Computed tomographic colonography versus double-contrast barium enema for the preoperative evaluation of rectal cancer.

PURPOSE: We investigated whether or not computed tomographic colonography (CTC) is a viable alternative to double-contrast barium enema (BE) for a preoperative rectal cancer evaluation. METHODS: The size and distance from the anal canal to the lower or upper tumor borders were laterally measured in 147 patients who underwent CTC and BE. Measurements were grouped into early cancer, advanced, and after chemoradiation therapy (CRT). RESULTS: In the early and advanced cancer groups, all lesions were visualized by BE. In contrast, 3 (7.8%) early and 8 (7.3%) advanced cases, located at the anterior wall near the anal canal, were not visualized by CTC because of liquid level formation. In the CRT group, 16 (23.5%) and 4 (5.8%) cases were not visualized by CTC and BE, respectively. The BE and CTC size measurements were similar among cohorts. However, the distance from the anal canal's superior margin tended to be longer with BE, especially in early cancer. The differences in distance from the anal canal were significantly larger in the early cancer group than in the other two groups (p = 0.0024). CONCLUSION: CTC may be a viable alternative imaging modality in some cases. However, BE should be employed in anterior wall cases near the anal canal and CRT cases.

Magnetic Resonance Rectal Enema Versus Computed Tomographic Colonography in the Diagnosis of Rectosigmoid Endometriosis.

OBJECTIVES: Rectosigmoid involvement by endometriosis causes intestinal symptoms such as constipation, diarrhea, and dyschezia. A precise diagnosis about the presence, location, and extent of bowel implants is required to plan the most appropriate treatment. The aim of the study was to compare the accuracy of magnetic resonance with distension of the rectosigmoid (MR-e) with computed colonography (CTC) for diagnosing rectosigmoid endometriosis. METHODS: This study was based on the retrospective analysis of a prospectively collected database of patients with suspicion of rectosigmoid endometriosis who underwent both MR-e and CTC, and subsequently were treated by laparoscopy. The findings of imaging techniques were compared with surgical and histological results. RESULTS: Of 90 women included in the study, 44 (48.9%) had rectosigmoid nodules and underwent bowel surgery. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for the diagnosis of rectosigmoid endometriosis were 88.6%, 93.5%, 92.9%, 89.6%, and 91.1% for CTC, and 93.2%, 97.9%, 97.6%, 93.8%, and 95.6% for MR-e. There was no significant difference in the accuracy of both radiologic examinations for diagnosing rectosigmoid endometriosis (P = 0.344). However, MR-e was more accurate than CTC in estimating the largest diameter of the main rectosigmoid nodule (P < 0.001). The pain perceived by the patients was significantly lower during MR-e than during CTC (P < 0.001). CONCLUSIONS: MR-e and CTC have similar diagnostic performance for the diagnosis of rectosigmoid involvement of endometriosis. However, MR-e is more accurate in the estimation of the largest diameter of main rectosigmoid nodule and more tolerated than CTC.

Bowel preparation in CT colonography: Is diet restriction necessary? A randomised trial (DIETSAN).

OBJECTIVES: To investigate whether diet restriction affects quality of colon cleansing and patient tolerance during reduced bowel preparation for CT colonography (CTC). METHODS: Asymptomatic and symptomatic patients were enrolled in this pragmatic, single-centre, randomised trial. All patients were randomly assigned (1:1 ratio, blocks of ten) to receive a reduced bowel preparation and faecal tagging with (Diet-Restriction-Group [DR]) or without (No-Diet-Restriction-Group [NDR]) dietary restriction. Five readers performed a blinded subjective image analysis, by means of 4-point Likert-scales from 0 (highest score) to 3 (worst score). Endpoints were the quality of large bowel cleansing and tolerance to the assigned bowel preparation regimen. The trial is registered at ClinicalTrial.gov (URomLSDBAL1). RESULTS: Ninety-five patients were randomly allocated to treatments (48 in NDR-group, 47 in DR-group). Both groups resulted in optimal colon cleansing. The mean residual stool (0.22, 95%CI 0.00-0.44) and fluid burden (0.39, 95%CI 0.25-0.53) scores for patients in DR-group were similar to those in patients in NDR-group (0.25, 95%CI 0.03-0.47 [p = 0.82] and 0.49, 95%CI 0.30-0.67 [p = 0.38], respectively). Tolerance was significantly better in NDR-group. CONCLUSION: A reduced bowel preparation in association with faecal tagging and without any dietary restriction demonstrated optimal colon cleansing effectiveness for CTC, providing better patient compliance compared with dietary restriction. KEY POINTS: • Dietary restriction in reduced bowel preparation regimen can be avoided. • The quality of colon cleansing is not affected by dietary restriction. • The quality of faecal tagging is not affected by dietary restriction. • Avoidance of dietary restriction improves patients' tolerance for CTC.

