Endoluminal ultrasound for early detection of local recurrence of rectal cancer

Advances in Endoscopic Photoacoustic Imaging

Photoacoustic (PA) imaging is able to provide extremely high molecular contrast while maintaining the superior imaging depth of ultrasound (US) imaging. Conventional microscopic PA imaging has limited access to deeper tissue due to strong light scattering and attenuation. Endoscopic PA technology enables direct delivery of excitation light into the interior of a hollow organ or cavity of the body for functional and molecular PA imaging of target tissue. Various endoscopic PA probes have been developed for different applications, including the intravascular imaging of lipids in atherosclerotic plaque and endoscopic imaging of colon cancer. In this paper, the authors review representative probe configurations and corresponding preclinical applications. In addition, the potential challenges and future directions of endoscopic PA imaging are discussed.

High-resolution photoacoustic/ultrasound imaging of the porcine stomach wall: an ex vivo feasibility study

Photoacoustic (PA) imaging has become invaluable in preclinical and clinical research. Endoscopic PA imaging in particular has been explored as a noninvasive imaging modality to view vasculature and diagnose cancers in the digestive system. However, these feasibility studies are still limited to rodents or rabbits. Here, we develop a fully synchronized simultaneous ultrasound and photoacoustic microscopy system using two spectral bands (i.e., the visible and near-infrared) in both optical- and acoustic-resolution modes. We investigate the feasibility of imaging gastric vasculature in an ex vivo porcine model. The entire gastric wall, including the mucosa, submucosa, muscularis propria, and serosa, was excised from fresh porcine stomachs immediately followed by ultrasound and PA imaging being performed within a few hours of sacrifice. PA images of the mucosal vasculature were obtained at depths of 1.90 mm, which is a clinically significant accomplishment considering that the average thickness of the human mucosa is 1.26 mm. The layer structure of the stomach wall could be clearly distinguished in the overlaid PA and US images. Because gastric cancer starts from the mucosal surface and infiltrates into the submucosa, PA imaging can cover a clinically relevant depth in early gastric cancer diagnosis. We were able to detect mucosal vasculature in the entire mucosal layer, suggesting the potential utility of combined PA/US imaging in gastroenterology.

Multimodal endoscopy for colorectal cancer detection by optical coherence tomography and near-infrared fluorescence imaging

While colonoscopy is the gold standard for diagnosis and classification of colorectal cancer (CRC), its sensitivity and specificity are operator-dependent and are especially poor for small and flat lesions. Contemporary imaging modalities, such as optical coherence tomography (OCT) and near-infrared (NIR) fluorescence, have been investigated to visualize microvasculature and morphological changes for detecting early stage CRC in the gastrointestinal (GI) tract. In our study, we developed a multimodal endoscopic system with simultaneous co-registered OCT and NIR fluorescence imaging. By introducing a contrast agent into the vascular network, NIR fluorescence is able to highlight the cancer-suspected area based on significant change of tumor vascular density and morphology caused by angiogenesis. With the addition of co-registered OCT images to reveal subsurface tissue layer architecture, the suspected regions can be further investigated by the altered light scattering resulting from the morphological abnormality. Using this multimodal imaging system, an in vivo animal study was performed using a F344-ApcPircUwm rat, in which the layered architecture and microvasculature of the colorectal wall at different time points were demonstrated. The co-registered OCT and NIR fluorescence images allowed the identification and differentiation of normal colon, hyperplastic polyp, adenomatous polyp, and adenocarcinoma. This multimodal imaging strategy using a single imaging probe has demonstrated the enhanced capability of identification and classification of CRC compared to using any of these technologies alone, thus has the potential to provide a new clinical tool to advance gastroenterology practice.

High-Speed Integrated Endoscopic Photoacoustic and Ultrasound Imaging System

Endoscopic integrated photoacoustic and ultrasound imaging has the potential for early detection of the cancer in the gastrointestinal tract. Currently, slow imaging speed is one of the limitations for clinical translation. Here, we developed a high speed integrated endoscopic PA and US imaging system, which is able to perform PA and US imaging simultaneously up to 50 frames per second. Using this system, the architectural morphology and vasculature of the rectum wall were visualized from a Sprague Dawley rat in-vivo.

