Endoscopic ultrasound in the pre-operative staging of rectal carcinoma

Endoscopic ultrasound-guided-fine-needle aspiration/fine-needle biopsy in diagnosis of mediastinal lymphadenopathy - A boon

Background/Objectives:

Evaluation of mediastinal lymphadenopathy (MLA) is a great diagnostic challenge considering the myriad of causes. In recent years, the role of endoscopic ultrasound (EUS) has been greatly extended in evaluation of MLA due to its safety, reliability, and accuracy. The present study details the role of EUS-guided-fine-needle aspiration/fine-needle biopsy (EUS-FNA/FNB) in MLA of unknown origin.

Methods:

Seventy-two patients (34 men) with MLA of unknown etiology were studied. Mediastinum was evaluated with linear echoendoscope and FNA/FNB was performed with 22-G needle and sent for cytology, histopathological, and mycobacterial growth indicator tube/GeneXpert evaluation. EUS-FNA/FNB diagnosis was based on cytology reporting by pathologists. Patients tolerated the procedure, and insertion of needle into the lesion was always successful without any complications.

Results:

EUS-FNA/FNB established a tissue diagnosis in 66/72 patients in first sitting, while six patients underwent repeat procedure. EUS-FNA diagnoses (after second sitting) were tuberculous lymphadenitis in 45/72 (62.5%), metastatic lymph nodes 12/72 (16.7%), reactive lymphadenopathy 6/72 (8.3%), sarcoidosis 4/72 (5.6%), and lymphoma 2/72 (2.8%), while it was nondiagnostic in 3/72 (4.1%) patients. Final diagnosis was based on combined clinical presentation, EUS-FNA/FNB result and clinicoradiological response to treatment on long-term follow-up of 6 months.

Conclusion:

EUS echo features along with EUS-FNA/FNB can diagnose MLA and surgical biopsy can be avoided.

High diagnostic yield of endoscopic ultrasound-guided fine needle aspiration without an on-site cytopathologist

BACKGROUND

Endoscopic ultrasound (EUS) is a well-established modality in diagnosing and staging of various neoplastic and non-neoplastic lesions. Its accuracy further increases in the presence of an on-site cytopathologist. There is a paucity of data on diagnostic yield of EUS-guided fine needle aspiration cytology (FNAC) without an on-site cytopathologist.

METHODS

Retrospective data were analyzed at SMS Medical College, Jaipur, from January 2014 to October 2015. All patients who underwent EUS-guided FNAC in the Department of Gastroenterology were included. Data related to demography, lesion parameters on EUS, and histology were analyzed.

RESULTS

Two hundred patients (age 46.2±18.6, 144 male) were studied. EUS-FNAC slides from 162 (82%) were considered adequate by cytopathologist for the diagnosis of benign or malignant lesions. Slide preparation adequacy was 100% for mediastinal and renal and suprarenal masses, 87.06% for pancreatic, 73.46% for lymph nodes, and 88.88% for other lesions. Mean number of passes was 1.92±0.82.

CONCLUSIONS

Diagnostic yield of EUS-guided FNAC is high even in the absence of on-site cytopathologist.

Rapid on-site evaluation of EUS-FNA by cytopathologist: an experience of a tertiary hospital

Endoscopic ultrasound-guided-fine-needle aspiration (EUS-FNA) is the preferred modality nowadays for the cytological diagnosis of various mediastinal and gastrointestinal lesions. Onsite cytopathology interpretation is not available in most centers. The objective of this study is to assess whether rapid on-site evaluation (ROSE) by cytopathologist of the tissue samples improves the diagnostic accuracy of EUS-FNA. This study is a retrospective review of all 646 patients undergoing EUS-FNA between January 2009 and October 2012 in our hospital. Patients in group I had cytology slides prepared by an endoscopy nurse. Patients in group II had cytology slides prepared, stained and assessed for adequacy of tissue sampling by a cytopathologist onsite. The adequacy of the samples and the final cytopathological diagnosis (definitely positive, definitely negative, inconclusive, or inadequate) was compared between the two groups. A total of 425 EUS-FNA procedures were performed in 375 patients in group I and 271 EUS-FNA procedures in 271 patients in group II. The mean of needle passes in group I was 3.12 passes per patient and 3.24 passes in group II. The difference in the number of needle passes was not statistically significant (P = 0.30). The final diagnosis was definite in 64.8% in group I compared with 97.7 % in group II (P = 0.001). The percentage of inconclusive and inadequate diagnoses was 5.6% and 29.3%, respectively in group I and 0% and 2.3% in group II (P = 0.001). In conclusion, ROSE by cytopathologist and interpretation significantly improves the diagnostic yield of EUS-FNA.

ACR Appropriateness Criteria pretreatment staging of colorectal cancer

Because virtually all patients with colonic cancer will undergo some form of surgical therapy, the role of preoperative imaging is directed at determining the presence or absence of synchronous carcinomas or adenomas and local or distant metastases. In contrast, preoperative staging for rectal carcinoma has significant therapeutic implications and will direct the use of radiation therapy, surgical excision, or chemotherapy. CT of the chest, abdomen, and pelvis is recommended for the initial evaluation for the preoperative assessment of patients with colorectal carcinoma. Although the overall accuracy of CT varies directly with the stage of colorectal carcinoma, CT can accurately assess the presence of metastatic disease. MRI using endorectal coils can accurately assess the depth of bowel wall penetration of rectal carcinomas. Phased-array coils provide additional information about lymph node involvement. Adding diffusion-weighted imaging to conventional MRI yields better diagnostic accuracy than conventional MRI alone. Transrectal ultrasound can distinguish layers within the rectal wall and provides accurate assessment of the depth of tumor penetration and perirectal spread, and PET and PET/CT have been shown to alter therapy in almost one-third of patients with advanced primary rectal cancer. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Oncologic outcome after preoperative chemoradiotherapy in patients with pathologic T0 (ypT0) rectal cancer

BACKGROUND

Little is known about the oncologic outcomes of patients with ypT0 rectal cancer after preoperative chemoradiotherapy.

OBJECTIVE

To evaluate the clinicopathologic characteristics and oncologic outcomes of patients with ypT0 rectal cancer after preoperative chemoradiotherapy and curative radical surgery.

DESIGN AND SETTINGS

This was a retrospective review of factors influencing outcome of patients treated with preoperative chemoradiotherapy for rectal cancer at a tertiary care university medical center in Seoul, Korea between 2000 and 2008.

PATIENTS

A total of 830 rectal cancer patients underwent surgery after preoperative chemoradiotherapy. Patients were included in the study if they had a pretreatment clinical classification of T3-4 or N+ (or T2N0 and preoperative chemoradiotherapy for sphincter preservation) and if they were classified on pathologic examination as ypT0 after preoperative CRT and curative radical surgery. Patients were classified as.

MAIN OUTCOME MEASURES

Overall survival and disease-free survival were evaluated in relation to ypT0N0 or ypT0N1-2 status and other factors that might influence outcome.

RESULTS

Of 91 patients included in the study, 54 (59.3%) were men; the mean patient age was 55 (SD, 11) years, and mean follow-up duration was 44 (SD, 23) months. Surgical procedures included low anterior resection in 68 patients, abdominoperineal resection in 21, and intersphincteric resection in 2. Mean tumor distance from the anal verge was 4.7 (SD, 1.8) cm. Of the 91 patients, 85 were classified as ypT0N0 and 6 as ypT0N1-2. No patient experienced local recurrence. A total of 11 patients (12.1%) had distant metastases, after a mean 11.1 months, including 7 (8.2%) with ypT0N0 and 4 (66.7%) with ypT0N1-2 tumors. One patient with ypT0N0 and 2 patients with ypT0N1-2 tumors died of metastasis. In patients classified as ypT0N0, the 5-year disease free survival and overall survival rates were 82.3% and 89.2%, respectively. Multivariate analysis showed that ypN1-2 status (p = 0.001) was a significant independent risk factor for recurrence (decreased 5-year disease-free survival), but no factor was associated with 5-year overall survival.