Is whole-colon investigation by colonoscopy, computerised tomography colonography or barium enema necessary for all patients with colorectal cancer symptoms, and for which patients would flexible sigmoidoscopy suffice? A retrospective cohort study.

BACKGROUND: For patients referred to hospital with suspected colorectal cancer (CRC), it is current standard clinical practice to conduct an examination of the whole colon and rectum. However, studies have shown that an examination of the distal colorectum using flexible sigmoidoscopy (FS) can be a safe and clinically effective investigation for some patients. These findings require validation in a multicentre study. OBJECTIVES: To investigate the links between patient symptoms at presentation and CRC risk by subsite, and to provide evidence of whether or not FS is an effective alternative to whole-colon investigation (WCI) in patients whose symptoms do not suggest proximal or obstructive disease. DESIGN: A multicentre retrospective study using data collected prospectively from two randomised controlled trials. Additional data were collected from trial diagnostic procedure reports and hospital records. CRC diagnoses within 3 years of referral were sourced from hospital records and national cancer registries via the Health and Social Care Information Centre. SETTING: Participants were recruited to the two randomised controlled trials from 21 NHS hospitals in England between 2004 and 2007. PARTICIPANTS: Men and women aged ≥ 55 years referred to secondary care for the investigation of symptoms suggestive of CRC. MAIN OUTCOME MEASURE: Diagnostic yield of CRC at distal (to the splenic flexure) and proximal subsites by symptoms/clinical signs at presentation. RESULTS: The data set for analysis comprised 7380 patients, of whom 59% were women (median age 69 years, interquartile range 62-76 years). Change in bowel habit (CIBH) was the most frequently presenting symptom (73%), followed by rectal bleeding (38%) and abdominal pain (29%); 26% of patients had anaemia. CRC was diagnosed in 551 patients (7.5%): 424 (77%) patients with distal CRC, 122 (22%) patients with cancer proximal to the descending colon and five patients with both proximal and distal CRC. Proximal cancer was diagnosed in 96 out of 2021 (4.8%) patients with anaemia and/or an abdominal mass. The yield of proximal cancer in patients without anaemia or an abdominal mass who presented with rectal bleeding with or without a CIBH or with a CIBH to looser and/or more frequent stools as a single symptom was low (0.5%). These low-risk groups for proximal cancer accounted for 41% (3032/7380) of the cohort; only three proximal cancers were diagnosed in 814 low-risk patients examined by FS (diagnostic yield 0.4%). LIMITATIONS: A limitation to this study is that changes to practice since the trial ended, such as new referral guidelines and improvements in endoscopy quality, potentially weaken the generalisability of our findings. CONCLUSIONS: Symptom profiles can be used to determine whether or not WCI is necessary. Most proximal cancers were diagnosed in patients who presented with anaemia and/or an abdominal mass. In patients without anaemia or an abdominal mass, proximal cancer diagnoses were rare in those with rectal bleeding with or without a CIBH or with a CIBH to looser and/or more frequent stools as a single symptom. FS alone should be a safe and clinically effective investigation in these patients. A cost-effectiveness analysis of symptom-based tailoring of diagnostic investigations for CRC is recommended. TRIAL REGISTRATION: Current Controlled Trials ISRCTN95152621. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 66. See the NIHR Journals Library website for further project information.

