Fig. 5.

IMRT planning according to preoperative magnetic resonance image (A, axial and C, sagittal) and postoperative simulation computed tomography (B, axial and D, sagittal). Irradiation fields include the hard palate and the course of V2 along the greater palatine canal to the medial cranial fossa, including the foramen rotundum and the vidian canal. Isodose line distribution of 60 Gy (100% of the prescription dose, red), 57 Gy (95% of the prescription dose, orange), and 55 Gy (the tolerance of the optic nerves and optic chiasma). IMRT, intensity-modulated radiotherapy.