Study population
In total, 356 patients with rHGG were evaluated from January 2016 to January 2019 (Supplementary Figure 1). Patients were excluded if they did not receive ICI monotherapy, ICI concurrently with SBRT (n=333), or if they had outside imaging during treatment that was not available for analysis (n=2), leaving 21 patients for analysis. Patient demographics are displayed in Table 1. Sixteen patients with rHGG were treated with ICI+ SBRT, of which 10 were WHO grade IV and 6 were WHO grade III. MGMT methylation, IDH1 and TERT mutations were present in 4 (25%), 3 (19%) and 10 (63%) patients, respectively. Twelve patients received concurrent chemoradiation following their initial resection, and underwent an average of 4.5 lines of therapy. Five patients received ICI monotherapy, of which 2 were WHO grade IV and 3 were WHO grade III. MGMT methylation and TERT mutations were present in 1 and 2 patients, respectively, with no patients in this cohort possessing IDH mutations. Four patients underwent concurrent chemoradiation following their initial resection and received an average of 4.5 lines of therapy.
On average, patients received 3 lines of therapy before they were offered ICI+SBRT (Table 2). SBRT doses ranged from 18 Gy in 1-3 fractions to 35 Gy in 5 fractions. A mean of 7.25 ICI cycles were given. Twelve patients received dexamethasone during their treatment, and 6 received bevacizumab during their treatment. Patients in the ICI monotherapy received an average of three prior lines of treatment. A mean of 6.2 ICI cycles were given. Three patients received dexamethasone and one was treated with bevacizumab.