Figure 2. Nomogram of Xer2y occurrence prediction. For each individual patient, the value of three variables (VMAT, CCRT and coMD) are translated into points by projecting them into the upper-most line (point scale), respectively. Summing the points of the three variables and projecting the total points value downward to the bottom-most line can determine the probability of this patient to have Xer2y (patient-reported xerostomia at least 2 years after radiotherapy). VMAT (volumetric modulated arc radiotherapy). CCRT (platinum-based concurrent chemoradiotherapy). coMD (Contralateral Parotid mean dose).