EGFR and neoplasm: No significant correlation was observed between initial tumor volume and MGMT promoter methylation (mean GTV: 37.8 ± 14.3 cm3 for methylated vs. 40.2 ± 13.9 cm3 for unmethylated tumors; p = 0.43), nor with EGFR amplification (mean GTV: 38.7 ± 14.1 cm3 for amplified vs. 39.5 ± 14.2 cm3 for non-amplified tumors; p = 0.61).