P13.19 * HYPOFRACTIONATED RADIOTHERAPY IN PATIENTS WITH HIGH GRADE GLIOMAS AND POOR PROGNOSTIC FACTORS: A RETROSPECTIVE STUDY

Abstract

PURPOSE: The standard treatment for patients with high-grade gliomas (HGG) and limited life expectancy is not well defined. Patients with an age over 65 years, poor Karnofsky performance status (KPS) and surgical biopsy/partial resection could not benefit from the combination of radiotherapy (60 Gy in 30 fractions) and chemotherapy with temozolomide (TMZ). In these patients hypofractionated radiotherapy (HypoRT) or TMZ alone have been suggested adequate treatments without significant differences in term of overall survival (OS) and progression free survival (PFS) compared to the standard approach. Furthermore, new clinical trials are investigating the role of a combination of HypoRT and TMZ. The aim of this retrospective study is to evaluate the outcome of HypoRT, with or without TMZ, in a cohort of HGG with poor prognostic factors. MATERIALS AND METHODS: Between January 2006 and December 2013, 69 patients with a diagnosis of HGG and poor prognostic factors (age ≥65 and/or KPS ≤60) were treated at our Institution. All patients were discussed in the Brain Tumor Board and treated with a dose of 42 Gy in 14 fractions with a conformal radiation treatment technique. TMZ was added either in elderly patients with no comorbidities or in poor KPS patients with younger age. Concomitant TMZ was given at a dose of 75 mg/m2 /d while adjuvant TMZ at a dose of 150-200 mg/m2 for 5 days every 28 days until tumor progression or unacceptable toxicity. During follow up a contrast-enhanced MRI was performed 4 weeks after the HypoRT, and thereafter every 3 months. The primary endpoint was overall survival (OS) measured from HypoRT start, according to the Kaplan-Meier method. RESULTS: Median age was 65 years (range, 34-80 years) and median KPS was 60 (range, 50-90). Fifty-four patients (78.3%) received a surgical resection (51 partial and 3 complete resections) and 15 patients (21.7%) underwent a biopsy. Fifty-eight patients had an histological diagnosis of glioblastoma, 7 of grade III glioma and 4 of high grade gliomas (not other specified). Five patients (7%) received concomitant, 5 (7%) concomitant and adjuvant and 13 (19%) adjuvant only TMZ. Median follow-up was 7.7 months (range, 1-34 months). The median survival time (MST) was 7 months; 6-month and 12-month OS rates were 54.4% and 29.5%, respectively. Univariate analysis was used to test the effects of prognostic factors on survival and none of these showed a statistical significance. After multivariate analysis there was a trend toward a better outcome with the addition of adjuvant TMZ (MST 9 vs. 6 months, Log Rank p = 0.06). CONCLUSIONS: Median survival of this cohort of HGG with poor prognostic factors is comparable to the data published in the literature. Adjuvant chemotherapy could improve OS, but prospectives studies with larger sample size and longer follow-up are needed.