Session Item

To report toxicity and survival outcomes, obtained in non-elderly patients with malignant gliomas, treated with hypofractionated radiotherapy (HFRT).

A retrospective analysis was performed, of 67 non-elderly patients with malignant gliomas, treated in Centro Médico Dean Funes Córdoba, Argentina, from September 2016 to October 2019. Treatment volume was contoured using brain MRI, which was fused with institutional computed tomography, in stereotactic conditions, and planned with IMRT. Total prescribed dose to target volume was between 35–54Gy, which was administered using three different hypofractionated schemes: 10, 15 or 20 continuous fractions, of 2.7–5 Gy. Treatment was delivered with 6MV photon beams of a Linear Accelerator, using IGRT ConeBeamCT. Acute and chronic toxicity was assessed according to CTCAEv4.0. Survival outcomes were obtained with Kaplan Meier survival analysis.

At a median follow up of 15 months, 41 (61%) patients were men and 26 (39%) were women, with a median age of 50, and a median KPS of 87. Glioblastoma multiforme was the most common histological type in 34 (51%) patients, followed by astrocytoma in 26 (39%) and oligodendroglioma in 7 (10%). 28 (42%) patients underwent total resection, 31 (46%) partial resection, and 8 (12%) biopsy only. Concurrent Temozolamide (TMZ) was administered to 76% of patients. All patients completed treatment, 78% without breaks, and 22% with 1-3 breaks. The most common acute adverse events were: G1 headache (27%), alopecia (14%), G1 fatigue (11%), and G1 epidermitis (11%). The most commonly registered chronic adverse events were: cognitive deficit (23%), partial seizures (23%), and vision change (15%). Acute toxicity was higher in the 20 fractions scheme (50%), while chronic toxicity was higher in the 10 fractions scheme (56%). Overall survival (OS) was of 94%, 90%, 75%, and 53% at 3, 6, 12, and 24 months respectively. 36 (54%) patients were still alive at last follow up. Progression free survival (PFS) was of 92%, 77%, 54%, and 44% at 3, 6, 12, and 24 months, respectively, reaching median PFS at 15 months. Treatment volumen <290 cc and total or partial resection showed better OS and PFS; Concurrent TMZ showed better OS; however, in univariate and multivariate analysis, none proved to be a survival predictive factor. At univariate analysis, age > 50 (p=0.009) and KPS <90 previous to HFRT (p=0.019), and KPS <90 at the end of HFRT (p=0.004), were associated with worse OS. While in multivariate analysis only age >50 (RR 2.71 p=0.030) and KPS <90 at the end of HFRT (RR 6.08 p=0.001], proved to be worse OS predictive factors.

HFRT is a feasible and safe treatment option, for malignant gliomas of non-elderly patients. We identified good survival prognostic factors, such as KPS >90, age <50, total and partial tumor resection, and concomitant TMZ. Treatment tolerance was acceptable and comparable with international published trials.