Gastrointestinal Toxicity and Quality of Life. a) Cumulative late gastrointestinal toxicity (grade 2 in blue and grade 3 in red). b) Average EPIC bowel domain scores. The thresholds for clinically significant changes in scores (1/2 standard deviation above and below the baseline) are indicated by the red and green lines. EPIC score range from 0-100 with higher values representing a more favorable health-related quality of life.