Is endoscopic ultrasonography still the modality of choice in preoperative staging of gastric cancer?

The treatment option for gastric cancer is usually based on preoperative staging by imaging modalities. Endoscopic ultrasonography (EUS) and computed tomography (CT) have been used as the diagnostic modality of choice in preoperative staging of gastric cancer. Magnetic resonance imaging (MRI) has been employed in several studies, and (¹⁸F) 2-Fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) has emerged as a new promising imaging modality. The purpose of this article is to provide summarized information on preoperative staging using EUS, multi-detector row CT (MDCT), MRI and PET for gastric cancer. In T staging, both EUS and MDCT show high accuracy. MRI seemed to have better performance, but the number of MRI studies is limited. FDG-PET is not able to properly evaluate the depth of invasion. In N staging, the diagnostic accuracy of EUS, MDCT and MRI is not sufficient. In preoperative M staging, MDCT and FDG-PET showed similar diagnostic accuracies. FDG-PET/CT fusion could be expected to show better performance in the future. Physicians should keep in mind that each diagnostic modality has advantages and limitations and choose an appropriate diagnostic strategy tailored for each patient.     

The Value of Restaging With Chest and Abdominal CT/MRI Scan After Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer

Little was known with regard to the value of preoperative systemic restaging for patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (CRT). This study was designed to evaluate the role of chest and abdominal computed tomography (CT) scan or magnetic resonance imaging (MRI) on preoperative restaging in LARC after neoadjuvant CRT and to assess the impact on treatment strategy.Between January 2007 and April 2013, 386 newly diagnosed consecutive patients with LARC who underwent neoadjuvant CRT and received restaging with chest and abdominal CT/MRI scan were included. Imaging results before and after CRT were analyzed.Twelve patients (3.1%) (6 liver lesions, 2 peritoneal lesions, 2 distant lymph node lesions, 1 lung lesions, 1 liver and lung lesions) were diagnosed as suspicious metastases on the restaging scan after radiotherapy. Seven patients (1.8%) were confirmed as metastases by pathology or long-term follow-up. The treatment strategy was changed in 5 of the 12 patients as a result of restaging CT/MRI findings. Another 10 patients (2.6%) who present with normal restaging imaging findings were diagnosed as metastases intra-operatively. The sensitivity, specificity accuracy, negative predictive value, and positive predictive values of restaging CT/MRI was 41.4%, 98.6%, 58.3%, and 97.3%, respectively.The low incidence of metastases and minimal consequences for the treatment plan question the clinical value of routine restaging of chest and abdomen after neoadjuvant CRT. Based on this study, a routine restaging CT/MRI of chest and abdomen in patients with rectal cancer after neoadjuvant CRT is not advocated, carcino-embryonic antigen (CEA) -guided CT/MRI restaging might be an alternative.     

Preoperative evaluation of colorectal cancer using CT colonography,MRI, and PET/CT

Imaging studies are a major component in the evaluation of patients for the screening,staging and surveillance of colorectal cancer.This review presents commonly encountered findings in the diagnosis and staging of patients with colorectal cancer using computed tomography(CT)colonography,magnetic resonance imaging(MRI),and positron emission tomography(PET)/CT colonography.CT colonography provides important information for the preoperative assessment of T staging.Wall deformities are associated with muscular or subserosal invasion.Lymph node metastases from colorectal cancer often present with calcifications.CT is superior to detect calcified metastases.Three-dimensional CT to image the vascular anatomy facilitates laparoscopic surgery.T staging of rectal cancer by MRI is an established modality because MRI can diagnose rectal wall laminar structure.N staging in patients with colorectal cancer is still challenging using any imaging modality.MRI is more accurate than CT for the evaluation of liver metastases.PET/CT colonography isvaluable in the evaluation of extra-colonic and hepatic disease.PET/CT colonography is useful for obstructing colorectal cancers that cannot be traversed colonoscopically.PET/CT colonography is able to localize synchronous colon cancers proximal to the obstruction precisely.However,there is no definite evidence to support the routine clinical use of PET/CT colonography.     

