The diagnostic reference levels in France

Full text of publication follows: Objectives - Within the framework of the directive 97/43 EURATOM implementation, diagnostic reference levels (D.R.L.s) in radiology and nuclear medicine were introduced into French regulation by the decree of 12 February 2004. For conventional radiology, D.R.L.s are given for 9 adult and 8 paediatric examinations as entrance surface dose. For computed tomography (CT), the relevant dosimetric quantities are the weighted CT Dose Index (CTDIw) and the Dose Length Product (D.L.P.). D.R.L.s are given only for 4 adult examinations. In nuclear medicine, D.R.L.s are established on the basis of survey of administered activities. For the moment, D.R.L.s are considered as 'the activity levels recommended in the radiopharmaceuticals manufacturer prescribing information' (value depending on the patient weight). They apply to 10 examinations. This paper presents the assessment of data collection for periodic update of D.R.L.s by the Institute of Radiation Protection and Nuclear Safety (I.R.S.N.) 18 months after publication of the decree (March 16, 2004). Materials and methods - In order to receive and centralize D.R.L.s, I.R.S.N. set up data sheets to the attention of departments practicing acts of conventional radiology, CT or nuclear medicine. Each department must choose every year 2 examinations among those listed in the decree and complete data for 20 standard patients. Results - So far, data collection is mainly limited to nuclear medicine departments where administered activities are often surveyed in routine. To date 65 among the 290 nuclear medicine departments in France and 11 among approximately 4000 radiology departments have transmitted their data. Results reported here are relating to nuclear medicine only and concern particularly bone (56 departments) and thyroid (20 departments) examinations for adult. For bone scan, the D.R.L. range is between 300 and 700 MBq. The average administered activity (AAA) is 701 ± 90 MBq. The administered activities are found to be above the value recommended by the manufacturer prescribing information in 51.8 % of the departments. For 99mTc thyroid scan, D.R.L. is between 20 and 80 MBq and the AAA is 174 ± 54 MBq. All the departments exceed the manufacturer prescribing information. For 123I thyroid scan, D.R.L. is between 5 and 15 MBq. The AAA is 8.7 ± 3.3 MBq. One department is under the lower limit. Conclusion - In France the collection of dosimetric information is new in the medical field where the transmission of this type of data is not common. As a result, a low rate of answer was noted to date. Nevertheless, one can stress that in nuclear medicine, for bone and thyroid scans, a large number of departments do not follow manufacturer prescribing information. In radiology significant effort must be addressed to train professionals and to incite them to send data. (authors)