Colonoscopy – Ready Colonoscopy – Ready to be Replaced as a to be Replaced as a
Screening Tool?Screening Tool?
Vivien WongVivien Wong
North District HospitalNorth District Hospital
January 16January 16thth, 2010, 2010
Joint Hospital Surgical Grand Round
Colorectal CancerColorectal Cancer High incidence among both male and High incidence among both male and
female in Hong Kongfemale in Hong Kong– 22ndnd most commonly diagnosed cancer most commonly diagnosed cancer
4000 cases per year4000 cases per year– 22ndnd most common cause for cancer death most common cause for cancer death
1700 cases per year1700 cases per yearHong Kong Cancer Registry 2007Hong Kong Cancer Registry 2007
Well-established treatmentWell-established treatment Known possible malignant transformation Known possible malignant transformation
of benign adenomatous polypsof benign adenomatous polyps– Removal of benign polyps can prevent Removal of benign polyps can prevent
development into invasive carcinomadevelopment into invasive carcinoma
ColonoscopyColonoscopy
Investigation of Investigation of choicechoice
InvasiveInvasive Risk of perforationRisk of perforation DiscomfortDiscomfort Sedation/GASedation/GA
Any non-invasive method to replace Any non-invasive method to replace colonoscopy for screening?colonoscopy for screening?
Barium enemaBarium enema
The conventional alternative in The conventional alternative in patients not suitable or unwilling to patients not suitable or unwilling to perform colonoscopyperform colonoscopy
Efficacy significantly lower compared Efficacy significantly lower compared to colonoscopyto colonoscopy
Sosna et al. Critical Analysis of the Performance of Double-Contrast Barium Enema for Detecting Colorectal Polyps 6 mm
in the Era of CT Colonography. Am J Roentgenol, Feb 2008; 190: 374 - 385.
Polyps ≥ Polyps ≥ 10mm10mm
Polyps 6-9 mmPolyps 6-9 mm
SensitivitySensitivity 70%70% 45%45%
SpecificitySpecificity 85%85%
New technologyNew technology
CT ColonographyCT ColonographyCapsule endoscopyCapsule endoscopy
CT ColonographyCT Colonography
CT Colonography (CTC)CT Colonography (CTC)
Introduced since mid-1990sIntroduced since mid-1990s
Uses computed tomography to Uses computed tomography to perform an imaging evaluation of the perform an imaging evaluation of the coloncolon
Requires distension of large bowel Requires distension of large bowel for viewing of intraluminal lesionsfor viewing of intraluminal lesions
a.k.a. “Virtual Colonoscopy”a.k.a. “Virtual Colonoscopy”
Recent screening guidelinesRecent screening guidelines– The ACS guideline 2010The ACS guideline 2010
CTC is listed as one of the option of CRC CTC is listed as one of the option of CRC screening in average-risk population over screening in average-risk population over age of 50age of 50
– The ACG guideline 2009The ACG guideline 2009 CTC every 5 years replaced barium enema CTC every 5 years replaced barium enema
as the alternative colorectal cancer as the alternative colorectal cancer prevention testprevention test
Advantages:Advantages: Non-invasiveNon-invasive Assessment of extra-colonic pathologyAssessment of extra-colonic pathology
Concerns:Concerns: Sensitivity and SpecificitySensitivity and Specificity Safety issueSafety issue
– Bowel preparationBowel preparation– Colonic distentionColonic distention– RadiationRadiation
Sensitivity and SpecificitySensitivity and Specificity
Initial small trials involved polyp-rich Initial small trials involved polyp-rich cohorts and focused largely on cohorts and focused largely on technique developmenttechnique development
Subsequent larger trials 2003-2005Subsequent larger trials 2003-2005
No. of No. of patientspatients
Polyps ≥ 6mmPolyps ≥ 6mm
SensitivitySensitivity SpecificitySpecificity
Cotton Cotton et al et al 20042004 600600 39%39% 90.5%90.5%
Rockey Rockey et al et al 614614 51%51% ----
Johnson Johnson et al et al 703703 57%57% 95%95%
New techniques developedNew techniques developed– Stool taggingStool tagging– 3D-reconstruction views3D-reconstruction views– Multidetector row CT scannersMultidetector row CT scanners
No. of No. of PatientPatient
ss
