ESTRO 38 Abstract book

S687 ESTRO 38

Albanesese 3 , A. Olivi 4 , V. Valentini 2 , M. Balducci 2 1 Fondazione Policlinico Universitario A. Gemelli IRCCS, Diagnostica per immagini- Radioterapia Oncologica ed Ematologia, Rome, Italy ; 2 Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Diagnostica per immagini- Radioterapia Oncologica ed Ematologia, Rome, Italy ; 3 Fondazione Policlinico Universitario A. Gemelli IRCCS, Scienze Neurologiche, Rome, Italy ; 4 Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Scienze Neurologiche, Rome, Italy Purpose or Objective Optimal management for recurrent glioblastoma (GBM) has not been established. Many therapies have been assessed with limited results and without significant increase in progression-free survival (PFS), or overall survival (OS). The object of this retrospective analysis was to evaluate the impact on OS with different salvage therapies, including systemic therapy, or re-irradiation plus systemic therapy or supportive care in patients affected by recurrent GBM to generate new hypotheses for future trials. Material and Methods Patients (pts) affected by GBM’s recurrence and treated with according to EORTC 26981-22981-NCIC trial, were included. Those who died less a month after progression or with a poor performance status were excluded. Patients were subdivided into 3 groups: reirradiation plus chemotherapy (group A), chemotherapy alone (group B), supportive care (group C). Overall Survival was estimated using the Kaplan-Meier method and compared between three groups. Results The analysis included 217 pts with GBM who developed relapse from January 2009 to May 2016. Among them, 153 patients were evaluable for this analysis; 64 patients were excluded because they died less than one month after progression or for a poor performance status. Sixty-nine out of 153 patients (45%) belonged to Group C, 63 (41%) to group B, and 21 (14%) to group A. Median follow-up was 48 months in all patients. Median survival time from diagnosis was 18 months for the entire cohort: 14 months for patients of Group C, 28 months for group B, and 30 months for those of group A. The kind of treatment at recurrence time proved to significantly impact on OS (p=0.0001). Conclusion Patients who did not receive any treatment had poorer survival than those who received chemotherapy alone or in combination with radiotherapy. Latter had a significantly better survival then chemotherapy group. Further investigations are needed to define the optimal choice of therapy, and in particular the role of re- irradiation and systemic treatment in patients with recurrent GBM. EP-1250 Outcomes of Multiple Brain Metastases Radiosurgery with Gantry-Based Linac P. Castro Peña 1 , C. Nino de Guzman 1 , D. Venencia 1 , L. Suarez Villasmil 1 , J. Suarez 1 , S. Zunino 1 1 Instituto Zunino - Fundacion Marie Curie, Radiation Oncology, Cordoba, Argentina Purpose or Objective To evaluate tolerance, toxicity and survival in patients with multiple brain metastases treated Novalis-BrainLab SRS platform. Material and Methods Between Nov'16&Dec'17, 24patients were treated with SRS of multiple brain metastases(2 to 23). Seven patients had previously received WBRT; . The brain was the only organ with metastases in 13/24 patients. Nineteen patients showed neurologic symptoms prior to diagnosis. For CT simulation a Frameless Brainlab System was utilized. Treatment planning was performed using Elements TPS

v1.5 (BrainLab). The patients were positioned on a 6D couch and snap verification in each angle was done. Radiosurgery was given by Novalis Tx accelerator HDMLC- IGRT with ExacTrac V6 using 6 MV photon beam with dose rate 1000 MU/minute. Early and late toxicities as well as survival were evaluated in all the patients. Patients with up to 5 metastases were compared with te ones with 6 or more, and the ones with a tumor volume <10cc were compared with the rest with >10cc tumor volume. OS from SRS until last follow up or death, and progression-free survival (PFS) from SRS until first brain progression or last follow up, were estimated by the Kaplan-Meyer method. Results Mean age:54.2years [10.3-73.9] and mean follow-up 8.16 months [3.2-16.6].The mean number of lesions per patient was 7 [2-23] while the average volume of irradiated metastases was 1.34 cc [0.02-20.8].The prescribed dose was 22.2Gy[20.0-35.0] in1-5 fractions. The brain volume receiving 12Gy=53.7cc[4.3-600.0].5 patients were re- irradiated because of tumor regrowth (22 lesions) or new lesions (12 lesions); Of the 24 patients, 19 showed no symptoms of early toxicity whereas the remaining 5 presented G1-2 toxicity .Late toxicity was evaluated in 19 patients who survived for more than 3 months. Of the 19 patients, 12 did not show any toxicity while the remaining group presented G1-2 toxicity .No differences were found in patients with 5 or more metastases regarding the presence or absence of toxicities, or related to fractioning.The overall survival (OS) for the 24 patients at 6 months was 71%, and at one year 59%. No differences were found in the OS of patients with five or more metastases when compared with patients with less than five lesions (Cox-Mantel test, p = 0.806); There were no differences when comparing patients with a total volume of metastases <10 cc and ≥10 cc (Cox-Mantel test, p = 0.865). The progression-free survival (PFS) at 6 months was 89% and at one year 62%. No differences were found in PFS related to the number of metastases (Cox-Mantel test, p = 0.982) or to the total volume of metastases (Cox- Mantel test, p = 0.296). Conclusion Despite the number of patients limiting the statistical comparison of subgroups, results suggest that irradiation to multiple metastases is safe with Novalis Plataform and Elements SRS, showing acceptable toxicity and survival. If well in literature a detrimental in OS is described with a total tumor volume >10cc, we didn't find these difference. EP-1251 focal hypofractionated stereotactic radiation therapy for brain metastases H.J. Rosales Gonzalez 1 , H. Perez Montero 2 , A. Alvarez 1 , A. Mañes 1 , S. Comas Anton 1 , E. Luguera 3 , G. Antelo 1 , E. Baena 1 , M. Villalobos 1 , S. Villà 1 1 Catalan Institute of Oncology, Radiation Oncology, Badalona, Spain ; 2 Catalan Institute of Oncology, Radiation Oncology, Hospitalet, Spain ; 3 Catalan Institute of Oncology, Medical Physics, Badalona, Spain Purpose or Objective Patients diagnosed with brain metastases have been traditionally treated with surgery, stereotactic radiosurgery (SRS) or whole-brain radiotherapy (WBRT). Focal Hypofractionated Stereotactial Radiation Therapy (FHSRT) may offer an alternative approach to conventional treatments for central nervous system metastases. Our objective was to analyze FHSRT outcomes at our institution. Material and Methods We retrospectively reviewed the records of 93 patients who were treated at our institution between 2014 and 2017. Eighty-two were diagnosed with a single metastasis, 19 patients with 2 metastases and 9 patients with 3 or more metastases. A total of 110 treatments were performed. Twenty-seven patients were treated with