In vivo photoacoustic/ultrasonic dual-modality endoscopy with a miniaturized full field-of-view catheter

Endoscopy is an essential clinical tool for the diagnosis of gastrointestinal (GI) tract cancer. A photoacoustic system that elegantly combines optical and ultrasound endoscopy advantages by providing high-sensitivity functional information and large imaging depth is a potentially powerful tool for GI tract imaging. Recently, several photoacoustic endoscopic imaging systems have been proposed and developed. However, the relatively large size and rigid length of the catheter make it difficult to translate them into wide clinical applications; while the existing system of a relatively small catheter, capable of in vivo animal imaging, is unable to acquire full (360°) field-of-view cross-section images. In this study, we developed a photoacoustic/ultrasonic dual-modality endoscopic system and a corresponding miniaturized, encapsulated imaging catheter, which provides a full 360° field-of-view. The diameter of the catheter is 2.5 mm, which is compatible with the 2.8-mm instrumental channel of a conventional clinical optical endoscope. Using this system, we demonstrate in vivo 3-dimensional endoscopic photoacoustic/ultrasonic imaging of the colorectum of a healthy Sprague Dawley rat, by depicting vasculature and morphology of the GI tract. The significantly improved imaging field of view, reduced catheter size, high-quality imaging results suggest that the developed photoacoustic/ultrasonic dual-modality endoscopy has a great potential to be translated into a broad range of clinical applications in gastroenterology.

Multimodality endoscopic optical coherence tomography and fluorescence imaging technology for visualization of layered architecture and subsurface microvasculature

Endoscopic imaging technologies, such as endoscopic optical coherence tomography (OCT) and near-infrared fluorescence, have been used to investigate vascular and morphological changes as hallmarks of early cancer in the gastrointestinal tract. Here we developed a high-speed multimodality endoscopic OCT and fluorescence imaging system. Using this system, the architectural morphology and vasculature of the rectum wall were obtained simultaneously from a Sprague Dawley rat in vivo. This multimodality imaging strategy in a single imaging system permits the use of a single imaging probe, thereby improving prognosis by early detection and reducing costs.

Secondary linitis plastica of the rectum: EUS features and tissue diagnosis (with video)

BACKGROUND

Luminal metastases to the GI tract may be seen at the time of the primary diagnosis or may represent evidence of a distant recurrence.

OBJECTIVES

To determine the prevalence of rectal-wall metastases in patients undergoing an EUS and to describe the EUS features and yield of EUS-guided FNA (EUS-FNA) and Trucut biopsy (TCB).

DESIGN

A case series.

SETTING

A single tertiary-referral center.

PATIENTS

Patients undergoing lower GI (LGI) EUS from July 1, 2005, to October 31, 2007.

INTERVENTION

EUS-FNA and/or TCB.

MAIN OUTCOME MEASUREMENTS

EUS features and cytologic and/or histologic confirmation of secondary rectal linitis plastica.

RESULTS

Over the 28-month period, an LGI-EUS was performed in 598 patients with presumed primary rectal cancer, of whom 6 (1%) were diagnosed with rectal-wall metastases. The EUS features were that of diffuse, circumferential, hypoechoic wall-thickening that mimics that of linitis plastica, breaching the muscularis propria in all cases. EUS-FNA and/or TCB of the rectal wall or perirectal lymph node established a diagnosis in all cases. The primary cancers originated from the bladder (n = 3), breast (n = 1), stomach (n = 1), and a right forearm cutaneous melanoma (n = 1). The time interval from the initial primary cancer diagnosis to that of GI-tract rectal metastasis ranged from 0 days (simultaneous diagnoses) to 119 months (mean +/- SD 49 +/- 43 months).

LIMITATIONS

Although firm EUS criteria of rectal-wall metastases cannot be established based on 6 patients alone, certain features may prove useful for the diagnosis in the clinical practice.

CONCLUSIONS

EUS-FNA and/or TCB can confirm the diagnosis of secondary linitis plastica of the rectum.

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

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

The postoperative surveillance of patients with colon cancer and rectal cancer

BACKGROUND

Colon cancer is relatively common; however, the results of treatment have marginally improved over the last half century. Though about 85% of patients have colorectal tumors resected with curative intent, a significant number of these patients will eventually die from cancer. As a result, many clinicians have advocated intensive follow-up in such patients as an attempt to increase survival.