Polyps Polyps ≥ 6mm≥ 6mm
Adenoma Adenoma ≥ 10mm≥ 10mm
SensitivitSensitivityy
SpecificiSpecificityty
SensitiviSensitivityty
SpecificiSpecificityty
Pickardt Pickardt et alet al 12331233 89%89% 94%94% 89%89%Stool taggingStool tagging3D polyp detection3D polyp detection
ACRIN 6664ACRIN 6664
>2500>2500in 15 in 15
centercenterss
---- 90%90% 86%86%
Stool taggingStool taggingAutomated CO2 deliveryAutomated CO2 delivery≥≥16 slice multidetector 16 slice multidetector row CTrow CT2D and 3D polyp detection2D and 3D polyp detection
MunichMunich 300300 ---- 92%92%64 slice multidetector CT64 slice multidetector CT3D polyp detection3D polyp detection
Mayo ClinicMayo Clinic 452452 ---- 95%95% 3D polyp detection3D polyp detection
Regge Regge et alet al
937937in 20 in 20
centercenterss
85%85% 88%88% ---- ----
The Recommended The Recommended SpecificationsSpecifications
Bowel preparationBowel preparation PEG or phosphosodaPEG or phosphosoda
Stool & fluid taggingStool & fluid tagging Not mandatory but recommended and Not mandatory but recommended and validatedvalidated
Bowel distensionBowel distension Scanning in two positionsScanning in two positions Automatic insufflation recommendedAutomatic insufflation recommended
Acquisition Acquisition parameters & parameters & radiation doseradiation dose
Multidetector CT ≥ 4 sliceMultidetector CT ≥ 4 slice Slice thickness ≤ 3mmSlice thickness ≤ 3mm Reconstruction level ≤ 2mmReconstruction level ≤ 2mm Low radiation dose, ≤ 50% of the diagnostic Low radiation dose, ≤ 50% of the diagnostic reference level for routine abdominopelvic CTreference level for routine abdominopelvic CT
Data interpretationData interpretation To ensure adequate bowel distension: 2D viewTo ensure adequate bowel distension: 2D view Polyp detection: Primary 2D or 3D searchPolyp detection: Primary 2D or 3D search Polyp characterization: 2D multiplanar or 3D Polyp characterization: 2D multiplanar or 3D images, data from both positions, and multiple images, data from both positions, and multiple window settingswindow settingsMcFarland et al. ACR Colon Cancer Committee White Paper: Status of
CT Colonography 2009. J Am Coll Radiology 2009;6:756-772
Capsule EndoscopyCapsule Endoscopyof the Colonof the Colon
Capsule endoscopy of the Capsule endoscopy of the coloncolon
Cleared for marketing in European Cleared for marketing in European Union since 2006Union since 2006
Uses an ingestibleUses an ingestiblecapsule with camerascapsule with camerasto acquire videoto acquire videoimages of the colonicimages of the colonicmucosa as it goesmucosa as it goesthrough the bowelthrough the bowel
PillCam Colon (Given Imaging, Yoqneam, Israel)PillCam Colon (Given Imaging, Yoqneam, Israel)
Capsule endoscopy of the Capsule endoscopy of the coloncolon
Cleared for marketing in European Cleared for marketing in European Union since 2006Union since 2006
Uses an ingestibleUses an ingestiblecapsule with camerascapsule with camerasto acquire videoto acquire videoimages of the colonicimages of the colonicmucosa as it goesmucosa as it goesthrough the bowelthrough the bowel
PillCam Colon (Given Imaging, Yoqneam, Israel)PillCam Colon (Given Imaging, Yoqneam, Israel)
•31mm x 11mm•Two cameras at each end covering 156°•Acquires pictures at rate of 4 fps
Esophagus& Stomach
SmallIntestine
Terminal ileum& ColonSleep
modeReactivationafter 2 hours
Bowel preparationBowel preparation– Polyethylene glycol solutionPolyethylene glycol solution– Sodium phosphateSodium phosphate– DomperidoneDomperidone– Bisacodyl rectal suppositoryBisacodyl rectal suppository
Data recordingData recording– Data transmitted from capsule to a data Data transmitted from capsule to a data
recorder connected to the patient during the recorder connected to the patient during the procedureprocedure
AnalysisAnalysis– Given Imaging RAPID workstationGiven Imaging RAPID workstation
Non-invasiveNon-invasive Less discomfortLess discomfort Sedation-freeSedation-free Away from doctor’s officeAway from doctor’s office
– Less disruption to patient’s routineLess disruption to patient’s routine
How well does it do?How well does it do?
