Endorectal Ultrasound in the Management of Patients With Malignant Rectal Polyps

PURPOSE This study was designed to determine the efficacy of endorectal ultrasound in the management of patients with malignant rectal polyps removed by snare excision during colonoscopy.METHODS A retrospective review of the medical records and endorectal ultrasound images of 63 patients with endoscopically removed rectal polyps containing invasive adenocarcinoma subsequently staged by endorectal ultrasound. Patients underwent surgery or were followed at a single institution. The polyp characteristics and ultrasound images were compared with the presence of residual tumor in the surgical specimen in patients who underwent further surgery or with recurrence in patients who did not.RESULTS The morphology of the polyps was described in 31 patients (49 percent); they were sessile in 26 (41 percent) and pedunculated in 6 (9 percent). The margins were positive in 22 patients (35 percent), negative in 19 (30 percent), and not specified in 22 (35 percent). Most tumors were well or moderately differentiated; only 3 (5 percent) were poorly differentiated. Thirty-three patients underwent further surgery (3 low anterior resection, and 30 transanal excision); 30 had no further surgery. The accuracy of endorectal ultrasound in assessing the presence of residual cancer in the rectal wall in patients who had surgery was 54 percent, with a 39 percent positive predictive value and 65 percent negative predictive value. Endorectal ultrasound accurately identified metastatic lymph nodes in two of three patients who had radical surgery. Endorectal ultrasound was more useful than polyp morphologic or histologic criteria to determine the presence of residual cancer in the rectal wall.CONCLUSIONS Endorectal ultrasound does not definitely exclude the possibility of residual tumor in the rectal wall or mesenteric nodes of patients who had a malignant polyp snared endoscopically. Consequently, decisions regarding the definitive management of these patients cannot be based exclusively on the endorectal ultrasound images of the polypectomy site.Reprints are not available.Read at the meeting of the Minnesota Surgical Society, St. Paul, Minnesota, May 5, 2000.     

Endorectal Ultrasound in the Follow-Up of Rectal Cancer Patients Treated by Local Excision or Radical Surgery

PURPOSE: This study was designed to investigate the role of a scheduled follow-up protocol using endorectal ultrasonography for the diagnosis of local recurrence after local excision and radical surgery for rectal cancer.METHODS: A selected group of 275 patients with invasive rectal cancer followed prospectively by endorectal ultrasonography after curative-intent local excision (n = 108) or radical surgery (n = 167) was reviewed. For the radical-surgery group, results were compared with a group of 176 rectal cancer patients who had similar operations during the same period of time and were not entered in follow-up protocol. Excluded were patients with invasive cancers removed by snare excision, male patients treated by abdominoperineal resection, and patients treated by endocavitary radiation. Students unpaired t-test was used to compare tumor and patient characteristics. Survival curves were estimated using the Kaplan-Meier method and compared using the log-rank test.RESULTS: In the local-excision group, 32 patients developed local recurrence, 26 (81 percent) were asymptomatic, and 10 of them (31 percent) were diagnosed only by endorectal ultrasound. We found no difference in the rates of salvage surgery or survival between patients diagnosed of recurrence by ultrasound or other methods. In the radical-surgery group, 12 patients developed local recurrence, 5 (42 percent) were asymptomatic, and 4 of them (33 percent) were diagnosed only by endorectal ultrasound. More patients with isolated local recurrence in the follow-up group underwent salvage surgery (4/9 patients; 44 percent) compared with patients without follow-up (3/13 patients; 23 percent), but the differences were not significant.CONCLUSIONS: Endorectal ultrasound identifies one-third of asymptomatic local recurrences that were missed by digital examination or proctoscopic examination. However, the impact of the earlier diagnosis in patient survival can only be determined by a larger, prospective, randomized trial.Poster presentation at the meeting of The American Society of Colon and Rectal Surgeon, San Diego, California, June 2 to 7, 2001.     

