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.