Patient preferences for CT colonography, conventional colonoscopy, and bowel preparation

Acceptance and Preference of Computed Tomographic Colonography and Colonoscopy: Results of a Nationwide Multicenter Comparative Questionnaire Survey in Japan

Objectives

To investigate patient acceptance and preference for computed tomographic colonography (CTC) over colonoscopy.

Methods

Participants were recruited from a nationwide multicenter trial in Japan to assess the accuracy of CTC detection. They were scheduled to undergo colonoscopy after CTC with common bowel preparation on the same day. Some were administered sedative drugs during colonoscopy, depending on the referring clinician and participant's preferences. The participants were requested to complete a questionnaire to evaluate the acceptability of bowel preparation, examinations, and preference for future examinations.

Results

Of the 1,257 enrolled participants, 1,180 (mean age: 60.6 years; women: 43.3%) completed the questionnaire. Sedative drugs were not administered in 687 participants (unsedated colonoscopy group) and were administered intravenously during colonoscopy in 493 participants (sedated colonoscopy group). Before propensity score matching, the mean participants' age, percentages of asymptomatic participants, insufflation of gas during colonoscopy, and number of participants with a history of abdominal/pelvic operation significantly differed between the groups. After propensity score matching, 912 participants from each group were included in the analysis. In the unsedated colonoscopy group, CTC was answered as significantly easier than colonoscopy (p<0.001). Conversely, CTC was significantly more difficult than colonoscopy in the sedated colonoscopy group (p<0.001). In the unsedated colonoscopy group, 48% preferred CTC and 22% preferred colonoscopy for future examinations, whereas in the sedated colonoscopy group, 26% preferred CTC and 38% preferred colonoscopy (p<0.001).

Conclusions

CTC has superior participant acceptability compared with unsedated colonoscopy. However, our study did not observe the advantages of CTC acceptance over sedative colonoscopy.

Systematic review with meta-analysis: Diagnostic performance of faecal calprotectin in distinguishing inflammatory bowel disease from irritable bowel syndrome in adults

BACKGROUND

Symptoms of inflammatory bowel disease (IBD) often overlap with those of irritable bowel syndrome (IBS).

AIM

To evaluate the diagnostic performance of faecal calprotectin in distinguishing patients with IBD from those with IBS METHODS: We searched MEDLINE, Embase, Scopus, and Cochrane Library databases up to 1 January 2023. Studies were included if they assessed the diagnostic performance of faecal calprotectin in distinguishing IBD from IBS (defined according to the Rome criteria) using colonoscopy with histology or radiology as reference standard in adults. We calculated summary sensitivity and specificity and their 95% confidence intervals (CI) using a random-effect bivariate model. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies II.

RESULTS

We included 17 studies with a total of 1956 patients. The summary sensitivity was 85.8% (95% CI: 78.3-91), and the specificity was 91.7% (95% CI: 84.5-95.7). At a prevalence of IBD of 1%, the negative predictive value was 99.8%, while the positive predictive value was only 9%. Subgroup analyses showed a higher sensitivity in Western than in Eastern countries (88% vs 73%) and at a cut-off of ≤50 μg/g than at >50 μg/g (87% vs. 79%), with similar estimates of specificity. All studies were at "high" or "unclear" risk of bias.

CONCLUSIONS

Faecal calprotectin is a reliable test in distinguishing patients with IBD from those with IBS. Faecal calprotectin seems to have a better sensitivity in Western countries and at a cut-off of ≤50 μg/g.

2021 Patient Perceptions Regarding Colonoscopy Experience

GOAL

We sought to document patient perceptions in 2021 regarding colonoscopy experience and potential deterrents to repeat colonoscopy.

BACKGROUND AND AIM

Bowel preparation has been previously considered by patients to be the worst part of a colonoscopy.

MATERIALS AND METHODS

We conducted a prospective survey of consecutive patients age 18 years and older who had just completed colonoscopy at 2 outpatient endoscopy centers at a tertiary academic hospital. The short survey was conducted in the recovery area. The main outcome measure was patient perceptions of the worst part of their colonoscopy experience and which factor would most deter them from a future colonoscopy.

RESULTS

Four hundred patients completed the survey of 405 approached. Average patient age was 64 years, and 48% were women. Seventy-five percent of patients used low-volume preparations. Bowel preparation was considered the worst part of colonoscopy by 71% of patients. Women were more likely to choose laxatives as the worst part of a colonoscopy. Bowel preparation was chosen most often (55%) as the most likely deterrent to a future colonoscopy. There were minimal differences in responses between those receiving low-volume versus high-volume (4 L) preparations.

CONCLUSION

Bowel preparation remains the worst part of the colonoscopy experience for patients, and the most likely deterrent to future colonoscopy.

Amino acids-targeted metabolomics reveals novel diagnostic biomarkers for ulcerative colitis and Crohn's disease

Inflammatory bowel disease (IBD), which mainly comprises ulcerative colitis (UC) and Crohn's disease (CD), is a common chronic intestinal inflammatory disease that affects the ileum, rectum, and colon. Currently, the diagnosis of IBD is based on clinical history, physical examination and complementary diagnostic tests. It is challenging for physicians to make a definitive diagnosis. This study aimed to analyze the variation in amino acid metabolites in IBD serum and to identify potential predictive biomarkers of IBD diagnosis and progression. Serum samples were collected from 158 UC patients, 130 CD patients and 138 healthy controls (HCs). The 37 amino acids in serum were determined by ultra-high-pressure liquid chromatography coupled to a mass spectrometer. A panel of three-amino-acid metabolites (taurine, homocitrulline and kynurenine) was identified as a specific biomarker panel of IBD. Receiver operating characteristic analysis (ROC) showed that the panel had a sensitivity of 88.4% with a specificity of 84.6% for discriminating CD patients from UC patients. The biomarkers identified are increased in CD compared to UC. Our approach demonstrated a strong relationship between serum amino acid levels and IBD. We successfully identified serum amino acid biomarkers associated with CD and UC. The biomarker panel has potential in clinical practice for IBD diagnosis and will provide new insights into IBD pathogenesis.

Effect of dose splitting of a low-volume bowel preparation macrogol-based solution on CT colonography tagging quality

Purpose

To compare examination quality and acceptability of three different low-volume bowel preparation regimens differing in scheduling of the oral administration of a Macrogol-based solution, in patients undergoing computed tomographic colonography (CTC). The secondary aim was to compare CTC quality according to anatomical and patient variables (dolichocolon, colonic diverticulosis, functional and secondary constipation).

Methods

One-hundred-eighty patients were randomized into one of three regimens where PEG was administered, respectively: in a single dose the day prior to (A), or in a fractionated dose 2 (B) and 3 days (C) before the examination. Two experienced radiologists evaluated fecal tagging (FT) density and homogeneity both qualitatively and quantitatively by assessing mean segment density (MSD) and relative standard deviation (RSD). Tolerance to the regimens and patient variables were also recorded.

Results

Compared to B and C, regimen A showed a lower percentage of segments with inadequate FT and a significantly higher median FT density and/or homogeneity scores as well as significantly higher MSD values in some colonic segments. No statistically significant differences were found in tolerance of the preparations. A higher number of inadequate segments were observed in patients with dolichocolon (p < 0.01) and secondary constipation (p < 0.01). Interobserver agreement was high for the assessment of both FT density (k = 0.887) and homogeneity (k = 0.852).

Conclusion

The best examination quality was obtained when PEG was administered the day before CTC in a single session. The presence of dolichocolon and secondary constipation represent a risk factor for the presence of inadequately tagged colonic segments.

Radiologic Imaging Modalities for Colorectal Cancer

BACKGROUND

Studies reported various diagnostic value of radiologic imaging modalities for diagnosis and management of colorectal cancer (CRC).

AIMS

To summary the diagnosis and management of CRC using computed tomography colonography (CTC), magnetic resonance colonography (MRC), and positron emission tomography (PET)/computed tomography (CT).

METHODS

Comprehensive literature searches were conducted in PubMed, EmBase, and the Cochrane library for studies published before April 2021. The diagnostic performance of CTC, MRC, and PET/CT for CRC was summarized.

RESULTS

A total of 54 studies (17 studies for CTC, 8 studies for MRC, and 29 studies for PET/CT) were selected for final analysis. The sensitivity and specificity for CTC ranged from 27 to 100%, 88 to 100%, respectively, and the pooled sensitivity and specificity for CTC were 0.97 (95% CI 0.88-0.99) and 0.99 (95% CI 0.99-1.00). The sensitivity and specificity for MRC ranged from 48 to 100%, 60 to 100%, respectively, and the pooled sensitivity and specificity for MRC were 0.98 (95% C: 0.77-1.00) and 0.94 (95% CI 0.84-0.98). The sensitivity and specificity for PET/CT ranged from 84 to 100%, 33 to 100%, respectively, and the pooled sensitivity and specificity for PET/CT were 0.94 (95% CI 0.92-0.96) and 0.94 (95% CI 0.90-0.97). The area under the receiver operating characteristic curve for CTC, MRC, and PET/CT was 1.00 (95% CI 0.99-1.00), 0.99 (95% CI 0.98-1.00), and 0.97 (0.95% CI 0.95-0.98), respectively.