Limitations of Early Rectal Cancer Nodal Staging may Explain Failure after Local Excision

Successful selection of patients with rectal cancer for local excision requires accurate preoperative lymph node staging. Although endorectal ultrasound is capable of detecting locally advanced disease, its ability to correctly identify nodal metastases in early rectal lesions is less well described. This study examines the accuracy of endorectal ultrasound in determining nodal stage based on depth of penetration of the primary lesion (T stage). Between 1998 and 2003, endorectal ultrasound was performed on 938 consecutive patients; 134 had biopsy-proven rectal cancers and were treated with radical resection, without neoadjuvant therapy. Lymph node metastases were measured pathologically and correlated with endorectal ultrasound and clinicopathologic features. Accuracy and specificity of endorectal ultrasound nodal staging was determined. The overall accuracy of endorectal ultrasound nodal staging for the study cohort was 70 percent, with a 16 percent false-positive rate and 14 percent false-negative rate. Endorectal ultrasound was more likely to overlook small metastatic lymph node deposits. The size of lymph node metastasis and accuracy of endorectal ultrasound nodal staging was related to T stage. The specificity of endorectal ultrasound nodal staging, or the ability to identify patients who were node-negative, was dependent on T stage. Early rectal lesions are more likely to have lymph node micrometastases not detected by endorectal ultrasound. The ability of endorectal ultrasound to correctly identify patients without lymph node metastasis is dependent on the T stage of the primary lesion. The limitations of endorectal ultrasound in accurately staging nodal disease in early rectal lesions may, in part, explain the relatively high recurrence rates seen after local excision. Poster presentation at the meeting of The American Society of Colon and Rectal Surgeons, Philadelphia, Pennsylvania, April 30 to May 5, 2005. Reprints are not available.     

Accuracy of Endorectal Ultrasonography in Preoperative Staging of Rectal Tumors

PURPOSE: Preoperative staging of rectal tumors is considered essential to tailor treatment for individual patients. The aim of the present study was to evaluate the accuracy of endorectal ultrasonography in preoperative staging of rectal tumors. METHODS: Eleven hundred eighty-four patients with rectal adenocarcinoma or villous adenoma underwent endorectal ultrasonography evaluation at a single institution during a ten-year period. We compared the endorectal ultrasonography staging with the pathology findings based on the surgical specimens in 545 patients who had surgery (307 by transanal excision, 238 by radical proctectomy) without adjuvant preoperative chemoradiation. Comparisons between groups were performed using chi-squared tests and logistic regression analysis. RESULTS: Overall accuracy in assessing the level of rectal wall invasion was 69 percent, with 18 percent of the tumors overstaged and 13 percent understaged. Accuracy depended on the tumor stage and on the ultrasonographer. Overall accuracy in assessing nodal involvement in the 238 patients treated with radical surgery was 64 percent, with 25 percent overstaged and 11 percent understaged. CONCLUSION: The accuracy of endorectal ultrasonography in assessing the depth of tumor invasion, particularly for early cancers, is lower than previously reported. The technique is more precise in distinguishing between benign tumors and invasive cancers and between tumors localized to the rectal wall and tumors with transmural invasion. Differences in image interpretation may in part explain discrepancies in accuracy between studies.     

The Role of Endorectal Ultrasound in Therapeutic Decision-Making for Local <Emphasis Type="Italic">vs.</Emphasis> Transabdominal Resection of Rectal Tumors