The role and clinical value of EUS in a multimodality esophageal carcinoma staging program with CT and positron emission tomography

BACKGROUND: EUS, CT, and positron emission tomography (PET) have all been used in the preoperative staging of esophageal cancer separately or in various combinations. OBJECTIVE: Our purpose was to determine the value and role of EUS when used in conjunction with CT and PET imaging in staging cancer of the esophagus and gastroesophageal junction. DESIGN: Retrospective single-center clinical trial. SETTING: Academic tertiary care center. PATIENTS: Data were examined for 56 patients who concomitantly underwent examination with EUS, CT, and PET in a multimodality staging program. MAIN OUTCOME MEASUREMENTS: EUS, CT, and PET were examined for their ability to detect the primary tumor, local tumor stage, locoregional adenopathy, and distant metastases. With use of surgical resection as baseline therapy, the frequency at which EUS, CT, and PET affected and changed management was examined. RESULTS: EUS is the only imaging test that identified all primary tumors and provided tumor staging. EUS identified a significantly greater number of patients (58.9%) with locoregional nodes than did CT (26.8%), P = .0006, or PET (37.5%), P = .02. CT identified 14.3% and PET identified 26.8% of patients with distant metastases. With CT alone, 15.2% of patients were not taken to surgery, whereas PET affected management by preventing surgery because of metastatic disease in 28.3% of patients. EUS changed management by guiding the need for neoadjuvant therapy in 34.8% of patients. LIMITATIONS: Retrospective study, nonblinded study, lack of pathologic reference standard. CONCLUSION: The primary strength of EUS in a multimodality staging strategy is in identifying patients with locally advanced disease and guiding the need for preoperative neoadjuvant therapy. EUS is not suited to determine resectability of esophageal cancer alone and thus is most effective when used in conjunction with other imaging tests such as CT and PET.     

Cost-effectiveness of endoscopic ultrasonography in the evaluation of proximal rectal cancer

OBJECTIVE: Clinical trials demonstrate the superiority of preoperative over postoperative radiotherapy (XRT) in diminishing rates of local recurrence of transmurally infiltrating (T3/4) rectal tumors. The dosage and cost of preoperative XRT are less than postoperative XRT. The economic and health impact of transrectal endoscopic ultrasound (EUS) on rectal cancer management has not been described. The aim of this study was to apply a decision analysis model to compare the cost-effectiveness of three staging strategies in the evaluation of nonmetastatic proximal rectal cancer: abdominal and pelvic CT versus abdominal CT plus EUS versus abdominal CT plus pelvic magnetic resonance imaging. METHODS: A decision model was designed using DATA Version 3.5 (TreeAge Software, Williamstown, MA), taking as entry criteria nonmetastatic proximal rectal cancer as determined by abdominal CT. In each arm, detection of transmural invasion prompted preoperative XRT. Baseline probabilities were varied through plausible ranges using sensitivity analysis. Cost inputs were based on Medicare professional plus facility fees. Endpoints were cost of treatment per patient and tumor recurrence-free rates. Cost-effectiveness (cost per prevention of local recurrence) and incremental cost-effectiveness ratios were calculated. RESULTS: For proximal rectal tumors, evaluation with abdominal CT plus EUS is the most cost-effective approach ($24,468/yr) compared with abdominal CT plus pelvic magnetic resonance imaging ($24,870) and CT alone ($26,076). Both the magnetic resonance imaging- and CT-only approaches were dominated (i.e., more costly and less effective). CONCLUSIONS: Abdominal CT plus EUS is the most cost-effective staging strategy for nonmetastatic proximal rectal cancer. Staging strategies incorporating EUS improve treatment allocation by achieving more accurate T staging, thereby optimizing the benefit of preoperative XRT to more advanced tumors.     