LIMITATIONS

The study is limited by its retrospective nature.

CONCLUSION

Oncologic outcomes in patients with ypT0N0 rectal cancer were excellent. The presence of residual cancer cells in mesorectal lymph nodes represents a risk factor for distant metastasis.

Utility of EUS-guided biopsy of extramural pelvic masses

BACKGROUND

The diagnostic utility of EUS-guided FNA (EUS-FNA) and EUS-guided Trucut biopsy (EUS-TCB) of pelvic masses has not been well described.

OBJECTIVE

To evaluate the utility of EUS in the diagnosis of pelvic masses.

DESIGN

Retrospective cohort study.

SETTING

Single tertiary referral hospital in Indianapolis, Indiana.

PATIENTS

Consecutive patients referred for EUS evaluation of pelvic mass from January 2002 to July 2009. Patients with newly diagnosed rectal cancer or a known/suspected intramural mass were excluded.

INTERVENTIONS

EUS-FNA and/or EUS-TCB.

MAIN OUTCOME MEASUREMENTS

Endosonographic features and cytological and pathological findings were evaluated. The final diagnosis was confirmed by surgical pathology or cytology and clinical follow-up. The sensitivities and specificities of EUS-TCB were calculated in a subset of patients with available surgical pathology.

RESULTS

A total of 69 patients were identified, and 40 with intramural lesions (n = 36) or incomplete follow-up (n = 4) were excluded. The remaining 29 patients (15 men, mean age 58.5 ± 10.8 years) with pelvic masses (mean size 40.8 ± 20.1 mm) were evaluated. EUS-FNA or EUS-TCB helped to make the diagnosis in 25 of 29 patients (86%). Compared with surgical pathology (available in 17 patients), EUS-FNA had a sensitivity of 88% (95% CI, 53%-98%) and specificity of 100% (95% CI, 65%-100%) for malignancy. EUS-TCB alone had a sensitivity of 67% (95% CI, 21%-94%) and specificity of 100% (95% CI, 34%-100%) for malignancy, but the combination of EUS-FNA and EUS-TCB had a sensitivity of 100% (95% CI, 68%-100%) and a specificity of 100% (95% CI, 68%-100%). Complications after EUS-FNA included a pelvic abscess in 2 patients (7%) with a cystic pelvic mass.

LIMITATION

Single-center study.

CONCLUSION

EUS-FNA and EUS-TCB are sensitive for the diagnosis of malignancy in pelvic masses. Sampling of cystic masses in this region is discouraged.

Does a learning curve exist in endorectal two-dimensional ultrasound accuracy?

BACKGROUND

Aim of the study was to assess adequacy of Colorectal Surgical Society of Australia and New Zealand (CSSANZ) endorectal ultrasound (ERUS) training and whether a subsequent learning curve exists.

METHODS

A prospective audit of ERUS for staging rectal cancer by a single surgeon from commencement of consultant practice was performed. Data were recorded in a prospectively maintained database. The audit commenced on completion of CSSANZ training. T- and N-stage were assessed clinically, then by ERUS prior to treatment and finally by histology over 8 years.

RESULTS

The results were compared over three time periods: the first a single year, then two three-year periods. Two hundred and seventy-two patients were examined. Two hundred and thirty-three were assessable for T-stage (13 no tumour excision, 26 long course pre-operative radiotherapy) and 142 for N-stage (74 endoanal excision, 17 proximal mesorectum un-assessable). Overall accuracy was 82% for T-stage and 73% for N-stage. Accuracy for T- and N-staging did not change significantly over the three time periods (T: 82.1, 82.3, 81.6%, P = 0.14; N: 83.3, 67.9, 74.2%, P = 0.31). The utility of ERUS was demonstrated by clinical assessment not being possible in 32% of cases and where the two modalities disagreed was correct 82% of the time.

CONCLUSIONS

Endorectal ultrasound rectal cancer staging is accurate for T-stage. Competency in ERUS can be achieved in the CSSANZ fellowship and accuracy does not improve with further experience. An ERUS accreditation scheme should be established for future trainees.

Does onsite cytotechnology evaluation improve the accuracy of endoscopic ultrasound-guided fine-needle aspiration biopsy?

BACKGROUND

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the preferred modality for the cytological diagnosis of various cancers. Onsite cytopathology interpretation is not available in most centres.

OBJECTIVE

To assess whether the the adequacy of tissue sampling assessed by an onsite cytotechnologist improves the diagnostic accuracy of EUS-FNA.

METHODS

The present study is a retrospective review of all patients undergoing solid mass EUS-FNA between September 2005 and August 2007. Patients in group I (September 2005 to August 2006) had cytology slides prepared by an endoscopy nurse. Patients in group II (September 2006 to August 2007) had cytology slides prepared, stained and assessed for adequacy of tissue sampling by a cytotechnologist in the endoscopy suite. The final cytopathological diagnosis (definitely positive, definitely negative or inconclusive) was compared between the two groups.

RESULTS

A total of 49 EUS-FNA procedures were performed in 47 patients in group I and 60 EUS-FNA procedures in 55 patients in group II. Pancreatic masses were the most common target site in both groups. The total number of needle passes was 105 in group I (mean 2.14 passes per patient; range one to five needle passes) and 158 in group II (mean 2.63 passes per patient; range one to four needle passes). The difference in the number of needle passes was not statistically significant between groups. The final diagnosis was definite in 53% in group I compared with 77% in group II (P=0.01). The percentage of inconclusive diagnoses was 47% in group I and 23% in group II (P=0.001).

CONCLUSION

Onsite cytotechnologist interpretation of adequacy of tissue sampling significantly improves the diagnostic yield of EUS-FNA. This appears to be independent of the total number of needle passes undertaken for tissue sampling.

Accuracy of endoscopic ultrasound to diagnose nodal invasion by rectal cancers: a meta-analysis and systematic review

BACKGROUND

Nodal staging in patients with rectal cancer predicts prognosis and directs therapy. Published data on the accuracy of endoscopic ultrasound (EUS) for diagnosing nodal invasion in patients with rectal cancer has been inconsistent.

AIM

To evaluate the accuracy of EUS in diagnosing nodal metastasis of rectal cancers.

METHOD

Study Selection Criteria: Only EUS studies confirmed by surgical histology were selected. Data Collection and Extraction: Articles were searched in Medline, Pubmed, and CENTRAL.

STATISTICAL METHOD

Pooling was conducted by both fixed-effects model and random-effects model.

RESULTS

The initial search identified 3610 reference articles in which 352 relevant articles were selected and reviewed. Data were extracted from 35 studies (N = 2732) that met the inclusion criteria. Pooled sensitivity of EUS in diagnosing nodal involvement by rectal cancers was 73.2% (95% confidence interval [95% CI] 70.6-75.6). EUS had a pooled specificity of 75.8% (95% CI 73.5-78.0). The positive likelihood ratio of EUS was 2.84 (95% CI 2.16-3.72), and negative likelihood ratio was 0.42 (95% CI 0.33-0.52). All the pooled estimates, calculated by fixed- and random-effect models, were similar. SROC curves showed an area under the curve of 0.79. The P for chi-squared heterogeneity for all the pooled accuracy estimates was >.10.

CONCLUSIONS

EUS is an important and accurate diagnostic tool for evaluating nodal metastasis of rectal cancers. This meta-analysis shows that the sensitivity and specificity of EUS is moderate. Further refinement in EUS technologies and diagnostic criteria are needed to improve the diagnostic accuracy.

