直肠癌MRI研究进展

MRI是目前直肠癌诊断、分期的首选影像学方法。在判断肿瘤对邻近器官、结构的浸润程度上具有明显优势,尤其是对有较高复发风险的低位肿瘤。常规MRI尤其是高分辨MRI能够清晰显示直肠相关解剖,结合扩散加权成像(Diffusion weighted imaging,DWI)通过确定肿瘤边界,直肠系膜有无受侵,淋巴结及远处转移情况,可以准确有效的进行术前诊断、分期;DWI有助于鉴别辅助治疗后失活与存活组织、筛选出辅助治疗有效的患者,在评估治疗后疗效、提示患者预后方面发挥重要作用,也为临床制定治疗方案提供依据。同时也发现准确进行淋巴结分期、鉴别复发仍然存在困难,需要在以后进一步探讨,提高评估的准确性。本文就近年来MRI在直肠癌术前评价、术后疗效评估、复发监测及表观弥散系数(Apparent diffusion coefficient,ADC)的应用做一综述。     

3.0 T高分辨磁共振在直肠癌术前T N分期、环周切缘有无累及淋巴结转移的评估价值

摘要 目的：研究3.0 T高分辨磁共振（MRI）在直肠癌术前T N分期、环周切缘有无累及淋巴结转移的评估价值。方法：将我院从2018年1月～2019年12月收治的直肠癌患者120例纳入研究。所有患者均接受3.0 T高分辨MRI检查,以术后病理结果为金标准,分析其对术前T N分期、环周切缘有无累及淋巴结转移的评估价值。结果：直肠癌术前3.0 T高分辨MRI T分期与病理结果一致性较高,检验结果显示Kappa值=0.543,P值=0.000。直肠癌术前3.0 T高分辨MRI N分期与病理结果一致性较高,检验结果显示Kappa值=0.519,P值=0.000。以术后病理结果为金标准,直肠癌术前3.0 T高分辨MRI诊断环周切缘累及的灵敏度、特异度、准确度、阴性预测值、阳性预测值分别为92.50%（37/40）、93.75%（75/80）、93.33%（112/120）、96.15%（75/78）、88.10%（37/42）。直肠癌淋巴结转移者MRI边缘模糊、肠周围脂肪信号不均匀占比较无淋巴结转移者更高,且短径较无淋巴结转移者更长（均P＜0.05）。结论：3.0 T高分辨MRI在直肠癌术前T N分期、环周切缘有无累及淋巴结转移的评估价值较高,具有一定的临床应用价值。     

MRI对直肠癌术前TN分期的评价

为了探讨MRI对直肠癌术前TN分期的评价,本研究选取31例行直肠系膜全切术治疗的直肠癌患者进行研究。患者术前均行MRI扫描,根据肿瘤的浸润肠壁深度、范围和淋巴结转移来确定TN分期,考察直肠系膜筋膜受累情况,并测量低位直肠癌患者肿瘤至肛缘的距离。研究显示,T分期总准确率为74.1%,Kappa值为0.630,N分期正确率为67.7%,κappa值为0.509。MRI判定直肠系膜筋膜受累情况正确率为90.3%,κappa值为0.784。将MRI曲线测得肿瘤下缘与肛缘距离,以及直肠指诊所测得数据进行T检验,两者差异无显著性,无统计学意义(p0.05)。本研究结果显示,MRI可以较准确的预测直肠癌的TN分期,可以为直肠癌术前评估提供重要的临床信息,是一种值得推广的临床检查方法。     