DATA SOURCES

A review of the literature focusing on studies that have specifically addressed postoperative surveillance programs in patients with colorectal cancer was conducted. Only studies with level A evidence were included. Further references were obtained through cross-referencing the bibliography cited in each work.

CONCLUSION

One of the six prospective randomized studies demonstrated a statistically significant survival benefit. Undoubtedly, survival benefits can be shown with a well-designed evidence-based follow-up strategy. However, well-designed large prospective multi-institutional randomized studies are needed to establish a consensus for follow-up.

Endorectal ultrasound-directed biopsy: a useful technique to detect local recurrence of rectal cancer

AIMS

This study assesses the value of endorectal ultrasound (ERUS)-directed biopsy in detecting local recurrence of rectal cancer.

METHODS

We reviewed the records of patients undergoing ERUS by a single surgeon for surveillance after treatment of rectal adenocarcinoma. Lesions suggestive of local recurrence underwent ERUS-assisted core-needle biopsy (EAB) via a proctoscope after precise ERUS localization or direct ERUS-guided biopsy (EGB) via a B&K Medical probe.

RESULTS

From 1991 to 2003, 525 patients underwent 2,490 surveillance ERUS. Of these patients, 51 underwent 62 biopsy sessions: 36 EGB and 26 EAB. The mean age of patients was 67.2 years (range 38-93 years); 22 (43%) were female. Only 11 patients (22%) had undergone prior radical resection of their primary tumor. No patient experienced a complication from the biopsies despite five being anticoagulated. Of 39 patients whose cancer recurrence was documented during follow-up, 32 (82%) were diagnosed at the initial biopsy session, and in five (13%), recurrence was detected only with ERUS. The combined sensitivity, specificity, and accuracy of EAB and EGB in detecting recurrence was 83, 100, and 87%, respectively. In 26 patients with local recurrence, resection was performed with curative intent.

CONCLUSION

ERUS with biopsy is useful in detecting local recurrence after treatment of rectal cancer. It is safe, with a high diagnostic yield. It may be particularly useful in patients at higher risk for local recurrence (i.e., after endocavitary radiation and local excision) and may allow early detection of local recurrence, thereby permitting attempts at curative resection.

Development of a cost-effective system for digital off-line analysis of transrectal ultrasound

BACKGROUND

Transrectal ultrasound (TRUS) is the most sensitive and accurate technique for preoperative staging and follow-up of rectal cancer. One of the most relevant problems of this technique is that the assessment of TRUS is possible only during real-time examination. Furthermore, interpretation of the ultrasound findings is difficult and requires long experience. We show the development of a new, cost-effective software solution for off-line examination and documentation of transrectal ultrasound.

METHODS

The ultrasound device is connected to a frame-grabber card in a standard PC. Video capturing is done using a freeware software solution and various video codecs. The whole examination course is recorded. The examiner only has to concentrate on producing an artifact-free realization of the examination.

RESULTS

The software solution offers a flexible review of each individual "frame" of the investigation on the personal computer, very similar to CT and MRI scans. Infiltration depth and lymph node status can be assessed at any time, independently of the investigation and the investigator. The picture quality is excellent even if a lossy codec is used. It is not necessary to do definitive assessment of the TRUS during the examination.

CONCLUSIONS

This new technique gives a cost-effective possibility for high-quality off-line staging, re-examination, re-evaluation, and documentation of rectal cancer. TRUS becomes an examiner-independent objective examination technique for staging and follow-up of rectal cancer.

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.

ASGE guideline: the role of endoscopy in the diagnosis, staging, and management of colorectal cancer

This is one of a series of statements discussing the utilization of GI endoscopy in common clinical situations. The Standards of Practice Committee of the American Society for Gastrointestinal Endoscopy prepared this text. In preparing this guideline, a MEDLINE literature search was performed, and additional references were obtained from the bibliographies of the identified articles and from recommendations of experts. When little or no data exist from well-designed prospective trials, emphasis is given to results from large series and reports from recognized experts. Guidelines for appropriate utilization of endoscopy are based on a critical review of the available data and expert consensus. Further controlled clinical studies are needed to clarify aspects of this statement and revision needed to clarify aspects of this statement and revision may be necessary as new data appear. Clinical consideration may justify a course of action at variance to the recommendations.

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.

