highly significantP < 0.001
In this nested case-control study, Gray’s test further indicated that CIFs for the patients with D1cc ≤71.14 Gy and patients with D1cc > 71.14 Gy were not statistically different for prior death (coded as 1) ( P = 0.166), but they were highly significant for TLI (coded as 2) ( P < 0.001).