术前CA125、OPN、CXCL8、NLR联合检测对乳腺癌改良根治术患者术后复发转移风险的评估价值

摘要 目的：探讨术前糖类抗原125（CA125）、骨桥蛋白（OPN）、趋化因子配体8（CXCL8）、中性粒细胞与淋巴细胞比值（NLR）联合检测对乳腺癌改良根治术患者术后复发转移风险的评估价值。方法：选取2015年4月-2016年4月期间我院收治的乳腺癌改良根治术患者384例按照术后有无复发转移分为未复发转移组（n=345）和复发转移组（n=39）,对比复发转移组、未复发转移组CA125、OPN、CXCL8、NLR,乳腺癌改良根治术患者术后复发转移的影响因素采用多因素Logistic回归分析。采用受试者工作特征（ROC）曲线来判断CA125、OPN、CXCL8、NLR检测对乳腺癌改良根治术患者术后复发转移风险的评估价值。结果：复发转移组的CA125、OPN、CXCL8、NLR高于未复发转移组,组间对比差异有统计学意义（P<0.05）。乳腺癌改良根治术患者术后复发转移与肿瘤最大直径、临床分期、术前新辅助化疗、人表皮生长因子受体2（HER2）、淋巴结转移、组织学类型、细胞增殖标志抗原（ki-67）、雌激素受体（ER）/孕激素受体（PR）、P53、术后放疗、术后内分泌治疗有关（P<0.05）。多因素Logistic回归分析结果显示：OPN偏高、CXCL8偏高、NLR偏高、肿瘤最大直径≥2 cm、淋巴结转移阳性、ER/PR双阴性、临床分期为III期、术前未接受新辅助化疗是乳腺癌改良根治术患者术后复发转移的危险因素（P<0.05）。术前CA125、OPN、CXCL8、NLR联合检测评估复发转移的曲线下面积（AUC）为0.855均高于各指标单独检测。结论：乳腺癌改良根治术后复发转移与OPN、CXCL8、NLR、肿瘤最大直径、淋巴结转移、ER/PR、临床分期、术前接受新辅助化疗均存在一定联系,临床需据此采取针对性干预措施加以防范。且术前CA125、OPN、CXCL8、NLR联合检测辅助评估术后复发转移的价值较高。     

DCE-MRI联合DWI对直肠癌患者术前T、N分期及系膜淋巴结良恶性的诊断价值

摘要 目的：探讨动态对比增强磁共振(DCE-MRI)联合弥散加权成像（DWI）诊断直肠癌术前T、N分期和系膜淋巴结良恶性的价值。方法：收集2017年2月至2019年10月中国医科大学附属本溪中心医院和中国医科大学附属盛京医院接诊的80例直肠癌患者,均进行常规核磁共振成像（MRI）、DCE-MRI、DWI扫描,获得DCE-MRI、DWI定量参数[转运常数（K ^trans ）、细胞外血管外空间的体积分数（V _e ）、速率常数（K _ep ）、表观扩散系数(ADC)],比较不同T、N分期、不同性质系膜淋巴结DCE-MRI、DWI参数,及其对T、N分期和系膜淋巴结性质的诊断效能。结果：直肠癌癌灶K ^trans 、 K _ep 、V _e 高于正常肠壁,ADC低于正常肠壁（P＜0.05）。TNM分期为T_Ⅲ～Ⅳ期的患者K ^trans 、 K _ep 、V _e 高于T_Ⅰ～Ⅱ期,ADC低于T_Ⅰ～Ⅱ期（P＜0.05）;TNM分期为N₁期的患者K ^trans 、K _ep 、V _e 高于N₀期,ADC低于N₀期（P＜0.05）。联合诊断的灵敏度、特异度、阳性预测值、阴性预测值较高。结论：DCE-MRI联合DWI对直肠癌术前T、N分期、系膜淋巴结性质诊断价值较高。     

新辅助化疗在局部晚期宫颈癌治疗中的疗效观察

目的：探讨新辅助化疗联合手术治疗较传统手术治疗Ib2、IIa2局部晚期宫颈癌的临床疗效。方法：选取2008年6月～2011年12月在黑龙江省哈尔滨医科大学附属第三医院初治宫颈癌患者120例,临床分期为Ib2期、IIa2期,术前均经病理证实为宫颈鳞癌,将其分为两组：研究组（新辅助化疗联合手术治疗组）;对照组（单纯手术治疗组）。研究组给予1～2个疗程的新辅助化疗后评估其化疗疗效,有效者化疗结束后行广泛性子宫切除＋盆腔淋巴结清扫术;对照组直接行手术治疗。结果：新辅助化疗能够使肿瘤体积较化疗前缩小或消失,临床有效率高达81.43%,从而降低了宫颈癌的临床分期,提高手术的切除率,扩大手术适应征,降低术后病理高危因素,同时手术治疗能保留卵巢功能,提高年轻宫颈癌患者生活质量。结论：术前新辅助化疗可以提高手术治疗局部晚期宫颈癌的临床疗效。     

