ESTRO 2023 - Abstract Book

S909

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ESTRO 2023

Conclusion SRT2 is an effective approach for local recurrence of BM after initial SRT treatment and is a potential salvage therapy option for well-selected people with good performance status. Surgery was associated with a higher LC.

PO-1137 Reirradiation versus systemic therapy for recurrent high-grade glioma: A systematic review

R. Marwah 1,2 , D. Xing 1,3 , Y.Y. Soon 4 , T. Squire 1,2 , H. Gan 5,6 , S.P. Ng 3

1 Townsville University Hospital, Department of Radiation Oncology, Townsville, Australia; 2 James Cook University, College of Medicine and Dentistry, Townsville, Australia; 3 Olivia Newton-John Cancer Wellness & Research Centre, Austin Health, Department of Radiation Oncology, Melbourne, Australia; 4 National University Cancer Institute, Department of Radiation Oncology, Singapore, Singapore; 5 Olivia Newton-John Cancer Wellness & Research Centre, Austin Health, Department of Medical Oncology, Melbourne, Australia; 6 Olivia Newton John Cancer Research Institute, Austin Health, Melbourne, Australia Purpose or Objective To compare the impact of reirradiation versus systemic therapy on overall survival (OS), progression free survival (PFS), adverse events (AEs) and quality of life (QoL) in patients with recurrent high-grade glioma (rHGG). Materials and Methods The systematic review was conducted in accordance with PRISMA guidelines. A search was performed on the PubMed, Scopus, Embase and CENTRAL databases on 18 March 2022. Studies published from 2010 comparing OS, PFS, AEs and/or QoL in patients with rHGG, and encompassing the following three groups were included; systemic therapy vs reirradiation, systemic therapy vs systemic therapy & reirradiation (combination therapy), reirradiation vs combination therapy. Data was extracted including information on study characteristics, participants, interventions, and relevant outcome measures. The logHR and SE(logHR) for OS and PFS, and logRR and SE(logRR) for AEs were extracted or estimated if not reported for each study. Data was pooled by each comparator group using the generic inverse variance method, and the DerSimionian and Laird random effects model was utilised. A subgroup analysis was performed on studies which accounted for confounders through methodology or multivariate analysis. Risk of bias (RoB) was assessed for randomised control trials (RCTs) using the Cochrane RoB 2 tool, while the ROBINS-I tool was used to assess RoB for non-randomised studies. Results 28 studies were included. In the systemic therapy vs reirradiation group; there was no difference in OS (3 studies, 237 participants; HR 0.83 (95%CI 0.51-1.35), p=0.45, I2=37%) and PFS (2 studies, 185 participants; HR 0.80 (95%CI 0.55-1.18), p=0.26, I2=0%). In the systemic therapy vs combination therapy group (Table 1); combination therapy improved OS (5 studies, 290 participants; HR 0.59 (95%CI 0.44-0.77), p=0.0002, I2=0%) and PFS (4 studies, 232 participants; HR= 0.53 (95%CI 0.36-0.77), p=0.001, I2=44%), and there was no difference in grade 3+ AEs (3 studies, 151 participants; RR 1.32 (95%CI 0.58-