CT colonography versus double-contrast barium enema for screening of colorectal cancer: comparison of radiation burden.
Our aim is to compare the radiation dose associated with a low-dose CT colonography (CTC) protocol for colorectal cancer screening with that delivered by double-contrast barium enema (DCBE). CTC of twenty asymptomatic individuals (M:F = 10:10) participating to a colorectal cancer screening program and DCBE of fifteen patients (M:F = 6:9) were evaluated. For CTC, absorbed dose was determined by calculating the dose-length product for each CTC examination from measurements on a CT dose phantom equipped with a CT ion chamber. For DCBE, the free-in-air Kerma at the patient's X-ray entry surface and the Kerma-area product during fluoroscopy and fluorography were measured with a Barracuda system, with fluoroscopy times being recorded blinded to the performing operator. Effective dose at CTC was 2.17 ± 0.12 mSv, with good and excellent image quality in 14/20 (70%) and 6/20 cases (30%), respectively. With DCBE, effective patient dose was 4.12 ± 0.17 mSv, 1.9 times greater than CTC (P < 0.0001). Our results show that effective dose from screening CTC is substantially lower than that from DCBE, suggesting that CTC is the radiological imaging technique of the large bowel with the lowest risk of stochastic radiation effects.
Diagnostic and Interventional Radiology, University of Pisa, Via Paradisa, 2, 56100, Pisa, Italy. neri@med.unipi.it
Emanuele
E
Neri
Lorenzo
L
Faggioni
Francesca
F
Cerri
Francesca
F
Turini
Simone
S
Angeli
Lorenzo
L
Cini
Franco
F
Perrone
Fabio
F
Paolicchi
Carlo
C
Bartolozzi
D001466:Barium Sulfate; D023881:Colonography, Computed Tomographic / Q000379:methods*; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging*; D003287:Contrast Media; D003974:Diatrizoate Meglumine; D004307:Dose-Response Relationship, Radiation; D004733:Enema; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D007327:Insufflation / Q000379:methods; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D018709:Statistics, Nonparametric
D003287:Contrast Media; D001466:Barium Sulfate; D003974:Diatrizoate Meglumine