Introduction In rectal tumors, preoperative biopsies frequently fail to diagnose an invasive carcinoma. Endorectal ultrasound is considered a useful adjunct in preoperative staging of rectal tumors. However, feasibility of endorectal ultrasound and its role in therapeutic decision-making in presumed rectal adenomas is sparsely studied. Methods Endorectal ultrasound was performed in 268 tumors referred for local excision because biopsies showed tubulovillous adenoma. Feasibility of endorectal ultrasound was studied and ultrasound staging was compared with definite histopathologic findings. Results In 231 tumors, endorectal ultrasound was technically feasible (86 percent). Median distance from the dentate line was 11 cm in nonassessable tumors and 7 cm in assessable tumors (P < 0.001). In 21 tumors, endorectal ultrasound was not conclusive, mainly in tumors being recurrent or after recent endoscopic manipulation (P < 0.001). With endorectal ultrasound the rate of preoperative missed carcinomas could be reduced from 21 to 3 percent (P < 0.01). In diagnosing tubulovillous adenomas, sensitivity and specificity of endorectal ultrasound was 89 and 86 percent, respectively. Conclusions Endorectal ultrasound is technically feasible in almost all presumed rectal adenomas, referred for local excision. Proper endorectal ultrasound interpretation is possible in 78 percent of all presumed rectal adenomas. Endorectal ultrasound is very reliable in diagnosing tubulovillous adenomas, and therapeutic decision-making regarding local excision vs. radical surgery based on endorectal ultrasound is valid.     

The Impact of 18-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography on the Staging and Management of Primary Rectal Cancer

Purpose  18-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) has a role in recurrent colorectal cancer. This study was designed to assess the impact of PET-CT on management of primary rectal cancer. Methods  Eighty-three patients with rectal cancer underwent PET-CT scan between 2002 and 2005. Referring physicians prospectively recorded stage and management plan after conventional imaging before PET-CT scan, which were compared to subsequent stage and management after PET-CT. Results  Staging PET-CT caused a change in stage from conventional imaging in 26 patients (31 percent). Twelve (14 percent) were upstaged (7 change in N stage; 4 change in M stage; 1 change in N and M stage), and 14 (17 percent) were downstaged (10 change in N stage; 3 change in M stage; 1 change in N and M stage). PET-CT scan altered management intent in seven patients (8 percent) (curative to palliative 6 patients; palliative to curative 1 patient). Management was altered in ten patients (12 percent). There was no difference in impact with respect to tumor height. Conclusions  PET-CT scan impacts the management of patients with primary rectal cancer and influences staging/therapy in a third of patients and should be a component of rectal cancer workup. Read at the meeting of The American Society of Colon and Rectal Surgeons, St Louis, Missouri, June 2 to 6, 2007.     

Endoanal Ultrasound in the Staging and Management of Squamous-Cell Carcinoma of the Anal Canal

PURPOSE: This study was performed to determine whether endoanal ultrasound could be used to accurately stage patients with squamous-cell carcinoma of the anal canal and to determine the response of these tumors to multimodality therapy. METHODS: Thirteen consecutive patients with biopsy-proven squamous-cell carcinoma of the anal canal between 1996 and 1999 were included in the study. All patients underwent a pretreatment staging endoanal ultrasound with a B&K 3535 ultrasound machine using the 1850 rotating 360° probe with a 10-MHz transducer. Tumors were staged using our own modification of a 1984 TNM staging system. For our study, a uT1 tumor was confined to the submucosa; a uT2a lesion invaded only the internal anal sphincter; a uT2b lesion penetrated into the external anal sphincter; a uT3 lesion invaded through the sphincter complex into the perianal tissues; and a uT4 lesion invaded adjacent structures. After the initial study, patients decided on a course of treatment, either primary surgery or chemoradiation. For patients choosing chemoradiation, a clinical examination with biopsies and a repeat endoanal ultrasound was performed after completion of therapy. Findings on physical examination and biopsy results were compared with the follow-up endoanal ultrasound. For those choosing surgery, the pathology specimen from the abdominoperineal resection was reviewed and compared with the initial endoanal ultrasound interpretation to determine the accuracy of endoanal ultrasound staging. RESULTS: One patient died of complications from acquired immunodeficiency syndrome before undergoing definitive treatment for his anal cancer. Of the remaining 12 patients who comprised the study, the endoscopic staging was as follows: 1 uT1, 5 uT2a, 3 uT2b, 2 uT3, and 1 uT4. Five of the 12 patients selected surgery as the primary treatment modality for their disease. The other seven patients underwent a full course of chemoradiation. In all five patients who had an abdominoperineal resection, the surgical staging correlated with the endoanal ultrasound staging (2 T2a tumors and 3 T2b tumors). In the remaining seven patients, six to eight weeks after completion of therapy, there was no evidence of residual tumor by clinical examination and biopsies. In one of the seven patients, no abnormalities were detected on endoanal ultrasound, and it was interpreted as normal with no evidence of disease. In the remaining six patients, endoanal ultrasound revealed abnormalities that were judged to represent radiation-induced changes rather than residual disease. A repeat endoanal ultrasound was done in these patients two to four months after the biopsies. Complete resolution of the postradiation changes occurred in all patients, and the scans were interpreted as showing no evidence of disease. CONCLUSIONS: Endoanal ultrasound can accurately determine the depth of penetration of squamous-cell carcinoma into the sphincter complex and can be used to gauge accurately the response of these tumors to chemoradiation therapy. Our newly proposed ultrasound staging system may be more useful in choosing treatment options; future studies should be aimed at using endoanal ultrasound in identifying early lesions that may be amenable to less aggressive therapy as well as determining the utility of ultrasound in the surveillance of patients after successful treatment of their initial tumors.     