CONCLUSIONS

This study suggested both CTC and MRC with relative higher diagnostic value for diagnosing CRC, while PET/CT with higher diagnostic value in detecting local recurrence for patients with CRC.

Can adjuncts to bowel preparation for colonoscopy improve patient experience and result in superior bowel cleanliness? A systematic review and meta-analysis

BACKGROUND

Bowel preparation for colonoscopy is often poorly tolerated due to poor palatability and adverse effects. This can negatively impact on the patient experience and on the quality of bowel preparation. This systematic review and meta-analysis was carried out to assess whether adjuncts to bowel preparation affected palatability, tolerability and quality of bowel preparation (bowel cleanliness).

METHODS

A systematic search strategy was conducted on PubMed, MEDLINE, EMBASE and the Cochrane Database of Systematic Reviews to identify studies evaluating adjunct use for colonoscopic bowel preparation. Studies comparing different regimens and volumes were excluded. Specific outcomes studied included palatability (taste), willingness to repeat bowel preparation, gastrointestinal adverse events and the quality of bowel preparation. Data across studies were pooled using a random-effects model and heterogeneity assessed using I2-statistics.

RESULTS

Of 467 studies screened, six were included for analysis (all single-blind randomised trials; n = 1187 patients). Adjuncts comprised citrus reticulata peel, orange juice, menthol candy drops, simethicone, Coke Zero and sugar-free chewing gum. Overall, adjunct use was associated with improved palatability (mean difference 0.62, 95% confidence interval 0.29-0.96, p < 0.001) on a scale of 0-5, acceptability of taste (odds ratio 2.75, 95% confidence interval: 1.52-4.95, p < 0.001) and willingness to repeat bowel preparation (odds ratio 2.92, 95% confidence interval: 1.97-4.35, p < 0.001). Patients in the adjunct group reported lower rates of bloating (odds ratio 0.48, 95% confidence interval: 0.29-0.77, p = 0.003) and vomiting (odds ratio 0.47, 95% confidence interval 0.27-0.81, p = 0.007), but no difference in nausea (p = 0.10) or abdominal pain (p = 0.62). Adjunct use resulted in superior bowel cleanliness (odds ratio 2.52, 95% confidence interval: 1.31-4.85, p = 0.006). Heterogeneity varied across outcomes, ranging from 0% (vomiting) to 81% (palatability), without evidence of publication bias. The overall quality of evidence was rated moderate.

CONCLUSION

In this meta-analysis, the use of adjuncts was associated with better palatability, less vomiting and bloating, willingness to repeat bowel preparation and superior quality of bowel preparation. The addition of adjuncts to bowel preparation may improve outcomes of colonoscopy and the overall patient experience.

You won't regret it (or love it) as much as you think: impact biases for everyday health behavior outcomes

When predicting the future, people tend to overestimate the intensity of their emotions, a phenomenon known as the impact bias. Design: In two studies, we examined the impact bias for health outcomes. In Study 1, participants were randomized to think about a negative health outcome in the future or one in the past. In Study 2, participants came to the laboratory and were asked to predict and report their emotions surrounding an actual health outcome (consuming an unhealthy food). Results: In both studies, an impact bias emerged. In Study 1, participants thinking about an outcome in the future estimated more negative emotion than those thinking about an outcome in the past. In Study 2, when facing an actual health outcome, participants anticipated more negative and positive emotion than they experienced. Impact biases were also associated with behavioral motivation - desire to change the outcome (Study 1) and increased preventive intentions (Study 2). Additional analyses revealed that regret was a particularly important emotion. Conclusion: Although research has highlighted an impact bias for severe health outcomes like disease, these studies provide evidence of an impact bias for health outcomes generally. They also suggest that the bias may have implications for behavior intentions.

Analytical and clinical performance of the fully-automated LIAISONXL calprotectin immunoassay from DiaSorin in IBD patients

Objectives

Distinction between inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) based on clinical symptoms is often difficult. In this study we assessed the performance of the fully-automated calprotectin immunoassay from DiaSorin in IBD diagnosis and follow-up and compared it to the EliA calprotectin 2 immunoassay.

Design

and Methods: The calprotectin immunoassay from DiaSorin run on the LIAISONXL was analytically and clinically validated and compared to the EliA calprotectin 2 immunoassay from Thermo Fisher Scientific run on the ImmunoCAP250. Five patient groups were measured (n ​= ​303): IBD: ulcerative colitis (UC) and Crohn’s disease (CD); non-IBD: IBS, other gastrointestinal diseases and controls (healthy patients with no gastrointestinal disease).

Results

The calprotectin immunoassay of DiaSorin showed good analytical performance with frozen samples. The presence of blood in the stool can interfere with the measurement of calprotectin. Patients suffering from IBD (UC or CD) showed significant higher concentrations of fecal calprotectin compared to controls (UC:710 ​± ​921 ​mg/kg; CD:967 ​± ​1243 ​mg/kg; controls:11±8 ​mg/kg) using DiaSorin’s immunoassay. The remaining non-IBD groups showed no significant difference compared to controls. Follow-up patients (n ​= ​9) showed a significant decrease in fecal calprotectin after treatment. At 50 ​mg/kg cut-off value, the negative predictive value for DiaSorin’s immunoassay was 96% and the positive predictive value 83% (sensitivity of 95% and specificity of 86%).

Conclusions

The lack of standardization contributes to the numerical differences between the two methods, but the qualitative conclusions do not differ. DiaSorin’s calprotectin immunoassay can be used both to distinguish between IBD and non-IBD patients as well as for follow-up of IBD patients.

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New calprotectin immunoassay has a short sample preparation time and is easy to use.

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DiaSorin’s immunoassay can be used to distinguish between high and low risk IBD patients, as opposed to IBS.

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Differences observed between immunoassays are due to lack of standardization.

•

Blood in the stool can effect the calprotectin measurement.

Computed tomography versus lower endoscopy as initial diagnostic method for evaluating patients with hematochezia at emergency room

For acute lower gastrointestinal bleeding (LGIB), lower gastrointestinal endoscopy is the preferred initial diagnostic test. However, it is difficult to perform urgently. Computed tomography (CT) is a convenient alternative.This study aimed to determine the diagnostic performance of CT compared to lower endoscopy as an initial test for evaluating acute LGIB.The medical records of 382 patients who visited our emergency department with hematochezia between January 2012 and January 2017 were retrospectively analyzed. Of them, 112 underwent CT, 65 underwent colonoscopy, and 205 underwent sigmoidoscopy as an initial test. For each method, sensitivity, specificity, positive predictive value, and negative predictive value were calculated upon active bleeding site detection and LGIB etiology diagnosis.The sensitivity, specificity, positive predictive value, and negative predictive value of CT for active bleeding site detection were 85.7%, 100%, 100%, and 96.9%, respectively, while those for identifying the etiology of LGIB were 87.4%, 40.0%, 83.5, and 47.6%, respectively.CT was not inferior to lower endoscopy for active bleeding site detection. Early localization and the exclusion of active bleeding were possible with CT. Etiology was diagnosed with high sensitivity and PPV by CT. Thus, CT can be an alternative initial diagnostic tool for evaluating acute LGIB.

Preference and Experience of Colonic Examination for Participants Presenting to Hospitals with a Positive Fecal Immunochemical Test Result

PURPOSE

Patients who test positive on the fecal immunochemical test (FIT) for colorectal cancer (CRC) are referred for colonoscopy for further diagnostic evaluation. Colonoscopy is not a perfect method and may be a challenge for some FIT-positive patients. Computed tomographic colonography (CTC) is an alternative method that is less invasive and allows examination of the whole colon. The study objective was to evaluate the preference of FIT-positive patients for either colonoscopy or CTC for CRC examination.

PATIENTS AND METHODS

Individuals older than 40 years with a positive FIT test at eight Japanese hospitals between December 2012 and July 2015 were invited to participate. Participants were given detailed information regarding colonoscopy and CTC before deciding on either examination. They completed questionnaires before the procedure regarding their preference and after the procedure regarding their experience.

RESULTS

The pre- and post-questionnaires of 846 and 834 participants, respectively, were analyzed. Participants preferred colonoscopy over CTC (colonoscopy, 72%; CTC, 28%). The possibility of obtaining biopsy samples and removing colorectal polyps during the procedure was the main reason for colonoscopy selection. Patients selected CTC to reduce discomfort but reported that CTC bowel preparation was more burdensome than colonoscopy bowel preparation. The overall experience of the examination did not differ between the groups.

CONCLUSION

Colonoscopy is the standard examination for FIT-positive patients. However, when given a choice, almost one-third of participants chose CTC because they thought it would be a more "comfortable" examination. Clinicians should therefore be aware of patients' potential preference for noninvasive colorectal examinations.

