@entity5 surveillance using serial computed tomography: evaluation of organ absorbed dose and XXXX .

@entity1 @entity24882 @entity5 @entity2073 @entity703
Computed tomography (CT) is used extensively in @entity5 diagnosis, staging, evaluation of response to treatment, and in active surveillance for @entity5 reoccurrence. A review of CT technology is provided, at a level of detail appropriate for a busy clinician to review. The basis of x-ray CT dosimetry is also discussed, and concepts of absorbed dose and @entity24882 ( @entity24882 ) are distinguished. Absorbed dose is a physical quantity (measured in milligray [mGy]) equal to the x-ray energy deposited in a mass of tissue, whereas @entity24882 uses an organ-specific weighting method that converts organ doses to @entity24882 measured in millisieverts ( @entity2073 ). The organ weighting values carry with them a measure of radiation risk, and so @entity24882 (in @entity2073 ) is not a physical dose metric but rather is one that conveys radiation risk. The use of CT in a @entity5 surveillance protocol was used as an example of a pediatric @entity1 who had @entity703 , with surgery and radiation therapy. The active use of CT for @entity5 surveillance along with diagnostic CT scans led to a total of 50 CT scans performed on this @entity1 in a 7-year period. It was estimated that the @entity1 received an average organ dose of 431 mGy from these CT scans. By comparison, the radiation therapy was performed and delivered 50.4 Gy to the @entity1 's abdomen. Thus, the total dose from CT represented only 0.8% of the @entity1 's radiation dose.
