Cumulative radiation exposure from CT in outpatient practice: impact of referral practices and unjustified imaging

Abstract

'Background. Computed tomography is a primary source of medical radiation exposure. Monitoring cumulative doses and assessing referral justification are essential for improving pati ent radiation safety. Materials and Methods. This retrospective observational study analyzed 2314 outpatient computed tomography scans in 1934 patients performed over a one-year period. Cumulative effective doses were calculated using organ dose estimates derived fram Monte Carlo simulations in accordance with ICRP Publication 103 tissue weighting factors. Referrals 'were classified as justified or unjustified based on clinical indications and established appropriateness criteria, Data were analyzed by age, gender, and anatomical region. Results, Repeated imaging occurred in 301 patients. The median annual cumulative effective dose ranged from 5.61 mSv in patients aged <18 years to 19.31 mSv in those aged 40- 50 years. Female patients received significantly higher cumulative doses than male patients (18.96 vs. 9.67 mSy, p = 0,001). The highest median cumulative effective doses were observed for area 3 {abdomen} (22.27 mSvl, followed by area 1 [spine] (18.96 mSvl, area 9 {pelvis} (18.96 mSv), and area 10 {knee} (18.30 mSv) Conclusion. Cumulative radiation exposure from computed tomography varies sig cantly, driven by utilization patterns and referral behavior. A preference for compul tomography over lower-dose or non-ionizing modalities contributes to avoidable radiation burden. Strengthening adherence to evidence-based referral guidelines and implementing systematic dose optimization strategies are vital to reducing unnecessary exposure and enhancing safety in outpatient practice.