The Accuracy of Multi-detector Row Computerized Tomography in Staging Rectal Cancer Compared to Endoscopic Ultrasound

Background/Aim:

Our aim was to evaluate the diagnostic accuracy of multi-detector row computerized tomography (MDCT) in staging of rectal cancer by comparing it to rectal endoscopic ultrasound (EUS).

Materials and Methods:

We prospectively included all patients with rectal cancer referred to our gastroenterology unit for staging of rectal cancer from December 2007 until February 2011, 53 patients whose biopsy had proven rectal cancer underwent both MDCT scan of the pelvis and rectal EUS. Both imaging modalities were compared and the agreement between T- and N-staging of the disease was assessed.

Results:

We staged 62 patients with rectal cancer during the study period. Of these, 53 patients met the inclusion criteria and were evaluated (25 women and 28 men). The mean age was 57.79 ± 14.99 years (range 21-87). MDCT had poor accuracy compared with EUS in T-staging with a low degree of agreement (kappa = 0.26), while for N-staging MDCT had a better accuracy and a moderate degree of agreement with EUS (kappa = 0.45).

Conclusions:

MDCT has a poor accuracy for predicting tumor invasion compared to EUS for T-staging while it has moderate accuracy for N-staging.     

Clinical Impact of Endoscopic Ultrasound and Endoscopic Ultrasound-Guided Fine-Needle Aspiration in the Management of Rectal Carcinoma

PURPOSE: There is scant data about the clinical impact of endoscopic ultrasound-guided fine-needle aspiration in rectal carcinoma. This study was designed to determine the impact of endoscopic ultrasound-guided fine-needle aspiration on the staging and management of rectal carcinoma and to compare the staging accuracy of computed tomography scan, endoscopic ultrasound, and endoscopic ultrasound-guided fine-needle aspiration. METHODS: The records of 60 consecutive patients diagnosed with rectal carcinoma referred for endoscopic ultrasound staging were reviewed. Computed tomography scans, endoscopic ultrasound imaging, endoscopic ultrasound-guided fine-needle aspiration staging, surgical pathology, and subsequent treatment were compared. RESULTS: Of 48 patients who underwent computed tomography scan imaging, the additional information provided by endoscopic ultrasound changed management in 38 percent of patients. Sixteen patients identified as having nonjuxtatumoral lymph nodes underwent fine-needle aspiration and the additional information obtained changed therapy in three (19 percent) of these patients. All five cases of recurrent rectal carcinoma were correctly diagnosed by fine-needle aspiration. Tumor staging accuracy was 45 percent (computed tomography) and 89 percent (endoscopic ultrasound; P < 0.0001); nodal staging accuracy was 68 percent (computed tomography), 85 percent (endoscopic ultrasound), and 92 percent (endoscopic ultrasound-guided fine-needle aspiration; P = not significant). CONCLUSIONS: Endoscopic ultrasound imaging was better than computed tomography scanning at overall tumor staging, whereas endoscopic ultrasound-guided fine-needle aspiration demonstrated a trend toward more accurate nodal staging. Preoperative staging with endoscopic ultrasound resulted in a change of management in 38 percent of patients. The addition of fine-needle aspiration changed the management in 19 percent of those who underwent nonjuxtatumoral lymph node sampling. Endoscopic ultrasound-guided fine-needle aspiration accurately diagnosed 100 percent of those with recurrent rectal carcinoma. Clearly, endoscopic ultrasound and endoscopic ultrasound-guided fine-needle aspiration are important for the staging and management of rectal carcinoma and for detecting disease recurrence.Presented at the EUS 13th International Symposium on Endoscopic Ultrasound, New York, New York, October 4 to 6, 2002     

