Purpose: To analyse the process of outpatient radiation therapy by dividing it into elementary acts, and to determine the cost-inducers (staff and machine time, equipment) in order to enhance the value of radiotherapy activity.
Material and methods: The care process was analysed from 1 June 1997 to 1 September 1997, in two institutions (Centre hospitalo-universitaire de Saint Etienne and centre de Lutte contre le Cancer de Lyon), in terms of consumption of human and equipment means, representing a cost for the care institution. The valorization was expressed in physics units for material means, and in time units for human and heavy equipment. Parameters able to modify the consumption of means had been defined. The following data had been collected for each activity: patient characteristics, characteristics of the process, specific parameters of each activity, data related to the care staff and care unit.
Results: The importance of the specific data of each activity was noteworthy. Two criteria modified the valorization: the complexity level of dosimetry and inclusion in a research trial. Total body irradiation and conformal radiotherapy were well individualized. There was no difference between the two care units. The lack of cost-inducers for the 'immobilization-simulation' activity reflects the large diversity of practice, and requires a global analysis of the 'treatment preparation' process.
Conclusion: The cost-inducers found in this study could permit the elaboration of the 'relative cost index' in radiation therapy. (The results obtained must be validated in other types of care units.) These relative cost indexes would describe the various phases of the treatment, such as treatment preparation, dosimetry, treatment, quality control. This approach is currently used by workshops in PMSI (Programme de Médicalisation des Systèmes d'Information) and NGAP (Nomenclature Générale des Actes Professionnels).