CT colonography: role in FOBT-based screening programs for colorectal cancer.

Computed tomographic colonography (CTC) is a minimally invasive imaging examination for the colon, and is safe, well tolerated and accurate for the detection of colorectal cancer (CRC) and advanced adenoma. While the role of CTC as a primary test for population screening of CRC is under investigation, the fecal occult blood test (FOBT) has been recommended for population screening of CRC in Europe. Subjects with positive FOBT are invited to undergo total colonoscopy, which has some critical issues, such as suboptimal compliance, contraindications and the possibility of an incomplete exploration of the colon. Based on available data, the integration of CTC in FOBT-based population screening programs for CRC may fall into three scenarios. First, CTC is recommended in FOBT-positive subjects when colonoscopy is refused, incomplete or contraindicated. For these indications CTC should replace double-contrast barium enema. Second, conversely, CTC is not currently recommended as a second-level examination prior to colonoscopy in all FOBT-positive subjects, as this strategy is most probably not cost-effective. Finally, CTC may be considered instead of colonoscopy for surveillance after adenoma removal, but specific studies are needed.

Diagnosis of early colorectal cancer invasion depth by quantitative evaluation of the basal indentation in CT colonography.

OBJECTIVE: To investigate the feasibility of diagnosing the invasion depth of early colorectal cancer (CRC) by quantitatively evaluating the basal indentation (BI)-i.e., the intestinal lateral deformity-in CT colonography (CTC). MATERIALS AND METHODS: 34 early CRCs (13 Tis CRCs and 21 T1 CRCs) in 32 patients who underwent a preoperative CTC were retrospectively examined. Two radiologists calculated the depth of the BI on a computed tomographic air-contrast enema (CT enema) image, the depth of the BI due to the geometric function (BI-G) on a cross-sectional multiplanar reconstruction (CS-MPR) image, and the ratio of the BI to the BI-G (i.e., the "BI ratio") for each lesion. The BI ratios of the Tis and T1 CRCs were compared. RESULTS: The BI ratios were significantly higher in the T1 CRCs than in the Tis CRCs (p < 0.0001). The optimum cutoff value of the BI ratio for differentiating the T1 CRCs from the Tis CRCs was 1.64, with a sensitivity, specificity, and area under the curve of 90.5 %, 100 %, and 0.974, respectively. CONCLUSIONS: We have demonstrated for the first time that quantitatively evaluating the BI can improve the accuracy of diagnosis of early CRC invasion depth.

Degree of colonic distension: intrapatient comparison between CT colonography and CT with water enema.

PURPOSE: Compare colonic distension using CT colonography (CTC) and CT with water enema (CTWE) in the same patients. METHODS AND MATERIALS: Twenty-seven patients who underwent both CTC and CTWE, considering separately supine (CTC-S) and prone (CTC-P) acquisition of CTC were included. The colon was divided into six segments, performing both a qualitative and quantitative analysis. RESULTS: Adequate distension of sigmoid colon was more frequently achieved with CTC-P and CTWE compared to CTC-S (P<.05). CTC-P and CTWE showed better distension of the left colon compared to CTC-S (P<.01 and P=.03 regarding sigmoid colon, respectively; P=.01 and P=.03 regarding descending colon, respectively). CONCLUSIONS: Computed tomography (CT) studies of the colon should be customized to fulfill the clinical query.

Alternatives to colonoscopy for population-wide colorectal cancer screening.

Colorectal cancer is one of the top three cancers in the world in terms of incidence. Colonoscopy, which many regard as the gold standard in diagnosis of colonic polyps and neoplasm, is costly, invasive and labour-intensive, and deemed an unsuitable population-wide index screening tool. Alternative modalities, including guaiac and immunohistochemical faecal occult blood tests, computed tomographic colonography, colon capsule endoscopy, flexible sigmoidoscopy, and double-contrast barium enema are available. The procedures, test characteristics, and their implications are reviewed. Immunohistochemical faecal occult blood testing appears to be the most suitable population-wide screening test for an average-risk population, with flexible sigmoidoscopy as an alternative. More evidence is needed to determine the role of computed tomographic colonography and colon capsule endoscopy in colorectal cancer screening.