Return to bowel screening after a false-positive faecal immunochemical test in BowelScreen (the National Bowel Screening Programme in Ireland)

Objective

Little research exists on what predicts individual return to screening after a false-positive faecal immunochemical test in a population bowel screening programme. We aimed to quantify the impact of false-positive faecal immunochemical test in the first round of screening on re-attendance in BowelScreen, the National Bowel Screening Programme in Ireland.

Methods

A retrospective cohort study was conducted. False-positivity was defined as a positive faecal immunochemical test with subsequent colonoscopy showing no evidence of malignancy or surveillance requirement. In those with a false-positive faecal immunochemical test, logistic regression was used to predict repeat participation in the second round.

Results

Of 196,149 individuals who attended the first screening round, 108,075 were eligible and re-invited in the second round, and 93,971 accepted the invitation (86.9%). Second round uptake was higher in faecal immunochemical test-negative individuals compared with those having false-positive results (87.5% vs. 73.1%; p < 0.001). Older age (odds ratio (OR) 0.75; 95% confidence interval (CI) 0.60–0.94), computed tomography colonography (unsuitability/failed colonoscopy) (OR 0.40; 95% CI 0.21–0.73), and longer duration from screening invitation to faecal immunochemical test result (OR 0.991; 95% CI 0.9872–0.995) were predictors of non-re-attendance in the next screening round.

Conclusion

There is a significant reduction in re-attendance rates for individuals with false-positive faecal immunochemical test results. The letter sent following a negative colonoscopy is being reviewed to ensure that it provides adequate encouragement to re-attend. There are roles for screening promotion and for Gastroenterologists and Advanced Nurse Practitioners to emphasize the importance of regular faecal immunochemical tests after a negative colonoscopy.

Fecal Calprotectin Responses Following Induction Therapy With Vedolizumab in Moderate to Severe Ulcerative Colitis: A Post Hoc Analysis of GEMINI 1

BACKGROUND

In patients with ulcerative colitis (UC), fecal calprotectin (FC) concentrations correlate with endoscopic inflammation evidence. This study investigated the effect of vedolizumab induction on FC concentrations and whether FC concentrations could be a reliable surrogate measure of disease status.

METHODS

Data from the placebo-controlled, phase 3 trial GEMINI 1 were used to evaluate week-6 relationships between outcomes (including clinical remission, mucosal healing [MH], and endoscopic remission) and both absolute FC concentration values and relative FC concentration changes from baseline (%FC0-6). Sensitivity and specificity were calculated by cross-tabulation; the value of week-6 FC concentration as surrogate biomarker was measured with Youden J statistic computed for various cut points.

RESULTS

GEMINI 1 induction phase enrolled 895 patients. Fecal calprotectin concentration decreases were deeper in patients with clinical remission, MH, and/or endoscopic remission than in patients without. The best week-6 indicator of clinical or endoscopic remission in this data set was absolute FC concentration ≤150 µg/g. The surrogate biomarker values (based on areas under the curve) for the best-performing cut points (FC0-6 reduction >90%, FC ≤150 µg/g) were fair (range, 0.70-0.77, total population). More patients met the ≤150 µg/g cut point with vedolizumab than with placebo. Baseline FC concentrations were not correlated with clinical outcomes.

CONCLUSIONS

Fecal calprotectin concentration reductions were greater with vedolizumab induction than with placebo. Week-6 FC concentrations had only fair surrogate biomarker value for endoscopic status. Our data suggest that, while FC may reflect inflammatory burden, FC concentration after vedolizumab induction may not be a robust biomarker of mucosal inflammation.

A novel volume-reduced CT colonography regimen using hypertonic laxative (polyethylene glycol with ascorbic acid): randomized controlled trial

OBJECTIVES

The aim of this study is to investigate the feasibility of bowel preparation using a hypertonic laxative (polyethylene glycol with ascorbic acid, PEG + Asc) for CT colonography (CTC) and to examine the volume limit of laxative.

METHODS

In one institution, patients who met the indications for CTC were enrolled and randomly assigned to CTC with regimen A (800 ml PEG + Asc), B (600 ml PEG + Asc), or C (400 ml PEG + Asc). Sodium diatrizoate was given orally for fecal tagging. On the previous day, patients ate low-residue meals and took the assigned lavage solution after dinner. A reader blinded to the preparation graded residual stool/fluid and fecal tagging quality in six segments of the colorectum. The primary outcome was a proportion of colon segments without stool. One hundred twenty segments in 20 patients with each regimen were needed to show a non-inferiority margin of 15%, assuming 85% of no stool.

RESULTS

A total of 360 segments in 60 patients were analyzed. There were 83% of segments with no stool in regimen A, 89% in regimen B, and 88% in regimen C. Using the delta method, the 95% confidence interval of the risk difference (6.7%) between regimens A and B was - 2.2% to 15.6%, and the risk difference (5.0%) between regimens A and C was - 4.1% to 14%, both within the non-inferiority margin. Residual fluid and fecal tagging quality were also within the non-inferiority margin. No adverse events occurred.

CONCLUSIONS

A novel CTC regimen using hypertonic laxative demonstrated optimal colon cleansing effectiveness even with the lowest volume of laxative (UMIN000022851).

KEY POINTS

• A novel CTC regimen using a hypertonic laxative is feasible. • The lowest volume of laxative provides excellent colon imaging. • However, the lowest volume of laxative did not improve patient acceptance.

Screening individuals' experiences of colonoscopy and colon capsule endoscopy; a mixed methods study

BACKGROUND

The standard investigation in colorectal cancer screening (optical colonoscopy [OC]) has a less invasive alternative with the colon capsule endoscopy (CCE). The experiences of screening individuals are needed to support a decision aid (DA) and to provide a patient view in future health technology assessments (HTA). We aimed to explore the experiences of CCE at home and OC in an outpatient clinic by screening participants who experienced both investigations on the same bowel preparation.

METHODS

In a mixed methods study, Danish screening individuals with a positive immunological fecal occult blood test (FIT) were consecutively included and underwent both CCE and OC in the same bowel preparation. They answered questionnaires about discomfort during CCE, delivered at home, and during a following OC in the outpatient clinic. Data were calculated in percentages and Wilcoxon signed rank test was used for comparisons. Among the 253 included patients, 10 participants were selected for a semi-structured interview about their experiences of the two examinations. The analysis and interpretation of the transcribed data were inspired by Ricoeur.

RESULTS

Questionnaire data were received from 239 participants and revealed significant less discomfort during the CCE than the OC. Interview data included explained discomfort elements in two categories: 'The examination' and 'The setting'. Compared to OC, the CCE was experienced with less pain, embarrassment and invasiveness, but presented challenges and disadvantages as well, i.e., a large camera capsule to swallow, a longer waiting time for test results after CCE and an additional OC, if pathologies were found. The home setting for CCE delivery made the participants feel less like they were ill or patients less restricted and that they received more personal care, but could induce technical challenges.

CONCLUSION

In screening individuals, CCE at home was associated with significantly less discomfort compared to OC at a hospital, and multiple reasons for this was identified.

Prevalence of polyps ≥6 mm on follow-up CT colonography in a cohort with no significant colon polyps at baseline

AIM

Assess the prevalence of neoplasia ≥6 mm at repeat CT colonoscopy (CTC) in individuals with no significant lesions at baseline.

METHODS

Individuals aged ≥18 years, with/without CRC risk factors, with no polyps ≥6 mm on baseline CTC (negative baseline) who underwent repeat CTC in a large HMO from 2001 to 2011 were retrospectively identified. Studies were reviewed by board-certified radiologists with experience interpreting CTC. Demographic details, CRC risk factors, and the number, size, and location of incident lesions were noted. Findings were classified using the C-RADS scale. Lesion prevalence at CTC-2 was determined, and study interval and risk characteristics of patients with- and without findings were compared.

RESULTS

Our study included 636 individuals (369 men [58.0%]; mean age 59.9 years) with negative baseline CTC who underwent repeat CTC after a mean 4.6 year interval (SD 1.6 years). At baseline, 469/636 (73.7%) were at average risk for CRC; 418 remained at average risk for CTC-2 with 51 (8.0%) developing new risk factors in the interval between studies. At CTC-2, 47 participants (7.4%) presented 52 significant neoplasia: 35 polyps 6-9 mm, 14 polyps ≥10 mm, and 3 masses in 3/636 participants (0.47%). 2/3 masses, 6/14 polyps ≥10 mm (42.9%), and 12/25 polyps 6-9 mm (48.0%) were in individuals with risk factors for CRC. Histopathology was available for 12/52 lesions (23.1%): 8 tubular adenomas, 2 villous adenomas, 1 hamartomatous polyp, 1 case of normal tissue.

CONCLUSION

A mean 4.6 years after negative-baseline CTC, neoplasia ≥6 mm were seen in 7.4% of participants, including masses in 0.47%, supporting recommendations for a 5-year study interval.