How good is endoscopic ultrasound in differentiating various T stages of rectal cancer? Meta-analysis and systematic review

Published data on accuracy of endoscopic ultrasound (EUS) in differentiating T stages of rectal cancers is varied. Study selection criteria were to select only EUS studies confirmed with results of surgical pathology. Articles were searched in Medline and Pubmed. Pooling was conducted by both fixed and random effects models. Initial search identified 3,630 reference articles, of which 42 studies (N = 5,039) met the inclusion criteria and were included in this analysis. The pooled sensitivity and specificity of EUS to determine T1 stage was 87.8% [95% confidence interval (CI) 85.3-90.0%] and 98.3% (95% CI 97.8-98.7%), respectively. For T2 stage, EUS had a pooled sensitivity and specificity of 80.5% (95% CI 77.9-82.9%) and 95.6% (95% CI 94.9-96.3%), respectively. To stage T3 stage, EUS had a pooled sensitivity and specificity of 96.4% (95% CI 95.4-97.2%) and 90.6% (95% CI 89.5-91.7%), respectively. In determining the T4 stage, EUS had a pooled sensitivity of 95.4% (95% CI 92.4-97.5%) and specificity of 98.3% (95% CI 97.8-98.7%). The p value for chi-squared heterogeneity for all the pooled accuracy estimates was > 0.10. We conclude that, as a result of the demonstrated sensitivity and specificity, EUS should be the investigation of choice to T stage rectal cancers. The sensitivity of EUS is higher for advanced disease than for early disease. EUS should be strongly considered for T staging of rectal cancers.

The use of a dedicated rectosigmoidoscope for ultrasound staging of tumours of the upper and middle third of the rectum

OBJECTIVE

Tumours of the upper rectum, and many in the middle third, are not accessible to endorectal ultrasound staging because of the difficulty in reaching all sites of the rectum with a rigid probe. The aim of this prospective study was to assess whether using a dedicated rectosigmoidoscope, endorectal ultrasonography (ERUS) can accurately stage any rectal lesion irrespective of its distance from the anal verge.

METHOD

A total of 173 consecutive patients with a primary rectal tumour were included. A rotating, high multifrequency (5.0-10 MHz) endoprobe was introduced through a dedicated rectosigmoidoscope and advanced above the lesion. A computer allowed for three-dimensional (3D) reconstruction of 2D images. Treatment was selected on the basis of 3D-ERUS findings. ERUS staging was correlated with pathological staging.

RESULTS

The depth of invasion was correctly determined by 3D-ERUS in 78.2% of tumours of the lower rectum, 76.4% of tumours extending between the lower and middle third of the rectum, 80.9% of tumours of the middle third of the rectum, 78.5% of tumours extending between the middle and upper third of the rectum and 78.9% of tumours of the upper rectum. The accuracy for the absence of lymph node metastases was 81.2% for tumours of the lower rectum, 78.5% for tumours extending between the lower and middle third of the rectum, 85.7% for tumours of the middle third of the rectum, 83.3% for tumours extending between the middle and upper third of the rectum and 78.5% for tumours of the upper rectum. Analysis showed that there was no difference between the various tumour sites.

CONCLUSION

Our findings indicate that using a dedicated proctosigmoidoscope, tumours of the upper and middle third of the rectum are equally accessible to ultrasonographic evaluation. The distance of the tumour from the anal verge does not influence the accuracy of examinations considered adequate by the operator.

An in vitro analysis of microbial transmission during EUS-guided FNA and the utility of sterilization agents

BACKGROUND

The risk of infection and potential microbial transmission with EUS-guided FNA (EUS-FNA) of cystic lesions remains unknown.

OBJECTIVE

We developed an in vitro model to study the incidence of transmucosal microbial transmission during EUS-FNA of cystic lesions and to evaluate the in vitro efficacy of bacteriocidal agent washings of mucosa before FNA under experimental conditions.

DESIGN

Conical tubes, 15 mL, filled with aerobic blood culture bottle media were prepared. Then sterile sections of bovine tripe were fastened over the top of the conical tubes in a sterile fashion (conical tube-tripe unit). FNA was performed with 22-gauge FNA needles. A series of 6 experiments were performed. Ten conical tube-tripe units underwent FNA once through the tripe into the blood culture media to ensure sterility. The surface of 10 conical tube-tripe units were inoculated with 50 microL of a 1.5 x 10(8) 1:1 mixture of Escherichia coli (E coli) and Enterococcus sp, and FNA was performed one time into the blood culture media to ensure contamination (controls). The surface of 40 conical tube-tripe units were inoculated with 50 microL of a 1.5 x 10(8) 1:1 mixture of E coli and Enterococcus sp Each of 4 sets of 10 conical tube-tripe units underwent experimental scenarios that consisted of washings with either 1 mL of 0.5% povidone iodine, chlorhexidine, absolute ethanol, or sterile water. FNA was performed once through the tripe into the blood culture media after washing the surface of the tripe. After each conical tube-tripe unit underwent FNA one time, 1 mL blood culture media was obtained and mixed on pour plate agar media and was incubated along with the conical tubes. Microbial evaluation of the conical tubes that contained the blood culture media and pour plates was performed after 48 hours of incubation.

SETTING

Gastroenterology and Microbiology Departments of Scott White Memorial Hospital and Clinic in Temple, Texas.

INTERVENTIONS

EUS-FNA of cystic lesions.

MAIN OUTCOME MEASUREMENTS

Microbial contamination during EUS-FNA of an in vitro cystic environment.

RESULTS

A control without E coli and Enterococcus sp was with 0% contamination. A control group with E coli and Enterococcus sp was with 100% contamination; sterile water washings, 100% contamination (P = 1.00); iodine washings, 20% contamination (P < .001); chlorhexidine washings, 80% contamination (P = .47); and absolute ethanol washings, 90% contamination (P = 1.00). Results were compared with our control group by statistical tests of proportions by using the Fisher exact test.

CONCLUSIONS

EUS-FNA of sterile cystic lesions resulted in transmucosal microbial contamination. However, our model demonstrated that iodine sterilization of a contaminated mucosal surface produced a very highly statistically significant (P < .001) reduction in the transmission of infectious agents into a sterile environment. This in vitro model could translate into clinical practice by providing evidence that microbial transmission by FNA occurred. The utility of povidone iodine washings could alter procedure methods and patient care.

Anorectal ultrasound for neoplastic and inflammatory lesions

Accurate staging of rectal and anal carcinoma is crucial for planning surgery and indicating adjuvant therapy. Although, computed tomography and magnetic resonance imaging are very sensitive in detecting metastatic disease, the local staging of rectal cancer with these techniques has been disappointing. Endorectal ultrasound (ERUS) and anal endosonography (AE) remain the most accurate methods for staging rectal and anal cancer. Anal endosonography is also of value in evaluating perianal sepsis: it can assist the surgeon in planning the surgical strategy by delineating the anatomy of fistula tracts, and can aid in puncturing abscesses in the operating room. Continued research and development has made the instrumentation for ERUS and AE more accurate and user-friendly. New techniques that have contributed significantly to the evolution of ERUS include three-dimensional ERUS, high-frequency miniprobes, transrectal ultrasound-guided biopsy techniques and hydrogen peroxide-enhanced endosonography. Further improvements can be expected from contrast enhancement with microbubbles and colour Doppler imaging. In this new millennium, new developments in ERUS and anal endosonography, such as tri-dimensional ERUS and anal endosonography and radial electronic probing, widen the role of ERUS in the staging of rectal and anal carcinoma, as well as for perianal inflammatory conditions.

Endoscopic ultrasound-guided fine-needle aspiration cytology for diagnosis above and below the diaphragm

Endosonography ultrasound (EUS) is a minimally invasive technology using a high-frequency ultrasound transducer that is incorporated into the tip of a conventional endoscope. This technique permits high-resolution imaging of the gastrointestinal wall and structures in its vicinity, as well as real-time endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA). This is a review of the literature on EUS-guided FNA of the mediastinal and abdominal lymph nodes, the pancreas, intramural gastrointestinal masses, and other miscellaneous organs and body cavities. EUS-guided FNA is a recently developed procedure that has established itself as a safe, highly accurate, and clinically useful modality.

