ESTRO 38 Abstract book

S891 ESTRO 38

way. These improvements should be additional justification for clinical implementation. EP-1655 Cost-effectiveness analysis of stereotactic radiotherapy in colorectal cancer brain metastases A. Paix 1 , F. Thillays 2 , J. Biau 3 , N. Vulquin 4 , I. Pop 5 , K. Debbi 6 , A.L. Grosu 5 , E.A. Sauleau 7 , G. Noël 1 1 Centre Paul Strauss, Radiothérapie, Strasbourg, France ; 2 Institut Cancérologique de l'ouest, Radiothérapie, Saint Herblain, France ; 3 Centre Jean Perrin, Radiothérapie, Clermont-Ferrand, France ; 4 Centre Georges-François Leclerc, Radiothérapie, Dijon, France ; 5 Universitätsklinikum Freiburg, Klinik für Strahlenheilkunde, Freiburg, Germany ; 6 Centre Henry Kaplan - CHU Tours, Radiothérapie, Tours, France ; 7 CHU Strasbourg, Methodological and clinical research group, strasbourg, France Purpose or Objective Colorectal cancer (CRC) is the third most common cancer in developed countries and brain metastases only occur in 1% of CRC patients, however this rate is likely to raise due to the increase of the overall survival as new systemic drugs became available. Stereotactic radiosurgery (SRS) and hypofractionated stereotactic radiotherapy (HFSRT) are treatment options. We developed a Markov model to evaluate the cost-effectiveness of SRS and HFSRT in patients with CRC brain metastases. Material and Methods We designed a Markov model, reported Figure 1, to simulate the clinical trajectory of a patient with a single CRC brain metastasis using data retrospectively collected in 6 hospitals in France and Germany.

Conclusion This is the first medico-economic evaluation of SRS and HFSRT in CRC brain metastases, and its results suggest that HFSRT is cost-effective compared to SRS, in the French payer perspective. EP-1656 Prevention of heterotopic ossification after total hip replacement: a cost-effectiveness analysis A. Paix 1 , T. Stévignon 2 , N. Baudrier 3 , G. Noël 1 1 Centre Paul Strauss, Radiothérapie, Strasbourg, France ; 2 Hôpital Saint Joseph, Orthopedic surgery, Paris, France ; 3 Centre chirurgical Emile Gallé, Orthopedic surgery, Nancy, France Purpose or Objective Heterotopic ossifications (HO) following total hip replacement can severely impact the quality of life of patients. While there are no guidelines for HO prophylaxis, non-steroidal anti-inflammatory drugs (NSAIDs) are widely used. However, radiotherapy delivered in a single fraction has also proven its efficacity. We conducted a medico-economic evaluation of NSAIDs and radiotherapy in the prevention of HO following total hip replacement. Material and Methods We designed a Markov model to simulate the clinical trajectory of a patient at risk for HO following total hip replacement. Two prevention strategies were compared: 3 x 25 mg per day for three weeks and a single radiation dose of 7 Gy. Patients treated with NSAIDs could experience upper digestive bleeding. In both cases, HO could occur despite prophylaxis and be treated with painkiller and physical therapy or surgery.

This analysis was conducted in a French payer perspective on a lifetime horizon. Utility values, recurrence risks, and costs were adapted from the literature. Deterministic (DSA) and probabilistic (PSA) sensitivity analyses were performed to assess the influence of the assumptions made. Results In the base case analysis, SRS and HFSRT total costs were 4,404.76€, and 5,921.34€ and the quality-adjusted life expectancies were 1.2545 and 1.2589. In the probabilistic sensitivity analysis, SRS and HFSRT were associated with a mean total cost of 4,407.80 € and 5,817.33€, and quality-adjusted life expectancies 1.2597 and 1.2987 QALYs, respectively. SRS appeared to be 1,409.53€ € cheaper than HFSRT with a decrease of quality-adjusted life expectancy of 0.039 QALYs. HFSRT had a probability of cost-effectiveness for the willingness- to-pay threshold of 30,000€ and 100,000€ of 33.2% and 94% respectively, as reported on the acceptability curves in Figure 2.

Our study was conducted from a French payer perspective, using payment data applicable in public hospitals in 2017. All the costs used are expressed in 2017 euros, and costs and Quality Adjusted Life Years (QALYs) were discounted at an annual rate of 4%.