Computed tomographic colonography with a reduced dose of laxative using a novel barium sulfate contrast agent in Japan

PURPOSE

To test the tagging efficacy, patient acceptability, and accuracy of computed tomographic colonography (CTC) with a reduced dose of laxative using a novel barium sulfate (BaSO₄) contrast agent.

MATERIALS AND METHODS

CTC followed by optical colonoscopy (OC) was performed on 73 patients with positive results in fecal occult blood tests. They were administrated a BaSO₄ suspension and a magnesium citrate solution for bowel preparation. Patients completed a questionnaire about the acceptability of bowel preparation. Tagging efficacy was estimated using a novel categorization system, which classified all segments into 8 categories. The accuracy of detecting protruded lesions ≥ 6 mm was calculated from the comparison of CTC and OC results, using the latter as a reference standard.

RESULTS

Tagging efficacy was good in 77.3% of colonic segments where residue was observed. The acceptability of bowel preparation for CTC was significantly higher than that for OC. The sensitivity, specificity, and positive and negative predictive values were 0.778, 0.945, 0.824, and 0.929, respectively. All lesions ≥ 7 mm were successfully detected by CTC.

CONCLUSION

CTC with a reduced dose of laxative using a novel BaSO₄ contrast agent has a favorable tagging efficacy, patient acceptability, and accuracy.

Split- versus single-dose preparation tolerability in a multiethnic population: decreased side effects but greater social barriers

BACKGROUND

This study was performed to compare patient-reported tolerability and its barriers in single- vs. split-dose 4-L polyethylene glycol (PEG) bowel preparation for colonoscopy in a large multiethnic, safety-net patient population.

METHODS

A cross-sectional, dual-center study using a multi-language survey was used to collect patient-reported demographic, medical, socioeconomic, and tolerability data from patients undergoing outpatient colonoscopy. Univariate and multivariate analyses were used to identify demographic and clinical factors significantly associated with patient-reported bowel preparation tolerability.

RESULTS

A total of 1023 complete surveys were included, of which 342 (33.4%) completed single-dose and 681 (66.6%) split-dose bowel preparation. Thirty-nine percent of the patients were Hispanic, 50% had Medicaid or no insurance, and 34% had limited English proficiency. Patients who underwent split-dose preparation were significantly more likely to report a tolerable preparation, with less severe symptoms, than were patients who underwent single-dose preparation. Multiple logistic regression revealed that male sex and instructions in the preferred language were associated with tolerability of the single-dose preparation, while male sex and concerns about medications were associated with tolerability of the split-dose preparation.

CONCLUSIONS

In a large multiethnic safety-net population, split-dose bowel preparation was significantly more tolerable and associated with less severe gastrointestinal symptoms than single-dose preparation. The tolerability of split-dose bowel preparation was associated with social barriers, including concerns about interfering with other medications.

Lubiprostone improves visualization of small bowel for capsule endoscopy: a double-blind, placebo-controlled 2-way crossover study

BACKGROUND AND STUDY AIMS

 Lubiprostone has been reported to be an anti-constipation drug. The aim of the study was to investigate the usefulness of lubiprostone both for bowel preparation and as a propulsive agent in small bowel endoscopy.

PATIENTS AND METHODS

 This was a double-blind, placebo-controlled, 2-way crossover study of subjects who volunteered to undergo capsule endoscopy (CE). A total of 20 subjects (16 male and 4 female volunteers) were randomly assigned to receive a 24-μg tablet of lubiprostone 120 minutes prior to capsule ingestion for CE (L regimen), or a placebo tablet 120 minutes prior to capsule ingestion for CE (P regimen). Main outcome was gastric transit time (GTT) and small-bowel transit time (SBTT). Secondary outcome was adequacy of small-bowel cleansing and the fluid score in the small bowel. The quality of the capsule endoscopic images and fluid in the small bowel were assessed on 5-point scale.

RESULTS

 The capsule passed into the small bowel in all cases. Median GTT was 57.3 (3 - 221) minutes for the P regimen and 61.3 (10 - 218) minutes for the L regimen ( P  = 0.836). Median SBTT was 245.0 (164 - 353) minutes for the P regimen and 228.05 (116 - 502) minutes for the L regimen ( P  = 0.501). The image quality score in the small bowel was 3.05 ± 1.08 for the P regimen and 3.80 ± 0.49 for the L regimen ( P  < 0.001). The fluid score in the small bowel was 2.04 ± 1.58 for the P regimen and 2.72 ± 1.43 for the L regimen ( P  < 0.001). There was a significant difference between the 2 regimens with regard to image quality. The fluid score was more plentiful for the L regimen than for the P regimen. There were no cases of capsule retention or serious adverse events in this study.

CONCLUSION

 Our study showed that use of lubiprostone prior to CE significantly improved visualization of the small bowel during CE as a result of inducing fluid secretion into the small bowel.

Calprotectin as a diagnostic tool for inflammatory bowel diseases

Inflammatory bowel diseases (IBD) are chronic intestinal disorders caused by a number of factors, including external influences, intestinal microbiota and genetics. The two major clinically defined types of IBD are Crohn's disease and ulcerative colitis, each of which is characterized by relapses in the clinical course, thus patients must be under constant observation via regular endoscopies. As endoscopy, which has been used for direct evaluation and diagnosis of IBD, requires uncomfortable and expensive bowel preparation, a non-invasive test was required to reduce the number of patients undergoing unnecessary endoscopy. Calprotectin is a protein occurring in the cytosol of inflammatory cells and is released by the activation of leukocytes. As it is elevated and stable in the faeces of patients with IBD and can be reliably detected in faecal samples of <5 g, it may serve as an inexpensive, non-invasive diagnostic method for IBD. This is explored in the following review.

Diagnostic Performance and Patient Acceptance of Reduced-Laxative CT Colonography for the Detection of Polypoid and Non-Polypoid Neoplasms: A Multicenter Prospective Trial

Purpose To evaluate the diagnostic accuracy and patient acceptance of reduced-laxative computed tomographic (CT) colonography without computer-aided detection (CAD) for the detection of colorectal polypoid and non-polypoid neoplasms in a population with a positive recent fecal immunochemical test (FIT). Materials and Methods Institutional review board approval and written informed consent were obtained. This multicenter prospective trial enrolled patients who had positive FIT results. Reduced-laxative CT colonography and colonoscopy were performed on the same day. Patients received 380 mL polyethylene glycol solution, 20 mL iodinated oral contrast agent, and two doses of 20 mg mosapride the day before CT colonography. The main outcome measures were the accuracy of CT colonography for the detection of neoplasms 6 mm or larger in per-patient and per-lesion analyses and a survey of patient perceptions regarding the preparation and examination. The Clopper-Pearson method was used for assessing the 95% confidence intervals of per-patient and per-lesion accuracy. Survey scores were analyzed by using the Wilcoxon and χ² tests. Results Three hundred four patients underwent both CT colonography and colonoscopy. Per-patient sensitivity, specificity, positive predictive value, and negative predictive value of CT colonography for detecting neoplasms 10 mm or larger were 0.91 (40 of 44), 0.99 (255 of 258), 0.93 (40 of 43), and 0.98 (255 of 259), respectively; these values for neoplasms 6 mm or larger were 0.90 (71 of 79), 0.93 (207 of 223), 0.82 (71 of 87), and 0.96 (207 of 215), respectively. Per-lesion sensitivities for detection of polypoid and non-polypoid neoplasms 10 mm or larger were 0.95 (40 of 42) and 0.67 (six of nine), respectively; those for neoplasms 6 mm or larger were 0.90 (104 of 115) and 0.38 (eight of 21), respectively (P < .05 for both). Patient acceptance of preparation and examination with CT colonography was significantly higher than that with colonoscopy, and 62% (176 of 282) of patients would choose CT colonography as the first examination if they have a positive FIT result in the future. Conclusion Reduced-laxative CT colonography without CAD is accurate in the detection of polypoid neoplasms 6 mm or larger but is less accurate in the detection of non-polypoid neoplasms. Reduced-laxative CT colonography has high patient acceptance and is an efficient triage examination for patients with a positive FIT. ^© RSNA, 2016 Online supplemental material is available for this article.