Imaging for Predicting the Risk Factors—the Circumferential Resection Margin and Nodal Disease—of Local Recurrence in Rectal Cancer: A Meta-Analysis

The aim of the present study was to conduct a meta-analysis of English literature on the accuracy of preoperative imaging in predicting the two most important risk factors for local recurrence in rectal cancer, the circumferential resection margin (CRM) and the nodal status (N-status). Articles published between 1985 and August 2004 that report on the diagnostic accuracy of endoluminal ultrasound (EUS), computed tomography (CT), or magnetic resonance imaging (MRI) in the evaluation of lymph node involvement were included. A similar search was done for the assessment of the circumferential resection margin in rectal cancer in the period from January 1985 till January 2005. The inclusion criteria were as follows: (1) more than 20 patients with histologically proven rectal cancer were included, (2) histology was used as the gold standard, and (3) results were given in a 2 x 2 contingency table or this table could otherwise be extracted from the article by two independent readers. Based on the results summary receiver operating characteristic (ROC) curves were constructed. Only 7 articles matching inclusion criteria were found concerning the CRM. The meta-analysis shows that MRI is rather accurate in diagnosing a close or involved CRM. For nodal status 84 articles could be included. The diagnostic odds ratio of EUS is estimated at 8.83. For MRI and CT, the diagnostic odds ratio are 6.53 and 5.86, respectively. The results show that EUS is slightly, but not significantly, better than MRI or CT for identification of nodal disease. There is no significant difference between the different modalities with respect to staging nodal status. At present, MRI is the only modality that predicts the circumferential resection margin with good accuracy, making it a good tool to identify high and low risk patients. Predicting the N-status remains a problem for the radiologist for every modality, although considering the new developments in MR imaging, this may change in the near future.

Endoscopic ultrasound for luminal malignancies

Luminal gastrointestinal (GI) tract cancers are responsible for substantial morbidity and mortality. Since the first pairing of ultrasonography with endoscopy in 1980, technologic advances and the increased availability of trained endosonographers have propelled endoscopic ultrasonography (EUS) to the forefront of luminal GI cancer staging. In this article we discuss the role of EUS for evaluating luminal GI cancers.

Development of a three-dimensional freehand endorectal ultrasound system for use in rectal cancer imaging

The initial study reporting the accuracy of an optically tracked endorectal ultrasound (TERUS) probe for the purpose of improving the staging of rectal cancer is presented here. In this work we describe the need for a more accurate ERUS system and why the incorporation of image guidance makes this goal feasible. A rectal phantom was constructed with five targets placed in positions where tumors normally occur. The locations of these targets were found using two different imaging modalities, CT and ultrasound, and the target registration error (TRE) between these two image sets was calculated. The average TRE of 33 image captures of the five targets using TERUS was 2.1 mm. This is a promising outcome because the desired tumor margins for rectal cancer are on the order of centimeters. These preliminary results support the proof of concept for a TERUS system that should improve ultrasound imaging in rectal cancer.

Assessment of publication bias in the reporting of EUS performance in staging rectal cancer

INTRODUCTION

Endoscopic ultrasound (EUS) has emerged as a promising diagnostic modality for locoregional staging of rectal cancer. However, as with any new technology, publication bias, the selective reporting of studies featuring positive results, may result in overestimation of the capability of EUS. The aim of this study was to systematically assess for publication bias in the reporting of the accuracy of EUS in staging rectal cancer.

METHODS

A MEDLINE search for all published estimates of EUS accuracy in staging rectal cancer between 1985 and 2003 was performed. All retrieved studies were fully published in the English literature. Published studies were analyzed and the following information was abstracted: accuracy of EUS, year of publication, number of subjects studied, impact factor of journal, and type of journal (gastroenterology, surgery, radiology, other).

RESULTS

Two hundred and two abstracts were reviewed; 41 publications met the stated criteria for inclusion. EUS T-staging accuracy was reported in 40 studies while EUS N-staging accuracy was reported in 27 studies. The experience of 4, 118 subjects was reported with an overall mean T-staging accuracy of 85.2% (median, 87.5%) and N-staging accuracy of 75.0% (median, 76.0%). There was a paucity of smaller studies expressing low EUS accuracy rates. Both T-staging and N-staging accuracy rates also declined over time with the lowest rates reported in more recent literature.

CONCLUSION

The performance of EUS in staging rectal cancer may be overestimated in the literature due to publication bias. This inflated estimate of the capability of EUS may lead to unrealistic expectations of this technology.

From Colonic Polyps to Colon Cancer: Pathophysiology, Clinical Presentation, and Diagnosis

Epidemiologists, basic researchers, clinicians, and public health administrators unite! Develop and implement a simple, safe, and effective preventive and screening test for colon cancer. The public will willingly and enthusiastically accept such a test. Many thousands of lives are at stake every year.

The pathophysiology, clinical presentation, and diagnosis of colon cancer and adenomatous polyps

A review of the pathophysiology, clinical presentation, and diagnosis of colon cancer and colonic polyps is important and timely. This field is rapidly changing because of breakthroughs in the molecular basis of carcinogenesis and in the technology for colon cancer detection and treatment. This article reviews colon cancer and colonic polyps, with a focus on recent dramatic advances, to help the pri-mary care physician and internist appropriately refer patients for screening colonoscopy and intelligently evaluate colonoscopic findings to reduce the mortality from this cancer.

Endoscopic ultrasound in the diagnosis, staging, and management of gastrointestinal and adjacent malignancies

Endoscopic ultrasound (EUS) is a superior modality for local staging of gastrointestinal cancer. In interventional endosonography linear array echoendoscopes permit real-time EUS-guided puncture of target lesions for cytologic evaluation of such lesions. This article describes the basic principles of EUS, established indications pertaining to gastrointestinal cancer and other malignancies, and emerging indications for this minimally invasive technology.

Rectal cancer: local staging and assessment of lymph node involvement with endoluminal US, CT, and MR imaging--a meta-analysis

PURPOSE

To perform a meta-analysis to compare endoluminal ultrasonography (US), computed tomography (CT), and magnetic resonance (MR) imaging in rectal cancer staging.

MATERIALS AND METHODS

Relevant articles published between 1985 and 2002 were included if more than 20 patients were studied, histopathologic findings were the reference standard, and data were presented for 2 x 2 tables; articles were excluded if data were reported elsewhere in more detail. Two reviewers independently extracted data on study characteristics and results. Bivariate random-effects approach was used to obtain summary estimates of sensitivity and specificity for invasion of muscularis propria, perirectal tissue, and adjacent organs and for lymph node involvement. Summary receiver operating characteristic (ROC) curves were fitted for perirectal tissue invasion and lymph node involvement.

RESULTS

Ninety articles fulfilled all inclusion criteria. For muscularis propria invasion, US and MR imaging had similar sensitivities; specificity of US (86% [95% confidence interval [CI]: 80, 90]) was significantly higher than that of MR imaging (69% [95% CI: 52, 82]) (P =.02). For perirectal tissue invasion, sensitivity of US (90% [95% CI: 88, 92]) was significantly higher than that of CT (79% [95% CI: 74, 84]) (P <.001) and MR imaging (82% [95% CI: 74, 87]) (P =.003); specificities were comparable. For adjacent organ invasion and lymph node involvement, estimates for US, CT, and MR imaging were comparable. Summary ROC curve for US of perirectal tissue invasion showed better diagnostic accuracy than that of CT and MR imaging. Summary ROC curves for lymph node involvement showed no differences in accuracy.

CONCLUSION

For local invasion, endoluminal US was most accurate and can be helpful in screening patients for available therapeutic strategies.

