Nasopharynx

Question 1

Nasopharynx T1N0

Answer 1

“Include MRI, ophtho and audiology consults. EBV

EBV DNA quantitative PCR: used to give surival and distant met prognosis, and monitor treatment response and recurrence. Can get before and after treatment (<1500 copies before treatment gives better prognosis, and undectable after tx is better)”

“Three volume: 6996/5940/5412
Two volume: 70-66 Gy SIB with 1.6 Gy daily to low risk neck”

“Neck: bilateral II-V, RP, and RSS.

“NPX cancers often present with CN deficits, anosmia, HA

Jacods = CN III-VI (cavernous sinus direct extension)
Villaret - CN IX-XII, RP nodes into lateral pharyngeal space”

Question 2

Nasopharynx T2-T4 or N+

Answer 2

“70/56 two volume approach allowed per guidelines

6996/5940/5412 (2.12/1.8/1.64)/ 35 fx

with concurrent chemo 100mg cisplatin concurrently, Cis 80mg d1 , 5-FU 1g d1-4 q4weeks x3 cycles

PET at 3 months then elective neck dissection if incomplete response”

“Fuse with MRI to include extent of primary tumor and neck nodes.

70 Gy to GTV and involved lymph nodes with 5 mm CTVP1. Some include whole nasopharynx in CTV-P1, others in CTV-P2 (caudal nasopharynx border is C1). If induction chemo is used, use post-chemo volumes (Yang 2018)

CTVP2 GTV+10mm, entire nasopharynx,
Superior: inferior cavernous sinus, entire vomer and posterior/inf ethmoid sinus, bilateral foramen ovale, rotunda, and lacera,
Anterior: post 5mm maxillary sinus, post 5mm of nasal cavity
Lateral: pterygoid muscle by 5+5 rule, entire parapharyngeal space,
Posterior: anterior 1/3 clivus (whole if involved)
For T3-T4, include entire sphenoid sinus and whole ipsilateral cavernous sinus.
Include jugular foramen and hypoglossa canal for posterior lateral infiltration of primary tumor or high jugular lymphadenopathy

CTV neck: bilateral II-V, RP, and RSS. For N3 also include Ib and Vc (some include Vc in all)
to node negative neck same levels.
Per Sun Yat Sen, RP and V should be increased, and levels Ib, II, and IV can be made smaller than in guidelines (Lin 2018).

3-5 mm PTV

"Brainstem PRV D0.03cc < 54 (variation acceptable < 60)
Spinal cord PRV D0.03 cc <45 (VA <50)
Optic chiasm, nerve PRV D0.03 cc < 54 (VA <60)
Temporal lobe PRV D0.03cc < 65 (T1-T2)
Temporal lobe PRV D0.03cc < 70 (T3-4)
Temporal lobe VA < 72 
Cochlea mean < 45 (VA < 55)
Eyeball mean < 35 (VA < 50 Gy)
Lens D0.03 cc <6 (VA < 15)
Pituitary D0.03 < 60 (VA < 65)

Brachial plexus PTV D.0.03 cc < 66 (VA < 70 Gy)

Parotid mean < 26 (VA V50 < 30)
Submandibular mean <35
Mandible D2% < 70 (VA < 75)

Oral cavity mean < 40 (VA < 50)

Pharyngeal constrictors mean < 45 (VA < 55)

Thyroid V50 < 60% (VA V60 < 10 cc)

Larynx mean < 30 (VA)

“WHO type now is simply keratinized or nonkeratinized. Asian types are nearly all nonkeratinized

Old WHO classification:
WHO I: squamous
WHO II: nonkeratinizing
WHO III: undifferentiated, lymphoepithelioma”

“3-yr OS 78%
(INT)

Asian:
3-yr OS 95% with induction cis/gem
(Zhang 2019)”

xerostomia, hearing loss, TLN, oral/dental complications, pituitary dysfunction, neural complications, soft tissue necrosis, osteonecrosis.

Question 3

“Nasopharynx stage IV

(nonkeratinizing)”

Answer 3

“chemo x3, then if CR or PR –>

additional chemotherapy x6 then RT to primary (no concurrent chemo)

(the trial used cisplatin 5FU, but gem-cis also seems reasonable)”