ESTRO 2020 Abstract Book

S540 ESTRO 2020

observed in 53 patients and 23 of them had local failure. Finally, 88 patients were dead. The 3-year LPFS, PFS, and OS for all patients were 69.2%, 57.1 % and 72.9%, respectively. The 3-year LPFS, PFS, and OS in non-anemia and anemia groups as follows: 3-year LPFS: 75.6% and 54.9 % (p < 0.05), 3-year PFS: 64.0 % and 41.7 % (p < 0.05), and 3-year OS: 79.2% and 58.9% (p < 0.05), respectively. In multivariate analysis, anemia was a significant factor for LPFS, PFS and OS. Conclusion The pretreatment anemia is a prognostic factor of LPFS, PFS and OS in stage I NSCLC patients treated with SBRT. The pretreatment anemia indicates poor clinical outcomes in these patients. PO-1013 A cost-effectiveness analysis of consolidation immunotherapy with durvalumab in stage III NSCLC. C. Panje 1 , J.E. Lupatsch 2 , M. Barbier 2 , E. Pardo 3 , M. Lorez 4 , K.J. Dedes 5 , D.M. Aebersold 6 , L. Plasswilm 7 , O. Gautschi 8 , M. Schwenkglenks 9 1 Cantonal Hospital St. Gallen, Radiation Oncology, St. Gallen, Switzerland ; 2 Swiss Group for Clinical Cancer Research Coordinating Centre and University of Basel, Institute of Pharmaceutical Medicine, Bern and Basel, Switzerland ; 3 Cantonal Hospital Lucerne, Medical Oncology, Lucerne, Switzerland ; 4 National Institute for Cancer Epidemiology and Registration NICER, Statistics, Zurich, Switzerland ; 5 University Hospital Zurich, Gynecology, Zurich, Switzerland ; 6 University Hospital Bern, Radiation Oncology, Bern, Switzerland ; 7 Cantonal Hospital St. Gallen and University Bern, Radiation Oncology, St. Gallen and Bern, Switzerland ; 8 Cantonal Hospital Lucerne and University Bern, Medical Oncology, Lucerne and Bern, Switzerland ; 9 University of Basel, Institute of Pharmaceutical Medicine, Basel, Switzerland Purpose or Objective Consolidation immunotherapy with the programmed death ligand 1 (PD-L1) inhibitor durvalumab has shown to improve survival in patients with stage III non-small cell lung cancer (NSCLC) responding to radiochemotherapy according to the PACIFIC trial. However, consolidation immunotherapy for up to twelve months leads to a considerable cost increase. The aim of this study was to assess the cost-effectiveness of durvalumab in Switzerland based on the most recent PACIFIC survival follow up. Material and Methods We constructed a Markov model based on the 3-year follow-up data of the PACIFIC trial and compared consolidation durvalumab against observation. We used published utility values and assessed costs for treatment strategies from the perspective of the Swiss healthcare payer. Cost-effectiveness was tested both in the intention- to-treat (ITT) population of the PACIFIC trial unselected for PD-L1 tumor expression and in patients with PD-L1 expressing tumors. Results In the unselected / PD-L1 positive patients, durvalumab showed an incremental effectiveness of 0.74 / 1.17 QALY and incremental costs of Swiss France (CHF) 67,688 / 83,023, resulting in ICERs of CHF 91,354 / 70,700 per QALY gained, respectively. The most influential factors for the ICER were the utility prior to first progression, costs for consolidation therapy with durvalumab, and the hazard ratio for overall survival under durvalumab versus observation. Durvalumab was cost-effective in 70% of the simulations in probabilistic sensitivity analysis. Conclusion Assuming a willingness-to-pay threshold of CHF 100,000 per QALY gained, consolidation durvalumab is likely to be cost-effective both in patients with inoperable stage III NSCLC unselected for PD-L1 status and in patients with PD- L1 expressing tumors in Switzerland.

Conclusion Previous or concurrent radiotherapy seemed to be a favorable prognostic factor of PFS and OS in patients with metastatic NSCLC treated by immunotherapy. More studies are needed in order to determine which characteristic of RT, such as timing, may be important to enhance this effect. PO-1012 Prognostic Value of Anemia in Lung Cancer Patients Treated with Stereotactic Body Radiation Therapy H. Nonaka 1 , H. Onishi 1 , S. Funayama 1 , H. Watanabe 1 1 University of Yamanashi, Department of Radiology, Chuo city, Japan Purpose or Objective Previous studies showed that preoperative anemia predicts for poor clinical outcomes in lung cancer patients with surgical resection. However, little is known regarding the prognostic value of pretreatment anemia in patients with stage I non-small-cell lung cancer (NSCLC) treated with stereotactic body radiation therapy (SBRT). Hence, we assessed whether pretreatment anemia associated with prognosis in stage I NSCLC patients treated with SBRT. Material and Methods We retrospectively reviewed patients treated with SBRT for stage I NSCLC between 2007 and 2016. Patients who had no blood tests within three months before SBRT were excluded. We divided the patients into two groups according to cutoff value of hemoglobin level using receiver operating characteristic analysis. The clinical outcome was evaluated based on 3-year local progression- free survival (LPFS), progression-free survival (PFS) and overall survival (OS). LPFS, PFS and OS were calculated using the Kaplan-Meier method, and examined with the log-rank test. Prognostic factors including age, sex, histology, T stage and hemoglobin level were examined with multivariate analyses using Cox proportional hazards Totally 166 patients (112 men and 54 women) with stage I (UICC 7th, T1aN0M0: 59, T1bN0M0: 42, T2aN0M0: 65) were enrolled in this study. The median age was 79 years old (range, 52-89). The median follow-up time after SBRT was 44.5 months (range, 1-125). The histology was adenocarcinoma in 80, squamous cell carcinoma in 40, other carcinoma in 10, and no pathological diagnosis in 36 patients. Patients were divided into non-anemia group in 112, and anemia group in 54 patients based on cutoff value of hemoglobin level of 11.6 g/dl. Disease progression was model. Results