ESTRO 2023 - Abstract Book

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ESTRO 2023

Results 148 patients were treated with sLITT, where 106 combined with SSRS and 31 alone as salvage. Median follow-up time was 11.5 months (95%CI 9.7-13.3). Primary tumor histology included RCC (37%), sarcoma (15.2%), NSCLC (10.9%), thyroid (7.2%) and others (29.7%). Pre-sLITT ESCC grade was 1c or higher in 95% of patients. Pre-sLITT Frankel scores were E(89.4%), D(9.4%), and C(1.2%). Median overall survival time was 15.2 months (95%CI 11.5-9). One and 2-year LC rates were 81.3% and 75.1%, respectively. Treatment was associated with a median decrease of 2 ESCC grades, and there was a significant difference between pre- and post-sLITT ESCC grades. Univariate analysis demonstrated that achievement of a low post sLITT ESCC (0-1b) was associated with 90% LC rate, significantly higher than 54.3% observed in cases with high post-sLITT ESCC (1c-3) (p<0.001). Additionally, paraspinal location of disease(p=0.02) and complications (p=0.047) were associated with poorer LC. There was no relationship between LC and sex (p=0.60), primary tumor histology(p=0.95), Frankel score(p=0.86), and pre-sLITT ESCC score (p=0.38). In multivariate analyses lower post-sLITT ESCC continued to independently predict better LC (p<0.001), and a trend toward paraspinal disease lowering LC (p=0.06). Mean hospital stay for sLITT was 1 day. Conclusion sLITT, in combination with or as salvage to SSRS, is highly effective in providing local control in patients with ESCC. Low post-sLITT ESCC score is a strong predictor of improved local control. Treatment with sLITT in combination to SSRS should be considered as an alternative to open surgery for selected patients with spinal metastasis. A. Surgo 1 , F. Gregucci 2 , L. Laera 3 , M.P. Ciliberti 2 , R. Carbonara 2 , M. Caliandro 4 , E. Paulicelli 2 , G. Surico 2 , I. Bonaparte 2 , A. Fiorentino 2 1 General Regional Hospital "F. Miulli", Radiation Oncology, Acquaviva delle Fonti (BA), Italy; 2 General Regional Hospital "F. Miulli", Radiation Oncology, Acquaviva delle fonti, Italy; 3 General Regional Hospital "F. Miulli", Medical Oncology, Acquaviva delle fonti, Italy; 4 General Regional Hospital "F. Miulli), Radiation Oncology, Acquaviva delle fonti, Italy Purpose or Objective In recurrent glioblastoma (GB) no standard therapeutic approach is reported, so surgery, chemotherapy and reirradiation could be proposed. Recently Regorafenib was approved for recurrent GB. The present retrospective study was conducted to evaluate safety and efficacy of re-irradiation with radiosurgery o stereotactic radiotherapy (SRS/SFRT) in patients with recurrent GB in association to Regorafenib. Materials and Methods Inclusion criteria were as follow: histological diagnosis of GB; carrying out primary/adjuvant chemo-radiotherapy treatment; magnetic resonance imaging (MRI) evidence of recurrent disease according to Response Assessment in Neuro Oncology (RANO) criteria after primary/adjuvant treatment; good performance status. All patients underwent re-RT with SRS/SFRT with a median dose of 24 Gy (range 18-36 Gy) and median fractions of 5 (range 1-6), Clinical outcome was evaluated by neurological examination and brain MRI performed, 1 month after radiation therapy and then every 3 months. Results From November 2019 to December 2021, 16 patients (6 women and 10 men) affected by GB recurrence were treated by re RT plus Regorafenib. The median time occurred between primary/adjuvant RT and disease recurrence was 8 months (range 2-20). Moreover, in 6 cases (40%) a second surgery was performed and in other 6 cases a third RT was administered. At the time of the analysis, 11 patients were dead for disease. The median OS and PFS after recurrence were 8 and 6 months. Regarding SRS/SFRT toxicity no acute or late neurological side effect grade ≥ 2 were reported. No case of radio-necrosis was detected. One patient that received Regorafenib after 45 days from re-surgery, suffered by surgical wound dehiscence, requiring the chemotherapy interruption. Grade 3-4 hematologic toxicity occurred in 5 cases, asthenia occurred in all patients. Conclusion Re-RT with SRT/SFRT in association with Regorafenib is a safe and feasible treatment and a combined ones as a better option for selected patients. A. Kumar 1 , P. Rajasekera 1 , V. Becker 1 , S. Biehn 2 , S. Beyer 1 , J. McElroy 3 , A. Becker 1 , B. Johnson 1 , T. Cui 1 , A. Grosu 4 , S. Lindert 2 , E. Bell 1 , H. Manring 1 , J. Haque 1 , A. Chakravarti 1 1 The Ohio State University Wexner Medical Center, Department of Radiation Oncology, Columbus, Ohio, USA; 2 The Ohio State University, Department of Chemistry & Biochemistry, Columbus, Ohio, USA; 3 The Ohio State University, Department of Biomedical Informatics, Columbus, Ohio, USA; 4 University of Freiburg Medical Center, Radiation Oncology, Freiburg, Germany Purpose or Objective Transgelin-2 is an actin-binding protein known to regulate actin cytoskeleton dynamics, thereby playing critical roles in cell proliferation, migration, invasion, and therapeutic resistance in GBM and other malignancies. Our clinical correlative studies revealed that TAGLN2 was upregulated in GBM patients with wild-type IDH1/2 compared to those with mutant IDH1/2, which was associated with worse patient outcomes suggesting that Transgelin-2 might serve as a novel biomarker and a potential therapeutic target in GBM. Accordingly, we hypothesize that targeting Transgelin-2 by small molecule inhibitors (SMIs) may improve patient outcome by circumventing therapeutic resistance in GBM. To this end, this study aims PO-1144 Radiosurgery and Regorafenib in recurrent high-grade gliomas: is it feasible? PO-1145 Targeting Transgelin-2 by novel small molecule inhibitors to circumvent resistance in glioblastoma