Table 3.

Percentage of CD8⁺ T-cell Subpopulations at the Four Evaluable Time Points

CD8+ T-cell Subpopulation	Baseline (n=37)	Day 1 after mdSBRT (n=37)	P Value *	Day 7 after mdSBRT (n=37)	P Value †	Day 14 after mdSBRT (n=37)	P Value §
%TN
Mean (± SD)	12.5 (11.7)	12.5 (13.6)	0.55	14.4 (14.0)	0.07	14.2 (15.7)	0.18
Median (IQR)	8.8 (3.4–16.9)	8.8 (3.6–13.4)		11.3 (3.3–17.5)		9.6 (3.0–16.2)
%TEF
Mean (± SD)	32.6 (18.3)	33.4 (18.9)	0.50	31.1 (18.5)	0.08	27.8 (17.3)	0.04
Median (IQR)	28.8 (17.5–41.2)	30.0 (18.6–44.4)		24.5 (17.5–41.6)		26.1 (15.9–32.6)
%TCM
Mean (± SD)	11.1 (7.6)	10.1 (6.5)	0.16	12.9 (8.1)	0.12	11.5 (7.0)	0.99
Median (IQR)	10.1 (5.9–14.0)	8.9 (5.5–14.8)		11.4 (7.3–18.6)		10.6 (6.7–15.9)
%TEM
Mean (± SD)	27.7 (14.3)	27.5 (13.0)	0.55	25.7 (11.2)	0.22	29.9 (13.8)	0.58
Median (IQR)	28.2 (16.6–39.8)	27.9 (18.6–35.2)		26.4 (19.0–34.1)		29.7 (20.7–38.9)
%TTR
Mean (± SD)	17.4 (11.4)	16.6 (12.8)	0.56	16.7 (12.8)	0.56	18.5 (14.2)	0.51
Median (IQR)	14.6 (9.6–20.0)	13.4 (10.6–21.5)		12.2 (8.3–22.0)		14.0 (9.0–23.7)

Abbreviations: mdSBRT, metastasis-directed Stereotactic Body Radiation Therapy; T_N (CD8⁺CCR7⁺CD45RA⁺), Naïve Tcell; T_EF (CD8⁺CCR7⁻CD45RA⁺), Effector T-cell; T_CM (CD8⁺CCR7⁺CD45RA⁻), Central Memory T-cell; T_EM (CD8⁺CCR7⁻CD45RA⁻), Effector Memory T-cell; T_TR (CD8⁺PD-1⁺CD11a^high), Tumor-Reactive T-cell; SD, Standard Deviation; IQR, Interquartile Range.

^*P Values based on paired sample t-test comparing means between baseline and day 1*, 7†, or 14§ after mdSBRT, respectively.

^†P Values based on paired sample t-test comparing means between baseline and day 1*, 7†, or 14§ after mdSBRT, respectively.

^§P Values based on paired sample t-test comparing means between baseline and day 1*, 7†, or 14§ after mdSBRT, respectively.