Radiation Treatment Technique (Nasopharynx)

Question 1

What is the definitive RT dose/fx for nasopharynx?

Answer 1

70 Gy in 33 - 35 fx to the gross disease (tumor plus involved nodes) + 3-5 mm margin

59.4 - 63 Gy in 33-35 fx to the intermediate risk (CTV IR)

Question 2

What anatomical structures should you include in intermediate risk CTV?

Answer 2

Entire nasopharynx, RP nodes, clivus (1/2 if uninvolved, entire clivus if involved), pterygoid fossa, parapharyngeal space, sphenoid sinus (interior 1/2 if uninvolved, entire if involved or cavernous sinus disease), posterior 1/3 of maxillary sinus and nasal cavity, cavernous sinus in locally advanced disease, and skull base (rotundum, ovale, lacerum)

Question 3

What volumes should you cover for low risk CTV?

Answer 3

neck levels II - IV