Comparative study between endoscopic ultrasonography and positron emission tomography‐computed tomography in staging patients with esophageal squamous cell carcinoma

Treatment strategy of esophageal cancer mainly depends on accurate staging. At present, no single ideal staging modality is superior to another in preoperative tumor‐node‐metastasis (TNM) staging of patients with esophageal cancer. We aimed to investigate the efficacy of endoscopic ultrasonography (EUS) and positron emission tomography‐computed tomography (PET‐CT) for staging of esophageal cancer. We retrospectively studied 118 consecutive patients with esophageal squamous cell carcinoma who underwent esophagectomy with or without neoadjuvant chemoradiotherapy (CRT) over a near 3‐year period between January 2005 and November 2008 at a tertiary hospital in Taiwan. Patients were separated into two groups: without neoadjuvant CRT (group 1, n= 28) and with CRT (group 2, n= 90). Medical records of demographic data and reports of EUS and PET‐CT of patients before surgery were reviewed. A database of clinical staging by EUS and PET‐CT was compared with one of pathological staging. The accuracies of T staging by EUS in groups 1 and 2 were 85.2% and 34.9%. The accuracies of N staging by EUS in groups 1 and 2 were 55.6% and 39.8%. The accuracies of T and N staging by means of PET‐CT scan were 100% and 54.5% in group 1, and were 69.4% and 86.1% in group 2, respectively. In group 2, 38 of 90 patients (42.2%) achieved pathologic complete remission. Among them, two of 34 (5.9%) and 12 of 17 (70.6%) patients were identified as tumor‐free by post‐CRT EUS and PET‐CT, respectively. EUS is useful for initial staging of esophageal cancer. PET‐CT is a more reliable modality for monitoring treatment response and restaging. Furthermore, the accuracy of PET‐CT with regard to N staging is higher in patients who have undergone CRT than those who have not.     

A prospective,blinded assessment of the impact of preoperative staging on the management of rectal cancer

BACKGROUND & AIMS: The influence of preoperative staging of rectal carcinoma on therapeutic decisions is uncertain. The use of fine-needle aspiration (FNA) of perirectal nodes in this setting has not been evaluated. The aim of this prospective, blinded study of patients with rectal cancer was to assess the impact of preoperative staging on treatment decisions and compare the tumor (T), nodal (N) staging performance characteristics of pelvic computed tomography (CT), rectal endoscopic ultrasonography (EUS), and EUS FNA. METHODS: Eighty consecutive patients with newly diagnosed rectal cancer were prospectively evaluated. Therapy decisions were recorded after sequential disclosure of staging information to the patient's surgeon. RESULTS: In 31% of patients (95% confidence interval, 21%-42%), EUS staging information changed the surgeon's original treatment plan based on CT alone. The further addition of FNA changed therapy in one patient. T staging accuracy was 71% (CT) and 91% (EUS) (P = 0.02); N staging accuracy was 76% (CT), 82% (EUS), and 76% (EUS FNA) (P = NS). CONCLUSIONS: Preoperative staging with EUS results in more frequent use of preoperative neoadjuvant therapy than if staging was performed with CT alone. The addition of FNA only changed the management of one patient, whereas FNA did not significantly improve N staging accuracy over EUS alone. FNA seems to offer the most potential for impacting management in those patients with early T stage disease, and its use should be confined to this subgroup of patients. EUS is more accurate than CT for determining T stage of rectal carcinoma.     

Endoscopic ultrasonography of neuroendocrine tumours

Neuroendocrine tumours (NETs) of the upper gastrointestinal tract are mainly located in the pancreas, stomach or duodenum. The aims of preoperative work-up are the localization of primary tumour(s), determination of local tumour invasion, of lymph node metastases and of the hormones secreted by the tumour. Endoscopic ultrasonography (EUS) offers ideal conditions to localize and stage NETs of the foregut. We report our results in localizing and staging NETs of the foregut in 40 patients examined between 1990 and 1997 by EUS, somatostatin receptor scintigraphy (SRS), computed tomography (CT), magnetic resonance imaging (MRI) and transabdominal ultrasound (US). EUS shows the highest sensitivity in localizing insulinomas compared with SRS, US, CT and MRI. US and EUS should be the first-line diagnostics if insulinoma has been proven by a fasting test. Further diagnostic procedures are unnecessary in most cases. Further diagnostics such as CT or MRI to search for distant metastases are necessary in large tumours or local invasive tumours. EUS shows the highest accuracy to detect or exclude pancreatic gastrinomas, but fails to detect extrapancreatic gastrinomas in about 50%. The combination of EUS and SRS gives additional information. First-line diagnostics in gastrinoma patients should be SRS and CT or MRI. If no metastases are detected, EUS should be the next preoperative imaging procedure. In nonfunctional NETs, EUS provides the best information on local tumor invasion and regional lymph node involvement.     

