- The method of DGs and the dosimetric system developed has proved to be a powerful tool to compare the radiological practice in different centres.
- It has been possible to study the influence of the choice of the radiological techniques, the quality of the radiological equipment, and the examination parameters on the effective dose to the patient.
- Important differences are detected in the radiological strategies used to set the three diagnoses; Renal Cell Carcinoma. Lumbar Hernia Discalis and Vesico Ureteral Reflux in Children in the co-operating centres. These differences are detected in the field of the choice of the examination type, the number of examinations performed, the way the examinations are performed and the technical specifications of the equipment.
- The above mentioned differences have all an important influence on the total effective dose to the patient. The mean dose per patient differs up to a factor of 6 between the centres for one diagnosis.
- The availability of equipment is one main reason for differences in the choice of examination types. Modern diagnostic techniques can, in some situations, reduce the dose considerable. e.g. MRI can replace Myelography.
- As the main reasons for differences in the total dose to the patient from a diagnostic path we clearly observed the choice of the examination types and the way these examinations are performed (number of slices, fluoroscopy time etc).
- In the chain of examinations of a diagnostic process one complex radiological examination (Angiography, Myelography or CT) can contribute for up to 80% of the total effective dose to the patient. Attention should, therefore, be given to the optimisation. Quality Control and use of these types of examinations.
- 'External parameters' as reimbursement regulations have an important influence on the total dose to the patient. An obligated minimal number of films can lead to a doubling of the dose to the patient. The reported practices showed that these regulations often intervene with complex examination types (CT abdomen, Myelography, IVU) and have, therefore, a severe effect on the dose to the patient.
- It is generally recognised by the representatives in the co-operating centres that the diagnostic protocols are insufficiently questioned internally in most hospitals. However, due to the magnitude and complexity of the task pertaining to the conclusions mentioned above, a multidisciplinary discussion on diagnosis related techniques is necessary.
Medical diagnostical examinations give a major contribution to the manmade exposure of human beings. The amount of radiation given before a certain diagnosis is made, depends on factors of medical, technical and organizing character. The protocol leading to a diagnosis and the choice of an examination shows a wide variety. This influences the dose to the patient and the risk. The pilot study "Diagnosis related doses'' (contract Bi7-054, sector C22) learned us that a diagnosis group can be established and clearly described -at least for some diagnoses- and that the elements determining the dose can be collected. The objectives of this project can be summarized in following items:
- the exploitation of the results obtained in the pilot study, determine a diagnostic group relevant topediatric radiology and complete the data collected up to now with data from periferal hospitals in the Netherlands and Belgium and university hospitals in other EC countries;
- the calculation of absorbed dose from skin-dose and used imaging techniques into absorbed dose, dose equivalent, and possibly to risk related to diagnosis strategy and individual exam;
- the use of the Image Quality Figure (see BIR Report 20) and the dose to rank different strategies mathematically;
- to make an inventory of the reasons that can lead to the choice of examinations and number of images and evaluate the medical and/or sociological data.
The project will be executed by the two centers that initiated the Diagnosis related dose project, with contributions from three centers with experience in quality assurance and patient dose reduction, and two centers that will be chosen by the contractors and subcontractors in a later stage.
A final report will include a concise report describing the methodology of the diagnostic groups, the dose and risk evaluation so it can be used in other institutes.
Funding SchemeCSC - Cost-sharing contracts
6500 HB Nijmegen