European Code against Cancer, 4th Edition: Cancer screening

In order to update the previous version of the European Code against Cancer and formulate evidence-based recommendations, a systematic search of the literature was performed according to the methodology agreed by the Code Working Groups. Based on the review, the 4th edition of the European Code against Cancer recommends: "Take part in organized cancer screening programmes for: Bowel cancer (men and women); Breast cancer (women); Cervical cancer (women)." Organized screening programs are preferable because they provide better conditions to ensure that the Guidelines for Quality Assurance in Screening are followed in order to achieve the greatest benefit with the least harm. Screening is recommended only for those cancers where a demonstrated life-saving effect substantially outweighs the potential harm of examining very large numbers of people who may otherwise never have, or suffer from, these cancers, and when an adequate quality of the screening is achieved. EU citizens are recommended to participate in cancer screening each time an invitation from the national or regional screening program is received and after having read the information materials provided and carefully considered the potential benefits and harms of screening. Screening programs in the European Union vary with respect to the age groups invited and to the interval between invitations, depending on each country's cancer burden, local resources, and the type of screening test used For colorectal cancer, most programs in the EU invite men and women starting at the age of 50-60 years, and from then on every 2 years if the screening test is the guaiac-based fecal occult blood test or fecal immunochemical test, or every 10 years or more if the screening test is flexible sigmoidoscopy or total colonoscopy. Most programs continue sending invitations to screening up to the age of 70-75 years. For breast cancer, most programs in the EU invite women starting at the age of 50 years, and not before the age of 40 years, and from then on every 2 years until the age of 70-75 years. For cervical cancer, if cytology (Pap) testing is used for screening, most programs in the EU invite women starting at the age of 25-30 years and from then on every 3 or 5 years. If human papillomavirus testing is used for screening, most women are invited starting at the age of 35 years (usually not before age 30 years) and from then on every 5 years or more. Irrespective of the test used, women continue participating in screening until the age of 60 or 65 years, and continue beyond this age unless the most recent test results are normal.

Patient willingness for repeat screening and preference for CT colonography and optical colonoscopy in ACRIN 6664: the National CT Colonography trial

BACKGROUND

Current American Cancer Society recommendations for colon cancer screening include optical colonoscopy every 10 years or computed tomography colonography (CTC) every 5 years. Bowel preparation (BP) is currently required for both screening modalities.

PURPOSE

To compare ACRIN 6664: the National CT Colonography Trial (NCTCT) participant experiences with CTC and optical colonoscopy (OC), procedure preference, and willingness to return for each procedure.

MATERIALS AND METHODS

Participants from fifteen NCTCT sites, who underwent CTC followed by OC under sedation, were invited to complete questionnaires 2 weeks postexam, asking about procedure preference, physical discomfort, and embarrassment experienced and whether that discomfort and embarrassment was better or worse than expected during BP, CTC, and OC, as well as willingness to return for repeat CTC and OC at different time intervals.

RESULTS

A total of 2,310 of 2,600 patients (89%) returned their questionnaires. Of patients reporting a preference, 1,058 (46.6%) preferred CTC, 569 (25.0%) preferred OC, and 626 (27.6%) reported no preference. Participant-reported discomfort worse than expected differed significantly between CTC (32.9%) and OC (5.0%) (P<0.001). About 79.3% were willing to be screened again with CTC in 5 years, and 96.6% with OC in 10 years. Discomfort and embarrassment worse than expected with OC were associated with increased intention to adhere with CTC in the future. Conversely, embarrassment experienced during CTC and discomfort worse than expected on CTC were associated with increased intention to adhere with OC in the future.

CONCLUSION

While a larger proportion of participants indicated that they preferred CTC to OC, willingness to undergo repeat CTC compared to OC was limited by unanticipated exam discomfort and embarrassment and CTC's shorter screening interval.

Lubiprostone decreases the small bowel transit time by capsule endoscopy: an exploratory, randomised, double-blind, placebo-controlled 3-way crossover study

The aim of this study was to investigate the usefulness of lubiprostone for bowel preparation and as a propulsive agent in small bowel endoscopy. Six healthy male volunteers participated in this randomized, 3-way crossover study. The subjects received a 24 μg tablet of lubiprostone 60 minutes prior to the capsule ingestion for capsule endoscopy (CE) and a placebo tablet 30 minutes before the capsule ingestion (L-P regimen), a placebo tablet 60 minutes prior to CE and a 24 μg tablet of lubiprostone 30 minutes prior to CE (P-L regimen), or a placebo tablet 60 minutes prior to r CE and a placebo tablet again 30 minutes prior to CE (P-P regimen). The quality of the capsule endoscopic images and the amount of water in the small bowel were assessed on 5-point scale. The median SBTT was 178.5 (117-407) minutes in the P-P regimen, 122.5 (27-282) minutes in the L-P regimen, and 110.5 (11-331) minutes in the P-L regimen (P = 0.042). This study showed that the use of lubiprostone significantly decreased the SBTT. We also confirmed that lubiprostone was effective for inducing water secretion into the small bowel during CE.

Bowel cleansing before CT colonography: comparison between two minimal-preparation regimens

AIM

To compare two regimens of reduced bowel preparation and faecal tagging for CT colonography.

MATERIALS AND METHODS

Single centre, prospective, randomized, noninferiority study, in which 52 consecutive adults underwent routine CT colonography. Patients, following a three-day low-fibre diet, received one of the two reduced preparations: 1-L polyethylene glycol and four tablets of bisacodyl in association with 90 mL of Iopamidol for faecal tagging administered on the same day as CTC examination (group 1); or a standard "iodine-only" preparation, consisting in 180 ml of Iopamidol the day before the examination (group 2). Primary outcome was the overall quality of bowel preparation.

RESULTS

Twenty-six patients per group were included. Per segment analysis showed preparation of diagnostic quality in 97.4% of segments in group 1 and in 95.5% in group 2 (p = ns). Per-patient analysis showed optimal quality of preparation in 76.9% of patients in group 1 and in 84.6% in group 2 (p = ns). Patient tolerability to both preparations was not different.

CONCLUSION

A limited bowel preparation consisting of 1-L PEG and four tablets of bisacodyl in association with 90 mL of Iodine for faecal tagging administered on the same day as CTC examination is feasible and offers bowel cleansing comparable to "iodine-only" preparation.

KEY POINTS

• Low-dose PEG bisacodyl and Iopamidol preparation is feasible, providing adequate bowel cleansing. • Faecal tagging is not different from the two limited preparations. • Patient tolerability to the two colon cleansing regimens is similar.

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

Electronic supplementary material

The online version of this article (doi:10.1007/s00330-014-3187-9) contains supplementary material, which is available to authorized users.

Quantifying public preferences for different bowel preparation options prior to screening CT colonography: a discrete choice experiment

OBJECTIVES

CT colonography (CTC) may be an acceptable test for colorectal cancer screening but bowel preparation can be a barrier to uptake. This study tested the hypothesis that prospective screening invitees would prefer full-laxative preparation with higher sensitivity and specificity for polyps, despite greater burden, over less burdensome reduced-laxative or non-laxative alternatives with lower sensitivity and specificity.

DESIGN

Discrete choice experiment.

SETTING

Online, web-based survey.

PARTICIPANTS

2819 adults (45-54 years) from the UK responded to an online invitation to take part in a cancer screening study. Quota sampling ensured that the sample reflected key demographics of the target population and had no relevant bowel disease or medical qualifications. The analysis comprised 607 participants.

INTERVENTIONS

After receiving information about screening and CTC, participants completed 3-4 choice scenarios. Scenarios showed two hypothetical forms of CTC with different permutations of three attributes: preparation, sensitivity and specificity for polyps.

PRIMARY OUTCOME MEASURES

Participants considered the trade-offs in each scenario and stated their preferred test (or chose neither).

RESULTS

Preparation and sensitivity for polyps were both significant predictors of preferences (coefficients: -3.834 to -6.346 for preparation, 0.207-0.257 for sensitivity; p<0.0005). These attributes predicted preferences to a similar extent. Realistic specificity values were non-significant (-0.002 to 0.025; p=0.953). Contrary to our hypothesis, probabilities of selecting tests were similar for realistic forms of full-laxative, reduced-laxative and non-laxative preparations (0.362-0.421). However, they were substantially higher for hypothetical improved forms of reduced-laxative or non-laxative preparations with better sensitivity for polyps (0.584-0.837).

CONCLUSIONS

Uptake of CTC following non-laxative or reduced-laxative preparations is unlikely to be greater than following full-laxative preparation as perceived gains from reduced burden may be diminished by reduced sensitivity. However, both attributes are important so a more sensitive form of reduced-laxative or non-laxative preparation might improve uptake substantially.

Competition in Colon Cancer Screening? What Is the Role of Colonoscopy?

BACKGROUND

Colorectal cancer (CRC) is one of the leading causes of cancer-related death in the Western world. The incidence could be reduced if this cancer were to be diagnosed at an early stage of disease. A competition has started between the existing screening methods to be the most efficient in detecting premalignant conditions. This review illustrates the current state of screening techniques for CRC.

METHOD

Pubmed was searched for meta-analyses and prospective studies on screening for CRC, with an emphasis on colonography, computed tomographic colonography (CTC), magnetic resonance colonography (MRC), stool DNA testing, and colon capsule endoscopy, and critical appraisal of the research was done by the reviewers.

RESULTS

The imaging techniques (CTC and MRC) had similar detection rates for bigger lesions (≥10 mm) as colonoscopy. High-definition colonoscopy showed better efficiency with smaller lesions. The techniques developing around colonoscopy such as the retro-viewing colonoscope, the balloon colonoscope, or the 330-degree viewing colonoscope try to enhance efficacy by reducing the adenoma miss rate in right-sided, non-polypoid lesions. Colon capsule endoscopy and the stool detection systems are limited to identifying cancer but not necessarily adenomas.