Role of endoscopic ultrasonography in the loco-regional staging of patients with rectal cancer

The prognosis of rectal cancer (RC) is strictly related to both T and N stage of the disease at the time of diagnosis. RC staging is crucial for choosing the best multimodal therapy: patients with high risk locally advanced RC (LARC) undergo surgery after neoadjuvant chemotherapy and radiotherapy (NAT); those with low risk LARC are operated on after a preoperative short-course radiation therapy; finally, surgery alone is recommended only for early RC. Several imaging methods are used for staging patients with RC: computerized tomography, magnetic resonance imaging, positron emission tomography, and endoscopic ultrasound (EUS). EUS is highly accurate for the loco-regional staging of RC, since it is capable to evaluate precisely the mural infiltration of the tumor (T), especially in early RC. On the other hand, EUS is less accurate in restaging RC after NAT and before surgery. Finally, EUS is indicated for follow-up of patients operated on for RC, where there is a need for the surveillance of the anastomosis. The aim of this review is to highlight the impact of EUS on the management of patients with RC, evaluating its role in both preoperative staging and follow-up of patients after surgery.     

Preoperative staging and tumor resectability assessment of pancreatic cancer: prospective study comparing endoscopic ultrasonography, helical computed tomography, magnetic resonance imaging, and angiography

OBJECTIVES: The objective of this study was to evaluate prospectively the efficacy of different strategies based on endoscopic ultrasonography (EUS), helical computed tomography (CT), magnetic resonance imaging (MRI), and angiography (A) in the staging and tumor resectability assessment of pancreatic cancer. METHODS: All consecutive patients with pancreatic carcinoma judged fit for laparotomy were studied by EUS, CT, MRI, and A. Results of each of the imaging techniques regarding primary tumor, locoregional extension, lymph-node involvement, vascular invasion, distant metastases, tumor TNM stage, and tumor resectability were compared with the surgical findings. Univariate, logistic regression, decision, and cost minimization analyses were performed. RESULTS: Sixty-two patients with pancreatic cancer were included. Helical CT had the highest accuracy in assessing extent of primary tumor (73%), locoregional extension (74%), vascular invasion (83%), distant metastases (88%), tumor TNM stage (46%), and tumor resectability (83%), whereas EUS had the highest accuracy in assessing tumor size (r = 0.85) and lymph node involvement (65%). The decision analysis demonstrated that the best strategy to assess tumor resectability was based on CT or EUS as initial test, followed by the alternative technique in those potentially resectable cases. Cost minimization analysis favored the sequential strategy in which EUS was used as a confirmatory technique in those patients in whom helical CT suggested resectability of the tumor. CONCLUSIONS: Helical CT and EUS are the most useful individual imaging techniques in the staging of pancreatic cancer. In those cases with potentially resectable tumors a sequential approach consisting of helical CT as an initial test and EUS as a confirmatory technique seems to be the most reliable and cost minimization strategy.     

Assessment of clinical impact of endoscopic ultrasound on rectal cancer

INTRODUCTION: Endoscopic ultrasound (EUS) with fine needle aspiration (FNA) is the most accurate imaging modality for locoregional staging of rectal cancer. It remains unclear whether this technology impacts the clinical outcome of patients with this malignancy. The aim of this study was to assess the impact of EUS FNA by comparing the clinical outcomes of patients with rectal cancer before and after the introduction of EUS in our institution. METHODS: Outcomes of patients with de novo nonmetastatic rectal cancer seen in 1999 without EUS evaluation (non-EUS control group) were compared to patients evaluated in 2000/2001 with EUS FNA (EUS group). RESULTS: Outcomes of 68 (non-EUS control group) and 73 (EUS group) patients with nonmetastatic rectal cancer were compared. Among patients with advanced T or N stage, adjuvant therapy was administered to 45 patients (84.9%; preoperative to 31 (58.5%) patients and postoperative to 14 (26.4%)) in the EUS group; adjuvant therapy was administered to 37 patients (78.7%; preoperative to 7 (14.9%) patients and postoperative to 30 (63.8%)) in the non-EUS group. Cox proportional hazards demonstrated EUS FNA to be associated with reduced tumor recurrence risk, hazard ratio, 0.72 (95% CI: 0.52-0.97, p= 0.03). CONCLUSIONS: EUS staging of rectal cancer appears to facilitate appropriate employment of preoperative neoadjuvant therapy in those patients with advanced disease. EUS use is associated with a recurrence-free survival advantage in patients, supporting its routine use in rectal cancer staging.     

