This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: ENT
Radiotherapy is used in treatment of angiofibroma when it involves: 
Select and explain. 
A. Cheek, B. Orbit, C. Middle cranial fossa, D. Cavernous sinus
C: Middle cranial fossa
Answer: C: Middle cranial fossa 
Explanation: Radiotherapy is useful only for advanced cases of the tumor, when there is intracranial extension.