Diagnosis of gastrointestinal tract lesions by endoscopic ultrasound-guided fine-needle aspiration biopsy

BACKGROUND

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) allows detailed imaging of both intramural and extramural structures of the gastrointestinal (GI) tract and also allows tissue samples to be obtained from masses and lesions in the GI tract. The objective of the current study was to determine the diagnostic utility of EUS-FNA in evaluating intramural and extramural GI tract lesions.

METHODS

The authors evaluated all EUS-FNA specimens of GI tract lesions obtained over a 30-month period (from August 2000 to February 2003). Samples of pancreatic and intrabdominal/mediastinal lymph nodes were excluded from the study. A single endosonographer performed all procedures. An attending cytopathologist also was present on site to assess specimen adequacy. Cytologic diagnoses were analyzed for correlations with final diagnoses, which were based on histologic examination of biopsied/resected pathology materials and/or clinical follow-up findings.

RESULTS

Sixty-two EUS-FNA specimens of intramural and extramural GI tract lesions were obtained from a total of 60 patients. The mean patient age was 58.8 years (standard deviation, 15.3 years). Thirty-six patients (60%) were male, and 24 (40%) were female. Twenty-eight patients had surgical pathologic evaluation of the corresponding lesions. The remaining 32 patients were followed clinically for a mean duration of 9.5 months (standard deviation, 7.7 months). The anatomic sites of the lesions were as follows: esophagus in 23 patients (37%), stomach in 13 patients (21%), duodenum in 15 patients (24%), and rectum/sigmoid in 11 patients (18%). It is noteworthy that 29 patients (43%) previously had experienced unsuccessful attempts at tissue diagnosis by endoscopic forceps biopsy. Of the 62 EUS-FNA specimens, 43, 4, and 15 were reported as being positive for a neoplasm, suspicious, and benign, respectively. Neoplastic lesions included carcinoma (n = 24), gastrointestinal stromal tumor (GIST; n = 18), neuroendocrine neoplasm (n = 2), and lymphoma (n = 1). There were two cases of endometriosis, three foregut duplication cysts, and one case of diverticulosis. There were two lesions that yielded false-negative findings (one gastric lymphoma and one GIST) secondary to sampling or interpretive error. There also were three cases that yielded false-positive findings (one case of endometriosis, one case of duodenal diverticula with smooth muscle hyperplasia, and one case of normal pancreas, which presented as a periduodenal mass). The sensitivity, specificity, and diagnostic accuracy of EUS-FNA in diagnosing GI tract neoplastic lesions were 89%, 88%, and 89%, respectively.

CONCLUSIONS

EUS-FNA provides accurate tissue diagnosis in a wide variety of extraintestinal mass lesions and intramural GI tumors, particularly in patients for whom previous endoscopic forceps biopsy was unsuccessful in establishing a diagnosis.

Impact of Preoperative Staging and Chemoradiation Versus Postoperative Chemoradiation on Outcome in Patients With Rectal Cancer: A Decision Analysis

BACKGROUND

Although radical resection and postoperative chemoradiation have been the standard therapy for patients with rectal cancer, preoperative staging by local imaging and chemoradiation are widely used. We used a decision analysis to compare the two strategies for rectal cancer management.

METHODS

We developed a decision model to compare survival outcomes after postoperative chemoradiation versus preoperative staging and chemoradiation in patients aged 70 years with resectable rectal cancer. In the postoperative chemoradiation strategy, patients undergo radical resection and receive postoperative chemoradiation. In the preoperative staging and chemoradiation strategy, patients with locally advanced cancer receive preoperative chemoradiation and radical resection, whereas those with amenable localized tumors undergo local excision. The cohorts of patients were entered into a Markov model incorporating age-adjusted and disease-specific mortality. Outcomes were evaluated by modeling 5-year disease-specific survival for preoperative chemoradiation as less than, equal to, or greater than that of postoperative chemoradiation. Base-case probabilities were derived from published data; the Surveillance, Epidemiology, and End Results (SEER) Program database; and U.S. Life Tables. One-way and two-way sensitivity analyses were performed. The outcome measures were life expectancy and quality-adjusted life expectancy.

RESULTS

Life expectancy and quality-adjusted life expectancy were 9.72 and 8.72 years, respectively, in the postoperative chemoradiation strategy. In the preoperative staging and chemoradiation strategy, life expectancy was 9.36, 9.72, and 10.09 years and quality-adjusted life expectancy was 8.71, 9.04, and 9.37 years when 5-year disease-specific survival was less than, equal to, or greater than that of postoperative chemoradiation, respectively. The decision model was sensitive to differences in the long-term toxicity of pre- and postoperative chemoradiation. When the 5-year disease-specific survival for patients after pre- or postoperative chemoradiation was equal, the decision model was sensitive to surgical mortality and to the probability of residual lymph node disease after local excision.

CONCLUSION

If efficacy and toxicity after preoperative chemoradiation are equal to or better than that after postoperative chemoradiation in patients with locally advanced rectal cancer, then preoperative staging to select patients appropriate for preoperative chemoradiation is beneficial.

Pitfalls of endoscopic ultrasound staging after application of electrocautery

Patients may be referred for endosonography after endoscopic resection of polyps because of cancer identified in the histologic specimen. To assess the effects of electrocautery-induced tissue changes on tumor staging by endosonography, endosonography findings after endoscopic removal of large polyps were correlated with surgical and endoscopic pathology. Endosonography findings revealed irregular and thickened wall layers, especially in the muscularis propria with pseudopod extensions. Five of 7 patients had evidence of cancer in the endoscopic specimen. However, no residual tumor was found in the surgically resected bowel (2 patients) or in subsequent biopsies of the endoscopic resection site (3 patients). In 2 other patients, no cancer was present in the endoscopic specimen, and follow-up biopsies of the endoscopic resection site were all benign. Electrocautery-induced inflammatory changes create hypoechoic changes within the gut wall that may mimic tumor invasion. Irregularities in the muscularis propria layer cannot be relied upon to diagnose a T2 or T3 lesion by endosonography in this setting. Patients with large polyps greater than 2 cm and other mucosal lesions with malignant potential should undergo endosonography prior to endoscopic resection.

Pelvic radiological imaging: a surgeon's perspective

Radiological imaging of the pelvis adds an important dimension to our understanding of rectal and perianal disease. By integrating relevant information obtained from these investigations into planning and conduct of surgical procedures, outcomes for patients may be optimised. This review focuses on three areas from a clinical viewpoint. (1) With the increased use of neoadjuvant treatments pretherapeutic staging strategies become central to the management of rectal cancer patients. At present, transrectal ultrasound (TRUS), computerised tomography and magnetic resonance imaging (MRI) serve in combination to provide the essential informations. (2) The advent of endoanal ultrasound and MRI in the diagnostic workup of patients with faecal incontinence has caused a paradigm shift both conceptionally and in the way treatments are tailored to individual patients. (3) Concerning primary perianal fistulas there is little place for endoanal ultrasound or MRI. However, when a recurrent or Crohn's fistula is present, a combination of surgical exploration with either endoanal ultrasound or MRI depending on local expertise and availability may be the optimal approach to maximise benefit for these patients.

Colon cancer during pregnancy

The medical community should become mobilized to diagnose colon cancer earlier in pregnancy to improve prognosis. The primary care physician or obstetrician should refer the pregnant patient with significant gastrointestinal complaints to the gastroenterologist for evaluation. Likewise, the gastroenterologist should be prepared to perform sigmoidoscopy, preferably without endoscopic medications, for significant lower gastrointestinal symptoms such as persistent rectal bleeding. Sigmoidoscopy is particularly sensitive in identifying colon cancer in pregnant patients because their cancers are usually distal and within reach of the sigmoidoscope.

