Do findings on immediate post-radiation advanced MRI change treatment decision and clinical outcome in glioblastoma? A propensity score-matched study

Purpose We aim to evaluate efficacy of immediate post-concurrent chemoradiotherapy (CCRT) advanced MRI in patients with glioblastoma to guide treatment decisions and improve survival outcomes. Methods This retrospective study included 168 patients with IDH wild-type glioblastoma who showed measurable enlarging enhancing lesion on MRI within 12 weeks after CCRT between January 2013 and August 2021. Patients were classified with positive MRI group when early progression was suspected on advanced MRI. The rate of switching to second-line treatment was compared between patients with positive and negative findings. Overall survival (OS) after adjustment with propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) was compared between patients continuing primary treatment and those switched to second-line treatment. Multivariable Cox proportional hazards analysis was performed on PSM patients. Results Among 168 patients, 110 exhibited positive findings and 58 showed negative findings on advanced MRI. The positive MRI group showed higher rate of switching to second-line treatment than negative MRI group (49% [54/110] vs. 2% [1/58]; p