Figure 1. Flow rate of parotid and submandibular-sublingual (SM/SL) saliva as a function of time after start of radiotherapy (conventional fractionation schedule, 2Gy per day, 5 days per week, total dose 60-70 Gy). The parotid, submandibular, and sublingual glands are located in the treatment portal. Initial flow rates were set to 100% (modified after Burlage et al,. 2001).