Multimodality imaging of pancreatic ductal adenocarcinoma: a review of the literature

Background

Accurate pre-operative imaging in pancreatic cancer helps avoid unsuccessful surgical explorations and forewarns surgeons regarding aberrant anatomy. This review aimed to determine the role of current imaging modalities in the diagnosis and determination of resectability of pancreatic and peri-ampullary adenocarcinomas.

Methods

A systematic search of the scientific literature was carried out using EMBASE, PubMed/MEDLINE and the Cochrane Central Register of Controlled Trials for the years 1990 to 2011 to obtain access to all publications, especially randomized controlled trials, reporting on the diagnostic accuracy of ultrasonography, multi-detector computed tomography (MDCT), magnetic resonance imaging (MRI), endoscopic ultrasonography (EUS) or positron emission tomography (PET)-computed tomography (CT) and the evaluation of resectability of pancreatic and peri-ampullary adenocarcinomas.

Results

Based on 66 articles analysed in the review, MDCT and MRI/MRCP have comparable sensitivity and specificity rates for diagnosis and staging of pancreatic cancers. EUS offers the best sensitivity and specificity rates for lesions <2 cm. Improved staging has been noted when PET-CT scans are added to pre-operative evaluation.

Conclusions

MDCT with angiography or MRI/MRCP should constitute the first imaging modality in suspected pancreatic adenocarcinomas. EUS is recommended for assessing lesions not clearly detected, but suspected, on CT/MRI and in tumours considered ‘borderline resectable’ on MDCT to assess vascular involvement. PET-CT in locally advanced lesions will help rule out distant metastases.     

Comparison of preoperative TN staging of gastric carcinoma by endoscopic ultrasonography with CT examination

ＣｏｍｐａｒｉｓｏｎｏｆｐｒｅｏｐｅｒａｔｉｖｅＴＮｓｔａｇｉｎｇｏｆｇａｓｔｒｉｃｃａｒｃｉｎｏｍａｂｙｅｎｄｏｓｃｏｐｉｃｕｌｔｒａｓｏｎｏｇｒａｐｈｙｗｉｔｈＣＴｅｘａｍｉｎａｔｉｏｎＧＵＯＷｅｎ１,ＺＨＡＮＧＹａＬｉ１,ＬＩＧｕｏＸｉｎ...     

Preoperative staging of rectal cancer

With the widespread introduction of preoperative radiotherapy for rectal cancer and the development of transanal endoscopic microsurgery for selected early lesions, preoperative radiological staging of these tumours has taken on increasing importance. This study is a systematic review to evaluate computed tomography (CT), endorectal sonography (ES) and magnetic resonance imaging (MRI) as preoperative staging modalities in rectal cancer. A Medline-based search identifying studies using CT, ES, or MRI in preoperative staging of rectal cancer between 1980 and 1998 was undertaken. The list of papers was supplemented by extensive cross-checking of citation lists. Studies were included if they met predetermined criteria. Data from the accepted studies were entered into pooled tables comparing radiological and pathological staging results for each modality both in determining bowel wall penetration and involvement of lymph nodes. Accuracy, sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio were determined for the pooled results. Eighty-three studies from 78 papers including 4897 patients met the inclusion criteria. In determining the wall penetration of the tumour the values for sensitivity for CT, ES, MRI and MRI with endorectal coil were 78%, 93%, 86% and 89%; for specificity 63%, 78%, 77% and 79%; and for accuracy 73%, 87%, 82% and 84%, respectively. In determining the nodal involvement by tumour the sensitivity values for CT, ES, MRI and MRI with endorectal coil 52%, 71%, 65% and 82%; for specificity 78%, 76%, 80% and 83%; and for accuracy 66%, 74%, 74% and 82%, respectively. MRI with an endorectal coil is the single investigation that most accurately predicts pathological stage in rectal cancer. Accepted: 14 October 1999     

