Table 2.

Dosimetric comparison of patients with or without spacer consecutively treated at our institution.

Parameter	Mean [SD]	Mean [SD]	P-value
	Spacer cohort (n=74)	Non-spacer cohort (n=136)
Prostate-rectal separation achieved (mm)	11.2 [3.3]
Isotope, median number of seeds [range]	Pd, 57 [34 – 96]	Pd (n=109), 65 [15 – 109]	0.001
		I-125 (n=26), 77 [34 – 98]
Isotope, median activity	Pd, 2.74 [1.54 – 4.02]	Pd, 2.29 [1.02 – 3.73]	0.000
		I-125, 0.46 [0.41 – 0.57]
Prostate volume (cc)	29.34 [12.35]	34.55 [12.11]	0.004
Prostate D90 (%)	112.37 [12.04]	109.60 [13.64]	0.082
Prostate V100 (%)	94.02 [3.81]	93.08 [3.96]	0.095
Prostate V150 (%)	70.03 [8.44]	65.64 [8.76]	0.001
Prostate V200 (%)	47.75 [9.02]	41.50 [12.27]	0.000
Urethra D20 (%)	122.02 [17.27]	118.87 [20.23]	0.259
Urethra D5 (%)	133.80 [22.75]	130.91 [22.75]	0.366
Urethra D1 (%)	143.95 [25.38]	143.07 [31.66]	0.838
Rectal V100 (cc)	0.01 [0.05]	0.07 [0.19]	0.000
Rectal D1cc (%)	25.27 [12.67]	52.74 [18.76]	0.000
Rectal D2cc (%)	20.47 [9.93]	43.16 [15.70]	0.000

D90 – dose to 90% of the prostate; prostate V100, V150 and V200 – prostate volumes receiving 100%, SD- standard deviation; 150% and 200% of the prescribed dose; urethra D20, D5 and D1 – percent of the prescribed dose to 20%, 5% and 1% of urethra; rectal V100 – rectal volume receiving 100% of prescribed dose; rectal D1cc and D2cc – percent of prescribed dose to 1cc and 2cc volumes of rectum.