Dosimetric feasibility of stereotactic body radiation therapy as an alternative to brachytherapy for definitive treatment of medically inoperable early stage endometrial cancer

Table 2 Normal tissue dosimetric comparison of stereotactic body radiation therapy and intracavitary brachytherapy

Site	Volume	Tolerance limit	Mean dose (Gy, per fx) ± SD		p-value
Site	Volume	Tolerance limit	I-BT	SBRT	p-value
Bladder
	D50%	4.25	2.04 ± 0.78	1.76 ± 1.08	NS
	D10%	7.65	3.73 ± 1.44	3.65 ± 1.37	NS
	D0.1 cc	-	6.44 ± 3.05	5.55 ± 1.46	NS
	D1 cc	8.93	5.22 ± 2.27	4.76 ± 1.48	NS
	D2 cc	4.60	4.68 ± 2.02	4.34 ± 1.51	NS
Rectum
	D50%	4.25	0.83 ± 0.37	1.20 ± 0.63	NS
	D20%	6.80	1.27 ± 0.85	2.25 ± 0.76	NS
	D10%	7.65	1.56 ± 1.21	2.65 ± 0.75	NS
	D0.1 cc	-	2.64 ± 2.68	4.25 ± 1.25	NS
	D1 cc	8.93	2.14 ± 1.98	3.37 ± 0.80	NS
	D2 cc	4.60	1.91 ± 1.65	3.07 ± 0.74	NS
	D20 cc	6.50	0.93 ± 0.50	1.40 ± 0.84	NS
Sigmoid
	D0.1 cc	-	5.41 ± 1.66	5.77 ± 0.52	NS
	D2 cc	4.80	4.05 ± 1.18	4.48 ± 0.49	NS
	D20 cc	6.50	1.73 ± 0.82	2.65 ± 0.78	0.02
Other bowel
	D0.1 cc	-	3.49 ± 1.43	6.69 ± 0.55	<0.005
	D2 cc	-	2.66 ± 1.11	5.56 ± 0.45	<0.005
	D5 cc	4.75	2.28 ± 0.99	5.03 ± 0.46	<0.005
	D20 cc	6.50	1.51 ± 0.64	3.94 ± 0.62	<0.005
Femoral Heads
	Max	6.89	0.83 ± 0.22	2.83 ± 1.22	<0.005
	D10 cc	4.59	0.57 ± 0.15	2.22 ± 1.09	<0.005

Abbreviations: SD standard deviation, I-BT intracavitary brachytherapy, SBRT stereotactic body radiation therapy, fx fraction, V(x)% the percentage volume of the structure receiving x percent of the prescription dose of 8.5Gy, D(x)% the highest dose received by x percent of the volume, NS non-significant.

ISSN: 1748-717X