Eligibility assessment for yttrium-90 radioembolisation in patients with recurrent glioblastoma: A single-centre cohort study based on the FRONTIER clinical trial criteria (NCT05303467)

INTRODUCTION: Glioblastoma (Gb) is the most common and aggressive primary malignant brain tumor in adults; median survival after diagnosis is less than 15 months, and the 2-year survival rate ranges from 26% to 33%1,2. Standard treatment includes surgical resection, followed by temozolomide and radiotherapy, although recurrences are frequent3. Endovascular radiotherapy with yttrium-90 (Y-90) microspheres is a promising treatment in patients with recurrent Gb. MATERIALS AND METHODS: A retrospective analysis of a prospective database was performed, including patients with a histologically confirmed diagnosis of Gb between January and December 2019 at a tertiary referral center. Recurrence was assessed by a multidisciplinary committee, based on Response Assessment in Neuro-oncology (RANO) criteria, follow-up imaging studies, and the patient's clinical condition. Patient inclusion was initially based on the following CRITERIA: RESULTS: Sixty-three patients with a histological diagnosis of Gb were included at a tertiary referral center for this pathology between January and December 2019 (37 men; mean age 61 ± 11.32 years). Figure 1 summarizes the patient flow diagram, where 49 patients were excluded for not meeting the clinical criteria. Of the 14 patients eligible based on clinical criteria, MRI images of patients with tumor recurrence were analyzed according to the angiographic inclusion criteria of the FRONTIER trial. DISCUSSION: This study identifies that only 1 patient (1.58%) of the 63 evaluated met the clinical-angiographic criteria of the FRONTIER trial, which limits the applicability of Y-90 microsphere treatment in this clinical context. This is mainly due to the trial's strict angiographic criteria, as the size of the Y-90-loaded particles (15-35 μm) does not allow their administration into non-pathological arteries without causing an infarction in that territory. Recurrences