微探头联合环扫内镜超声对直肠癌术前分期的价值

目的 评价微探头超声联合环扫内镜超声检查对直肠癌术前分期的特异性、敏感性和准确性以及判断其对直肠癌治疗方案选择的价值.方法 对2007年8月-2008年8月60例术前直肠癌患者行微探头和环扫超声内镜联合探查.参照TNM分期标准进行分期诊断,并与MRI、手术后组织病理学结果对比,总结EUS分期对治疗方案选择的参考价值.结果 在60例直肠癌患者中,EUS分期T1期4例,T2期18例,T3期30例,T4期8例,存在7例分期过度和4例分期不足;MRI分期T1期1例,T2期18例,T3期30例,T4期10例,存在14例分期过度和3例分期不足.微探头超声内镜结合环扫型超声内镜对直肠癌T分期诊断综合准确率为81.67%(49/60),N分期的准确率为78.33%,敏感性和特异性为71.43%和91.03%;MRI对直肠癌T分期准确率为71.67%(43/60),周围淋巴结转移诊断的准确率为83.33%,敏感性和特异性为85.71%和86.96%.结论 微探头联合环扫内镜超声检查是一有效估计直肠癌肠壁浸润深度并对其进行TN分期的方法,且操作简便、痛苦小、诊断准确率较高.     

Preoperative staging of rectal carcinoma by computed tomography and 0.15T magnetic resonance imaging

A prospective study was done on 34 patients using magnetic resonance imaging (MRI) and computed tomography (CT) preoperatively to stage patients with known rectal carcinoma. The study was done to determine the accuracy and clinical usefulness of CT and MRI. The Thoeni staging method was used. Twenty-four of 30 cases were staged correctly by CT. Sixteen of 27 were staged correctly by MRI. CT detected lymph node metastases in six of 15 cases with one false-positive. MRI detected lymph node metastases in two of 15 patients with one false-positive. CT was the preferred examination, and was useful in some cases. These cases included patients with small tumors who were considered for local excision and patients with extensive disease who were candidates for preoperative or intraoperative radiation treatment. MRI demonstrated extensive disease, as did CT in our later cases. Read at the meeting of the American Society of Colon and Rectal Surgeons, San Diego, California, May 5 to 10, 1985.     

EUS compared with CT, magnetic resonance imaging, and angiography and the influence of biliary stenting on staging accuracy of ampullary neoplasms.

BACKGROUND: Computerized tomography (CT), magnetic resonance imaging (MRI), and transabdominal ultrasound frequently fail to detect ampullary lesions. Endoscopic ultrasound (EUS) is a sensitive modality for detecting and staging ampullary tumors. Accurate staging may be affected by biliary stenting, which is frequently performed in these patients with obstructive jaundice. The present study assessed the accuracy of ampullary tumor staging with multiple imaging modalities in patients with and those without endobiliary stents. METHODS: Fifty consecutive patients with ampullary neoplasms from two endosonography centers were preoperatively staged by EUS plus CT (37 patients), MRI (13 patients), or angiography (10 patients) over a 3(1/2) year period. Twenty-five of the 50 patients had a transpapillary endobiliary stent present at the time of endosonographic examination. Accuracy of EUS, CT, MRI, and angiography was assessed with the TNM classification system and compared with surgical-pathologic staging. The influence of an endobiliary stent present at the time of EUS on staging accuracy of EUS was also evaluated. RESULTS: EUS was more accurate than CT and MRI in the overall assessment of the T stage of ampullary neoplasms (EUS 78%, CT 24%, MRI 46%). No significant difference in N stage accuracy was noted between the three imaging modalities (EUS 68%, CT 59%, MRI 77%). EUS T stage accuracy was reduced from 84% to 72% in the presence of a transpapillary endobiliary stent. This was most prominent in the understaging of T2/T3 carcinomas. CONCLUSIONS: EUS is superior to CT and MRI in assessing T stage but not N stage of ampullary lesions. The presence of an endobiliary stent at EUS may result in underestimating the need for a Whipple resection because of tumor understaging.     

