Figure 4

Kaplan–Meier survival plots for local relapse-free survival after radiotherapy alone or with carbogen and nicotinamide and stratified according to (A) necrosis present, (B) necrosis absent, (C) necrosis present and HIF-1 α >19 and (D) necrosis absent or HIF-1 α <19. Log-rank P-values and number of patients at risk in each yearly interval are also shown.