ESTRO 2020 Abstract book

S524 ESTRO 2020

The agreement between the GPA and the OS was very low (ICC: 0.25). 50% of the patients had 8 months of difference in survival between the estimated and the observed.

Conclusion Median overall survival after WBRT was less than 3 months. Patients receiving systemic treatment with immune checkpoint inhibitors and local therapy with stereotactic radiosurgery had a significantly improved survival. Treatment with supportive care alone should be considered for patients with a poor performance status. PO-0895 GPA in brain metastases treated with Stereotactic Radiosurgery M.A. Rodriguez Medizabal 1 , M. Rico Oses 1 , S. Flamarique Andueza 1 , M. Campo Vargas 1 , A. Martin Martinez 1 , L.O. Rosas 1 , E. Martinez Lopez 1 , M. Barrado 1 , S. Pellejero 2 , F. Mañeru 2 1 Complejo hospitalario de Navarra, Radiation Oncology, Pamplona, Spain ; 2 Complejo hospitalario de Navarra, Radiophysics, Pamplona, Spain Purpose or Objective The Graded Prognostic Assessment (GPA), is a prognostic index widely used for patients with brain metastases that has evolved since the initial reports. We wonder if it would be useful to estimate the survival after Stereotactic Radiosurgery (SRS). Our Hypothesis was that the overall survival (OS) of our patients correlates with the GPA.And our main objective to estimate the prognostic as OS of patients with brain metastases treated with RS in our center (CHN) and We retrospectively reviewed patients treated with SRS for brain metastasis between January 2011 and December 2018. We used a multivariate analysis to find association between possible risk factors ( age, size, dose, previous whole brain radiotherapy (WBRT) and previous surgery) and OS. We use intraclass correlation coefficient (ICC), Bland- altman method and survival-agreement plots to measure the agreement between GPA and OS. BrainMetGPA application was used to calculate the estimated survival expectancy. Results 112 patients underwent SRS during that period. The most common primary tumor was lung adenocarcinoma (46,6%), followed by breast cancer(10,7%), the mean size was 16mm, the mean dose 19,2Gy. 11,6% had previous surgery and 41,1% WBRT. Median OS was 15 months. We found statistically significant differences between OS and previous surgery HR 3.206 IC95% (1.16, 8.8)(P=0.024). compare it with GPA. Material and Methods

Conclusion The GPA does not give an accurate estimation of the survival for our patients with brain metastases treated with SRS PO-0896 Radionecrosis in brain metastases treated with Stereotactic radiosurgery M.A. Rodriguez Medizabal 1 , M. Rico 1 , S. Flamarique 1 , M. Campo 1 , A. Martin 1 , L.O. Rosas 1 , E. Martinez 1 , M. Barrado 1 , S. Pellejero 2 , F. Mañeru 2 1 Complejo hospitalario de Navarra, Radiation Oncology, Pamplona, Spain ; 2 Complejo hospitalario de Navarra, Radiophysics, Pamplona, Spain Purpose or Objective Our main objective was to estimate the incidence and risk factors for radionecrosis (RN) and overall survival (OS) in a cohort of patients with brain metastases treated with Stereotactic radiosurgery (SRS). Material and Methods We retrospectively reviewed patients treated with SRS for brain metastases between January 2011 and December 2018. All RN were diagnosed by RM .We used T-test, Fisher test and Chi2 to analyzed possible risk factors: age, size, dose, previous surgery and previous whole brain radiotherapy (WBRT). We used Kaplan-Meier and Log-rank test to analyze OS. Results 118 patients (with a total of 139 tumors) underwent SRS for brain metastases in our hospital during that period. 12 of them (8,6%) had RN. The most common primary tumor was lung adenocarcinoma (45,3%), the mean size was 16mm, the mean dose 19,2Gy, the mean time of RN diagnosis from SRS was 15,5 months. 8,6% had previous surgery and 46% WBRT. We found no significant statistical association, between possible risk factors and RN. However a difference of 2.8 mm in tumor size was observed, with an inclination to be larger in RN group (p=0.14)