Is the irradiated small bowel volume still a predictor for acute lower gastrointestinal toxicity during preoperative concurrent chemo-radiotherapy for rectal cancer when using intensity-modulated radiation therapy?

Table 4 Factors associated with grade ≥ 2 lower GI toxicity

Factors	Median	Univariate		Multivariate
Factors	Median	OR (95 % CL)	P value	OR (95 % CL)	P value
Age (years)	≤55/>55	0.716 (0.259–1.946)	0.513
Gender	Female/Male	0.351 (0.114–1.084)	0.069	0.376 0.108 1.308	0.124
T stage	≤ T3/>T3	0.859 (0.313–2.361)	0.769
N stage	N-/N+	0.735 (0.097–5.581)	0.766
Tumor volume (cc)	≤64/> 64	0.185 (0.062–0.550)	0.002	0.147 0.043 0.499	0.002
Tumor location^a	≤6/>6	0.700 (0.248–1.978)	0.501
Pre-existing BM^b	<4/≥ 4	0.374 (0.134–1.048)	0.061	0.272 0.080 0.922	0.036
Small bowel V5 (cc)	≤213/>213	1.562 (0.572–4.265)	0.384
Small bowel V10 (cc)	≤191/>191	1.562 (0.572–4.265)	0.384
Small bowel V15 (cc)	≤174/>174	1.818 (0.662–4.995)	0.246
Small bowel V20 (cc)	≤146/>146	1.818 (0.662–4.995)	0.246
Small bowel V25 (cc)	≤100/>100	1.626 (0.593–4.458)	0.345
Small bowel V30 (cc)	≤53/>53	1.818 (0.662–4.995)	0.246
Small bowel V35 (cc)	≤23/>23	0.550 (0.200–1.511)	0.246
Small bowel V40 (cc)	≤11/>11	0.640 (0.234–1.747)	0.384

ISSN: 1748-717X