GRIX Xerostomia and Sticky Saliva Scores by Trial Arms. A, GRIX xerostomia daytime score (AUC score for first 3 cycles; P=.02). B, GRIX xerostomia total score (P=. 02). C, GRIX sticky saliva daytime score (P=.04). D, GRIX sticky saliva total score (P=.12). For cycle numbers, 0 indicates baseline, 1-8 indicate weekly measurements during RT, and 9-11 indicate 14, 45, and 90 days post RT, respectively. Arm A = placebo rinse; Arm B = NAC rinse; AUC = area under the curve; GRIX = Groningen Radiation-Induced Xerostomia; NAC = N-acetylcysteine; RT= radiotherapy.