Alternatives to Incomplete Colonoscopy.

A thorough and complete colonoscopy is critically important in preventing colorectal cancer. Factors associated with difficult and incomplete colonoscopy include a poor bowel preparation, severe diverticulosis, redundant colon, looping, adhesions, young and female patients, patient discomfort, and the expertise of the endoscopist. For difficult colonoscopy, focusing on bowel preparation techniques, appropriate sedation and adjunct techniques such as water immersion, abdominal pressure techniques, and patient positioning can overcome many of these challenges. Occasionally, these fail and other alternatives to incomplete colonoscopy have to be considered. If patients have low risk of polyps, then noninvasive imaging options such as computed tomography (CT) or magnetic resonance (MR) colonography can be considered. Novel applications such as Colon Capsule™ and Check-Cap are also emerging. In patients in whom a clinically significant lesion is noted on a noninvasive imaging test or if they are at a higher risk of having polyps, balloon-assisted colonoscopy can be performed with either a single- or double-balloon enteroscope or colonoscope. The application of these techniques enables complete colonoscopic examination in the vast majority of patients.

Computed tomographic colonography compared with colonoscopy or barium enema for diagnosis of colorectal cancer in older symptomatic patients: two multicentre randomised trials with economic evaluation (the SIGGAR trials).

BACKGROUND: Computed tomographic colonography (CTC) is a relatively new diagnostic test that may be superior to existing alternatives to investigate the large bowel. OBJECTIVES: To compare the diagnostic efficacy, acceptability, safety and cost-effectiveness of CTC with barium enema (BE) or colonoscopy. DESIGN: Parallel randomised trials: BE compared with CTC and colonoscopy compared with CTC (randomisation 2 : 1, respectively). SETTING: A total of 21 NHS hospitals. PARTICIPANTS: Patients aged ≥ 55 years with symptoms suggestive of colorectal cancer (CRC). INTERVENTIONS: CTC, BE and colonoscopy. MAIN OUTCOME MEASURES: For the trial of CTC compared with BE, the primary outcome was the detection rate of CRC and large polyps (≥ 10 mm), with the proportion of patients referred for additional colonic investigation as a secondary outcome. For the trial of CTC compared with colonoscopy, the primary outcome was the proportion of patients referred for additional colonic investigation, with the detection rate of CRC and large polyps as a secondary outcome. Secondary outcomes for both trials were miss rates for cancer (via registry data), all-cause mortality, serious adverse events, patient acceptability, extracolonic pathology and cost-effectiveness. RESULTS: A total of 8484 patients were registered and 5384 were randomised and analysed (BE trial: 2527 BE, 1277 CTC; colonoscopy trial: 1047 colonoscopy, 533 CTC). Detection rates in the BE trial were 7.3% (93/1277) for CTC, compared with 5.6% (141/2527) for BE (p = 0.0390). The difference was due to better detection of large polyps by CTC (3.6% vs. 2.2%; p = 0.0098), with no significant difference for cancer (3.7% vs. 3.4%; p = 0.66). Significantly more patients having CTC underwent additional investigation (23.5% vs. 18.3%; p = 0.0003). At the 3-year follow-up, the miss rate for CRC was 6.7% for CTC (three missed cancers) and 14.1% for BE (12 missed cancers). Significantly more patients randomised to CTC than to colonoscopy underwent additional investigation (30% vs. 8.2%; p < 0.0001). There was no significant difference in detection rates for cancer or large polyps (10.7% for CTC vs. 11.4% for colonoscopy; p = 0.69), with no difference when cancers (p = 0.94) and large polyps (p = 0.53) were analysed separately. At the 3-year follow-up, the miss rate for cancer was nil for colonoscopy and 3.4% for CTC (one missed cancer). Adverse events were uncommon for all procedures. In 1042 of 1748 (59.6%) CTC examinations, at least one extracolonic finding was reported, and this proportion increased with age (p < 0.0001). A total of 149 patients (8.5%) were subsequently investigated, and extracolonic neoplasia was diagnosed in 79 patients (4.5%) and malignancy in 29 (1.7%). In the short term, CTC was significantly more acceptable to patients than BE or colonoscopy. Total costs for CTC and colonoscopy were finely balanced, but CTC was associated with higher health-care costs than BE. The cost per large polyp or cancer detected was £4235 (95% confidence interval £395 to £9656). CONCLUSIONS: CTC is superior to BE for detection of cancers and large polyps in symptomatic patients. CTC and colonoscopy detect a similar proportion of large polyps and cancers and their costs are also similar. CTC precipitates significantly more additional investigations than either BE or colonoscopy, and evidence-based referral criteria are needed. Further work is recommended to clarify the extent to which patients initially referred for colonoscopy or BE undergo subsequent abdominopelvic imaging, for example by computed tomography, which will have a significant impact on health economic estimates. TRIAL REGISTRATION: Current Controlled Trials ISRCTN95152621.