The preoperative assessment and postoperative surveillance of patients with colon and rectal cancer

Many advances have been made in the field of colorectal cancer follow-up since the pioneering efforts of Wangensteen and others with second-look operations in the 1950s. The understanding of the biology and natural history of colorectal malignancy has been advanced. Diagnostic methods for detection of recurrent disease have also advanced tremendously with CEA monitoring, immunoscintigraphy. CT, MRI, and PET imaging. As has been discussed in this article, however, no strategy of postoperative follow-up has been shown unequivocally to produce improved survival benefit or cure rate. It is quite possible that benefit will be shown, but well-controlled trials will be required. Cost considerations will likely prove important, because the rate of detection of curable disease will likely.be low. Quality of life issues will also be important in such trials. Better treatment and outcome ol recurrent disease would provide a strong rationale for vigorous postoperative surveillance. New recommendations are currently evolving [54]. Early diagnosis seems likely to enhance the curability of both local and distant relapses and second primary tumors. Furthermore, there may be a survival and quality of life advantage that results from the early institution of chemotherapy, even for those tumors found to be inoperable [55]. In devising a plan for follow-up in patients, it is important to recognize the anatomic and temporal patterns of recurrence as well as their relationships to the initial tumor staging. Although there is little proof that the identification of recurrent disease in follow-up programs increases the likelihood of resectability, cure, or prolonged survival, many physicians have witnessed successful treatment of recurrent colorectal cancer. These anecdotal experiences, the unproven belief that follow-up is beneficial, and traditions imparted during training are among the likely motivating factors for most physicians caring for colorectal cancer patients.

Follow-up of patients with colorectal cancer: numbers needed to test and treat

Follow-up after curative treatment of patients with colorectal cancer has as its main aims the quality assessment of the treatment given, patient support, and improved outcome by the early detection and treatment of cancer recurrence. How often, and to what extent, the final aim, improved survival, is indeed realised is so far unclear. A literature search was performed to provide quantitative estimates for the main determinants of the effectiveness of the follow-up. Data were extracted from a total of 267 articles and databases, and were aggregated using modern meta-analytic methods. In order to provide one more colorectal cancer patient with long-term survival through follow-up, 360 positive follow-up tests and 11 operations for colorectal cancer recurrence are needed. In the remaining 359 tests and 10 operations, either no gains are achieved or harm is done. As the third aim of colorectal cancer follow-up, improved survival, is realised in only few patients, follow-up should focus less on diagnosis and treatment of recurrences. It should be of limited intensity and duration (3 years), and the search for preclinical cancer recurrence should primarily be performed by carcino-embryonic antigen (CEA) testing and ultrasound (US). The focus of colorectal cancer follow-up should shift from the early detection of recurrence towards quality assessment and patient support. As support that is as good or even better can be provided by a patient's general practitioner (GP) or by specialised nursing personnel, there is no need for routine follow-up to be performed by the surgeon.

Effectiveness of endoluminal sonography in the identification of occult local rectal cancer recurrences

PURPOSE

Local recurrence of rectal cancer after curative surgery appears in 5 to 30 percent of all cases. It is necessary to detect local recurrence in a resectable stage to have an opportunity for curative reintervention or palliative prevention of those symptoms. Because most local recurrences occur extraluminally, conventional follow-up fails to detect them at an early stage. Therefore, a prospective study was performed to assess the diagnostic potential of endorectal and endovaginal ultrasound to detect asymptomatic resectable local recurrence.

METHODS

In 338 patients 721 endoluminal ultrasound examinations were added to routine follow-up of rectal and left colonic cancer, with a mean of 2.1 (range, 1-10) endoluminal ultrasound examinations for each patient.

RESULTS

A total of 116 patients (34.3 percent) were shown to have local recurrence, which was suggested by endoluminal ultrasound and proven by endoluminal ultrasound-guided needle biopsy in all cases of unclear pararectal structures that could not be verified by endoscopic biopsy. Digital examination failed to detect local recurrence in 91 patients, endoscopy failed to detect local recurrence in 80 patients, and the levels of tumor markers were normal in 25 patients with confirmed local recurrence. In 33 cases of local recurrence, both digital examination and endoscopy results were normal. Twenty-five patients, in whom carcinoembryonic antigen levels, digital examination, and endoscopy results were normal, underwent potential curative reoperation, with total resection of the local recurrence. All 25 patients were still alive at the end of the study period, and 21 were free from disease. On the other hand, only 6 of 67 patients with local recurrence detectable by conventional follow-up could be operated on with curative intention.

