AUTHOR=Muracciole Xavier , El-amine Wassim , Tabouret Emmeline , Boucekine Mohamed , Barlier Anne , Petrirena Gregorio , Harivony Tovo , Solignac Laetitia , Chinot Olivier L. , Macagno Nicolas , Figarella-Branger Dominique , Padovani Laetitia 

TITLE=Negative Survival Impact of High Radiation Doses to Neural Stem Cells Niches in an IDH-Wild-Type Glioblastoma Population

JOURNAL=Frontiers in Oncology

VOLUME=8

YEAR=2018

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2018.00426

DOI=10.3389/fonc.2018.00426

ISSN=2234-943X

ABSTRACT=<p><bold>Aims:</bold> Assess the impact of radiation doses to neural stem cell (NSC) niches in patients with IDH-wild-type glioblastoma.</p><p><bold>Materials and Methods:</bold> Fifty patients were included in the study. NSC niches [SubVentricular Zone (SVZ) and Sub Granular Zone (SGZ)] were contoured by fusing CT scans and pre-therapy MRI, Tumor location defined ipsilateral and contralateral SVZ and SGZ. Prognostic significance of clinical, biological and dosimetric parameters were examined. We generated a Recursive Partitioning Analysis (RPA) model with independent prognostic classes.</p><p><bold>Results:</bold> Median follow-up: 23.8 months. Event free and overall survival (OS): 10 and 19.1 months. Incomplete surgery, PTV (planning target volume), ipsilateral SVZ or NSC niche mean dose &gt; 57.4 Gy, contralateral NSC niche mean dose &gt; 35 Gy and bilateral NSC niche mean dose &gt; 44 Gy were significantly correlated with reduced OS. Only EGFR amplification was an independent prognostic factor (<italic>p</italic> = 0.019) for OS. RPA generated independent risk groups: 1 (low risk): [ipsilateral NSC mean dose (INMD) &lt; 58.01 Gy and methylated MGMT promoter], 2: (INMD &lt; 58.01 Gy and unmethylated MGMT promoter and contralateral SVZ mean dose &lt; 18.6 Gy; <italic>p</italic> = 0.43), 3: (INMD &lt; 58.01 Gy and unmethylated MGMT promoter and contralateral SVZ mean dose &gt; 18.6 Gy; <italic>p</italic> = 0.002) and 4: (very high risk) (INMD &gt; 58.01 Gy; <italic>p</italic> &lt; 0.001).</p><p><bold>Conclusion:</bold> High radiation doses to ipsilateral NSC and contralateral SVZ could have a negative impact on overall survival in IDH-wild-type glioblastoma population.</p>