An action plan for dose reduction from computed tomography in Luxembourg

Computed tomography (CT) is generally associated with high performance in radiological diagnostics, but also with high patient dose. The last developments towards faster CT scan systems (spiral, MSCT) and PACS archiving allow wide scan volumes and an increased passage of patients. Actual data from Luxembourg shows that CT contributed with 1 mSv 50% to the collective dose in 2002, comparable to the international trend of increased CT examinations frequency. Luxembourg has reached today with 157 exams per 1000 inhabitants one of the highest CT examination rate compared to other health care level I countries, which were reported by UNSCEAR with an average of 57 exams per 1000 inhabitants. The European Directive 97/43/EURATOM has been implemented in the Grand Duchy of Luxembourg with the ordinance of March 16th 2001. This ordinance regulates the measures towards the radiation protection of patients, as well as the role of the medical physics experts in the realization of quality assurance controls. The Radiation Protection Department of the Ministry of Health has planned in cooperation with the Luxembourgish Association of Hospitals, which employs the medical physicists working in diagnostic radiology, actions in order to reduce the collective dose from computed tomography: 1. Carrying out a dose measurement survey using a CT-phantom and by evaluating a representative number of patient doses through a dedicated software. 2. Analysing the clinical protocols of the most common CT-examinations by a working group of specialists (physicians, radiographers and medical physicists) in order to optimize and if necessary standardize them. 3. Establishing lower national Diagnostic Reference Levels (DRL) compared to the European ones by taking into account the results of the dose survey as well as the optimization procedures of the protocols. Special DRLs will be defined for pediatric patients because of the higher radiation risk involved. 4. Developing an electronic X ray card for the population of Luxembourg using the records of the radiological information systems (RIS) of the hospitals and the HealthNet infrastructure (a national intranet). This project is embedded in the national e-health plan, having as main objective to avoid unecessary repeated radiological examinations and to provide the health authorities with current frequency data for future collective dose calculations. 5. Improving the justification of radiological examinations by introducing referral guidelines for imaging focused on the CT in relation with other modalities like MRI and ultrasound. As shown, the increment of MRI exams since 2002 in Luxembourg did not decrease the CT frequency as expected. 6. Providing regular feedback to all participants and partners involved in this work in order to show them the importance of their actions in dose reduction from computed tomography imaging. The practical implementation of this action plan should show first results before the end of this year and could be part of international activities like the WHO CT Safety Project