Identification of Extracolonic Pathologies by Computed Tomographic Colonography in Colorectal Cancer Symptomatic Patients.

BACKGROUND & AIMS: Symptoms suggestive of colorectal cancer may originate outside the colorectum. Computed tomographic colonography (CTC) is used to examine the colorectum and abdominopelvic organs simultaneously. We performed a prospective randomized controlled trial to quantify the frequency, nature, and consequences of extracolonic findings. METHODS: We studied 5384 patients from 21 UK National Health Service hospitals referred by their family doctor for the investigation of colorectal cancer symptoms from March 2004 through December 2007. The patients were assigned randomly to groups that received the requested test (barium enema or colonoscopy, n = 3574) or CTC (n = 1810). We determined the frequency and nature of extracolonic findings, subsequent investigations, ultimate diagnosis, and extracolonic cancer diagnoses 1 and 3 years after testing patients without colorectal cancer. RESULTS: Extracolonic pathologies were detected in 959 patients by CTC (58.7%), in 42 patients by barium enema analysis (1.9%), and in no patients by colonoscopy. Extracolonic findings were investigated in 142 patients (14.2%) and a diagnosis was made for 126 patients (88.1%). Symptoms were explained by extracolonic findings in 4 patients analyzed by barium enema (0.2%) and in 33 patients analyzed by CTC (2.8%). CTC identified 72 extracolonic neoplasms, however, barium enema analysis found only 3 (colonoscopy found none). Overall, CTC diagnosed extracolonic neoplasms in 72 of 1634 patients (4.4%); 26 of these were malignant (1.6%). There were significantly more extracolonic malignancies detected than expected 1 year after examination, but these did not differ between patients evaluated by CTC (22.2/1000 person-years), barium enema (26.5/1000 person-years; P = .43), or colonoscopy (32.0/1000 person-years; P = .88). CONCLUSIONS: More than half of the patients with symptoms of colorectal cancer are found to have extracolonic pathologies by CTC analysis. However, the proportion of patients found to have extracolonic malignancies after 1 year of CTC examination is not significantly greater than after barium enema or colonoscopy examinations. International Standard Randomised Controlled Trials no: 95152621.isrctn.com.

The effect of thyme honey nasal spray on chronic rhinosinusitis: a double-blind randomized controlled clinical trial.

Chronic rhinosinusitis is a common disease which causes persisting inflammatory conditions of one or more sinuses. This study was designed to evaluate the effect of thyme honey nasal spray as an adjunctive medication on chronic rhinosinusitis after functional endoscopic sinus surgery. This was a randomized, placebo controlled, double-blind clinical study. 64 patients with chronic rhinosinusitis undergoing functional endoscopic sinus surgery were enrolled in this study. Patients were randomized and blinded to receive either placebo or thyme honey nasal spray in addition to the standard regimen postoperatively. Patients were visited on postoperative days 7, 30 and 60. The sino-nasal outcome test, endoscopic grading system and sinus CT-scan were scored before operation and on the day 60 after surgery. 54 patients completed the study. Significant improvement was observed in both treatment groups. There were no significant changes in SNOT-22, endoscopy and CT-scan scores between the two study groups. However, a greater reduction in endoscopic scores was shown in thyme honey group. The incidence of adverse effects was not significantly different between the groups, but synechiae formation and epistaxis were lower in treatment group. Thyme honey nasal spray seems to be a low-priced potential adjuvant remedy with excellent safety profile, to reduce inflammation and polyp formation and also fostering mucosal healing for patients suffering from chronic rhinosinusitis. However, further studies are recommended.

