L. van Dam 1 ; MC de Haan 2 ; TR de Wijkerslooth 3 ; EM Stoop 1 ; PMM Bossuyt 4 ; P. Fockens 3 ; ... more L. van Dam 1 ; MC de Haan 2 ; TR de Wijkerslooth 3 ; EM Stoop 1 ; PMM Bossuyt 4 ; P. Fockens 3 ; M. Thomeer 5 ; EJ Kuipers 1, 6 ; ME van Leerdam 1 ; M. van Ballegooijen 7 ; J. Stoker 2 ; E. Dekker 3 ; EW ... Of 600 eligible subjects, 538 (90%) were willing to complete the diary. ...
ABSTRACT PURPOSE Not all of those invited to population programs for colorectal screening with CT... more ABSTRACT PURPOSE Not all of those invited to population programs for colorectal screening with CT-colonography or colonoscopy participate, although uncertainty exists about the exact reasons. We systematically evaluated reasons for non-participation in a randomized trial of both screening modalities. METHOD AND MATERIALS Data were collected in the Colonoscopy or Colonography for Screening (COCOS) trial, a multicenter screening trial. In total 8,842 citizens aged 50-74 were randomly invited for CRC screening by CTC (n=2,919) or colonoscopy (n=5,923). Non-responders received a reminder 4 weeks after the initial invitation, accompanied by a questionnaire. Several reasons to decline could be indicated by ticking one or more of 20 (CTC) or 18 (colonoscopy) response options. Invitees could also report other reasons, and were asked to indicate the most decisive reason. RESULTS The questionnaire was completed by 203 (10%) of 1,937 CTC non-participants (42% male, median age 61 yrs) and 789 (17%) of 4,647 colonoscopy non-participants (43% male, median age 60 yrs). The most frequently cited reasons to decline CTC or colonoscopy were: ‘I do not have symptoms of CRC’ (31% vs. 23%;p=0.01), ‘it seems an unpleasant examination’ (30% vs. 65%;p<0.001), ‘low priority’ (20% vs. 14%;p<0.05), ‘I cannot oversee the consequences’ (20% vs. 21%;p=0.89) and ‘preparation is too burdensome” (19% vs. 34%;p<0.001). Most frequently reported decisive reasons for non-participation in CTC screening were ‘low priority’ (13%) and ‘I do not have symptoms of CRC’ (12%); for colonoscopy this was ‘colonoscopy seems an unpleasant examination’ (34%). CONCLUSION The most often reported reason not to participate in CTC screening was an absence of symptoms, while the expected burden was the most frequently cited reason in colonoscopy non-participants. Information leaflets in a future screening program could be designed in such a way that they make invitees more aware of the fact that most large polyps and CRCs do not cause symptoms. CLINICAL RELEVANCE/APPLICATION Most decisive reasons for CTC invitees to decline CRC screening are ‘low priority’ and ‘no symptoms’, while most decisive reason for colonoscopy invitees is ‘seems an unpleasant examination’.
Surveillance CT colonography (CTC) is a viable option for 6-9 mm polyps at CTC screening for colo... more Surveillance CT colonography (CTC) is a viable option for 6-9 mm polyps at CTC screening for colorectal cancer. We established participation and diagnostic yield of surveillance and determined overall yield of CTC screening. In an invitational CTC screening trial 82 of 982 participants harboured 6-9 mm polyps as the largest lesion(s) for which surveillance CTC was advised. Only participants with one or more lesion(s) ≥6 mm at surveillance CTC were offered colonoscopy (OC); 13 had undergone preliminary OC. The surveillance CTC yield was defined as the number of participants with advanced neoplasia in the 82 surveillance participants, and was added to the primary screening yield. Sixty-five of 82 participants were eligible for surveillance CTC of which 56 (86.2 %) participated. Advanced neoplasia was diagnosed in 15/56 participants (26.8 %) and 9/13 (69.2 %) with preliminary OC. Total surveillance yield was 24/82 (29.3 %). No carcinomas were detected. Adding surveillance results to in...
