Table 2.

RBI volume and minimum prostate–rectum distance dynamics

	RBI volume (cm3; median [range])	Prostate–rectum distance (cm; median [range])
Planning CT	20.0 [12.9–22.6]	2.3 [1.9–2.9]
CBCT 1	19.6 [12.8–21.7]	2.2 [1.8–2.8]
CBCT 7	16.0 [12.8–20.7]	2.0 [1.7–2.5]
CBCT 11	15.8 [11.7–20.7]	1.9 [1.6–2.4]
CBCT 15	15.6 [11.7–20.6]	1.9 [1.5–2.4]
CBCT 19	14.5 [11.3–20.0]	1.9 [1.3–2.4]
CBCT 23	14.0 [9.6–19.8]	1.7 [1.1–2.3]
CBCT 27	11.9 [6.3–19.8]	1.4 [1.1–2.3]

RBI rectal balloon implant, CBCT cone-beam computed tomography