经直肠超声在直肠癌术前分期中的应用及进展

直肠癌治疗手段主要为根治性切除术为主并辅以放化疗治疗;肿瘤侵润的范围、淋巴结及远处转移的有无构成了临床TNM分期并影响着直肠癌的治疗和判断预后。经直肠超声检查术(Transrectal ultrasound,TRUS)可以显示直肠壁各层组织的变化,不仅对肿瘤浸润深度诊断准确性较高,而且提高了术前对肠周淋巴结转移诊断的准确性,对直肠癌术前的TNM分期具有重要的意义,从而指导医师选择最佳的手术方式及是否需要术前放化疗以达到根治直肠癌、提高患者生活质量与延长寿命的目的。     

局限性前列腺癌病理分期比较的临床研究进展

目的：探讨指诊分期和动态增强核磁（DCE—MRI）分期预测局限性前列腺癌病理结果的临床价值。方法：对42例局限性前列腺癌患者术前行经直肠指诊分期及MRI、DCE—MRI分期,并与根治术后的病理结果进行比较,评价临床分期及DCE—MRI分期的临床意义。结果：DCE—MRI分期与病理分期相比总体检测结果相同（0．25〈P〈0．5）,能很好的预测前列腺内肿瘤的病理分期;直肠指诊诊断局限性前列腺癌有较高的敏感性（89．5％）,DCE—MRI则有较高的特异性（79．17％）及准确性（83．33％）。结论：直肠指诊是筛查前列腺癌的重要手段,DCE—MRI则能更好的了解肿瘤的范围及浸润情况,更准确的预测肿瘤的病理分期。     

CT及MRI在直肠癌诊断和分期的应用价值研究

目的:探究在直肠癌的诊断以及分期方面,CT与MRI技术的应用价值。方法:选取我院近年来经过病理检测,确诊为直肠癌的患者160例,随机分为两个实验组,其中一组采取CT成像方法,另一组患者采取MRI成像。并记录在不同的分期中CT及MRI的应用价值。CT诊断包含了常规CT平扫以及CT增强扫描,MRI诊断包括轴位DWI、T2W1冠状位以及矢状位、轴位T1WI、轴位T2WI的图像。结果:在直肠癌的诊断中,CT诊断的T分期与病理性T分期差异不大,其准确率为70.0%。MRI诊断的T分期和病理性T分期差异极小,其准确率为85.0%。CT诊断的N分期与病理性N分期差异不大,准确率为72.5%;MRI诊断的N分期与病理性N分期差异较小,其准确率为87.5%。CT诊断的T分期以及N分期的准确率与MRI诊断的T分期以及N分期的准确率之间差异均存在统计学意义(P0.05)。结论:在直肠癌的术前诊断以及局部分期中,MRI诊断与CT诊断相比,有更高的诊断价值。     

MRI与CT检查对卵巢癌病理分期及复发转移的诊断价值对比研究

摘要 目的：对比磁共振成像（MRI）与计算机断层扫描（CT）检查对卵巢癌病理分期及复发转移的诊断价值。方法：纳入2017年1月～2019年1月于我院接受诊治的卵巢癌患者100例进行研究。所有患者术前均进行MRI与CT检查,并以术后病理组织活检结果为金标准,对比MRI与CT诊断卵巢癌与卵巢癌病理分期的准确率。所有患者均于首次检查6个月后进行复诊,对比MRI与CT诊断卵巢癌复发转移的准确率。结果：MRI诊断卵巢癌的确诊率为94.00%（94/100）,高于CT诊断的81.00%（81/100）;漏诊率为2.00%（2/100）,低于CT诊断的10.00%（10/100）（均P＜0.05）。MRI诊断卵巢癌Ⅰ期、Ⅱ期、Ⅲ期的准确率分别为93.33%（14/15）、95.00%（19/20）、93.33%（28/30）,高于CT诊断的60.00%（9/15）、65.00%（13/20）、73.33%（22/30）（均P＜0.05）。MRI诊断肠管及周围、盆腔淋巴结、腹膜后淋巴结、肝脏等远处侵袭和转移中的准确率分别为100.00%（26/26）、88.89%（24/27）、75.00%（18/24）、95.00%（19/20）,高于CT诊断的76.92%（20/26）、48.15%（13/27）、41.67%（10/24）、45.00%（9/20）（均P＜0.05）。结论：相较于CT检查,MRI检查诊断卵巢癌的准确率更高,漏诊率更低,且在卵巢癌病理分期以及复发转移的诊断准确率更高,具有较好的临床应用价值。     