The American journal of gastroenterology, Jan 20, 2015
Volumetric growth assessment has been proposed for predicting advanced histology at surveillance ... more Volumetric growth assessment has been proposed for predicting advanced histology at surveillance computed tomography (CT) colonography (CTC). We examined whether is it possible to predict which small (6-9 mm) polyps are likely to become advanced adenomas at surveillance by assessing volumetric growth. In an invitational population-based CTC screening trial, 93 participants were diagnosed with one or two 6-9 mm polyps as the largest lesion(s). They were offered a 3-year surveillance CTC. Participants in whom surveillance CTC showed lesion(s) of ≥6 mm were offered colonoscopy. Volumetric measurements were performed on index and surveillance CTC, and polyps were classified into growth categories according to ±30% volumetric change (>30% growth as progression, 30% growth to 30% decrease as stable, and >30% decrease as regression). Polyp growth was related to histopathology. Between July 2012 and May 2014, 70 patients underwent surveillance CTC after a mean surveillance interval of...
IEEE transactions on bio-medical engineering, Jan 23, 2014
This paper studies a novel method to compensate for respiratory and peristaltic motions in abdomi... more This paper studies a novel method to compensate for respiratory and peristaltic motions in abdominal Dynamic Contrast Enhanced MRI. The method consists of two steps: (1) expiration-phase 'template' construction and retrospective gating of the data to the template; (2) non-rigid registration of the gated volumes. Landmarks annotated by three experts were used to directly assess the registration performance. A tri-exponential function fit to time intensity curves from regions of interest was used to indirectly assess the performance. One of the parameters of the tri-exponential fit was used to quantify the contrast enhancement. Our method achieved a mean target registration error (MTRE) of 2.12 mm, 2.27 mm and 2.33mm with respect to annotations by expert, which was close to the average inter-observer variability (2.07mm). A state-of-the-art registration method achieved a MTRE of 2.83-3.10 mm. The correlation coefficient of the contrast enhancement parameter to the Crohn's ...
L. van Dam 1 ; MC de Haan 2 ; TR de Wijkerslooth 3 ; EM Stoop 1 ; PMM Bossuyt 4 ; P. Fockens 3 ; ... more L. van Dam 1 ; MC de Haan 2 ; TR de Wijkerslooth 3 ; EM Stoop 1 ; PMM Bossuyt 4 ; P. Fockens 3 ; M. Thomeer 5 ; EJ Kuipers 1, 6 ; ME van Leerdam 1 ; M. van Ballegooijen 7 ; J. Stoker 2 ; E. Dekker 3 ; EW ... Of 600 eligible subjects, 538 (90%) were willing to complete the diary. ...
ABSTRACT PURPOSE Not all of those invited to population programs for colorectal screening with CT... more ABSTRACT PURPOSE Not all of those invited to population programs for colorectal screening with CT-colonography or colonoscopy participate, although uncertainty exists about the exact reasons. We systematically evaluated reasons for non-participation in a randomized trial of both screening modalities. METHOD AND MATERIALS Data were collected in the Colonoscopy or Colonography for Screening (COCOS) trial, a multicenter screening trial. In total 8,842 citizens aged 50-74 were randomly invited for CRC screening by CTC (n=2,919) or colonoscopy (n=5,923). Non-responders received a reminder 4 weeks after the initial invitation, accompanied by a questionnaire. Several reasons to decline could be indicated by ticking one or more of 20 (CTC) or 18 (colonoscopy) response options. Invitees could also report other reasons, and were asked to indicate the most decisive reason. RESULTS The questionnaire was completed by 203 (10%) of 1,937 CTC non-participants (42% male, median age 61 yrs) and 789 (17%) of 4,647 colonoscopy non-participants (43% male, median age 60 yrs). The most frequently cited reasons to decline CTC or colonoscopy were: ‘I do not have symptoms of CRC’ (31% vs. 23%;p=0.01), ‘it seems an unpleasant examination’ (30% vs. 65%;p<0.001), ‘low priority’ (20% vs. 14%;p<0.05), ‘I cannot oversee the consequences’ (20% vs. 21%;p=0.89) and ‘preparation is too burdensome” (19% vs. 34%;p<0.001). Most frequently reported decisive reasons for non-participation in CTC screening were ‘low priority’ (13%) and ‘I do not have symptoms of CRC’ (12%); for colonoscopy this was ‘colonoscopy seems an unpleasant examination’ (34%). CONCLUSION The most often reported reason not to participate in CTC screening was an absence of symptoms, while the expected burden was the most frequently cited reason in colonoscopy non-participants. Information leaflets in a future screening program could be designed in such a way that they make invitees more aware of the fact that most large polyps and CRCs do not cause symptoms. CLINICAL RELEVANCE/APPLICATION Most decisive reasons for CTC invitees to decline CRC screening are ‘low priority’ and ‘no symptoms’, while most decisive reason for colonoscopy invitees is ‘seems an unpleasant examination’.
