Fig. 1.

Transverse view of a treatment plan for Patient 2 delivering 65 Gy in 30 fractions to the planning target volume (PTV) using intensity-modulated radiotherapy (IMRT). Gross tumor volume (GTV), green; clinical target volume (CTV), yellow; PTV, red. In this case, the GTV extends superiorly and can be seen involving the ethmoid sinuses and nasal cavity medial to the globe. Isodose lines are demonstrated as a color wash according to the key on the left of the image. The globes and left lens are also outlined.