Fig. 1.

Dose distributions superimposed on the (a) standardized planning magnetic resonance imaging (MRI-1) and (b) repeat verification MRI (MRI-2) scans for a patient with enlarged brain tumor. (c) Comparison of dose volume histograms for the MRI-1 (solid line) and MRI-2 (dashed line) scans (No. 1). The gross tumor volume is expressed in red. The MRI-2 provided substantially lower doses to the GTV and PTV compared with the MRI-1 scan. The brain curve on MRI-1 is perfectly superimposed on MRI-2. Abbreviations: GTV = gross tumor volume; PTV = planning target volume.