Abstract 301P
Background
During the initial approach to the COVID-19 pandemic, some international recommendations regarding high-grade gliomas (HGG) favored the use of hypofractionated radiotherapy (HFR) regiments, particularly in elderly and frail patients. In our institution, to reduce the risk of COVID-19 infection and the treatment interruptions, the multidisciplinary group decided to carry out a modified STUPP protocol (HFR - 40,05Gy/15 fractions over 3 weeks - with TMZ), even in younger patients with good performance status (PS). However, a few data exist about the role of HFR in this subgroup of patients.
Methods
Retrospective analysis of patients with a newly diagnosed HGG treated with chemoradiotherapy with temozolomide (TMZ) followed by adjuvant TMZ, between 2016 and 2021. Patients with ≤ 70 years old and ECOG PS ≤ 2, treated with conventional fraction RT (CFR, 60Gy/30 fractions, over 6 weeks) or HFR concurrent with TMZ (75 mg/m2/day), followed by adjuvant TMZ (150-200 mg/m2/day for 5 days, every 4 weeks) were included. Survival analysis was performed using the Kaplan-Meier method and prognostic factors assessed by univariate analysis and by the Cox regression model.
Results
A total of 157 patients were included, with a median age of 56 years old (26-69). The majority (82,2%) was submited to surgical resection. About 24% (n=37) were treated with HFR-TMZ and 76% (n=120) with CFR-TMZ. The most frequent adverse event was thrombocytopenia (n=39), with no difference between groups (p=0,828). The patients treated with HFR had a median overall survival (mOS) of 18 months vs. 21 months with CFR (p=0,221). The median progression free survival (mPFS) was 13 months for patients treated with HFR, and 10 months for CFR (p=0,418). In multivariate analysis, IDH mutation (OS: HR 0,47; 95% CI 0,26-0,86; p= 0,014. PFS: HR 0,47; 95% CI 0,27-0,84; p=0,010) and absence of corticotherapy (OS: HR 0,65; 95% CI 0,44-0,98; p=0,038. PFS: HR 0,65; 95% CI 0,44-0,97, p=0,034) had a positive impact on OS and PFS.
Conclusions
According to our data, in HGG patients with ≤70 years old and a good PS, the use of HFR with TMZ had no impact on median PFS and OS, when compared with CFR-TMZ. However, the role of HFR in this setting needs further research.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.