ESTRO 37 Abstract book

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ESTRO 37

Purpose or Objective Glioblastoma Multiforme (GBM) is the most common primary brain tumour in adults and is a fatal illness that is associated with a median survival (MS) of less than 15 months with optimal treatment. The highest incidence is observed in those aged 75 to 84 years. Clear management guidelines are lacking in elderly patients with most of these patients excluded from randomised clinical trials due to age, co-morbidities and poor performance status. The purpose of this retrospective study was to report the survival of elderly patients (defined as Age > 70 years)with GBM treated with radiotherapy (RT) in our institution and to establish whether our survival data compared with reported literature and ultimately to guide the optimal treatment approach in this patient population. Material and Methods A retrospective analysis of all GBM patients managed at our institution from January 2011 to December 2016 was carried out. Inclusion criteria included histologically proven GBM, age > 70 at diagnosis, referred from the Neuro-oncology MDT and treated with RT and/or Temozolomide (TMZ). Results One hundred and four patients were eligible. The age range was 70-86 years with a median age of 73.8 years. Ninety-three percent of patients had ECOG Performance status 0-2. Thirty-three patients received radical RT and 71 received palliative RT. The median radical dose was 60 Gy and median palliative dose was 34 Gy. Radical patients who had RT and TMZ (n=31) had a MS of 11.4 months whilst patients who had RT alone (n=2) had a MS of 6.6 months. Palliative patients who had RT alone (n=63) had a MS of 4.6 months and a MS of 4.3 months with RT and TMZ (n=8). Patients who had debulking surgery in both the radical (n=22) and palliative (n=33) groups had a statistically longer survival time than those who had biopsy only (p < 0.005). Using the Cox proportional hazard model for determination of effect of variables on risk of death in the radical cohort of patients, our analysis showed that the risk of death increased by 10% for each increase of 1 year in age (p<.0005) and decreases by 4% for each increasing Gy in dose (p<.0005). Conclusion Our data showed that we currently have a pro-active approach to the treatment of elderly GBM patients. Debulking surgery was associated with statistically increased survival compared to biopsy only in both radical and palliative patients. The MS for radically treated patients in our study is comparable to current literature for the under 70 age group. In our palliative cohort of patients, the MS was poor in the RT alone group. A very small number of patients received palliative RT and TMZ however the addition of chemotherapy did not have an impact on survival and was not comparable with current literature. Our study highlights the need for further studies in this age group and also raises the important question of whether age should be defined on the basis of functional and cognitive status rather than chronologically. EP-1185 Outcome for brain metastasis of NSCLC treated with SRS or hypofractionation M. Sallabanda 1 , M. García-Berrocal 1 , M. Expósito 2 , V. García-Jarabo 1 , D. Rincón 3 , S. Sánchez 1 , I. Martínez 1 , R. Magallón 1 , I. Zapata 1 , A. De la Torre 1 1 Hospital Universitario Puerta de Hierro Majadahonda, Radiation Oncology, Madrid, Spain 2 Hospital de Fuenlabrada, Radiation Oncology, Madrid, Spain 3 Grupo IMO, Radiation Oncology, Alcázar de San Juan, Spain

Purpose or Objective The aim of this study is to assess treatment outcome and prognostic factors associated with better survival in patients with brain metastasIs (BM) of non-small cell lung cancer (NSCLC) treated with Novalis or Tomotherapy based stereotactic radiosurgery (SRS) or hypofractionated stereotactic radiotherapy (HSRT). Material and Methods This study retrospectively reviewed 121 targets in 77 patients treated with a single fraction (15 to 21 Gy) or 5 to10 fractions (25 to 40 Gy) between January 2010 and January 2016. Demographics, prognostic scales, systemic disease, local brain control and cause of death were retrospectively collected and further analysed. Results Median overall survival (OS) was 12,4 months at BM diagnosis. 71% of patients were males and 28% females. Median age at BM diagnosis was 63,1 years old. Median Karnofsky performance status was 90%. 87% of lung cancer histology was adenocarcinoma and 13% squamous cell carcinoma. 23% of patients at diagnosis of BM received whole brain radiotherapy (WBRT) and 26% received surgery. Median number of BM treated with SRS or HSRT was 1 (range 1-6). Median PTV volume treated was 11,7cc. Local recurrence during follow-up was 10,3% and new lesions were diagnosed in 30% of patients. 7,8% of patients received rescue surgery. Grade 1 RTOG classification toxicity after treatment was diagnosed in 9% of patients and 3 patients experienced radiation necrosis. On univariate analysis, primary disease control (p<0,002), surgery at diagnosis (p<0,008) and as rescue (p<0,01) were predictive factors of better OS. On the contrary, metastatic onset of primary tumor (p <0,003) and WBRT at BM diagnosis (p<0,006) predicted poor outcome. Only 7% of deaths were due to intracranial progression. Conclusion SRS and HSRT are safe and effective local treatment for BM in patients with NSCLC. Associated surgery impacts favorably in outcome but WBRT should be avoided as an onset treatment if feasible. Uncontrolled primary lung disease remains the main predictor of OS. EP-1186 Dosimetric comparison of planning modalities for GammaKnife radiosurgery of brain metastases D. Greto 1 , D. Pezzulla 1 , M. Loi 1 , F. Terziani 1 , G. Caramia 1 , M. Lo Russo 1 , A. Teriaca 1 , I. Desideri 1 , S. Scoccianti 1 , P. Bonomo 1 , I. Meattini 1 , G. Simontacchi 1 , L. Livi 1 1 Azienda Ospedaliera Universitaria Careggi, Radiotherapy, Firenze, Italy Purpose or Objective Brain metastases (BMs) represent a significant healthcare problem in cancer patients and radiosurgery (RS) is one of the treatment options in selected patients with BMs : among the devices used to perform RS, a major role is played by the Gamma Knife (GK). The aim of our study is to analyze if there is any difference in terms of dosimetric parameters and clinical outcome treating lesions with a diameter inferior to 10 mm with one or two isocenters (shots). Material and Methods Data of 86 patients for a total of 282 BMs, treated with the Leksell Gamma Knife® Perfexion™ were retrospectively collected. Demographic and disease features were collected. Each lesion was treated using one or two shots with a diameter of 4 and/or 8 mm ; for each lesion Coverage, Gradient Index (GI) and Selectivity was recorded. Radiological response to the RS treatment was evaluated following RANO criteria with an MRI at 1, 3, 6 and 9 months. Results 210 (74.5%) brain metastases were treated with a single isocenter and 72 (25.5%) with a single shot. Mean metastases volume was 103.1 mm3 (2.4-721 mm3). Mean