CONCLUSION

Postoperative endoluminal ultrasound is able to detect local recurrence at an earlier and asymptomatic stage and can be verified by endosonography-guided needle biopsy. Routine use in follow-up may raise the ratio of curative retreatment by early detection of extramural local recurrence.

Tumor angiogenesis predicts recurrence with normal serum carcinoembryonic antigen in advanced rectal carcinoma patients

Many studies have established the usefulness of serum carcinoembryonic antigen (CEA) oriented serial monitoring for predicting recurrence and prognosis; however, few studies have so far investigated serum CEA-negative recurrence. The aim of this study was to elucidate the nature of CEA-negative recurrence regarding tumor angiogenesis. Fifty-seven patients with T3/T4 rectal cancer were divided into the two groups according to the serum CEA status. Angiogenesis was defined as the intratumoral vessel count by immunohistochemical staining using CD31. The CD31 count was significantly higher in the recurrent patients in both groups and the ratio of nodal involvement was significantly higher in the recurrent patients of the CEA-negative group. Local recurrence mainly developed in the CEA-negative group; however, the CD31 count did not predict the sites of recurrence nor the relapse period in the both groups. A multivariate analysis showed a high CD31 count >26) to be a prognostic factor not only for recurrence but also for survival (P = 0.001, 0.043, respectively). These results suggest that a high degree of tumor angiogenesis in sections of T3/T4 rectal cancer may therefore be an important predictor for CEA-negative recurrence.

Additional value of whole-body positron emission tomography with fluorine-18-2-fluoro-2-deoxy-D-glucose in recurrent colorectal cancer

PURPOSE

To assess the additional value of the whole-body [18F]-2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) scan as a staging modality complementing conventional diagnostic methods (CDM) in patients suspected of having recurrent colorectal adenocarcinoma.

PATIENTS AND METHODS

In 103 patients, the discordances between FDG-PET and CDM results were identified and related to the final diagnosis obtained by histopathology or clinical follow-up (> 1 year). All FDG-PET studies were reviewed with full knowledge of the CDM findings.

RESULTS

In a region-based analysis, discordances between CDM and FDG-PET findings were found in 40 of 412 regions (10%). In these, FDG-PET had additional diagnostic value in 14 of 16 locoregional, six of seven hepatic, seven of eight abdominal, and eight of nine extra-abdominal regions. In a patient-based analysis, CDM categorized a subgroup of 60 patients as having resectable recurrent disease limited to the liver (n = 37) or locoregional region (n = 23). In 13 of these patients, there were discordant FDG-PET findings, detecting additional tumor sites in nine patients and excluding disease in three patients and yielding an additional diagnostic value in 20% of the patients. A second subgroup consisted of 13 patients with inconclusive CDM findings (n = 5) or with elevated plasma carcinoembryonic antigen levels and an otherwise negative conventional work-up (n = 8). In these patients, FDG-PET results were correct in eight of nine discordances, yielding a positive additional diagnostic value in 62% of the patients.

CONCLUSION

Whole-body FDG-PET can have a clear impact on the therapeutic management in the follow-up of patients with colorectal cancer.

Multidisciplinary management of recurrent colorectal cancer

Isolated pelvic recurrence of rectal carcinoma may occur in up to one third of patients following definitive resection of primary disease. The means by which recurrence is diagnosed, methods by which it may be treated, and reported outcomes are all evolving and improving. Current data indicate that a substantial proportion of patients treated by aggressive multi-modality salvage therapy may be provided with durable survival. This review highlights current concepts in the diagnosis and management of locally recurrent rectal carcinoma.

Surgeon-performed ultrasound: its use in clinical practice

OBJECTIVE

To highlight areas where surgeon-performed ultrasound (US) is an effective diagnostic and therapeutic tool.

SUMMARY BACKGROUND DATA

The success of US in trauma and technologic advances have enhanced the interest and ability of surgeons to perform their own US examinations.

METHODS

General surgeons perform US examinations of the thyroid gland, breast, gastrointestinal tract, peritoneal cavity (laparoscopy), and vascular system. Essentials of these examinations are discussed and a plan for educating surgical residents in US is outlined.