Endoscopic ultrasound for rectal cancer

The application of EUS has improved the way we evaluate and manage patients with rectal cancer. EUS has substantially greater sensitivity than CT in detecting advanced T stage tumors. Such improved sensitivity results in changes in preoperative therapy that would not otherwise have occurred without EUS. Although the addition of FNA provides little incremental effect on patient management, it carries the most potential for impacting management in those patients with early T stage disease, and its use should be considered in this subgroup of patients. Whether the accurate staging ability of EUS translates into improved outcomes in terms of reduced recurrence rates and ultimately prolonged survival remains uncertain. This will require further long-term outcome studies focusing on the endpoint of tumor recurrence and patient survival.

Endoscopic ultrasound-guided fine-needle aspiration biopsy: a study of 103 cases

BACKGROUND

Endoscopic ultrasound (EUS) provides detailed imaging of both intramural and extramural structures within the abdomen and mediastinum. However, EUS is limited in its ability to differentiate an inflammatory/reactive process from a malignancy. Fine-needle aspiration biopsy (FNAB), coupled with EUS, allows for the sampling of the target lesion under ultrasound guidance in real time. To better evaluate the clinical utility and efficiency of EUS-FNAB, a retrospective analysis of the first 103 EUS-FNABs performed at our institute was undertaken.

METHODS

EUS-FNABs was performed in 80 patients with 103 lesions. Both air-dried and alcohol-fixed smears were prepared and stained with Diff-Quik (American Scientific Products, McGraw Park, IL) and Papanicolaou stains, respectively. In addition, ThinPrep slides (Cytyc, Boxborough, MA) and cell blocks, when additional material was available, were also prepared. Immunohistochemical stains were performed on cell blocks wherever required. Cytologic diagnoses were then correlated with the final diagnoses. The latter was based on histologic examination of biopsies/resected pathology materials (n = 54) and clinical follow up (n = 48). Follow-up information was not available for one lesion.

RESULTS

Of 103 EUS-FNABs, 42 FNABs were from the pancreas, 38 from the lymph nodes (10 mediastinal and 28 intraabdominal), 10 from the gastrointestinal tract, 7 from the liver, 4 from the adrenal gland, 1 from the biliary tract, and 1 from a retroperitoneal mass. The mean number of passes to obtain diagnostic materials was 3.3. Of 103 EUS-FNABs, 45, 9, 6, and 37 were reported as malignant, suspicious, atypical, and benign, respectively. Six FNABs were nondiagnostic. The authors did not encounter any false-positive cases. There were three false-negative cases (two pancreatic carcinomas and one gastrointestinal stromal tumor of the stomach). No complications were encountered. The sensitivity, specificity, and accuracy were 71%, 100%, and 81%, respectively. If the FNABs that were classified as suspicious were considered as malignant, the sensitivity, specificity, and accuracy were 86%, 100%, and 91%, respectively.

CONCLUSIONS

EUS-FNAB is a safe and accurate diagnostic procedure for the evaluation of intramural and extramural lesions of the gastrointestinal tract. In the majority of cases, it obviates the need for more invasive diagnostic procedures to obtain a tissue diagnosis.

Endoscopic ultrasound and endoscopic mucosal resection for rectal cancers and villous adenomas

EUS is the most accurate tool for local staging of rectal carcinoma. In addition to providing accurate T- and N-stages, EUS allows assessment of the internal and external anal sphincters. Accurate endosonographic staging directs the optimal method of management of rectal carcinoma, type of resection, and candidacy for neoadjuvant therapy. EMR may be applied to large rectal adenomas as an alternative to surgical resection in selected patients. EUS is important in discriminating lesions suitable for EMR.

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.

EUS-guided fine needle aspiration in mediastinal lymphadenopathy of unknown etiology

BACKGROUND

EUS-guided fine needle aspiration (EUS-FNA) has significantly expanded the diagnostic capability of GI EUS. FNA technology can also be helpful in the diagnosis of non-GI disorders. The role of EUS-guided FNA in the diagnosis of mediastinal lymphadenopathy of unknown etiology has not been described. The aim of this study was to evaluate the diagnostic accuracy and impact on subsequent evaluation and therapy of EUS-FNA in mediastinal lymphadenopathy of unknown cause.

METHODS

Sixty-two patients (40 men, 22 woman; mean age 56 years, range 16-91 years) with mediastinal lymphadenopathy of unknown etiology underwent EUS-FNA at 6 tertiary referral centers. Presenting symptoms included the following: dysphagia, 6 patients; night sweats, 14; cough, 8; chest pain, 10; odynophagia, 10; fever, 6; weight loss, 8; and asymptomatic/abnormal radiograph, 12. A final diagnosis by EUS-FNA, surgery, autopsy, or long-term follow-up was available for all patients. EUS-FNA results were classified under 3 disease categories: (1) benign/infectious; (2) malignant pulmonary; and (3) malignant mediastinal (e.g., lymphoma, metastatic malignancy). Four EUS features were used as criteria for lymph node metastases: size greater than 1 cm, round shape, sharp border, and homogeneous/hypoechoic echo pattern.

RESULTS

Final diagnoses included benign/infectious lymph nodes, 26; malignant pulmonary, 24; and malignant mediastinal, 12. EUS-FNA established a tissue diagnosis in 56 of 62 patients (90%). EUS criteria for malignant lymph nodes were more frequently present in malignant pulmonary (mean 2.6 features) and malignant mediastinal (mean 2.8) than benign/infectious (mean 1.9) lymph nodes. EUS results influenced subsequent evaluation in 87% and therapy in 87% of patients. There was no complication of EUS-FNA.

CONCLUSIONS

EUS-FNA in patients with mediastinal lymphadenopathy is safe and guides subsequent therapy in the great majority of cases. Transesophageal EUS-FNA of mediastinal lymph nodes provides minimally invasive tissue sampling, obviating the need for mediastinoscopy or bronchoscopy.

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.

A resource utilization projection study of EUS

BACKGROUND

EUS has emerged as standard practice with respect to the diagnosis and staging of GI malignancies. Whether currently available resources are sufficient to meet the potential need for EUS is uncertain. This study examines the hypothetical demand for EUS in the United States.

METHODS

EUS cases performed at 3 centers with well-established expertise in EUS in 1997 were retrospectively reviewed and trends were extrapolated to national cancer statistics. Indications for EUS fell into 3 categories: (1) diagnosis/staging of esophageal, gastric, pancreatic, or rectal cancers (established indications); (2) suspected GI malignancy (obligate "rule out"); and (3) "other" (emerging indications). Hypothetical total numbers of cases in which EUS could be performed in the United States were calculated taking into consideration the expected number of GI malignancies for which EUS would be appropriate (based on cancer statistics for 2000), the fraction unresectable by CT, the fraction of elderly nonsurgical candidates, proportionate "rule out" cases, as well as "other" emerging indications.

RESULTS

The calculated hypothetical number of cases (United States) in which EUS would be indicated is 79,568 per year (10,287 esophagus, 10,666 stomach, 23,069 pancreas, and 35,546 rectal). If "other" indications remained constant at 12%, there would potentially be 89,116 EUS procedures performed per year, with a conservative estimate of 79,572 per year.

CONCLUSIONS

This model suggests that currently available EUS resources are not sufficient to meet hypothetical demand. Future considerations include the number of endoscopy units in which EUS is performed, the capacity of individual units, and the implications for training programs in the United States.

Utility of an upper echoendoscope for endoscopic ultrasonography of malignant and benign conditions of the sigmoid/left colon and the rectum

OBJECTIVE

The majority of data on colonic endoscopic ultrasound (EUS) are limited to malignant lesions in the rectum and diseases of the anal sphincter. The forward-oblique-viewing upper echoendoscope has been mostly applied for staging rectal cancer. A front-viewing echocolonoscope is available but has not been widely used because of limited indications and the expense of buying another instrument. The purpose of our study was to evaluate the utility of a forward-oblique-viewing upper echoendoscope for EUS of malignant and benign lesions of the sigmoid/left colon and the rectum.

