ESTRO 38 Abstract book

S684 ESTRO 38

dexamethasone after treatment or both were considered having benefitted a form the therapy. Results 22 patients who received bevacizumab due to radiation necrosis were identified. For 10 patients (45,5%) the symptoms improved, 11 patients (50,0%) did symptomatically not improve during the treatment, 1 patient (4,5%) worsened. With 14 patients (63,6%) the dexamethasone dose could be reduced during therapy, 5 patients (22,7%) received the same dose of dexamethasone before and after treatment and 3 patients (13,6%) received a higher dose after treatment. According to this analysis 18 patients (81,8%) were able to benefit from the treatment with bevacizumab. No severe adverse effects e.g. bleedings were reported. Conclusion Bevacizumab is a good therapeutic option for patients with radiation necrosis as a complication after cranial radiation therapy. Patients could benefit from this treatment by improving symptomatically or through reduction of dexamethasone. EP-1244 The impact of multidisciplinary tumor board in brain tumor management: the OMNYBuS Project S. Chiesa 1 , C. Mazzarella 2 , G. Sabatino 3 , S. Gaudino 1 , M. Iezzi 1 , S. Luzi 1 , F. Beghella Bartoli 1 , G. La Rocca 3 , G.F. D'Onofrio 3 , C. Colosimo 1 , A. Olivi 3 , V. Valentini 1 , M. Balducci 1 1 Istituto di Radiologia-Fondazione Policlinico A. Gemelli IRCCS- Università Cattolica Sacro Cuore, Dipartimento Scienze Radiologiche- Radioterapiche ed Ematologiche, Rome, Italy ; 2 Istituto di Radiologia-Fondazione Policlinico A. Gemelli IRCCS, Dipartimento Scienze Radiologiche- Radioterapiche ed Ematologiche, Rome, Italy ; 3 Istituto di Radiologia-Fondazione Policlinico A. Gemelli IRCCS- Università Cattolica Sacro Cuore, Dipartimento Scienze dell'invecchiamento- neurologiche- ortopediche e della Testa-Collo- UOC Neurochirurgia, Rome, Italy Purpose or Objective A shared decision making in multidisciplinary context has become the standard practice for cancer care worldwide. The aim of the OMNYBuS project is to investigate the impact of tumor board in brain tumor management in order to obtain the best personalized treatment plan. Material and Methods Neurosurgeons, radiation oncologist, radiologist, anatomo pathologists and residents were involved in the multidisciplinary discussion. In this first phase of the study, we collected data retrospectively obtained from one year experience of multidisciplinary tumor board in order to arrange a strategy of the prospective phase. The primary endpoint was the evaluation of management change rate in terms of exchange, addition, or subtraction of treatment modality. The secondary endpoints were the delay considering treatment starting time, extra diagnostic work-up and time needed for academic discussion. Results Between March 2017 and March 2018, 148 consecutive cases were presented and discussed: 33,3% high grade gliomas, 10,8% anaplastic astrocytomas, 6,5% oligodendrogliomas, 2,2% low grade gliomas, 14% meningiomas, 14% single metastases, 8,6% multiple metastases, 5,4% other type of lesion. The multidisciplinary discussion focused on diagnostic imaging results and interpretation, medical, surgical, and/or radiation treatment planning, and pathology results and interpretation. The median time for case discussion was 10 minutes with a median tumor team members presence of 22 clinicians. The therapeutic plan change rate was 9.2%, mostly for high grade gliomas. A reduction of diagnostic work-up accounted for 65,7%. No delay was observed in treatment starting time.

3 Fondazione IRCCS Istituto Neurologico C. Besta, Neuro- oncology, Milan, Italy Purpose or Objective Despite being various treatment strategies available, recurrent multiforme glioblastomas (rGBM) are difficult to manage. Limited evidence exists to suggest the superiority of any treatment modality for rGBM. The aim of this study is to evaluate the effectiveness of multisession radiosurgery (mRS) reirradiation as salvage treatment in terms of overall survival (OS) and progression free survival (PFS). Material and Methods Patients previously treated with surgery and chemo- radiotherapy and re-irradiated with radiosurgery for rGBM from January 2014 to December 2016 were considered eligible. Global OS (gOS) was defined as the time between first surgery and death, OS as the time between the end of reirradiation and death, PFS as the time between reirradiation and disease progression. The statistical analysis was conducted using the Kaplan-Meier method. Results Forty-six patients were included in the analysis. Median time from primary treatment to recurrence was 14 months (range 1–79 months). Median follow-up was 4 months (range 2 days–32 months). All patients were treated with robotic radiosurgery (CyberKnife®). At the time of the analysis six of the 46 patients were alive. The median survival from initial diagnosis was 26 months (range 12–107 months). The 1-, 2-, and 3-years actuarial survival rates from diagnosis were 100, 70, and 50% respectively. Median survival following mRS was 7 months (range 1–24 months). The 1-, and 2-years actuarial survival rate following mRS were 29, and 11% respectively. The acute toxicity rate was 17%. Conclusion Our data suggest that mRS is a safe and effective treatment option for patients with rGBM. Further research and prospective studies are needed to better define the parameters of re-irradiation in this subset of patients. EP-1243 Bevacizumab as treatment option for cerebral radiation necrosis A case series of 22 patients R. Bodensohn 1 , I. Hadi 1 , D.F. Fleischmann 1 , C. Belka 1 , M. Niyazi 1 1 University Hospital- LMU Munich, Department of Radiation Oncology, Munich, Germany Purpose or Objective Radiation necrosis is one of the most serious adverse effects after cranial radiation therapy. The VEGF inhibitor Bevacizumab might be a feasible therapeutic option for symptomatic radiation necrosis when traditional treatments such as dexamethasone or mannitol fail. However, so far only few randomized studies with small cohorts (such as Levin et al with n=14) exist to show a beneficial effect for patients. Therefore, real life data is needed in order to support the data. This retrospective monocentric case study evaluates patients who received bevacizumab due to radiation necrosis in relation to Using the internal database for cytostatic medication all patients who received bevacizumab in our department were identified. Only patients who received bevacizumab for radiation necrosis were included. Next to general patient characteristics symptoms before, during and after treatment and use of dexamethasone were evaluated using medical reports and internal documentation. The symptoms were coded with the CTCAE code for general neurological symptoms. Each patient received a code directly before each cycle and after the treatment (approximately 6 weeks). Additionally, the daily dose of dexamethasone was collected at these times. The patients that either improved in the symptoms or received less clinical development. Material and Methods