Impact of target volume delineation accuracy on locoregional control and survival after postoperative radiotherapy for colorectal cancer

Table 8 Comparison of adverse events between two groups, n (%)

Adverse event	Accurate target volume group (n = 126)	Inaccurate target volume group (n = 92)	χ2 value	P value
Acute adverse events
Grade 1-2 gastrointestinal reactions	94 (74.6)	72 (78.3)	0.424	0.515
Grade 3-4 gastrointestinal reactions	12 (9.5)	10 (10.9)	0.118	0.731
Grade 1-2 hematologic toxicity	68 (54.0)	54 (58.7)	0.491	0.484
Grade 3-4 hematologic toxicity	7 (5.6)	6 (6.5)	0.083	0.773
Grade 1-2 urinary system reactions	32 (25.4)	26 (28.3)	0.23	0.632
Grade 3-4 urinary system reactions	2 (1.6)	3 (3.3)	0.678	0.41
Grade 1-2 skin reactions	28 (22.2)	24 (26.1)	0.449	0.503
Grade 3-4 skin reactions	1 (0.8)	2 (2.2)	0.799	0.371
Any grade 3-4 acute adverse events1	19 (15.1)	16 (17.4)	0.215	0.643
Late adverse events
Grade ≥ 2 intestinal adverse events	11 (8.7)	17 (18.5)	4.554	0.033
Grade ≥ 2 urinary system adverse events	6 (4.8)	8 (8.7)	1.464	0.226
Intestinal obstruction	3 (2.4)	6 (6.5)	2.245	0.134

¹Any grade 3-4 acute adverse events refer to the total number of patients experiencing any grade 3-4 toxic reaction. In the accurate target volume group, 3 patients experienced two types of grade 3-4 toxicities simultaneously; in the inaccurate target volume group, 5 patients experienced two types of grade 3-4 toxicities simultaneously.