CONCLUSION

Colonoscopy is the preferred CRC screening strategy and the undisputed gold standard in terms of efficacy.

Radiation risk from CT: implications for cancer screening

OBJECTIVE

The cancer risks associated with patient exposure to radiation from medical imaging have become a major topic of debate. The higher doses necessary for technologies such as CT and the increasing utilization of these technologies further increase medical radiation exposure to the population. Furthermore, the use of CT for population-based cancer screening continues to be explored for common malignancies such as lung cancer and colorectal cancer. Given the known carcinogenic effects of ionizing radiation, this warrants evaluation of the balance between the benefit of early cancer detection and the risk of screening-induced malignancy.

CONCLUSION

This report provides a brief review of the process of radiation carcino-genesis and the literature evaluating the risk of malignancy from CT, with a focus on the risks and benefits of CT for cancer screening. The available data suggest a small but real risk of radiation-induced malignancy from CT that could become significant at the population level with widespread use of CT-based screening. However, a growing body of literature suggests that the benefits of CT screening for lung cancer in high-risk patients and CT colonography for colorectal cancer may significantly outweigh the radiation risk. Future studies evaluating the benefits of CT screening should continue to consider potential radiation risks.

Predictors of CT colonography utilization among asymptomatic medicare beneficiaries

BACKGROUND

Although the Centers for Medicare and Medicaid Services (CMS) denied coverage for screening computed tomography colonography (CTC) in March 2009, little is understood about whether CTC was targeted to the appropriate patient population prior to this decision.

OBJECTIVE

Evaluate patient characteristics and known relative clinical indications for screening CTC among patients who received CTC compared to optical colonoscopy (OC).

DESIGN/PARTICIPANTS

Cross-sectional study of all 10,538 asymptomatic Medicare beneficiaries who underwent CTC between January 2007 and December 2008, compared to a cohort of 160,113 asymptomatic beneficiaries who underwent OC, matched on county of residence and year of examination.

MAIN MEASURES

Patient characteristics and known relative appropriate and inappropriate clinical indications for screening CTC.

KEY RESULTS

CTC utilization was higher among women, patients > 65 years of age, white patients, and those with household income > 75 % (p = 0.001). Patients with relatively appropriate clinical indications for screening CTC were more likely to undergo CTC than OC including presumed incomplete OC (OR 80.7, 95 % CI 76.01-85.63); sedation risk (OR 1.11, 95 % CI 1.05-1.17); and chronic anticoagulation risk (OR 1.46, 95 % CI 1.38-1.54), after adjusting for patient characteristics and known clinical indications. Conversely, patients undergoing high-risk screening, an inappropriate indication, were less likely to receive CTC (OR 0.4, 95 % CI 0.37-0.42). Overall, 83 % of asymptomatic patients referred to CTC had at least one clinical indication relatively appropriate for CTC (8,772/10,538).

CONCLUSION

During the 2 years preceding CMS denial for screening, CTC was targeted to asymptomatic patients with relatively appropriate clinical indications for CTC/not receiving OC. However, CTC utilization was lower among certain demographic groups, including minority patients. These findings raise the possibility that future coverage of screening CTC might exacerbate disparities in colorectal cancer screening while increasing overall screening rates.

Evaluating patients' preferences for type of bowel preparation prior to screening CT colonography: convenience and comfort versus sensitivity and specificity

AIMS

To explore the relative value patients place on comfort and convenience versus test sensitivity and specificity in the context of computed tomographic colonography (CTC) screening.

MATERIALS AND METHODS

Twenty semi-structured interviews were carried out with patients attending hospital for radiological tests unrelated to CTC. Preferences for CTC with different types of bowel preparation for CTC screening were examined and interviews were analysed thematically. The discussion guide included separate sections on CTC, bowel preparation methods (non-, reduced- and full-laxative), and sensitivity and specificity. Patients were given information on each topic in turn and asked about their views and preferences during each section.

RESULTS

Following information about the test, patients' attitudes towards CTC were positive. Following information on bowel preparation, full-laxative purgation was anticipated to cause more adverse physical and lifestyle effects than using reduced- or non-laxative preparation. However, stated preferences were approximately equally divided, largely due to patients anticipating that non-laxative preparations would reduce test accuracy (because the bowel was not thoroughly cleansed). Following information on sensitivity and specificity (which supported patients' expectations), the predominant stated preference was for full-laxative preparation.

CONCLUSIONS

Patients are likely to value test sensitivity and specificity over a more comfortable and convenient preparation. Future research should test this hypothesis on a larger sample.

Acceptability of oral iodinated contrast media: a head-to-head comparison of four media

OBJECTIVE

To assess the palatability of iodinated oral contrast media commonly used in abdominopelvic CT and CT colonography (CTC).

METHODS

80 volunteers assessed the palatability of a 20-ml sample of a standard 30 mg ml(-1) dilution of Omnipaque® (iohexol; GE Healthcare, Cork, Ireland), Telebrix® (meglumine ioxithalamate; Guerbet, Aulnay-sous-Bois, France), Gastromiro® (iopamidol; Bracco, High Wycombe, UK) and Gastrografin® (sodium diatrizoate and meglumine diatrizoate; Bayer, Newbury, UK) in a computer-generated random order.

RESULTS

Gastrografin is rated significantly less palatable than the remaining media (p<0.005). Omnipaque and Telebrix are significantly more palatable than Gastromiro. No difference existed between Omnipaque and Telebrix. 39% of participants would refuse to consume the quantities of Gastrografin required for a CTC examination compared with Telebrix (7%) and Omnipaque (9%) (p<0.05).

CONCLUSION

Omnipaque and Telebrix are significantly more palatable than both Gastromiro and Gastrografin, with participants more willing to ingest them in larger quantities as well as being less expensive.

ADVANCES IN KNOWLEDGE

Omnipaque and Telebrix are significantly more palatable iodinated oral contrast media than both Gastromiro and Gastrografin, which has potential implications in compliance with both abdominopelvic CT and CTC.

An interview study analysing patients' experiences and perceptions of non-laxative or full-laxative preparation with faecal tagging prior to CT colonography

AIM

To compare patients' experiences of either non- or full-laxative bowel preparation with additional faecal tagging and subsequent computed tomographic (CT) colonography using in-depth interviews to elicit detailed responses.

MATERIALS AND METHODS

Patients who received CT colonography after non- (n = 9) or full-laxative (n = 9) preparation participated in a semi-structured telephone interview at least 2 days after the investigation. Full-laxative preparation consisted of magnesium citrate and sodium picosulphate administered at home (or polyethylene glycol, if contraindicated), followed by hospital-based faecal tagging with iohexol. Non-laxative preparation was home-based barium sulphate for faecal tagging. Interviews were transcribed and thematically analysed to identify recurrent themes on patients' perceptions and experiences.

RESULTS

Experiences of full-laxative preparation were usually negative and characterized by pre-test diarrhoea that caused significant interference with daily routine. Post-test flatus was common. Non-laxative preparation was well-tolerated; patients reported no or minimal changes to bowel habit and rapid return to daily routine. Patients reported worry and uncertainty about the purpose of faecal tagging. For iohexol, this also added burden from waiting before testing.

CONCLUSION

Patients' responses supported previous findings that non-laxative preparation is more acceptable than full-laxative preparation but both can be improved. Faecal tagging used in combination with laxative preparation is poorly understood, adding burden and worry. Home-based non-laxative preparation is also poorly understood and patients require better information on the purpose and mechanism in order to give fully informed consent. This may also optimize adherence to instructions. Allowing home-based self-administration of all types of preparation would prevent waiting before testing.

Preference for colonoscopy versus computerized tomographic colonography: a systematic review and meta-analysis of observational studies

In recent years, colorectal cancer (CRC) screening using computerized tomographic colonography (CTC) has attracted considerable attention. In order to better understand patient preferences for CTC versus colonoscopy, we performed a systematic review and meta-analysis of the available literature. Data sources included published studies, abstracts and book chapters, in any language, with publication dates from 1995 through February 2012, and with prospective or retrospective enrollment of diagnostic or screening patients who had undergone both procedures and explicit assessment of their preference for colonoscopy versus CTC. A predefined algorithm identified eligible studies using computer and hand searches performed by two independent investigators. We used a mixed effects model to pool preference differences (defined as the proportion of subjects who preferred CTC minus the proportion who preferred colonoscopy for each study). Twenty-three studies met inclusion criteria, totaling 5616 subjects. In 16 of these studies, patients preferred CTC over colonoscopy, while colonoscopy was preferred in three studies. Due to the high degree of heterogeneity, an overall pooled preference difference was not calculated. Stratified analysis revealed that studies published in radiology journals (preference difference 0.590 [95 % CI 0.485, 0.694]) seemed more likely than studies in gastroenterology (0.218 [-0.015-0.451]) or general medicine journals (-0.158 [-0.389-0.072]) to report preference for CTC (p<0.001). Studies by radiology authors showed a trend towards stronger preference for CTC compared with studies by gastroenterology authors. Symptomatic patients expressed no preference, but screening patients preferred CTC. There was no difference in preferences between studies using "masked" and "unmasked" preference ascertainment methods. Three studies featuring limited bowel preparations for CTC reported marked preference for CTC. There was no evidence of publication bias, while cumulative and exclusion analysis did not show any temporal trend or dominant study. Limitations included data heterogeneity and preference ascertainment limitations. In conclusion, most included studies reported preference for CTC. On stratified analysis, screening patients preferred CTC while diagnostic patients showed no preference. Studies published in radiology journals showed significantly stronger preference for CTC compared with studies in gastroenterology or general medicine journals.