Computed tomography colonography in 2014: an update on technique and indications.

Twenty years after its introduction, computed tomographic colonography (CTC) has reached its maturity, and it can reasonably be considered the best radiological diagnostic test for imaging colorectal cancer (CRC) and polyps. This examination technique is less invasive than colonoscopy (CS), easy to perform, and standardized. Reduced bowel preparation and colonic distention using carbon dioxide favor patient compliance. Widespread implementation of a new image reconstruction algorithm has minimized radiation exposure, and the use of dedicated software with enhanced views has enabled easier image interpretation. Integration in the routine workflow of a computer-aided detection algorithm reduces perceptual errors, particularly for small polyps. Consolidated evidence from the literature shows that the diagnostic performances for the detection of CRC and large polyps in symptomatic and asymptomatic individuals are similar to CS and are largely superior to barium enema, the latter of which should be strongly discouraged. Favorable data regarding CTC performance open the possibility for many different indications, some of which are already supported by evidence-based data: incomplete, failed, or unfeasible CS; symptomatic, elderly, and frail patients; and investigation of diverticular disease. Other indications are still being debated and, thus, are recommended only if CS is unfeasible: the use of CTC in CRC screening and in surveillance after surgery for CRC or polypectomy. In order for CTC to be used appropriately, contraindications such as acute abdominal conditions (diverticulitis or the acute phase of inflammatory bowel diseases) and surveillance in patients with a long-standing history of ulcerative colitis or Crohn's disease and in those with hereditary colonic syndromes should not be overlooked. This will maximize the benefits of the technique and minimize potential sources of frustration or disappointment for both referring clinicians and patients.

In vivo MRI virtual colonography in a mouse model of colon cancer.

We have developed a reliable noninvasive method for monitoring colonic tumors and mucosal inflammation in a mouse model of colon cancer using magnetic resonance colonography (MRC). After a mild cleansing enema, the colon is filled with Fluorinert, a perfluorinated liquid that does not produce a proton MR signal. The mouse is placed in a dedicated volume MR receiver coil, and high-resolution images are acquired in three planes. The Fluorinert enema distends the mouse colon, creating an artifact-free black homogeneous background, allowing clear delineation of the inflamed colonic wall and visualization of luminal tumors in various stages of development. A gadolinium-based contrast agent can be administered i.v. to the animal to detect mural inflammation or tumor vascularity. This technique is useful for serial monitoring of the effects of preventive or therapeutic strategies on tumor development without killing the animal or requiring invasive endoscopies. The animal preparation and imaging can be completed in ∼1.5 h.

Non- or full-laxative CT colonography vs. endoscopic tests for colorectal cancer screening: a randomised survey comparing public perceptions and intentions to undergo testing.

OBJECTIVES: Compare public perceptions and intentions to undergo colorectal cancer screening tests following detailed information regarding CT colonography (CTC; after non-laxative preparation or full-laxative preparation), optical colonoscopy (OC) or flexible sigmoidoscopy (FS). METHODS: A total of 3,100 invitees approaching screening age (45-54 years) were randomly allocated to receive detailed information on a single test and asked to return a questionnaire. Outcomes included perceptions of preparation and test tolerability, health benefits, sensitivity and specificity, and intention to undergo the test. RESULTS: Six hundred three invitees responded with valid questionnaire data. Non-laxative preparation was rated more positively than enema or full-laxative preparations [effect size (r) = 0.13 to 0.54; p < 0.0005 to 0.036]; both forms of CTC and FS were rated more positively than OC in terms of test experience (r = 0.26 to 0.28; all p-values < 0.0005). Perceptions of health benefits, sensitivity and specificity (p = 0.250 to 0.901), and intention to undergo the test (p = 0.213) did not differ between tests (n = 144-155 for each test). CONCLUSIONS: Despite non-laxative CTC being rated more favourably, this study did not find evidence that offering it would lead to substantially higher uptake than full-laxative CTC or other methods. However, this study was limited by a lower than anticipated response rate. KEY POINTS: • Improving uptake of colorectal cancer screening tests could improve health benefits • Potential invitees rate CTC and flexible sigmoidoscopy more positively than colonoscopy • Non-laxative bowel preparation is rated better than enema or full-laxative preparations • These positive perceptions alone may not be sufficient to improve uptake • Health benefits and accuracy are rated similarly for preventative screening tests.

