ESTRO 2021 Abstract Book

S102

ESTRO 2021

PH-0166 Hypofractionated radiotherapy preserves/improves quality-of-life in poor-prognosis high-grade glioma Y. Baviskar 1 , B. Likonda 1 , S. Pant 1 , A. Dasgupta 1 , A. Chatterjee 1 , S. Mokal 1 , P. Maitre 1 , S. Kanan 1 , J. Goda Sastri 1 , R. Jalali 1 , T. Gupta 1 1 Tata Memorial Centre, Neuro-Oncology Disease Management Group, Mumbai, India Purpose or Objective High-grade gliomas (HGG) in elderly (>65 years) and/or those with low performance status (Karnofsky score ≤60%) have poor prognosis with a median overall survival of 6-10 months despite aggressive multi-modality treatment. We herein report quality-of-life (QoL) outcomes in this cohort of patients treated at our institute with short-course palliative hypofractionated radiotherapy (RT) delivering 35Gy in 10 fractions over 2 weeks using conformal techniques. Materials and Methods EORTC core questionnaire QLQ-30 and brain cancer module BN20 were used in validated vernacular Indian languages and English for assessment of QoL at baseline (pre-RT), conclusion of RT, 1-month post-RT and at 1- monthly intervals subsequently until disease progression/death. Raw scores were transformed to a linear scale ranging from 0 to 100 and compared longitudinally across the first three time points. We also compared mean transformed scores of these patients at baseline with a previous cohort of 110 HGG patients treated with standard fractionation at our institute. Results Forty-nine of 55 patients accrued on the phase II study completed the planned short-course RT with longitudinal QoL data being available in 42 of these 49 patients for the present analysis. Median age of the included patients was 57 years (inter-quartile range 50-66 years), comprised mainly of glioblastoma (81%), with median baseline Karnosfsky score of 60 (inter-quartile range 50-60). The mean scores of the hypofractionated RT cohort (N=42) at baseline were significantly worse than our previous cohort of normofractionated RT (N=110) for several domains - lower in functional domains of global QoL (p- value=0.029), physical functioning (p-value=0.025) and higher in communication deficit domain (p- value=0.007), symptom scales of dyspnea (p-value=0.004) and itchy skin (p-value<0.001) reflecting an inherent negative selection bias in the hypofractionated RT cohort. Mean scores for all domains at baseline and subsequent two follow-ups for the hypofractionated RT cohort are shown in Figure 1. Patient-reported QoL was largely stable over time for most domains/scales with statistically significant improvements in motor dysfunction (p-value=0.036), fatigue (p-value=0.032) and dyspnea (p-value=0.042). QoL scores of surviving patients remained stable on subsequent follow-up until disease progression.

Conclusion Short-course palliative hypofractionated RT for patients with poor-prognosis HGG does not impair QoL in the short-term but is associated with preservation and/or improvement in several domains/symptom scales making it a viable resource-sparing alternative regimen. PH-0167 MRI features correlate with a molecular signature in glioblastoma stem cells F. Eckert 1,6 , K. Ganser 1 , N. Stransky 2 , B. Bender 3,7 , J. Schittenhelm 4,7 , S. Noell 5,7 , E. Hoffmann 1 , L. Klumpp 1 , D. Zips 1,7 , F. Paulsen 1 , S. Huber 1 1 University Hospital Tuebingen, Department of Radiation Oncology, Tuebingen, Germany; 2 University Hospital Tuebingen, Deparmtent of Radiation Oncology, Tuebingen, Germany; 3 University Hospital Tuebingen, Department of Diagnostic and Interventional Neuroradiology, Tuebingen, Germany; 4 University Hospital Tuebingen, Department of Neuropathology, Tuebingen, Germany; 5 University Hospital Tuebingen, Department of Neurosurgery, Tuebingen, Germany; 6 University Hospital Tuebingen, Center for Neurooncolocy, CCC, Tuebingen, Germany; 7 University Hospital Tuebingen, Center for Neurooncology, CCC, Tuebingen, Germany