Endoscopic ultrasound and magnetic resonance imaging for re-staging rectal cancer after radiotherapy

AIM: To compare the sensitivity and specificity of two imaging techniques, endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI), in patients with rectal cancer after neoadjuvant chemoradiation therapy.And we compared EUS and MRI data with histological findings from surgical specimens.METHODS: Thirty-nine consecutive patients (51.3% Male; mean age: 68.2 ± 8.9 years) with histologically confirmed distal rectal cancer were examined for staging.All patients underwent EUS and MRI imaging beforeand after neoadjuvant chemoradiation therapy.RESULTS: After neoadjuvant chemoradiation, EUS and MRI correctly classified 46% (18/39) and 44% (17/39) of patients, respectively, in line with their histological T stage ( P > 0.05). These proportions were higher for both techniques when nodal involvement was considered:69% (27/39) and 62% (24/39). When patients were sorted into T and N subgroups, the diagnostic accuracy of EUS was better than MRI for patients with T0-T2 (44% vs 33%, P > 0.05) and N0 disease (87% vs 52%, P = 0.013). However, MRI was more accurate than EUS in T and N staging for patients with more advanceddisease after radiotherapy, though these differencesdid not reach statistical significance.CONCLUSION: EUS and MRI are accurate imaging techniques for staging rectal cancer. However, after neoadjuvant RT-CT, the role of both methods in the assessmentof residual rectal tumors remains uncertain.     

Endoscopic ultrasound in non-small cell lung cancer and negative mediastinum on computed tomography

Despite technical advances in staging non-small cell lung cancer (NSCLC), accurate staging remains a challenge. Endoscopic ultrasound is useful in staging NSCLC when lymphadenopathy is present on a computed tomography (CT), but its role in the absence of lymphadenopathy on CT has not been well defined. Therefore, we sought to determine the clinical impact of endoscopic ultrasound (EUS) in staging NSCLC in absence of mediastinal lymphadenopathy on CT. Seventy-six patients with NSCLC with absence of mediastinal lymphadenopathy on CT were enrolled and followed prospectively. EUS-guided fine-needle aspiration was performed on sites that were suspicious for metastases. Surgical pathology after thoracotomy was used as the reference standard for assessing accuracy. Sixty-two (86%) patients underwent surgery, and 10 (13%) did not. EUS precluded surgery in 9 patients (12%) and influenced management in 18 (25%) of all patients in this study. EUS detected malignant mediastinal lymphadenopathy more frequently in patients with lower lobe and hilar cancers combined compared with upper lobe cancers (p = 0.004). EUS played a significant role in identifying patients with unresectable (N3) NSCLC when adenopathy was not present on CT imaging and appears to be more sensitive in detecting lymph node metastases in lower lobe and hilar NSCLC compared with upper lobe NSCLC.     

Preoperative assessment of the circumferential margin in rectal cancer is more informative in treatment planning than the T stage

Preventing local recurrence in rectal cancer means achieving a free circumferential resection margin (CRM) through an optimal combination of surgery, radiotherapy and chemotherapy. This requires a differentiation between primary resectable and locally advanced cancers. The T staging used, while being a powerful marker of prognosis, has two major downsides. First, accuracy of preoperative predictions of the T stage is unacceptably low. Second, a T3 tumor can be either primary resectable or locally advanced. A review of the literature was performed to establish the value of the CRM as the preferred preoperative staging classification, and to establish the feasibility of predicting the CRM using modern day, highresolution imaging techniques. We advocate using the CRM as preoperative staging classification. Magnetic resonance imaging and multislice computed tomography offer an accurate pre-operative prediction of the CRM, and staging by means of predicted CRM offers the ideal combination of accuracy and clinical relevance.