直肠癌的磁共振成像诊断及其分期的临床应用

探讨直肠癌磁共振成像诊断及分期的临床应用价值。直肠癌磁共振成像既可以分析肿瘤浸润肠壁的深度和范围,还可判断是否有淋巴结和远处脏器转移,并且很好地预测环状切缘。经研究证明,直肠癌磁共振成像诊断分期与术后病理诊断具有密切的相关性。故直肠癌磁共振成像检查对选择合理的治疗方案、手术方式及判断预后均具有重要的价值。     

How useful is rectal endosonography in the staging of rectal cancer?

It is essential in treating rectal cancer to have adequate preoperative imaging,as accurate staging can influence the management strategy,type of resection,and candidacy for neoadjuvant therapy.In the last twenty years,endorectal ultrasound(ERUS) has become the primary method for locoregional staging of rectal cancer.ERUS is the most accurate modality for assessing local depth of invasion of rectal carcinoma into the rectal wall layers(T stage) .Lower accuracy for T2 tumors is commonly reported,which could ...     

Staging laparotomy for inoperable or borderline operable cancer of the rectum

The authors report their experience with the staging laparotomy as a means of identifying and preparing patients for high-dose preoperative radiotherapy. Twelve patients had clinically unresectable cancers of the rectum. The goal of the staging laparotomy is to assess mobility and tumor size by means of bimanual palpation, to stage the abdominal cavity, and to fashion an end colostomy at the level of the descending colon. Eight patients ultimately underwent radical resection. Three died during follow-up due to hematogenic metastases without recurrent pelvic disease. Five patients are alive with no evidence of disease and have been followed for an average of 34 months (range, 20 to 64 months).     

Three-Dimensional Anal Endosonography May Improve Staging of Anal Cancer Compared With Two-Dimensional Endosonography

PURPOSE Three-dimensional (3-D) endosonography is a new method of staging anal carcinoma that has not yet been validated in comparison with two-dimensional (2-D) endosonography, the latter using only a single scan plane. The aim of this study was to investigate the differences between the two endosonographic techniques.METHODS Thirty patients with an endosonographically detectable anal tumor were examined with a 10 MHz rotating endoprobe. Cross-sectional images of the anal sphincters were stored on a 3-D system during retraction of the endoprobe through the anal canal. Afterwards, any projection could be reconstructed. Cross-sectional images (2-D) were compared with reconstructed projections (3-D) according to five parameters concerning tumor spread and presence of regional lymph nodes. In this study, a scale of 0 to 5 points on critical issues was used; ideally, the results should be identical in 2-D and 3-D endosonography.RESULTS The 3-D method detected a median of 5 diagnostic findings, compared with a median of 4 findings with the 2-D method (P = 0.001). In eight patients the lateral tumor margin was visualized only by 3-D endosonography. The median number of lymph nodes visualized in 3-D was 1 (range, 0-13), in 2-D the median number was 0 (range, 0-6), P = 0.002.CONCLUSIONS Use of 3-D endosonography in patients with anal carcinoma improves detection of perirectal lymph nodes and may improve that of tumor invasion, compared with 2-D endosonography. This may affect local tumor staging and thus planning of treatment. A study with histopathologic correlation is needed to verify this endosonographic study.Supported by grants from Mogens Andreasen Fonden and Ragnhild Ibsens Legat for Medicinsk Forskning.Presented at the European Congress of Radiology, Vienna, Austria, March 6 to 11, 2003.     