METHODS

Thirty-two EUS exams were performed for a variety of indications in the rectum and the sigmoid/left colon. The patients were prepared for the exam in a manner similar to the performance of flexible sigmoidoscopy. Flexible sigmoidoscopy was performed in all cases before performing EUS. Surgical path data were reviewed in all cases if the patient had surgery after EUS.

RESULTS

Twenty-six exams were done for staging of rectosigmoid carcinoma, follow-up after chemotherapy and/or radiation, or to look for recurrence after resection of colorectal cancer. Surgical pathology results were available in 20 patients. The accuracies of EUS were 85% for T staging and 80% for N staging. Six EUS exams were for benign causes, including evaluation for the presence of a perirectal abscess in two (no abscess found), to rule out rectal varices in one (EUS confirmed rectal varices), and evaluation of submucosal lesions. One patient subsequent to EUS imaging also underwent a linear EUS-guided fine-needle aspiration of a submucosal mass in the rectum with the fine-needle aspirate consistent with a myogenic tumor.

CONCLUSIONS

The forward-oblique-viewing upper echoendoscope is a versatile instrument that can be applied for EUS imaging of malignant and benign indications not only in the rectum but also in the sigmoid/left colon.

Transit endoscopic ultrasound of colorectal cancer using a 12 MHz catheter probe

The objective of this study was to examine the accuracy of a 12 MHz ultrasound catheter probe in the pre-operative staging of colorectal cancer by assessing the depth of tumour infiltration and involvement of pericolonic lymph nodes. 159 patients with colorectal cancer who underwent ultrasound examination with a 12 MHz catheter probe were studied prospectively. The results of this imaging procedure were compared with the histological findings of the resected specimens. The accuracy of the 12 MHz ultrasound catheter probe for depth of invasion (T category) was 85% (131/154) for all tumours, 87% (46/53) for pT1 tumours, 60% (9/15) for pT2 tumours, 89% (74/83) for pT3 tumours and 67% (2/3) for pT4 tumours. The accuracy for tumours of the rectum and colon was 81% and 89%, respectively. The accuracy of the probe for nodal staging (N category) was 67% (76/114) overall. The sensitivity was 70% (33/47), the specificity 64% (43/67), the positive predictive value 58% (33/57) and the negative predictive value 75% (43/57). Endoscopic ultrasound using a 12 MHz catheter probe accurately assessed tumour stage, although nodal staging remained suboptimal. This method may aid in the selection of treatment for patients with colorectal cancer.

Evaluation of the role of pre-operative magnetic resonance imaging in the management of rectal cancer

OBJECTIVES

This study assesses the ability of body coil magnetic resonance imaging (MRI) to pre-operatively stage mural penetration, nodal status and circumferential resection margin (CRM) involvement of rectal cancer.

PATIENTS AND METHODS

Between 1995 and 1997, MRI using a body coil was performed in consecutive patients with primary rectal carcinomas. Group A: 67 patients underwent surgery without long course neo-adjuvant therapy. Predicted tumour stage was compared to the histology of the specimen. Group B: 21 patients with MRI evidence of advanced disease, underwent long course neo-adjuvant therapy followed by repeat MRI prior to surgery. The second scan assessed response to treatment and likelihood of CRM involvement at subsequent surgery.

RESULTS

Group A: Accuracy of pre-operative staging was: 'T' stage - 54%, 'N' stage - 77%, involvement of CRM by tumour - 97%. Group B: After long course neo-adjuvant therapy the second MRI scan was 95% accurate in predicting CRM involvement by tumour.

CONCLUSION

In this study pre-operative rectal cancer staging with MRI and a body coil lacks accuracy in predicting mural penetration and nodal involvement. Body coil MRI can accurately predict the potential for CRM involvement. This technique may help determine which patients require long course neo-adjuvant therapy.

Local excision of T2 and T3 rectal cancers after downstaging chemoradiation

OBJECTIVE

To evaluate the safety and efficacy of local excision in patients with T2 and T3 distal rectal cancers that have been downstaged by preoperative chemoradiation.

SUMMARY BACKGROUND DATA

T2 and T3 cancers treated by local excision alone are associated with unacceptably high recurrence rates. The authors hypothesized that preoperative chemoradiation might downstage both T2 and T3 lesions and significantly expand the indications for local excision.

METHODS

Local excision was performed after preoperative chemoradiation on patients with a complete clinical response or on patients who were either ineligible for or refused to undergo abdominoperineal resection. Local excision was approached transanally by removing full-thickness rectal wall and the underlying mesorectum.

RESULTS

From 1994 to 2000, 95 patients with rectal cancers underwent preoperative chemoradiation and surgical resection for curative intent. Of these, 26 patients (28%), 19 men and 7 women, with a mean age of 63 years (range 44-90), underwent local excision. Pretreatment endoscopic ultrasound classifications included 5 T2N0, 13 T3N0, 7 T3N1, and 1 not done. Pathologic partial and complete responses were achieved in 9 of 26 (35%) and 17 of 26 (65%) patients, respectively. Two of nine partial responders underwent immediate abdominoperineal resection. The mean follow-up was 24 months (median 19, range 6-77). The only recurrence was in a patient who refused to undergo abdominoperineal resection after a partial response. There was one postoperative death from a stroke. This treatment was associated with a low rate of complications.

CONCLUSION

Local excision appears to be an effective alternative treatment to radical surgical resection for a highly select subset of patients with T2 and T3 adenocarcinomas of the distal rectum who show a complete pathologic response to preoperative chemoradiation.

Role of endoscopy in staging colorectal cancer

The treatment of colorectal cancer depends in large measure on the depth of tumor invasion and the extent of lymph node involvement. Endoscopic ultrasonography (EUS) has added a new dimension to the evaluation of tumor invasion and lymph node involvement in gastrointestinal cancer. The overall EUS accuracy for colorectal cancer T-staging is 78%, specificity is 73%, and sensitivity is 94%. In determining the nodal involvement by tumor, EUS has an accuracy of 75%, specificity of 73%, and sensitivity of 74%. Comparison with computerized tomography (CT), magnetic resonance imaging (MRI), and MRI with endorectal coil (MRIEC) shows that EUS is an effective single modality for assessing tumor penetration of the rectal wall. It does not, however, allow the assessment of distant metastatic disease. For assessing lymph node involvement, MRIEC offers the most comprehensive information.

Preoperative staging of rectal cancer using a 7.5 MHz front-loading US probe

BACKGROUND

Conventional echoendoscopes have disadvantages when used for staging colorectal cancer including the inability to pass the instrument through tight stenosis and limited maneuverability. This study evaluated the preoperative use of a newly developed 7.5 MHz front-loading ultrasound probe (FLUP) for local staging of rectal cancer.

METHODS

A 7.5 MHz FLUP, diameter 7.3 mm, was used in this study. The mechanical shaft portion of the probe can be passed in retrograde fashion through the accessory channel of a standard colonoscope. Thirty-nine patients with rectal cancer underwent ultrasonography with this probe. The tumors were staged using the TNM system, and the results were compared with the histologic findings of the resected specimens.

RESULTS

The FLUP proved to be satisfactory, with respect to maneuverability, for traversing stenosis and accurate recognition of small tumors under direct endoscopic control. The accuracy of the FLUP for T staging was 82% (32 of 39) for all tumors, 90% in pT1, and 79% in pT2 to pT4 tumors. The accuracy of the FLUP for N staging was 72% (23 of 32) overall. The sensitivity was 83%, the specificity was 65%, the positive predictive value was 59%, and the negative predictive value was 87%.

CONCLUSIONS

The 7.5 MHz FLUP appears to be useful for preoperative local staging of rectal cancer. This system makes it technically easier to image small cancers as well as advanced rectal cancers.

