Abstract Book

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ESTRO 37

spinal bones) by Choline PET-CT or/and WB-DWI-MRI after primary treatment for their disease, were assigned to receive SBRT (Vertebral metastases: 1x16-18Gy or 3x8-- 9Gy. Lymph node metastases: 3x10-11 Gy or 6x7,5Gy. Non-spinal bone metastases: 1x16Gy or 3x10Gy). Inclusion criteria included: time from primary treatment to biochemical recurrence of more than 1 year and PSA doubling time> 2 months. A minimum of 24 months of LhRh analogues from the time of the enrollment was required. Local control rates, biochemical control rates, progression free survival, chemotherapy free survival and SBRT impact on patient’s quality of life were assessed. Toxicity was prospectively evaluated according to CTCAE criteria. Concomitant treatment with chemotherapy, abiraterone or enzalutamide was not allowed. Results From 07/2014 to 06/2017, 67 patients from 11 Spanish centers were recruited with a total of 100 oligometastases treated, 54 in lymph nodes, 42 in non-- -spinal bones and 4 in spinal bones. Twelve patients had castration-resistance disease. With a median follow-up after SBRT of 9 months, (range 1–30 months) local and biochemical control was 100%. Ten patients (15%) presented distant disease progression, 4 of them were castration-resistant (CRPC). Specifically, in patients with CRPC, after a median follow- up of 9.8 months, 8 of the 12 CRPC patients (66%) are free from disease progression at last follow-up, without the need to start second generation hormonal treatment. Tolerance and toxicity profiles were excellent, none of the patients developed toxicity ≥G3 or symptoms related to local progression of OC-0063 Medico-economics analysis of SBRT and surgery for early stage non small cell lung cancer. A. Paix 1 , G. Noel 1 , P.E. Falcoz 2 , A. Filipovic Pierucci 3 , P. Lévy 4 1 Centre Paul Strauss, Radiothérapie, Strasbourg, France 2 Hôpitaux Universitaires de Strasbourg, Department of thoracic surgery, strasbourg, France 3 Assistance Publique des Hôpitaux de Paris, URCéco, Paris, France 4 Université Paris Dauphine, LEDa LEGOS, Paris, France Purpose or Objective Projections estimate an increase of 50% of the incidence of lung cancers by 2030. Early stage NSCLC represented 19% of NSCLC diagnosed in France in 2004.There are rising evidences in favor of a lung cancer screening which will reduced the occurrence of later-stage lung cancers while rising the incidence of early stage NSCLC. Current guidelines states that for early stage NSCLC surgical resection should be performed and stereotactic body radiotherapy (SBRT) is an option in patient non-medically operable. In this study, we compared the cost- effectiveness of SBRT with lobectomy in medically operable patients. Material and Methods We developed a Markov model, based on the survival results of STARS and ROSEL, two randomized studies comparing SBRT and lobectomy in early stage NSCLC, to describe survival and treatment related complications of a patient treated for early stage NSCLC. This analysis was conducted from the French payer perspective on a lifetime perspective. Utility values, recurrence risks, and the disease. Conclusion Preliminary results of this trial demonstrate that combination of SBRT and ADT is safe treatment with encouraging local and biochemical control. Proffered Papers: CL 2: Health services research to improve value and access

costs were adapted from the literature. Deterministic (DSA) and probabilistic (PSA) sensitivity analyses were performed to assess the influence of the assumptions made. Results The Markov model developed was found consistent with survival data reported in the pool analysis of the randomized studies. SBRT and lobectomy total cost was 8,681€ and 10,616€ respectively, and the quality- adjusted life expectancy was 16.3 and 15.8 QALY respectively. The DSA, ran on every assumptions made, revealed that the incremental cost-effectiveness ratio was mainly sensitive to the decrement of utility cause by treatment related complications and initial cost of both surgery and SBRT.

The PSA showed that SBRT had the highest probability of cost-effectiveness compared to lobectomy.

For a willingness to pay of 30,000 and 100,000€/QALY, probability of cost effectiveness of SBRT compared to surgery is 64% and 61% respectively. Conclusion This is the first medico-economic study evaluating SBRT and lobectomy in stage I NSCLC based on randomized studies and our analyses suggest that SBRT is dominant over lobectomy in operable early stage NSCLC treatment. Deterministic and probabilistic sensitivity analyses confirmed that this result was robust and that it was not significantly modified by the assumptions made in the Markov model building. OC-0064 Estimating the cost benefit of radiotherapy for overall survival and local control V. Batumalai 1,2,3 , K. Wong 1,2,3 , J. Shafiq 2,3 , T. Hanna 2,4 , G. Gabriel 2,3 , J. Heberle 5 , I. Koprivic 5 , L. Cassapi 6 , N. Kaadan 1 , D. Forstner 1 , O. King 1 , G.P. Delaney 1,2,3 , M. Barton 1,2,3 1 Department of Radiation Oncology, South Western