Efficiency of Non-Contrast-Enhanced Liver Imaging Sequences Added to Initial Rectal MRI in Rectal Cancer Patients

Purpose

The purpose of this study was to estimate the value of addition of liver imaging to initial rectal magnetic resonance imaging (MRI) for detection of liver metastasis and evaluate imaging predictors of a high risk of liver metastasis on rectal MRI.

Methods

We enrolled 144 patients who from October 2010 to May 2013 underwent rectal MRI with T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) (b values = 50, 500, and 900 s/mm²) of the liver and abdominopelvic computed tomography (APCT) for the initial staging of rectal cancer. Two reviewers scored the possibility of liver metastasis on different sets of liver images (T2WI, DWI, and combined T2WI and DWI) and APCT and reached a conclusion by consensus for different analytic results. Imaging features from rectal MRI were also analyzed. The diagnostic performances of CT and an additional liver scan to detect liver metastasis were compared. Multivariate logistic regression to determine independent predictors of liver metastasis among rectal MRI features and tumor markers was performed. This retrospective study was approved by the Institutional Review Board, and the requirement for informed consent was waived.

Results

All sets of liver images were more effective than APCT for detecting liver metastasis, and DWI was the most effective. Perivascular stranding and anal sphincter invasion were statistically significant for liver metastasis (p = 0.0077 and p = 0.0471), while extramural vascular invasion based on MRI (mrEMVI) was marginally significant (p = 0.0534).

Conclusion

The addition of non-contrast-enhanced liver imaging, particularly DWI, to initial rectal MRI in rectal cancer patients could facilitate detection of liver metastasis without APCT. Perivascular stranding, anal sphincter invasion, and mrEMVI detected on rectal MRI were important imaging predictors of liver metastasis.     

CT联合肿瘤标志物与MRI联合肿瘤标志物对于直肠癌患者术前诊断 的准确率与特异性的研究

目的:探讨CT联合肿瘤标志物与MRI联合肿瘤标志物对于直肠癌患者术前诊断的准确率与特异性,为大肠癌的术前诊断提供一定的理论依据。方法:选取我院在2015年01月至2016年01月间收治的86例直肠癌患者以及64例肠道良性病变患者分别作为观察组I组和观察II组的研究对象,另外选取来我院进行健康体检的80例人员作为对照组研究,分别分析CT联合肿瘤标志物与MRI联合肿瘤标志物(CEA、CA125、CA199、CA242、CA724)对大肠癌患者诊断的准确率与特异性之间的差别。结果:观察I组肿瘤标志物水平要明显高于观察II组和对照组,差异显著,具有统计学意义;肿瘤标志物CEA、CA125、CA199、CA242、CA724对大肠癌患者检测的阳性率分别为67.44%(58/86)、26.74%(23/86)、84.88%(73/86)、72.09%(62/86)、33.72%(29/86),肿瘤标志物并联检测对大肠癌的阳性检测率为94.19%(81/86)。CT联合肿瘤标志物对大肠癌的准确率为97.67%(84/86),特异性为94.44%(136/144);MRI联合肿瘤标志物对大肠癌的阳性检测率为100.00%(86/86),特异性为98.61%(142/144)。结论:CT联合肿瘤标志物对大肠癌诊断的准确率与特异性均不如MRI联合肿瘤标志物,因此MRI联合肿瘤标志物可作为大肠癌除病理学鉴定外最佳的诊断方式。     

MR Molecular Imaging of Prostate Cancer with a Small Molecular CLT1 Peptide Targeted Contrast Agent

Tumor extracellular matrix has abundance of cancer related proteins that can be used as biomarkers for cancer molecular imaging. In this work, we demonstrated effective MR cancer molecular imaging with a small molecular peptide targeted Gd-DOTA monoamide complex as a targeted MRI contrast agent specific to clotted plasma proteins in tumor stroma. We performed the experiment of evaluating the effectiveness of the agent for non-invasive detection of prostate tumor with MRI in a mouse orthotopic PC-3 prostate cancer model. The targeted contrast agent was effective to produce significant tumor contrast enhancement at a low dose of 0.03 mmol Gd/kg. The peptide targeted MRI contrast agent is promising for MR molecular imaging of prostate tumor.     

