Radiation dose and cancer risk estimates in 16-slice computed tomography coronary angiography.
BACKGROUND
Recent advances have led to a rapid increase in the number of computed tomography coronary angiography (CTCA) studies performed. Whereas several studies have reported the effective dose, there are no data available on cancer risk for current CTCA protocols.


RESULTS
Effective and organ doses were estimated, by use of scanner-derived parameters and Monte Carlo methods, for 50 patients having 16-slice CTCA performed for clinical indications. Lifetime attributable risks were estimated with models developed in the National Academies' Biological Effects of Ionizing Radiation VII report. The effective dose of a complete CTCA averaged 9.5 mSv, whereas that of a complete study, including calcium scoring when indicated, averaged 11.7 mSv. Calcium scoring increased effective dose by 25%, whereas tube current modulation reduced it by 34% and was more effective at lower heart rates. Organ doses to the lungs and female breast were highest. The lifetime attributable risk of cancer incidence from CTCA averaged approximately 1 in 1,600 but varied widely among patients, being highest in younger women. For all patients, the greatest risk was from lung cancer.


CONCLUSIONS
CTCA is associated with non-negligible risk of malignancy. Doses can be reduced by careful attention to scanning protocol.
Einstein
Andrew J
AJ
Department of Medicine, Division of Cardiology, The Mount Sinai Medical Center, New York, NY, USA. andrew.einstein@columbia.edu
Sanz
Javier
J
Dellegrottaglie
Santo
S
Milite
Margherita
M
Sirol
Marc
M
Henzlova
Milena
M
Rajagopalan
Sanjay
S
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001822:Body Burden; D017023:Coronary Angiography / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology*; D009518:New York / Q000453:epidemiology; D011829:Radiation Dosage; D011874:Radiometry / Q000706:statistics & numerical data*; D012062:Relative Biological Effectiveness; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*