[Cost of radiotherapy for bone metastases in France: A monocentric retrospective study]. / Coût de la radiothérapie des métastases osseuses en France : étude rétrospective monocentrique.

PURPOSE: The cost of radiotherapy is a concern for health systems. The conventional non fractionated or multifractionated schemes have shown the same efficacy in terms of pain relief but a non fractionated treatment seems less expensive. However, in general practice, multifractionated treatments are still the majority, which represents an additional cost for society. Moreover, the use of stereotactic body radiotherapy becomes more democratic and offers new curative perspectives, but at what price? MATERIAL AND METHODS: A monocentric retrospective study was conducted in a French radiotherapy department to evaluate and compare the cost of irradiation of uncomplicated bone metastases according to the selected radiotherapy regimen : 30Gy in 10 fractions, 20Gy in five fractions, 8Gy in one fraction or stereotactic body radiotherapy. RESULTS: Between January 2014 and December 2015, 91 patients receiving 116 treatments were included in the study, including 44 men (48%) and 47 women (52%) were 63 years old (25-88 years). Thirty-four treatments (29%) were performed by 30Gy in 10 fractions (30Gy group), 24 treatments (21%) by 20Gy in 5 fractions (20Gy group), 25 treatments (22%) by 8Gy in one fraction (8Gy group) and 33 treatments (28%) by stereotactic body radiotherapy (SBRT group). The cost of stereotactic body radiotherapy was significantly higher than that of three-dimensional treatments (P<0.001). If the cost of transport was added to this cost, stereotactic body radiotherapy remained the most expensive (P<0.001). The cost of the irradiation delivering 30Gy treatment was significantly higher than the cost of treatment with 20Gy (P=0.006) or 8Gy (P<0.001), even after adding the transport cost (P<0.001), with no significant difference between 20Gy and 8Gy (P=0.11). For the overall cost of treatment including the total cost of treatments, associated transport and reirradiation, stereotactic body radiotherapy was the most expensive treatment (P<0.001) and this cost was significantly higher in the 30Gy group than in the 20Gy group (P=0.012) or 8Gy group (P=0.001), with no significant difference between 20Gy and 8Gy (P=0.38). There was no significant difference in the cost of follow-up between 30Gy, 20Gy, 8Gy and stereotactic body radiotherapy at one month (P=0.09) but at three months (P=0.01) and six months (P=0.0001), this cost was significantly higher after a three-dimensional treatment. There was no significant difference in overall cost including initial radiotherapy, transport and overall follow-up over 6 months between groups (P=0.04). CONCLUSION: Stereotactic body radiotherapy is an efficient and curative irradiation technique but more expensive. It is preferred for some patients with a longer life expectancy in a non-palliative treatment setting. The treatment delivering 8Gy treatment appears to be the most cost-effective while leading to an equivalent efficiency to multifractionated treatments and preserving the quality of life of patients.