Does CT colonography have a role for population-based colorectal cancer screening?

Colorectal cancer (CRC) is the second most common cancer and second most common cause of cancer-related deaths in Europe. CRC screening has been proven to reduce disease-specific mortality and several European countries employ national screening programmes. These almost exclusively rely on stool tests, with endoscopy used as an adjunct in some countries. Computed tomographic colonography (CTC) is a potential screening test, with an estimated sensitivity of 88 % for advanced neoplasia ≥10 mm. Recent randomised studies have shown that CTC and colonoscopy have similar yields of advanced neoplasia per screened invitee, indicating that CTC is potentially viable as a primary screening test. However, the evidence is not fully elaborated. It is unclear whether CTC screening is cost-effective and the impact of extracolonic findings, both medical and economic, remains unknown. Furthermore, the effect of CTC screening on CRC-related mortality is unknown, as it is also unknown for colonoscopy. It is plausible that both techniques could lead to decreased mortality, as for sigmoidoscopy and gFOBT. Although radiation exposure is a drawback, this disadvantage may be over-emphasised. In conclusion, the detection characteristics and acceptability of CTC suggest it is a viable screening investigation. Implementation will depend on detection of extracolonic disease and health-economic impact. Key Points • Meta-analysis of CT colonographic screening showed high sensitivity for advanced neoplasia ≥10mm. • CTC, colonoscopy and sigmoidoscopy screening all have similar yields for advanced neoplasia. • Good quality information regarding the cost-effectiveness of CTC screening is lacking. • There is little good quality data regarding the impact of extracolonic findings. • CTC triage is not clinically effective in first round gFOBT/FIT positives.

Evaluation of two minimal-preparation regimes for CT colonography: optimising image quality and patient acceptability

OBJECTIVE

To compare a 2 day bowel preparation regime of barium, iodine and a mild stimulant laxative with a 1 day iodine-only regime for CT colonography (CTC).

METHODS

100 consecutive patients underwent CTC. The first 50 patients (Regime 1) ingested 1 bisacodyl tablet twice a day 3 days before CTC and 1 dose each of 50 ml of barium and 20 ml of iodinated contrast per day starting 2 days before CTC. The second 50 patients (Regime 2) ingested 3 doses of iodinated contrast over 24 h prior to CTC. Volumes of residual stool and fluid, and the effectiveness of stool and fluid tagging, were graded according to methods established by Taylor et al (Taylor S, Slaker A, Burling D, Tam E, Greenhalgh R, Gartner L, et al. CT colonography: optimisation, diagnostic performance and patient acceptability of reduced-laxative regimens using barium-based faecal tagging. Eur Radiol 2008; 18: 32-42). A 3 day low-residue diet was taken by both cohorts. Questionnaires rating the side-effects and burden of the bowel preparation were compared to a control cohort of patients undergoing barium enema.

RESULTS

The proportion of colons producing none/scattered stool (score 1) was 90.3% with Regime 1 and 65.0% with Regime 2 (p<0.005). Any residual stool was significantly better tagged with Regime 1 (score 5), with 91.7% of Regime 1 exhibiting optimum tagging vs 71.3% of Regime 2 (p<0.05). No significant differences in side-effects between the bowel preparation regimes for CTC were elicited. Bowel preparation for barium enema was tolerated significantly worse than both of the CTC bowel preparation regimes.

CONCLUSION

Regime 1, containing a 3 day preparation of a mild laxative, barium and iodine, produced a significantly better prepared colon, with no difference in patient acceptability.

Patients' experiences and reported barriers to colonoscopy in the screening context--a systematic review of the literature

OBJECTIVE

A systematic review of the literature was conducted to characterise patients' own experience of colonoscopy in the screening context.

METHODS

A search strategy was applied in MEDLINE, EMBASE and PSYCHinfo (1996-2009). Thematic analysis and narrative summary techniques were used.

RESULTS

Fifty-six studies met eligibility criteria and were included in the analysis. Seven studies examined patients' views after having colonoscopy. Forty-seven studies addressed patient-reported barriers to an anticipated primary colonoscopy. Most patients perceived the laxative bowel preparation to be the most burdensome part of colonoscopy. Other reported difficulties included anxiety, anticipation of pain, feelings of embarrassment and vulnerability. Inadequate knowledge and fear of finding cancer were identified as obstacles to the uptake of screening colonoscopy. Physician endorsement, having a family history, knowing someone with cancer, and perceived accuracy of the test were incentives to having a colonoscopy. Two studies focused on colonoscopy after faecal occult blood screening. Similar procedural, personal, and practical concerns were reported.

CONCLUSIONS

Bowel preparation, lack of awareness of the importance of screening, and feelings of vulnerability in women are all significant barriers to screening colonoscopy.

PRACTICE IMPLICATIONS

Patient reported obstacles and barriers to screening colonoscopy needs to be addressed to improve adherence.

Preferência do paciente no rastreamento do câncer colorretal: uma comparação entre colonografia por tomografia computadorizada e colonoscopia

OBJETIVO: Avaliar o grau de aceitação do paciente submetido a colonografia por tomografia computadorizada (CTC) em comparação com a colonoscopia, quando realizadas para rastreamento de doença colorretal. MATERIAIS E MÉTODOS: Cinquenta pacientes com suspeita de doença colorretal foram submetidos a CTC e colonoscopia. Questionários foram aplicados antes e após a realização da CTC e após a colonoscopia. Graduou-se o desconforto esperado e experimentado antes e após a realização da CTC e da colonoscopia, bem como a preferência do paciente por exame. RESULTADOS: Em relação à CTC, antes de iniciar o exame 18% dos pacientes afirmaram esperar pouco desconforto, 78%, desconforto moderado e 4%, muito desconforto. Após a realização do exame, 72% dos pacientes relataram pouco desconforto, 26%, desconforto moderado e apenas um (2%) dos pacientes referiu muito desconforto. Após a realização da colonoscopia, 86% dos pacientes relataram preferência pela CTC. O grau de distensão colônica e a quantidade de fluido residual não influenciaram na preferência dos pacientes. CONCLUSÃO: Os pacientes preferiram a CTC à colonoscopia, não havendo relação estatística com o grau de distensão colônica na CTC e a eficiência do preparo intestinal.

CT colonography: patient tolerance of laxative free fecal tagging regimen versus traditional cathartic cleansing

PURPOSE

The aim of our prospective study was to compare patient tolerance of laxative free fecal tagging regimen (LFT) versus traditional cathartic cleansing (TC).

MATERIALS AND METHODS

264 patients, at average risk for development of colorectal cancer (105 men and 159 women; mean age 62 years ± 5 SD), underwent 32 rows CT colonography. Patients were alternatively placed into 2 study groups: Group 1 (n = 132) followed TC and Group 2 (n = 132) LFT. TC protocol consisted of no fiber diet and Phospho-lax(®) 80 mL in 2 L of water the day before imaging. LFT protocol consisted of no fiber diet and ingestion with meals of 30 mL of water-soluble iodinated contrast agent (Gastrografin(®)) for 2 days before imaging. No frank laxative drugs were administered. All studies were reviewed in a combined fashion, primary 2D followed by 3D endoluminal and dissected views. After the examination all patients were asked to provide a feedback about tolerance to the each bowel preparation. The first 30 patients of each group were also investigated with optical colonoscopy (OC) used as gold standard to confirm our diagnosis (Group 1* and Group 2*).

CONCLUSIONS

LFT reduces discomfort and seems to improve diagnostic accuracy of CTC.

Preferences for CT colonography and colonoscopy as diagnostic tests for colorectal cancer: a discrete choice experiment

OBJECTIVE

Computed tomography colonography (CTC) is an alternative diagnostic test to colonoscopy for colorectal cancer and polyps. The aim of this study was to determine test characteristics important to patients and to examine trade-offs in attributes that patients are willing to accept in the context of the diagnosis of colorectal cancer.

METHODS

A discrete choice study was used to assess preferences of patients with clinical indications suspicious of colorectal cancer who experienced both CTC and colonoscopy as part of a diagnostic accuracy study in South Australia. Results were analyzed by using a mixed logit model and presented as odds ratios (ORs) for preferring CTC over colonoscopy.