Indications of Endoscopic Polypectomy for Rectal Carcinoid Tumors and Clinical Usefulness of Endoscopic Ultrasonography

PURPOSE This study was designed to define the indications of endoscopic polypectomy for rectal carcinoid tumors and evaluate the diagnostic value of endoscopic ultrasonography.METHODS A total of 66 rectal carcinoid tumors treated at our hospital were analyzed histopathologically to clarify risk factors for metastasis. The depth of invasion was determined for 52 lesions examined by endoscopic ultrasonography, and the value of endoscopic ultrasonography for deciding whether a lesion is indicated for endoscopic polypectomy was assessed.RESULTS None of the 57 lesions measuring 10 mm in diameter invaded the muscularis propria or had metastasis. Of nine lesions with a diameter of 11 mm, five invaded the muscularis propria and four had metastasis. A central depression was found in three of the lesions with metastasis. The depth of invasion of 49 lesions examined by endoscopic ultrasonography was limited to the submucosa; 3 lesions invaded the muscularis propria. The depth of invasion of all lesions was correctly diagnosed by endoscopic ultrasonography. Ninety-six percent of the lesions that had submucosal invasion with narrowing of the upper two-thirds of the third layer (submucosa) as evaluated by endoscopic ultrasonography could be completely resected by endoscopic polypectomy.CONCLUSIONS Rectal carcinoid tumors that satisfy the following three conditions are indicated for local resection, including endoscopic polypectomy: a maximum diameter of 10 mm, no invasion of the muscularis propria, and no depression or ulceration in the lesion. Endoscopic ultrasonography also is useful for estimating the depth of invasion of rectal carcinoid tumors and for determining whether endoscopic polypectomy is indicated.Published online: 28 January 2005.Reprints are not available.     

The Accuracy of Clinical Examination in the Diagnosis of Rectal Intussusception

PURPOSE: This study was designed to compare routine clinical examination and defecography in the diagnosis of rectal intussusception in constipated patients and study relationships between rectal intussusception and symptoms.METHODS: A total of 127 consecutive patients with functional constipation were examined in the left-lateral position with rectal palpation and rectoscopy according to a protocol. An overall clinical judgment was made if the patient had intussusception, unclear finding, or no intussusception. Defecography was performed without knowledge of the results of the clinical evaluation. Symptom duration varied between 0.5 to 60 (median, 10) years. All patients fulfilled a bowel questionnaire and all had a full physiologic workup.RESULTS: A diagnosis by digital examination (P = 0.002) and by rectoscopy (P = 0.002) as well as the overall judgment (P = 0.0002) was clearly related to a longer intussusception as measured by defecography. Five of six intra-anal intussusceptions were correctly assessed by clinical examination, whereas the correlation to defecography was poor in the group with short intussusceptions. Neither clinical nor defecographic diagnosis of rectal intussusception were related to the main symptoms of constipation but both were associated with a tendency toward lower anal resting pressures (P = 0.04 and P = 0.06) and an obtuse anorectal angle (during evacuation, P = 0.01 and P = 0.01).CONCLUSIONS: There is no clear relationship between rectal intussusception and constipation. However, intussusception is related to sphincter function and may be of clinical relevance. A normal clinical examination will exclude most long intussusceptions, whereas a positive finding needs further evaluation with defecography.Reprints are not available.     