Pubmed and MEDLINE search:Pubmed and MEDLINE search:– ““Pillcam colon”, “capsule colon Pillcam colon”, “capsule colon
endoscopy”endoscopy”
Six prospective trialsSix prospective trials One cost-effectiveness studyOne cost-effectiveness study One safety study with pacemakersOne safety study with pacemakers Case reportsCase reports
Venue of Venue of studystudy
Patients Patients recruited recruited (analyzed(analyzed
))
Age of Age of patientpatient
s s (mean)(mean)
Any polypsAny polyps Polyp ≥ 6mmPolyp ≥ 6mm
SensitiviSensitivity (95% ty (95%
CI)CI)
SpecificitSpecificityy
(95% CI)(95% CI)
SensitiviSensitivity (95% ty (95%
CI)CI)
SpecificitSpecificityy
(95% CI) (95% CI)
EliakimEliakim et al 2006 et al 2006 IsraelIsrael 9191(84)(84)
26-75 26-75 (57)(57)
56%56%(39-72)(39-72)
69%69%(56-82)(56-82)
50%50%(26-75)(26-75)
83%83%(73-91)(73-91)
Schoofs Schoofs et al et al 20062006 BelgiumBelgium 4141
(36)(36)26-75 26-75 (56)(56) 76%76% 64%64% 60%60% 73%73%
Gay Gay et al 2009et al 2009 FranceFrance 128128(126)(126)
n/an/a(55)(55) 76%76% 76%76% 69%69% n/an/a
Sieg Sieg et al 2009et al 2009 GermanGermanyy
3838(36)(36)
23-73 23-73 (56)(56) 55%55% 96%96% n/an/a n/an/a
Gossum Gossum et al et al 20092009
8 8 EuropeaEuropea
n n centrescentres
332332(320)(320)
22-84 22-84 (58)(58)
72%72%(68-75)(68-75)
78%78%(71-84)(71-84)
64%64%(59-72)(59-72)
84%84%(81-87)(81-87)
Comparative Studies:Comparative Studies:Pillcam Colon vs ColonoscopyPillcam Colon vs Colonoscopy
Venue of Venue of studystudy
Patients Patients recruited recruited (analyzed(analyzed
))
Age of Age of patientpatient
s s (mean)(mean)
Any polypsAny polyps Polyp ≥ 6mmPolyp ≥ 6mm
SensitiviSensitivity (95% ty (95%
CI)CI)
SpecificitSpecificityy
(95% CI)(95% CI)
SensitiviSensitivity (95% ty (95%
CI)CI)
SpecificitSpecificityy
(95% CI) (95% CI)
EliakimEliakim et al 2006 et al 2006 IsraelIsrael 9191(84)(84)
26-75 26-75 (57)(57)
56%56%(39-72)(39-72)
69%69%(56-82)(56-82)
50%50%(26-75)(26-75)
83%83%(73-91)(73-91)
Schoofs Schoofs et al et al 20062006 BelgiumBelgium 4141
(36)(36)26-75 26-75 (56)(56) 76%76% 64%64% 60%60% 73%73%
Gay Gay et al 2009et al 2009 FranceFrance 128128(126)(126)
n/an/a(55)(55) 76%76% 76%76% 69%69% n/an/a
Sieg Sieg et al 2009et al 2009 GermanGermanyy
3838(36)(36)
23-73 23-73 (56)(56) 55%55% 96%96% n/an/a n/an/a
Gossum Gossum et al et al 20092009
8 8 EuropeaEuropea
n n centrescentres
332332(320)(320)
22-84 22-84 (58)(58)
72%72%(68-75)(68-75)
78%78%(71-84)(71-84)
64%64%(59-72)(59-72)
84%84%(81-87)(81-87)
Comparative Studies vs Comparative Studies vs ColonoscopyColonoscopy
11.6mm x 31.5mm11.6mm x 31.5mm Increased angle of Increased angle of
view to 172°view to 172°
Adjusts frame rate Adjusts frame rate automaticallyautomatically– 35 fps while in 35 fps while in
motionmotion– 4 fps while 4 fps while
