Table 3.

Prevalence of immune checkpoints within CD8 + T lymphocytes in tumor microenvironment after RT in high-dose rate using flattening filter-free beams versus standard low-dose rate.

	PD1	TIGIT	Tim3	LAG3	PDL1
Control	58.04% [36.23; 61.35]	28.23% [25.54; 39.03]	9.41% [6.65; 10.71]	29.2% [24.75; 49.19]	1.72% [0.99; 5.14]
LDR (4 Gy/min)	85.69% [82.76; 91.41]	50.99% [42.47; 62.27]	22.61% [17.44; 28.31]	41.95% [38.75; 57.6]	47.51% [37.14; 48.43]
HDR (24 Gy/min)	90.08% [75.07; 91.81]	56.59% [44.95; 62.3]	23.68% [20.19; 27.89]	46.52% [36.64; 58.47]	56.09% [29.84; 59.01]
HDR VS LDR	p = 0.72	p = 0.89	p = 0.86	p = 0.89	p = 0.72
LDR VS Control	p = 0.013	p = 0.024	p = 0.017	p = 0.23	p = 0.013
HDR VS Control	p = 0.005	p = 0.016	p = 0.01	p = 0.18	p = 0.005

Proportion of CD8 + T lymphocytes expressing immune checkpoints within tumor microenvironment of CT26 tumors at J7 post-irradiation. Results for PD1, TIGIT, Tim3 and LAG3 expressed in percentages among T CD8 + lymphocytes. Result for PDL1 expressed in percentage among tumor cells. All results presented in medians with interquartile ranges. Data comparisons done using a Mann-Whitney non-parametric test. N = 5 samples for each condition. LDR: Low-dose rate; HDR: High-dose rate.