Fig. 4
From: A Nomogram to predict parotid gland overdose in head and neck IMRT
a Nomogram to predict PG overdose. The nomogram enables easy prediction of the difference between the mean cumulated parotid gland (PG) dose and the mean planned PG dose (in Gy), using three parameters calculated on the planning computed tomography (CT) (CT0) and on a CT performed during the first week of the treatment (CT1). CTV70 (in cm3): clinical target volume receiving 70Gy; ΔCTV70 (in cm3): difference between the CTV70 of CT1 and CT0; ΔDosePG (in Gy): mean PG dose difference between CT1 and CT0. b Quantiles-quantiles plot (Q-Q plot) of the nomogram. The more accurately the quantile position is aligned, the more linear the model