Prediction of Nodal Involvement in Primary Rectal Carcinoma without Invasion to Pelvic Structures: Accuracy of Preoperative CT,MR, and DWIBS Assessments Relative to Histopathologic Findings

Objective

To investigate the accuracy of preoperative computed tomography (CT), magnetic resonance (MR) imaging and diffusion-weighted imaging with background body signal suppression (DWIBS) in the prediction of nodal involvement in primary rectal carcinoma patients in the absence of tumor invasion into pelvic structures.

Methods and Materials

Fifty-two subjects with primary rectal cancer were preoperatively assessed by CT and MRI at 1.5 T with a phased-array coil. Preoperative lymph node staging with imaging modalities (CT, MRI, and DWIBS) were compared with the final histological findings.

Results

The accuracy of CT, MRI, and DWIBS were 57.7%, 63.5%, and 40.4%. The accuracy of DWIBS with higher sensitivity and negative predictive value for evaluating primary rectal cancer patients was lower than that of CT and MRI. Nodal staging agreement between imaging and pathology was fairly strong for CT and MRI (Kappa value = 0.331 and 0.348, P<0.01) but was relatively weaker for DWIBS (Kappa value = 0.174, P<0.05). The accuracy was 57.7% and 59.6%, respectively, for CT and MRI when the lymph node border information was used as the criteria, and was 57.7% and 61.5%, respectively, for enhanced CT and MRI when the lymph node enhancement pattern was used as the criteria.

Conclusion

MRI is more accurate than CT in predicting nodal involvement in primary rectal carcinoma patients in the absence of tumor invasion into pelvic structures. DWIBS has a great diagnostic value in differentiating small malignant from benign lymph nodes.     

Primed Infusion with Delayed Equilibrium of Gd.DTPA for Enhanced Imaging of Small Pulmonary Metastases

Objectives

To use primed infusions of the magnetic resonance imaging (MRI) contrast agent Gd.DTPA (Magnevist), to achieve an equilibrium between blood and tissue (eqMRI). This may increase tumor Gd concentrations as a novel cancer imaging methodology for the enhancement of small tumor nodules within the low signal-to-noise background of the lung.

Methods

A primed infusion with a delay before equilibrium (eqMRI) of the Gd(III) chelator Gd.DTPA, via the intraperitoneal route, was used to evaluate gadolinium tumor enhancement as a function of a bolus injection, which is applied routinely in the clinic, compared to gadolinium maintained at equilibrium. A double gated (respiration and cardiac) spin-echo sequence at 9.4T was used to evaluate whole lungs pre contrast and then at 15 (representative of bolus enhancement), 25 and 35 minutes (representative of eqMRI). This was carried out in two lung metastasis models representative of high and low tumor cell seeding. Lungs containing discrete tumor nodes where inflation fixed and taken for haematoxylin and eosin staining as well as CD34 staining for correlation to MRI.

Results

We demonstrate that sustained Gd enhancement, afforded by Gd equilibrium, increases the detection of pulmonary metastases compared to bolus enhancement and those tumors which enhance at equilibrium are sub-millimetre in size (<0.7 mm²) with a similar morphology to early bronchoalveolar cell carcinomas.

Conclusion

As Gd-chelates are routinely used in the clinic for detecting tumors by MRI, this methodology is readily transferable to the clinic and advances MRI as a methodology for the detection of small pulmonary tumors.     

