RISK OF CANCER ASSOCIATED WITH COMPUTED TOMOGRAPHY AND RADIOGRAPHY PERFORMED IN THE ICU PATIENTS

Abstract

The purpose of this study was to quantify the X-ray and CT exams performed during ICU stay and to estimate their cumulative radiation dose and lifetime attributable risk of developing cancer. The study included 283 of 456 patients who were admitted in the ICU over a period of one year. Demographic data of patients were collected from HIS. The radiological information was obtained from RIS and PACS. For X-rays, E values published in the literature were used. For TC, the E values were estimated by multiplying the DLP made available in the DICOM RDSR by the conversion factors published in the report 96 of AAPM task group 23. The lifetime cancer risk was estimated from E, based on the risk values set out in the BEIR VII report. An average of 5 (0-45) X-rays and 2 (0-11) CT were performed on patients with a mean age of 52 years (13-90 years) and mean ICU stay of 25 days (1-129 days). Only 3% of patients did not undergo any of these procedures. The X-rays and CT frequency was 69% and 31 % respectively. The cumulative effective dose contribution was 4% from X-ray and 96 % from CT. The mean and median of cumulative doses were 18 mSv and 13 mSv, respectively, with a maximum of 133 mSv. The lifetime cancer risk was estimated as a mean of 0.10% and a median of 0.06%, with the highest risk being 1.11%. The results of this study may be used by physicians to judge the risk-benefit ratio, applying the principle of justification for radiological procedures.