ESTRO 38 Abstract book

S669 ESTRO 38

impacted survival rates, advanced stages were associated with lower rates (P= 0.08 and 0.05 respectively). Finally, patients receiving Temezolomide had bad outcomes when compared to the new standard protocol used in the department (P=0.03). The most commonly reported late toxicity was growth suppression in 35 patients (52.2%).Hypothyroidism requiring hormone replacement was recorded in 29% of the cases. Hearing loss, and problems including poor concentration, poor memory and learning difficulties were reported in 19% and 25% of the cases respectively. Second cancers were noted in three cases. Conclusion Overall, our results are comparable to those reported in the literature; nevertheless efforts should be made to ensure longer follow ups and correctly assess treatment related toxicities. EP-1209 First clinical results using HyperArcTM and Linac-based VMAT radiosurgery in brain metastases. F. Alongi 1,2 , F. Gregucci 1 , R. Mazzola 1 , N. Giaj-Levra 1 , M. Rigo 1 , V. Figlia 1 , L. Nicosia 1 , S. Corradini 3 , F. Ricchetti 1 , R. Ruggeri 1 1 Hospital Sacro Cuore Don Calabria- Cancer Care Center, Radiation Oncology, Negrar, Italy ; 2 University of Brescia, Radiation Oncology, Brescia, Italy ; 3 LMU University Hospital, Radiation Oncology, Munich, Germany Purpose or Objective The use of Stereotactic Fractionated Radiotherapy (SFRT) or Radiosurgery (SRS) is increasing in the treatment of brain metastases (BMs), also for multiple BMs. Aim of the present study is to evaluate safety and effectiveness of SRS/SFRT for BMs, using a new non-coplanar mono- isocenter technique (HyperArc TM Varian Medical System). Material and Methods Patients with a diagnosis of BMs with a diameter inferior to 3 cm, a life expectancy more than 3 months and good performance status, were eligible for Linac-based volumetric modulated arc therapy (VMAT) SFRT/SRS with HyperArc TM . Clinical evaluation and MRI were requested after 45-60 days by the SRS/SFRT, and every 2-3 months during follow-up (FU). A retrospective analysis of patients, BMs, treatment characteristics and outcomes included toxicity, local control (LC), overall survival (OS) and intracranial time to progression (iTTP), were performed. Results From August 2017 to May 2018, 381 BMs in 64 patients were treated. Two hundred forty-six BMs (43 patients) were evaluated, 73 BMs (10 patients) were excluded due to Karnofsky performance status (KPS) < 60 and died before first control and 62 BMs (11 patients) did not yet perform FU visit at the time of the analysis. The median BMs number for each patients was 5 (range 1-21). With a median FU time of 6 months (range 1-10), 244 out 246 (99%) BMs were controlled (18% complete response; 41% partial response, 40% stable disease), only 2 BMs (1%) showed a progression disease, at the first control. No acute (within 3 months) and late (above 3 months) toxicities were reported. At the time of analysis, median OS has not yet been achieved, while median iTTP was 5 months. In univariate analysis, statistically negative prognostic factors for OS were histology of primary tumor (P=0.009): lung/breast cancer had better survival rates as compared to melanoma/other; cumulative volume of intracranial disease ≥ 15cc (P=0.04) and systemic progression disease (P=0.005). At multivariate analysis, cumulative volume of intracranial disease ≥ 15cc (P=0.04) and systemic progression disease (P=0.009) were confirmed independent negative prognostic factors for OS. Considering CR/PR as “local treatment response”, while SD/PD as “not local treatment response”, the analysis of LC profile stratified by histology, PTV and BED, using Chi- square test, showed that melanoma/other histological

Material and Methods Between May 2011 and August 2018, 19 patients (pts) with surgical resected BM were irradiated with FSRT in 5 fractions. Median age was 66,5 years (range 50-74); primary tumor was non-small cell lung cancer (7 pts), breast cancer (4 pts), gastrointestinal cancer (5 pts), others (3 pts). All patients were evaluated by Karnofsky performance status (KPS) and neurologic functional score (NFS). Localization was obtained using fusion imaging from computed tomography (CT) and magnetic resonance imaging (MRI) of the brain. Gross tumor volume (GTV) was defined as radiologically visible surgery cavity in contrast- enhancing T1-weighted MRI sequences, clinical target volume (CTV) was coincident with GTV and planning target volume was GTV/CTV plus an additional 2-3 mm in all directions (average PTV 28.6 cc). Pts were treated with a 6-MV linear accelerator fitted with a dynamic micro- multileaf collimator. Ten pts received 5x6 Gy and eight 5x7 Gy. All pts were followed by MRI and clinical examination 3 months after FSRT and at 3 months intervals thereafter. Local control (LC) was defined as a lack of relapse of the irradiated surgical cavity, and brain control (BC) as LC in absence of other documented BM. A brain failure at the site of FSRT was defined “in-field relapse”, whereas appearance of new BM “out-field relapse”. Results After a median follow-up of 16 months (range 4-79), 17 of 19 pts were evaluable because one was lost to follow up and one too early. 9 pts (52,9%) had LC and BC, seven (41,1%) reached LC without BC, one (6%) had in- and out- field relapse. So, in 16 (94,1%) pts, postoperative FSRT reached a LC and in more than one-half LC and BC. All pts in progression were re-irradiated, four with SRS, two with WBRT and two with WBRT plus SRS to a second progression. Altogether, after cavity stereotactic radiotherapy, 19 new lesions were treated with SRS. No acute neither late toxicity was registered, no treatment- related NFS decline was observed. Conclusion Our preliminary report showed that surgical cavity FSRT for resected BM was effective in more than one half of pts with a good neuro-cognitive outcome. WBRT and/or SRS can be reserved to pts with brain progression of disease. EP-1208 Twenty years experience in treating Childhood medulloblastoma: Between the past and the present . J. Khalil 1 1 National Institute of Oncology Sidi Mohamed Ben Ab, Radiotherapy, Rabat, Morocco Purpose or Objective Medulloblastoma (MB) is the most common primary malignant central nervous system tumor of childhood. These last decades, treatment modalities have largely evolved resulting in better survival rates. Nevertheless, long term toxicities are a major concern in this setting. Material and Methods Our study is a retrospective one conducted at Xhinhua Hospital in Shanghai, China. It included 121 patients treated for medulloblastoma from 1993 to December 2013. Results Mean age at diagnosis was 6.7 years (range 1–14.3 years). Total surgical resection was achieved in 60% of the cases. Classic medulloblastoma was found in 59% of the cases. Adjuvant radiotherapy was delivered in all cases and chemotherapy concerned 70.2% of the studied cohort. The median follow-up time of the study was 84 months (range, 24-120months). 5 and 10 years Progression free survival (PFS) were 83.2% (95% CI), 69.5% (95% CI) and 5 years and 10 years Overall survival (OS) were 82.5% (95% CI), and 72.5% (95% CI). Patient’s age significantly influenced survival; patients under 3 years old had the worse outcomes (P=0.01). T and M stages also significantly