ESTRO 2022 - Abstract Book

S965

Abstract book

ESTRO 2022

methylated for 19 (46.3%), unmethylated for 18 (43.9%), while in 4 patients the data was not available. The median number of cycles received was 4 (range 1-12) and 4 (9.7%) patients were still on active treatment at the time of analysis. The most common adverse events (grade 1-2) were fatigue (75%), rash and desquamation (12.2%), hand-foot skin reaction (9.7%), hypertension (18%), hyperbilirubinemia (2.4%) and hypertransaminasaemia (18%). The most common grade 3 or 4 were fatigue (10%), oedema (14%), rash (4.8%), neutropenia (2.4%) and thrombocytopenia (2.4%). Common reasons for discontinuing regorafenib included progressive disease (70.5%) and toxicity (12%). In patients treated with regorafenib, median PFS was 4 months (95% confidence interval: 3 to 6 months) and OS was 22 months (95% confidence interval: 19 to 41 months). Conclusion In our “real-life” experience, regorafenib is associated with survival similar to that reported in clinical trials. Side effects lead to treatment discontinuation in nearly one third of our patients and the most frequent limit is the severe fatigue in patients already compromised. Further investigations are needed to identify the patients most likely to benefit in order to maximize the results and reduce side effects.

PO-1136 Linac-based Radiosurgery and Hypofractionated radiotherapy for the Meingeomas

A. Gawish 1 , B. Röllich 1 , M. Walke 1 , T.B. Brunner 1

1 Medical Faculty University Hospital Magdeburg, University Clinic for Radiation Therapy, Magdeburg, Germany

Purpose or Objective Meningeoma is a common type of benign tumor that can be managed in several ways, ranging from close observation, surgical resection, and various types of radiation. We present here results from a 10-year experience treating meningiomas with a hypofractionated approach. Materials and Methods To define the rate of tumor control and factors associated with relief of symptoms and radiation-related complications after radiosurgery and hypofractionated radiosurgery for patients with imaging defined intracranial meningiomas.We reviewed the charts of 48 patients treated with stereotactic radiosurgery (SRS) or hypofractionated stereotactic radiotherapy (SRT) from 2008 to 2018. A total of 37 (82%) patients had WHO Grade 1 disease and 11 (22 %) had Grade 2. Outcomes that were analyzed included local control rates and the rate and grade of any reported toxicity. Results : only 34 Patients with 37 lesions, who underwent the follow-Up regiem, are enrolled in the restrospective anaylsis. Follow- Up mean was 40 months (12-120 months). 25/34 patients had surgery before the radiotherapy. 14 underwent SRS with a median dose of 13,5 and 20 recieved hypofractioned SBRT with a median dose of 26,4 (22-45Gy) in median 6,8 fractions (6- 15 fractions). Local control at 2 and 5 years for all patients was 90% and 88%, respectively. No patient suffered from toxicity >1 CTC. 21/34 patients showed stable disease, while 6/34 patients showed partiell Remission. 7/34 patients with meingeomas WHO II showed progression in a median of 22 months (13- 48 months) Conclusion : Hypofractionated radiosurgery with a dose of appears to provide a high rate of tumor control and a low incidence of side effects for patients with imaging defined intracranial meningiomas I. Desideri 1 , L. Visani 2 , V. Salvestrini 1 , M. Mariotti 1 , M. Banini 1 , L. Angelini 1 , M.G. Carnevale 1 , I. Bonaparte 1 , L. Zisca 1 , B. Detti 2 , D. Greto 2 , I. Meattini 1 , L. Livi 1 1 University of Florence, Radiation Oncology Unit, Florence, Italy; 2 Azienda Ospedaliera Universitaria Careggi, Radiation Oncology Unit, Florence, Italy Purpose or Objective Brain metastases (BMs) develop in up to 30% of patients (pts) with cancer. Survival of BMs pts is extremely variable and remarkably poor in absence of active treatment. The use of stereotactic radiosurgery (SRS) for the treatment of BMs has increased in recent years providing excellent local control rates even though radiological assessment of the response to treatment can often be challenging. Preclinical studies showed that silibinin - a natural polyphenolic flavonoid isolated from seed extracts of the herb milk thistle - demonstrates anticancer effects in vitro and in vivo. The use of a silibinin- based nutraceutical resulted in significant clinical and radiological improvement of BMs in non-small cell lung cancer (NSCLC) pts that progressed after whole brain radiotherapy and chemotherapy. Thus, the aim of the present explorative study (SUSTAIN trial) is to evaluate whether the use of silibinin-based nutraceuticals (SILLBRAIN®) can significantly reduce distant brain failure (DBF) rate at 6 months in pts with first diagnosis of BMs treated with SRS with or without surgery. Here a preliminary analysis on the first 18 pts enrolled is reported. PO-1137 Safety And Efficacy Of Silibinin In Patients With Brain Metastases after Radiosurgery: Sustain Trial

Materials and Methods SUSTAIN is a prospective, single arm, phase II study planning to recruit a total of 80 pts with up to 10 BMs from all primary tumors (except small cell lung cancer), aged 18 or older, amenable for treatment with SRS or surgery followed by SRS to