以较为直观地显示病灶。     

Diagnostic accuracy of diffusion‐weighted imaging‐ magnetic resonance imaging compared to positron emission tomography/computed tomography in evaluating and assessing pathological response to treatment in adult patients with lymphoma: A systematic review

The use of Positron emission tomography/computerised tomography (PET/CT) is well established in the staging and assessment of treatment response of lymphoma. Recent studies have suggested that whole body diffusion‐weighted imaging –magnetic resonance imaging (WB‐DW‐MRI) may be an alternative to PET/CT in both staging and assessment of treatment response. A systematic review was performed to assess the ability of DW‐MRI in the assessment of treatment response in lymphoma. Pubmed, Medline, Web of Science and Embase databases were queried for studies examining whole body DW‐MRI compared to PET/CT in adult patients using a protocol of search terms. We carried out an extensive assessment of titles, abstracts and full texts of relevant paper as well as quality assessment with the Quality Assessment of Diagnostic Accuracy (QUADAS‐2) tool. Eight studies were found to meet the criteria and were included in our review and analysis. Overall, the quality of studies was found to be moderate, with good inter‐rater agreement (K = 0.74). Data analysis showed that lesion‐based assessment in 5 studies with pooled results had a sensitivity and specificity of 94.7% and 99.3%. Assessment with Cohen's Kappa coefficient showed agreement to be excellent (K = 0.88). Three studies were included for qualitative analysis, two of which showed good equivalence between PET/CT and DW‐MRI. WB‐DWI‐MRI can be considered a sensitive and specific method for assessing treatment response in Lymphoma without the use of ionising radiation or administration of F‐18 Flurodeoxyglucose. Further studies are needed to evaluate the optimum b‐values in assessing treatment response.     

The role of chemical,physical, or viral exposures and health factors in neurocarcinogenesis: implications for epidemiologic studies of brain tumors

This review highlights some future prospects and implications for epidemiologic research on the etiology of nervous system tumors. It reviews some points regarding physiology of the nervous system, in connection with mechanism of neurocarcinogenesis, and experimental studies in animals. The results of epidemiologic studies are summarized in the light of the biological and experimental observations. The following aspects are particularly emphasized: (i) higher susceptibility of the developing nervous system to neurocarcinogenic agents (in the fetus and after birth); (ii) possible implications of knowledge about mechanisms of neurocarcinogenesis regarding crossing of the blood-brain barrier, activation of oncogenes and inactivation of anti-oncogenes, relationship between chemical structure and neurocarcinogenic action; (iii) necessity of further investigation concerning the occurrence of nitrosoureas and their precursors in the environment, and the potential role of nitroso compounds in the development of human brain tumors; (iv) lack of information about promoting or inhibiting neurocarcinogenic effects, and co-carcinogenesis—among others, interaction between X-irradiation and exposure to neurocarcinogenic nitrosoureas; (v) need for studying the potential neurocarcinogenic risk of polyomaviruses BKV, JCV, and SV40 to humans.Authors are with the Institut National de la Santé et Recherche Médicale, Villejuif, France. Address for correspondence to Dr Cordier, INSERM U170, 16 Avenue Paul Vaillant-Couturier, 94807 Villejuif, France.