Medical radiation exposure and justification at a large teaching hospital. Comparison of radiation-related and disease-related risks

The medical X-ray exposure was determined in a 2400-bed hospital. The radiation-related risk was compared with the severity of disease (ICD) to verify the justification for X-ray procedures. A model to estimate radiation and disease-related ''loss of lifetime'' was applied. X-ray exposure from radiography, fluoroscopy and CT was determined for diagnostic and interventional procedures during one hospital stay of 403 patients (0.5 % of all 80 000 patients/year). CTDI and DLP in CT, DAP in fluoroscopy or SED in radiography were used to calculate the effective dose (ED). The disease and radiation-related risk were compared with a simple ''loss of lifetime'' model. The mean age of all patients was 60. Only a subgroup of 170 patients (42 %) with a mean age of 67.6 had one or more X-ray procedures. The average ED of these exposed patients was 5.12 mSv. 14.4 % CT examinations had a dose contribution of 52.5 % followed by 5.3 % radiology and cardiology procedures at 37.2 %. 90 % of ED was applied to only 44 patients (11 %) and 50 % of ED was applied to only 10 patients (2.5 %) with a mean age of 71.2. 4 of these 10 patients had malignant tumors, the other 6 suffered from pulmonary embolism, pneumonia, stentgraft infection, CAD, Crohn's disease and severe hypertension. The ratio of disease vs. radiation-related risk was between 2.1:1 and 1800:1. In this study referral for justified X-ray procedures in a large hospital with high level medical care offers a significant patient benefit. (orig.)