stationarystationary
Measuring tool in Measuring tool in the analysis the analysis software for polyp software for polyp sizesize
Venue of studyVenue of study 5 Israeli centres5 Israeli centres
Patients recruitedPatients recruited 104104
Patients analyzedPatients analyzed 9898
Age of patients (mean)Age of patients (mean) 18-57 (50)18-57 (50)
Polyps ≥ 6mmPolyps ≥ 6mm
SensitivitySensitivity 8989
SpecificitySpecificity 7676
Polyps ≥ 10mmPolyps ≥ 10mm
SensitivitySensitivity 8888
SpecificitySpecificity 8989Eliakim et al. Prospective mulitcenter performance evaluation of the second-generation colon capsule
compared with colonoscopy. Endoscopy 2009;41:1026-1031.
Comparative Study:Comparative Study:Pillcam Colon Pillcam Colon 22 vs Colonoscopy vs Colonoscopy
SafetySafety– No complication from the capsule in all No complication from the capsule in all
the six prospective trialsthe six prospective trials– Incompliance mainly due to anxiety (and Incompliance mainly due to anxiety (and
hence inability to swallow the capsule)hence inability to swallow the capsule)– Capsules were proven safe to use in Capsules were proven safe to use in
patients with implantable cardioverter-patients with implantable cardioverter-defibrillatorsdefibrillators Bandorski et al. Do endoscopy capsules interfere with
implantable cardioverter-defibrillators? Endoscopy 2009;41:457-461
ConclusionConclusion Colorectal cancer is a significant disease Colorectal cancer is a significant disease
suitable for population screeningsuitable for population screening Colonoscopy is the screening tool of Colonoscopy is the screening tool of
choice at the moment in suitable patientschoice at the moment in suitable patients Non-invasive screening tool is under Non-invasive screening tool is under
development in hope to replace the development in hope to replace the invasive colonoscopyinvasive colonoscopy
CT colonography is now accepted as a CT colonography is now accepted as a primary screening tool in the average-risk primary screening tool in the average-risk population in Americapopulation in America
Efficacy of colon capsule endoscopy is yet Efficacy of colon capsule endoscopy is yet to be provento be proven
In our locality…?In our locality…?
HospitalHospital ColonoscopyColonoscopy CTCCTC CapsuleCapsule
AA $14820-$27840$14820-$27840 $5800$5800 $17000-$17000-$20000$20000
BB $7300$7300 $5000-$7600$5000-$7600 n/an/a
CC n/an/a $4500$4500 n/an/a
No official colorectal cancer screening No official colorectal cancer screening programme launched yetprogramme launched yet
Which method to adopt as the primary Which method to adopt as the primary investigation to achieve best efficacy is investigation to achieve best efficacy is still yet to be definedstill yet to be defined
Thank youThank you