Development of a Clinically-Precise Mouse Model of Rectal Cancer

Currently-used rodent tumor models, including transgenic tumor models, or subcutaneously growing tumors in mice, do not sufficiently represent clinical cancer. We report here development of methods to obtain a highly clinically-accurate rectal cancer model. This model was established by intrarectal transplantation of mouse rectal cancer cells, stably expressing green fluorescent protein (GFP), followed by disrupting the epithelial cell layer of the rectal mucosa by instilling an acetic acid solution. Early-stage tumor was detected in the rectal mucosa by 6 days after transplantation. The tumor then became invasive into the submucosal tissue. The tumor incidence was 100% and mean volume (±SD) was 1232.4 ± 994.7 mm³ at 4 weeks after transplantation detected by fluorescence imaging. Spontaneous lymph node metastasis and lung metastasis were also found approximately 4 weeks after transplantation in over 90% of mice. This rectal tumor model precisely mimics the natural history of rectal cancer and can be used to study early tumor development, metastasis, and discovery and evaluation of novel therapeutics for this treatment-resistant disease.     

Noninvasive magnetic resonance imaging of the development of individual colon cancer tumors in rat liver

Monitoring tumor development is essential for the understanding of mechanisms involved in tumor progression and to determine efficacy of therapy. One of the evolving approaches is longitudinal noninvasive magnetic resonance imaging (MRI) of tumors in experimental models. We applied high-resolution MRI at 7 Tesla to study the development of colon cancer tumors in rat liver. MRI acquisition was triggered to the respiratory cycle to minimize motion artifacts. A special radio frequency (RF) coil was designed to acquire detailed T1-weighted and T2-weighted images of the liver. T2-weighted images identified hyperintense lesions representing tumors with a minimum diameter of 2 mm, enabling the determination of growth rates and morphological aspects of individual tumors. It is concluded that high-resolution MRI using a dedicated RF coil and triggering to the respiratory cycle is an excellent tool for quantitative and morphological analysis of individual diffusely distributed tumors throughout the liver. However, at present, MRI requires expensive equipment and expertise and is a time-consuming methodology. Therefore, it should preferably be used for dedicated applications rather than for high-throughput assessment of total tumor load in animals.     

In vivo imaging of siRNA delivery and silencing in tumors

With the increased potential of RNA interference (RNAi) as a therapeutic strategy, new noninvasive methods for detection of siRNA delivery and silencing are urgently needed. Here we describe the development of dual-purpose probes for in vivo transfer of siRNA and the simultaneous imaging of its accumulation in tumors by high-resolution magnetic resonance imaging (MRI) and near-infrared in vivo optical imaging (NIRF). These probes consisted of magnetic nanoparticles labeled with a near-infrared dye and covalently linked to siRNA molecules specific for model or therapeutic targets. Additionally, these nanoparticles were modified with a membrane translocation peptide for intracellular delivery. We show the feasibility of in vivo tracking of tumor uptake of these probes by MRI and optical imaging in two separate tumor models. We also used proof-of-principle optical imaging to corroborate the efficiency of the silencing process. These studies represent the first step toward the advancement of siRNA delivery and imaging strategies, essential for cancer therapeutic product development and optimization.     

Long-term follow-up of patients treated with radical surgery for rectal cancer

In developed societies colorectal cancer (CRC) is the second most frequent malignant tumor which causes more than 5000 deaths yearly in Hungary. We have attempted to answer the question how to improve the above mentioned data by the long-term follow-up of patients operated upon for rectal cancer at our department. Of the patients operated on for rectal cancer at our department between March 1990 and April 2006, we have conducted regular follow-up of 297 patients according to a protocol developed by us. We have examined the length of time between the rectum operation and the diagnosis and the number of local recurrences, distant metastases, tumor progression in more than one organ as well as second tumors (independent of the rectal cancer). During this period we found 24 local recurrences, 32 distant metastases, 43 tumor progressions in more than one organ, and 21 second tumors. In two patients, in addition to distant metastases, we found a second CRC independent of the original rectal cancer, and in one patient with tumor progression in more than one organ we also detected breast cancer. In one patient we found 3 second tumors (CR, lung and urinary bladder) independent of the original rectal cancer. Altogether we found tumors in 117 out of 297 patients. During the same period, we performed 69/117 operations and 31/117 patients were alive at the end of our study with a median survival of 60.4 (3-184) months. In summary, we can state that this work is beneficial for curing the recurrence of rectal cancer, making the patients' life longer or making the quality of life better for the patients operated on for rectal cancer.