Table 1.

Dosimetric parameters in PTV and OAR at different phases; all values are dose in Gy(RBE)

Organs	Criteria	Elapsed time from spacer placement
		2 weeks	4 weeks	6 weeks	8 weeks	10 weeks
PTV	D98% > 53.0	53.9	53.1	53.2	53.8	54.1
Rectum	Dmax ≤ 55.8	46.7	53.1	47.0	49.3	49.3
Large bowel		34.2	43.6	45.6	41.3	55.5
Small bowel		1.1	1.8	1.2	1.4	1.4
Bladder		1.8	3.7	22.7	16.8	2.7