RESULTS

Focused assessment for the sonographic examination of the trauma patient, or FAST, is replacing central venous pressure measurements to detect hemopericardium and diagnostic peritoneal lavage to detect hemoperitoneum. Bedside US can be used to detect a pleural effusion so well in critically ill patients that lateral decubitus x-rays are rarely needed. US-directed biopsy of breast lesions is a common office procedure. Laparoscopic US allows tumor staging without formal celiotomy, and many hepatic and pancreatic surgical procedures include US as an adjunct. Endoscopic and endorectal US have added a new dimension to the assessment of many gastrointestinal lesions. Color flow duplex imaging and endoluminal US have significantly expanded the diagnostic and therapeutic aspects of vascular imaging. The training program developed at Emory University and Grady Memorial Hospital is offered as a model for educating surgical residents in US techniques.

CONCLUSIONS

US is a valuable addition to the general surgeon's diagnostic armamentarium and is rapidly becoming an integral part of the surgeon's clinical practice.

Preoperative and postoperative imaging for colorectal cancer

Management and survival in colorectal cancer are dictated by the extent of the disease at the initial diagnosis. Technological advances over the past 25 years have improved the ability to accurately preoperatively stage these lesions and detect recurrence. This article reviews the focus on the utility of computerized tomography, magnetic resonance, endoscopic ultrasound, and newer imaging methods including PET scan and monoclonal antibodies in the management of colorectal carcinoma.

Early detection of locally recurrent rectal cancer by endosonography

After curative surgery for rectal cancer, the goal of an aggressive surveillance programme is the detection of local recurrence (LR) at an early and potentially curable stage 62 patients (mean age 66.2 years) operated on for rectal cancer were prospectively enrolled in a follow-up study including endorectal ultrasound (EUS), serial CEA levels, digital examination, colonoscopy and pelvic CT. A total of 192 sonographic scans were performed, with a mean of three (range 2-7) for each patient. LR occurred in 11 patients; in all cases this was suggested by EUS. In two patients (18%) other techniques had failed to detect recurrent disease, which was identified solely by EUS. These two were treated radically and the remainder received radiotherapy or other palliative management. Five patients are alive at, on average, 18 months after LR (range 4-26 months). These include both cases treated with salvage surgery and who remain disease free. EUS is a valuable tool in the detection of locally recurrent rectal cancer.

Reliability and validity studies of endoluminal ultrasonography for anorectal disorders

PURPOSE

Endoluminal ultrasonography (ELUS) is accurate in the assessment of penetration through the rectal wall by carcinoma. Clinical studies were performed to determine the reliability and validity of ELUS.

METHODS

The interobserver reliability among four observers with varying experience with ELUS was determined for staging the penetration of rectal cancer through the rectal wall. The ability of ELUS to change the clinical management of the referring clinician (comprehensiveness) was assessed on all referrals over a six-month period.

RESULTS

The reliability of ELUS for staging rectal cancer demonstrated only fair to moderate correlation (weighted kappa range, 0.22-0.47). The accuracy of ELUS compared with surgical pathology demonstrated a learning curve proportional to the experience of the observer. In 45 percent of referrals, ELUS changed the clinical management of patients and in 76 percent of referrals the clinician's confidence in the diagnosis and management of patients was altered. ELUS was more likely to change the management of patients with pelvic pouch sepsis (70 percent) and early neoplastic lesions (57 percent) than in more advanced neoplastic lesions (40 percent), perianal Crohn's disease (40 percent), complex noninflammatory bowel disease sepsis (33 percent), and incontinence (31 percent).

CONCLUSIONS

ELUS has the ability to change the clinical management of a variety of anorectal conditions. However, for neoplasia the interobserver reliability is only moderate and a learning curve exists.

Optimal follow-up in colorectal cancer patients: what tests and how often?

Patients' benefit from follow-up examinations after curative surgery for colorectal cancer is unproven in spite of numerous different programs' having been designed for that purpose. Unfortunately, no final results from prospective randomized studies have been published yet and no ideal marker for recurrent cancer is available to identify patients in whom new curative treatment may be possible. So far, screening for metachronous neoplasia with intervals of several years may influence survival, whereas benefit from detecting recurrent colorectal cancer may be claimed only by using historical or other inappropriate controls. The tradition of follow-up is expensive and prospective evidence for any cost benefit is needed to justify continuous use of our limited resources in this area of patient care.

