Fig. 2
The Kaplan-Meier curve demonstrating a overall survival and b progression-free survival according to lung V20 and V5 groups. Group 1, V20 ≤ 23% and V5 ≤ 56%; Group 2, V20 ≤ 23% or V5 ≤ 56%; Group 3, V20 > 23% and V5 > 56%. Vx was defined as the percentage of total organ volume receiving a radiation dose of x (Gy) or more