RESULTS

Colonoscopy was preferred over CTC as the need for a second procedure after CTC increased (OR of preferring CTC to colonoscopy = 0.013), as the likelihood of missing cancers or polyps increased (OR of preferring CTC to colonoscopy = 0.62), and as CTC test cost increased (OR of preferring CTC to colonoscopy = 0.65-0.80). CTC would be preferred to colonoscopy if a minimal bowel preparation was available (OR = 1.7). Some patients were prepared to trade off the diagnostic and therapeutic advantage of colonoscopy for a CTC study with a less intensive bowel preparation. Preferences also varied significantly with sociodemographic characteristics.

CONCLUSIONS

Despite CTC's often being perceived as a preferred test, this may not always be the case. Informed decision making for diagnostic tests for colorectal cancer should include discussion of the benefits, downsides, and uncertainties associated with alternative tests, as patients are willing and able to make trade-offs between what they perceive as the advantages and disadvantages of these diagnostic tests.

Comparative economic evaluation of data from the ACRIN National CT Colonography Trial with three cancer intervention and surveillance modeling network microsimulations

PURPOSE

To estimate the cost-effectiveness of computed tomographic (CT) colonography for colorectal cancer (CRC) screening in average-risk asymptomatic subjects in the United States aged 50 years.

MATERIALS AND METHODS

Enrollees in the American College of Radiology Imaging Network National CT Colonography Trial provided informed consent, and approval was obtained from the institutional review board at each site. CT colonography performance estimates from the trial were incorporated into three Cancer Intervention and Surveillance Modeling Network CRC microsimulations. Simulated survival and lifetime costs for screening 50-year-old subjects in the United States with CT colonography every 5 or 10 years were compared with those for guideline-concordant screening with colonoscopy, flexible sigmoidoscopy plus either sensitive unrehydrated fecal occult blood testing (FOBT) or fecal immunochemical testing (FIT), and no screening. Perfect and reduced screening adherence scenarios were considered. Incremental cost-effectiveness and net health benefits were estimated from the U.S. health care sector perspective, assuming a 3% discount rate.

RESULTS

CT colonography at 5- and 10-year screening intervals was more costly and less effective than FOBT plus flexible sigmoidoscopy in all three models in both 100% and 50% adherence scenarios. Colonoscopy also was more costly and less effective than FOBT plus flexible sigmoidoscopy, except in the CRC-SPIN model assuming 100% adherence (incremental cost-effectiveness ratio: $26,300 per life-year gained). CT colonography at 5- and 10-year screening intervals and colonoscopy were net beneficial compared with no screening in all model scenarios. The 5-year screening interval was net beneficial over the 10-year interval except in the MISCAN model when assuming 100% adherence and willingness to pay $50,000 per life-year gained.

CONCLUSION

All three models predict CT colonography to be more costly and less effective than non-CT colonographic screening but net beneficial compared with no screening given model assumptions.

Mosaic decomposition: an electronic cleansing method for inhomogeneously tagged regions in noncathartic CT colonography

Electronic cleansing (EC) is a method that segments fecal material tagged by an X-ray-opaque oral contrast agent in computed tomographic colonography (CTC) images, and effectively removes the material for digitally cleansing the colon. In this study, we developed a novel EC method, called mosaic decomposition (MD), for reduction of the artifacts due to incomplete cleansing of inhomogeneously tagged fecal material in CTC images, especially in noncathartic CTC images. In our approach, the entire colonic region, including the residual fecal regions, was first decomposed into a set of local homogeneous regions, called tiles, after application of a 3-D watershed transform to the CTC images. Each tile was then subjected to a single-class support vector machine (SVM) classifier for soft-tissue discrimination. The feature set of the soft-tissue SVM classifier was selected by a genetic algorithm (GA). A scalar index, called a soft-tissue likelihood, is formulated for differentiation of the soft-tissue tiles from those of other materials. Then, EC based on MD, called MD-cleansing, is performed by first initializing of the level-set front with the classified tagged regions; the front is then evolved by use of a speed function that was designed, based on the soft-tissue index, to reserve the submerged soft-tissue structures while suppressing the residual fecal regions. The performance of the MD-cleansing method was evaluated by use of a phantom and of clinical cases. In the phantom evaluation, our MD-cleansing was trained with the supine (prone) scan and tested on the prone (supine) scan, respectively. In both cases, the sensitivity and specificity of classification were 100%. The average cleansing ratio was 90.6%, and the soft-tissue preservation ratio was 97.6%. In the clinical evaluation, 10 noncathartic CTC cases (20 scans) were collected, and the ground truth of a total of 2095 tiles was established by manual assignment of a material class to each tile. Five cases were randomly selected for training GA/SVM, and the remaining five cases were used for testing. The overall sensitivity and specificity of the proposed classification scheme were 97.1% and 85.3%, respectively, and the accuracy was 94.6%. The area under the ROC curve (Az) was 0.96. Our results indicated that the use of MD-cleansing substantially improved the effectiveness of our EC method in the reduction of incomplete cleansing artifacts.

CT colonography may improve colorectal cancer screening compliance

OBJECTIVE

While colonoscopy is currently the preferred test for colorectal cancer (CRC) screening, the invasive and time-consuming characteristics of the test are often cited as reasons for noncompliance with screening. CT colonography (CTC) is a less invasive screening method that is comparable to colonoscopy for the detection of advanced neoplasia. The aim of this project was to assess patient preferences between colonoscopy and CTC in an open access system.

MATERIALS AND METHODS

Two hundred fifty consecutive average-risk patients undergoing CRC screening completed a survey that assessed reasons for choosing CTC in lieu of colonoscopy, compliance with CRC screening if CTC was not offered, and which of the two tests they preferred.

RESULTS

The most common reasons for undergoing CTC included convenience (33.6%), recommendation by referring provider (13.2%), and perceived safety (10.8%). Had CTC not been an available option, 91 of the 250 patients (36%) would have foregone CRC screening. Among the 57 patients who had experienced both procedures, 95% (n = 54) preferred CTC.

CONCLUSION

These findings show the importance of providing CTC as an alternative screening option for CRC at our institution, which may increase CRC adherence screening rates.

Non-laxative CT colonography with barium-based faecal tagging: is additional phosphate enema beneficial and well tolerated?

OBJECTIVE

The purpose of this study was to investigate the efficacy and tolerance of an additional phosphate enema prior to non-laxative CT colonography (CTC).

METHODS

71 patients (mean age 80 years, 28 male, 43 female) underwent non-laxative CTC following 4 oral doses of diluted 2% w/w barium sulphate. Patients were invited to self-administer a phosphate enema 2 h before CTC. An experienced observer graded the volume of retained stool (1 (nil) to 4 (>75% bowel circumference coated)), retained fluid ((1 (nil) to 4 (>50% circumference obscured)), retained stool tagging quality (1 (untagged) to 5 (≥75% to 100%) tagged) and confidence a polyp ≥6 mm could be excluded (yes/no) for each of six colonic segments. Tolerance of the enema was assessed via questionnaire. Data were analysed between those using and not using the enema by Mann-Whitney and Fisher's exact test. 18/71 patients declined the enema.

RESULTS

There was no reduction in residual stool volume with enema use compared with non-use either overall (mean score 2.6 vs 2.7, p = 0.76) or in the left colon (mean 2.3 vs 2.4, p = 0.47). Overall tagging quality was no different (mean score 4.4 vs 4.3, p = 0.43). There was significantly more retained left colonic fluid post enema (mean score 1.9 vs 1.1, p<0.0001), and diagnostic confidence in excluding polyps was significantly reduced (exclusion not possible in 35% segments vs 21% without enema, p = 0.006). Of 53 patients, 30 (56%) found the enema straightforward to use, but 4 (8%) found it unpleasant.

CONCLUSION

Phosphate enema use prior to non-laxative CTC leads to greater retained fluid, reducing diagnostic confidence, and is not recommended.

Analysis of barriers to and patients' preferences for CT colonography for colorectal cancer screening in a nonadherent urban population

OBJECTIVE

The aim of this study was to evaluate patients' barriers against colorectal cancer screening tests and to assess patients' preferences and cost influences for CT colonography (CTC) in a nonadherent urban subpopulation.

SUBJECTS AND METHODS

Patients who had been offered colorectal cancer screening but were nonadherent were asked to participate in this questionnaire study. Patients' demographic information was obtained, and patients' reasons for not being screened were explored. Subjects were given an information sheet that described a CTC procedure and then were asked about their willingness to undergo CTC and about other relevant factors, such as fees.

RESULTS

One hundred seventy-five patients were invited to participate; 53 declined and 54 did not respond, which left 68 subjects to be included in the analysis. After being informed about CTC screening, most (83%) subjects stated that they would be willing to undergo a CTC study. However, 70% stated that they would not be willing to pay out-of-pocket fees if insurance did not cover the study, and even among the 30% who were willing to pay the fees, the average amount they were willing to pay (mean, $244; median, $150) was well below currently charged rates.

CONCLUSION

Our study suggests that most nonadherent patients would be willing to undergo CTC as long as out-of-pocket fees are reasonable.