Local recurrence of rectal adenocarcinoma after 'curative' surgery with and without preoperative radiotherapy

The natural history of locally recurrent rectal cancer was analysed to assess whether preoperative irradiation altered the clinical course of the disease. In a randomized controlled trial of 849 patients, the value of preoperative radiotherapy in those with operable rectal adenocarcinoma was examined. After a minimum follow-up of 4 years, 156 patients who developed local recurrence were studied retrospectively. There were no differences concerning symptoms and the site of local recurrence between irradiated and non-irradiated patients. Curative treatment was rarely possible and median survival was only about 1 year, irrespective of adjuvant treatment. Local recurrence was the only manifestation of disease in 30-50 per cent of patients. An earlier and more aggressive surgical approach might improve survival.

New staging techniques. Endoscopic ultrasound

Rectal ultrasonography allows detailed images of rectal tumors and provides the most accurate method of staging rectal cancer. Ultrasound assessment of the extent of tumor invasion and lymph node involvement is superior to computed tomography (CT) scan, though CT is still the best method to assess liver involvement. Ultrasound assessment of cancers above the peritoneal reflection is less useful clinically because it currently does not alter management. Outcome studies have not been reported using ultrasound to stage rectal cancer but should be forthcoming. Inflammation present at the leading edge of the tumor is the greatest cause for overstaging, and difficulty in determining tumor involvement into, but not through, the muscularis propria is another important cause of inaccurate staging. Lymph node assessment can be problematic, but future developments in ultrasound-guided fine-needle aspiration cytology holds promise for more accurate assessment of lymph node status. Surgery will remain the standard method to treat rectal cancer, but new methods, such as high-intensity focused ultrasound, may provide new ways to treat some patients.

Intrarectal ultrasound in the evaluation of perirectal abscesses

Experience with intrarectal ultrasonography (IRUS) is limited for the evaluation of perianal sepsis. The purpose of this article is to report our experience with IRUS in evaluating 24 cases of suspected perianal abscess and fistula. IRUS was performed intraoperatively using a Brüel & Kjaer (Model #1846; Naerum, Denmark) endoanal ultrasound scanner with a 7-MHz transducer. After completion of the IRUS, careful anorectal examination and appropriate surgical therapy were performed. At surgery, 19/24 patients were found to have perirectal abscesses, with all 19 cases correctly identified preoperatively by IRUS. In 12 cases (63 percent), IRUS correctly defined the relationship between the abscesses and sphincters by Parks' classification. At surgery, internal openings of fistulous tracts were found in 14/19 cases, but IRUS identified only 4/14 (28 percent). In 6/24 cases, IRUS and clinical evaluation did not demonstrate a perirectal abscess. The role of IRUS in the evaluation of perirectal abscess is evolving. Certainly, uncomplicated abscesses can be managed without ultrasonography. However, IRUS can be an adjunct to careful evaluation of complex perianal suppurative disease.

Endoluminal transrectal ultrasonography: accuracy, reliability, and validity

The significant risk of local recurrence after curative resection and the relative inaccuracy of preoperative clinical assessment justify a more sophisticated assessment for carcinoma of the rectum. Endoluminal rectal ultrasonography (EU) can directly visualize the degree of rectal wall penetration by tumor and the immediate pararectal lymph nodes. Despite several reports reporting excellent accuracy of EU compared with pathology in detecting the degree of tumor penetration, EU remains restricted in terms of widespread availability. A review of the literature was performed to determine the accuracy, reliability, and current validity of EU. Raw data were collected from cross-sectional surveys assessing the degree of tumor penetration in 873 patients and lymph node involvement in 571 patients with primary rectal cancer. EU is very accurate at determining tumor penetration (kappa = 0.85) but is only moderately accurate at detecting lymph node involvement (kappa = 0.58). The reliability of EU has not been assessed, and a simple protocol is proposed. The validity of EU was assessed in only a few studies. EU is credible and feasible, makes intuitive biologic sense, and is, perhaps, sensitive to change. The ability to make clinical decisions based on EU (content validity) will decide whether widespread implementation is applicable.

How accurate is endorectal ultrasound in the preoperative staging of rectal cancer?