Surveillance CT colonography (CTC) is a viable option for 6-9 mm polyps at CTC screening for colo... more Surveillance CT colonography (CTC) is a viable option for 6-9 mm polyps at CTC screening for colorectal cancer. We established participation and diagnostic yield of surveillance and determined overall yield of CTC screening. In an invitational CTC screening trial 82 of 982 participants harboured 6-9 mm polyps as the largest lesion(s) for which surveillance CTC was advised. Only participants with one or more lesion(s) ≥6 mm at surveillance CTC were offered colonoscopy (OC); 13 had undergone preliminary OC. The surveillance CTC yield was defined as the number of participants with advanced neoplasia in the 82 surveillance participants, and was added to the primary screening yield. Sixty-five of 82 participants were eligible for surveillance CTC of which 56 (86.2 %) participated. Advanced neoplasia was diagnosed in 15/56 participants (26.8 %) and 9/13 (69.2 %) with preliminary OC. Total surveillance yield was 24/82 (29.3 %). No carcinomas were detected. Adding surveillance results to in...
The American journal of gastroenterology, Jan 20, 2015
Volumetric growth assessment has been proposed for predicting advanced histology at surveillance ... more Volumetric growth assessment has been proposed for predicting advanced histology at surveillance computed tomography (CT) colonography (CTC). We examined whether is it possible to predict which small (6-9 mm) polyps are likely to become advanced adenomas at surveillance by assessing volumetric growth. In an invitational population-based CTC screening trial, 93 participants were diagnosed with one or two 6-9 mm polyps as the largest lesion(s). They were offered a 3-year surveillance CTC. Participants in whom surveillance CTC showed lesion(s) of ≥6 mm were offered colonoscopy. Volumetric measurements were performed on index and surveillance CTC, and polyps were classified into growth categories according to ±30% volumetric change (>30% growth as progression, 30% growth to 30% decrease as stable, and >30% decrease as regression). Polyp growth was related to histopathology. Between July 2012 and May 2014, 70 patients underwent surveillance CTC after a mean surveillance interval of...
IEEE transactions on bio-medical engineering, Jan 23, 2014
This paper studies a novel method to compensate for respiratory and peristaltic motions in abdomi... more This paper studies a novel method to compensate for respiratory and peristaltic motions in abdominal Dynamic Contrast Enhanced MRI. The method consists of two steps: (1) expiration-phase 'template' construction and retrospective gating of the data to the template; (2) non-rigid registration of the gated volumes. Landmarks annotated by three experts were used to directly assess the registration performance. A tri-exponential function fit to time intensity curves from regions of interest was used to indirectly assess the performance. One of the parameters of the tri-exponential fit was used to quantify the contrast enhancement. Our method achieved a mean target registration error (MTRE) of 2.12 mm, 2.27 mm and 2.33mm with respect to annotations by expert, which was close to the average inter-observer variability (2.07mm). A state-of-the-art registration method achieved a MTRE of 2.83-3.10 mm. The correlation coefficient of the contrast enhancement parameter to the Crohn's ...
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