Imaging in colonic cancer.

Whilst the diagnosis of colonic cancer is always based on visually guided flexible colonoscopy, which is the only technique that provides a histological diagnosis, the pre-treatment assessment of the cancer involves computed tomography. This can determine the exact site of the cancer in the colon, its dimensions and juxta-colonic extension and is used to investigate for liver, mesenteric or lung metastases.

[Early detection of colorectal cancer: role of endoscopy and imaging]. / Früherkennung des kolorektalen Karzinoms: rolle der Endoskopie und bildgebenden Verfahren.

Colorectal cancer is one of the leading causes of cancer-related morbidity and mortality. Colorectal cancer commonly develops slowly via adenomatous polyps, a process usually requiring ≥ 10 years. This allows for early detection. Endoscopic polypectomy and surgery of early disease can reduce the incidence and mortality of colorectal cancer. Both hemoccult testing and colonoscopy are the most widely used tests for colorectal cancer screening; however, colonoscopy has the highest sensitivity for colorectal neoplasia. Sigmoidoscopy is not commonly used for screening in Germany. Colon contrast enema is no longer recommended for screening. As colonoscopy serves as a diagnostic and therapeutic tool and is the reference method in hemoccult and sigmoidoscopy studies, it is viewed as the gold standard for the diagnosis of colonic disease. New methods including capsule colonoscopy and virtual colonoscopy have great potential but are currently not recommended for early detection of colonic neoplasia.

Impact of contrast-enhanced computed tomography colonography on laparoscopic surgical planning of colorectal cancer.

AIM: To evaluate the impact of contrast-enhanced computed tomography colonography (CE-CTC) on laparoscopic surgery planning in patient with stenosing colorectal cancer. MATERIALS AND METHODS: Sixty-nine patients with endoscopically proven colorectal cancer underwent CE-CTC, after incomplete conventional colonoscopy. Two experienced radiologists evaluated site, length, and TNM staging of colorectal cancers on three-dimensional double contrast enema-like views, 2D axial and multiplanar reconstructions. All the patients underwent colorectal resection and surgery bulletin, pathology of surgical specimens, and radiological follow-up at about 8 months were used as reference standard. RESULTS: The detection rate of colorectal cancer was 100 % (75/75); CE-CTC allowed for a diagnosis of a synchronous colorectal cancer in five patients (7 %). CE-CTC correctly judged the site of the lesions in all the cases; clinically significant localization errors at conventional colonoscopy were noted in 3 out of 69 patients (4 %). Additional colonic polyps greater than 6 mm in diameter were found in 21 out of 69 patients (30 %); in two patients (3 %) the surgeon performed an enlarged colectomy to include synchronous polyps proximal to colorectal cancer. Sensitivity, specificity, PPV, NPV, and accuracy were for T1-T2 vs. T3-T4: 96 %, 71 %, 92 %, 87 %, and 91 %, respectively; for N: 94 %, 42 %, 64 %, 86 %, and 70 %; for M: 100 %, 100 %, 83 %, 100 %, and 97 %. There were no complications associated with CE-CTC. CONCLUSION: Information given by CE-CTC concerning colorectal cancer location and synchronous colonic cancers and polyps changed the laparoscopic surgical strategy in almost 14 % of patients.