In rectal cancer, depth of infiltration and metastatic involvement of lymph nodes are important prognostic factors. The correct choice of operative treatment depends on the extent of the disease. In a prospective study, the value of endorectal ultrasound in staging rectal cancer was evaluated, and factors affecting the method's accuracy are discussed. The overall accuracy in staging depth of infiltration was 89 percent. Overstaging occurred in 10.2 percent, understaging in 0.8 percent. Tumors of the lower rectum are incorrectly staged in 16.7 percent, whereas tumors of the middle and upper rectum had an incorrect staging in 6.3 percent (P < 0.001). Compared with computed tomography, endorectal sonography is the more accurate staging method (74.7 vs. 90.8 percent). In staging lymph nodes, the overall accuracy was 80.2 percent, sensitivity was 89.4 percent, specificity was 73.4 percent, positive predictive value (PPV) was 71.2 percent, and negative predictive value (NPV) was 90.4 percent. The staging accuracy depends on the size of the node. Endorectal ultrasound is a safe, inexpensive, and accurate staging method, in the assessment of both depth of infiltration and nodal status. The results are strongly related to the experience of the investigator.

Early results of follow-up after radical resection for colorectal cancer. Preliminary results of a prospective randomized trial

One-hundred and six consecutive patients were included in a prospective study of intensive monitoring after radical resection for colorectal cancer, 54 being randomized into a conventional follow-up group (Group I) and 52 into an intensified follow-up group (Group II). After a median follow-up of 2 years the overall rate of detection recurrence in Group I was 24% (13/54) and in Group II 25% (13/52). The recurrence rates among those followed up for at least 2 years were 36% (10/28) and 30% (9/30), respectively. Of the recurrences in Group I, one was local, five regional and six distant, and the corresponding figures in Group II were three, four and five. One radical extirpation of a local perineal recurrence has been performed in Group I, whereas two intestinal reresections for local anastomotic recurrences and two hepatic resections for solitary hepatic metastases have been performed in Group II. Mortality to date is 13% (7/54) in Group I and 8% (4/52) in Group II. Two adenomatous polyps have been removed from the colon in Group I during endoscopic surveillance and seven in Group II. These preliminary results encourage us to continue the trial up to 5 years after primary surgery.

Endoscopic ultrasonography in colorectal diseases

Since new flexible high-frequency ultrasound endoscopes are now available, the use of this technique in colorectal disease has been determined. Its role in the preoperative staging of rectal cancer, and in follow-up after surgery has been established, but its use in cases of anal cancer and in non-neoplastic rectal diseases still has to be demonstrated more precisely.

Ultrasonic endoluminal examination in the follow-up of colorectal cancer. Initial experience and results

We have been using endoluminal ultrasonography since 1988 as part of the follow-up procedure after colorectal surgery. A total of 106 patients with anterior resection of the rectum or the sigmoid colon were involved in 1988. The follow-up period for these patients ranged from 1 to 56 months after surgery (23.1 +/- 15.1 months after anterior resection of the rectum; 25.7 +/- 22 months after anterior resection of the sigmoid). During the observation period 7 patients developed recurrence after anterior resection of the rectum and 5 after anterior resection of the sigmoid. The primary stages for these patients had been 7 cases of Dukes' B, 3 of Dukes' C1 and 2 of Dukes' D. Raised serum CEA levels were found in 5 cases. In 3 other cases, we found pathological changes in the anastomotic region by means of endoscopy. In these the endorectal ultrasonic scan showed hypodense masses as a sign of recurrence. In 2 of these 3 cases, the serum CEA level was normal. In 4 cases endoluminal rectal ultrasonography alone was suspicious. This led to further diagnostic procedures and finally to radical excision. All suspicious ultrasonic images were monitored 2 to 4 weeks later. In cases of suspicion, endoscopic, needle or surgical transrectal biopsies were taken from all patients. In all cases, histological analysis confirmed the ultrasonic diagnosis of local recurrence.

Indications of endoscopic ultrasonography of the digestive tract

Endoscopic ultrasonography of the digestive tract provides for a precise ultrasonic study of the accessible gastrointestinal walls (esophagus, stomach, duodenum, rectum) and through the walls, of the adjacent organs (lymph node clusters, posterior mediastinum, pancreas, extrahepatic biliary ducts and perirectal environment). This method is more efficient than computerized tomography to evaluate the local and regional extension of esophageal, gastric and rectal carcinomas, producing little or no stenosis. It is the examination of choice to detect a perianastomotic recurrence of these cancers in the aetiological diagnosis of obstacles in the biliary tract and in the diagnosis and the pretherapeutic assessment of pancreatic cancers.