Preoperative radiochemotherapy in locally advanced or recurrent rectal cancer: regional radiofrequency hyperthermia correlates with clinical parameters

PURPOSE

Preoperative radiochemotherapy (RCT) is a widely used means of treatment for patients suffering from primary, locally advanced, or recurrent rectal cancer. We evaluated the efficacy of treatment due to additional application of regional hyperthermia (HRCT) to this conventional therapy regime in a Phase II study, employing the annular phased-array system BSD-2000 (SIGMA-60 applicator). The clinical results of the trial were encouraging. We investigated the relationship between a variety of thermal and clinical parameters in order to assess the adequacy of thermometry, the effectiveness of hyperthermia therapy, and its potential contribution to clinical endpoints.

METHODS AND MATERIALS

A preoperative combination of radiotherapy (1.8 Gy for 5 days a week, total dose 45 Gy applied over 5 weeks) and chemotherapy (low-dose 5-fluorouracil [5-FU] plus leucovorin in the first and fourth week) was administered to 37 patients with primary rectal cancer (PRC) and 18 patients with recurrent rectal cancer (RRC). Regional hyperthermia (RHT) was applied once a week prior to the daily irradiation fraction of 1.8 Gy. Temperatures were registered along rectal catheters using Bowman thermistors. Measurement points related to the tumor were specified after estimating the section of the catheter in near contact with the tumor. Three patients with local recurrence after abdominoperineal resection, had their catheters positioned transgluteally under CT guidance, where the section of the catheter related to the tumor was estimated from the CT scans. Index temperatures (especially T(max), T(90)) averaged over time, cumulative minutes (cum min) (here for T(90) > reference temperature 40.5 degrees C), and equivalent minutes (equ min) (with respect to 43 degrees C) were derived from repetitive temperature-position scans (5- to 10-min intervals) utilizing software specially developed for this purpose on a PC platform. Using the statistical software package SPSS a careful analysis was performed, not only of the variance of thermal parameters with respect to clinical criteria such as toxicity, response, and survival but also its dependency on tumor characteristics.

RESULTS

The rate of resectability (89%) and response (59%) were high for the PRC group, and a clear positive correlation existed between index temperatures (T(90)) and thermal doses (cum min T(90) >/= 40.5 degrees C). Even though the overall 5-year survival was encouraging (60%) and significantly associated with response, there was no statistically significant relationship between temperature parameters and long-term survival for this limited number of patients. However, nonresectable tumors with higher thermal parameters (especially cum min T(90) >/= 40.5 degrees C) had a tendency for better overall survival. We found even higher temperatures in patients with recurrences (T(90) = 40.7 degrees C versus T(90) = 40.2 degrees C). However, these conditions for easier heating did not involve a favorable clinical outcome, since surgical resectability (22%) and response rate (28%) for the RRC group were low. We did not notice any other dependency of thermal parameters to a specific tumor or patient characteristics. Finally, neither acute toxicity (hot spots) induced by hyperthermia or RCT nor perioperative morbidity were correlated with temperature-derived parameters. Only a higher probability for the occurrence of hot spots was found during treatment with elevated power levels.

CONCLUSION

In this study with two subgroups, i.e., patients with PRC (n = 37) and RRC (n = 18), there exists a positive interrelationship between thermal parameters (such as T(90), cum min T(90) >/= 40,5 degrees C) and clinical parameters concerning effectiveness. Additional hyperthermia treatment does not seem to enhance toxicity or subacute morbidity. Procedures to measure temperatures and to derive thermal parameters, as well as the hyperthermia technique itself appear adequate enough to classify heat treatments in

Mistakes on EUS staging of colorectal carcinoma: error in interpretation or deception from innate pathologic features?

BACKGROUND

Because endoscopic ultrasound (EUS) accuracy for staging gastrointestinal tract tumors is limited by many factors, this study was designed to analyze potential sources of error in the EUS staging of colorectal carcinoma.

METHODS

All patients referred for EUS evaluation of colorectal carcinoma were staged prospectively by one ultrasonographer and retrospectively by two others with EUS videotape recordings. Pathologic staging was done independently in a blinded fashion. Deceptive pathologic features were defined for T staging by presence of inflammation extending beyond tumor or microscopic spread without inflammation extending to a level consistent with the next stage, and for N staging by large (> or = 10 mm) benign lymph nodes or small (< 10 mm) malignant lymph nodes.

RESULTS

Of 22 patients entered into the study, an inflammatory reaction around microscopic tumor spread thought to actually enhance detection by EUS was present in 57.1% of cases. Nine deceptive pathologic lesions were present in 36.4% (8 of 22) of patients (5 T stage, 4 N stage lesions). Of 40 T and N stage mistakes made by the three physicians, 45% were made in the presence and 55% in the absence of deceptive pathologic lesions. Accuracy increased significantly from the presence to absence of deceptive pathologic lesions, from 53.3% to 83.7% (p = 0.029) for T stage, and 8.3% to 73. 1% for N stage (p = 0.0001). Confidence of T staging correlated significantly with accuracy, increasing from 63.3% when unsure to 88. 2% with staging certainty (p = 0.017), an effect not seen for N staging.

CONCLUSIONS

Inflammation and desmoplasia around colorectal carcinoma are often present, but may actually enhance EUS detection of microscopic tumor spread. Deceptive pathologic lesions are present in only one third of patients, but account for almost half (45%) of the errors in T and N staging by EUS. Diagnostic accuracy for EUS was increased with confidence in T stage assessment (but not N stage) and in the absence of deceptive pathologic lesions. Errors in interpretation still accounted for the majority of mistakes (55%) made in EUS staging of colorectal carcinoma.

Endoscopic ultrasonography (EUS) and EUS-guided fine needle aspiration for accurate staging of rectal cancer: explanation of tumor staging and a case report

This article describes the diagnosis, staging, and therapeutic options for rectal cancer and the importance of endoscopic ultrasonography (EUS) and EUS-guided fine-needle aspiration (FNA) as a relatively new diagnostic modality. A case study is presented from initial diagnosis through surgery to illustrate how EUS and EUS-guided FNA influenced the treatment plan. Discussion focuses on rectal cancer and the importance of early detection through routine screening. The internationally accepted Tumor Node Metastasis (TNM) staging classification system for rectal cancer is included, followed by a description of EUS and EUS-guided FNA with regard to accuracy in staging. In conclusion, the various stage-dependent treatment options available for rectal cancer that can be individualized based on the patient's medical problems and preferences are discussed.

The role of endoscopic ultrasonography in diagnosis, staging, and management of pancreatic disease states

The role of endoscopic ultrasound in evaluation of pancreatic diseases is evolving. This article reviews the advantages and limitations of endoscopic ultrasound when compared with other available imaging technologies in the evaluation of chronic pancreatitis, pancreatic cancer, neuroendocrine tumors, and cystic lesions of the pancreas. New therapeutic procedures using endoscopic ultrasound in the treatment of pancreatic disease are discussed, in addition to potential future applications.

Staging of rectosigmoid neoplasia with colonoscopic endoluminal ultrasonography

BACKGROUND

The accurate staging of colorectal neoplasia may aid the stratification of patients for adjuvant treatment. At present the mural extent of neoplasia proximal to the mid rectum is difficult to determine. Prediction of mural invasion could help identify patients suitable for radical resection, minimal access surgery or endoscopic treatment. Colonoscopic endoluminal ultrasonography (EUS) was used in a prospective study to determine the stage of rectosigmoid neoplasia in 121 patients.

METHODS

Mural tumour (T) stage was designated by EUS as uT0/1-uT4 in 121 patients. Nodal (N) staging was performed in 39 cases. EUS staging was compared with histological stage (pT and pN) in 93 patients who underwent resection.

RESULTS

Mural staging of disease using colonoscopic EUS showed good correlation with histo-pathological stage (kappa = 0.85 (95 per cent confidence interval 0.76-0.95)). Overall pT and pN stage accuracy of EUS was 92 and 65 per cent respectively.

CONCLUSION

EUS accurately assessed tumour stage although node staging remained suboptimal. Colonoscopic EUS may aid the selection of treatment in patients with rectosigmoid neoplasia.