Endorectal ultrasound in the preoperative staging of rectal tumors

The preoperative staging of rectal cancer has important implications for treatment as local therapies become increasingly utilized. Seventy-seven patients underwent preoperative staging using endorectal ultrasonography. All patients had complete pathologic staging and none had preoperative radiotherapy. Depth of invasion of the tumor was accurately predicted in 75 percent of cases in the entire group, with 22 percent overstaged and 3 percent understaged. Accuracy improved greatly over the study period, and in the past six months, 95 percent have been accurately staged for depth of invasion with 5 percent overstaged. Lymph nodes have been properly classified into positive and negative groups in 88 percent of cases in the past year, with a specificity of 90 percent and a sensitivity of 88 percent. Endorectal ultrasound is an accurate preoperative staging modality. Accuracy is improved greatly with increased experience and it has been found that the 5-layer anatomical model facilitates accurate staging. Introduction of the ultrasound probe through a previously placed proctoscope ensures complete scanning of the entire lesion and should be used for the majority of examinations.Read at the meeting of The American Society of Colon and Rectal Surgeons, Toronto, Canada, June 11 to 16, 1989.     

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.     

The use of endoscopic ultrasonography and other imaging modalities in the preoperative staging of rectal villous tumours: A case of overstaging by magnetic resonance imaging

A case of a 60-year-old man with recurrent rectal villous adenoma is described. Preoperative staging with endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI) revealed very discordant results. EUS showed a tumour present in the mucosa with no submucosal invasion, while MRI revealed invasion of the muscularis propria consistent with an invasive stage T2 carcinoma. Based on the MRI findings, the patient underwent a low anterior resection of the tumour. The surgical pathology specimen revealed a villous adenoma with low-grade dysplasia but no carcinoma and no extension into the muscularis propria. The present case highlights the uncertainty that currently exists as to which imaging modality provides the greatest accuracy in the staging of rectal cancer and in guiding the type of surgical procedure performed. Two recent meta-analyses and a systematic review of the literature point to EUS as the imaging modality of choice for determining muscularis propria and perirectal tissue invasion, as well as nodal involvement.     

Accuracy of Magnetic Resonance Imaging in Rectal Cancer Depends on Location of the Tumor

PURPOSE This study was designed to evaluate prospectively magnetic resonance imaging for the prediction of the circumferential resection margin in rectal cancer to identify in which patient magnetic resonance imaging could accurately assess the circumferential resection margin before surgery and in which patients it could not.METHODS During a 17-month period, a preoperative magnetic resonance imaging for the assessment of circumferential resection margin was obtained prospectively in 38 patients with mid or low rectal cancer. The agreement of magnetic resonance imaging and pathologic examination for assessment of circumferential resection margin was analyzed.RESULTS Overall, magnetic resonance imaging agreed with histologic examination of the circumferential resection margin assessment in 28 patients (73 percent; κ = 0.47). In all cases of disagreement between magnetic resonance imaging and pathology, magnetic resonance imaging overestimated the circumferential resection margin involvement. For the 11 patients with mid rectal cancer, circumferential resection margin was well predicted by magnetic resonance imaging in all cases (κ = 1). For 27 patients with low rectal tumor, overall agreement between magnetic resonance imaging and histologic assessment was 63 percent (κ = 0.35). Agreement was 22 percent (κ = 0.03) for the 9 patients with low anterior and 83 percent (κ = 0.67) for the 18 patients with low posterior rectal tumor. Univariate analysis revealed that only low and anterior rectal tumor was risk factor of overestimation of the circumferential resection margin by magnetic resonance imaging.CONCLUSIONS Although magnetic resonance imaging remains the best imaging tool for the preoperative assessment of the circumferential resection margin in patients with rectal cancer, it can overestimate the circumferential resection margin involvement in low and anterior tumor with the risk of overtreating the patients.Presented at the meeting of the French Society of Digestive Surgery, Paris, France, March 29 to April 2, 2003.