Nasopharynx

Question 1

what is the lining made up of

Answer 1

ciliated columnar epithelium

Question 2

what level is it at

Answer 2

soft palate level

Question 3

what connects the naso to the middle ear

Answer 3

estachian tube which equalizes pressure between the inner and outer ear, maintaining balance

Question 4

what is the nasopharynx role

Answer 4

equalizes pressure between the inner and outer ear, enabling balance, warms and humidifies air

Question 5

what are the pharyngeal tonsils

Answer 5

they are lymphoid tissue which has a immune response role, once these are removed people are more prone to infection

Question 6

what is the epidemiology

Answer 6

40-60
3:1 [m:f]
high incidence in SE asia

Question 7

aetiology

Answer 7

chronic nasal infection
exposure to nitrosamines + polycyclic hydrocarbons
genetics: human leukocytes antigen (HLA) gene, 3 HLA allele (variations)
poor nasopharyngeal ventilation
smoking + curing fish
chronic nasal infection
EPV

Question 8

pathology

Answer 8

salivary adenocarcinomas
melanoma
adenoid cystic carcinoma
SCC [rapid growth, invasive]
sarcomas
lymphomas - adenoids + pharyngeal tonsils

Question 9

spread types

Answer 9

direct and lymphatic

Question 10

direct spread

Answer 10

surrounding bony anatomy + soft tissue
orbit, NC, PNS, cribiform plate, auditory tube, base of skull, upper C vertebrae

Question 11

what is the lymphatic spread

Answer 11

retropharyngeal + cervical nodes
[70% have occult or overt lymph involvement]

Question 12

what differentiation do they tend to be

Answer 12

well differentiated or anaplastic

Question 13

what is N1

Answer 13

unilateral mets in cervical LN and/or unilateral/bilateral met in retropharyngeal < 6cms above caudal border of the cricoid cartilage

Question 14

what is N2

Answer 14

bilat LN < 6cm above caudal border of cricoid cartilage

Question 15

what is N3

Answer 15

any LN> 6cm and/or extension below caudal border of cricoid cartilage

Question 16

what is the role of surgery

Answer 16

remove residual LN
limited role
biopsy
salvage therapy for recurrent disease [debulk]

Question 17

what are the investigations

Answer 17

blood test: FBC, U&E, LFT, serum tumour marker [EBV-DNA]
biopsy: US guided FNA
dental review: condition of teeth, unhealthy teeth need to be removed
examination under GA: nasopharyngoscopy, biopsy of primary, access nasopharynx difficult, determines site, mucosal limits
radiography: plain chest x-ray, MRI preferred due to better soft tissue differentiation

Question 18

what is important to identify weight changes

Answer 18

SSD

Question 19

what are the OARS

Answer 19

eye and bilateral lens
temporal lobe
brainstem
cochlea
optic nerve
optic chiasm
pituitary gland
parotid
spinal cord

Question 20

what pathology is RT for

Answer 20

SCC and lymphomas

Question 21

what is the GTV

Answer 21

the tumour itself [high dose], with a margin of 5mm

Question 22

what differs from the standard position

Answer 22

the head rest differs allows for neck extension to avoid OARs

Question 23

state the CTVs

Answer 23

CTV = includes areas of spread
CTV 1 = primary + involved nodes
CTV 2 = any potential spread
CTV 3 = may be required

Question 24

what is IGRT

Answer 24

real time imaging, uses IMRT
checks patient position

Question 25

IMRT

Answer 25

5-7 equally spaced beams
beam shape around the SC
SIB or SMART = locally advanced disease, deliver different doses to CTV
inverse
better conformity

Question 26

what is the PTV dose

Answer 26

PTV 1 = 65Gy in 30
PTV 2 = 54Gy in 30

Question 27

what are the SE

Answer 27

standard ones +
increased dental cavities
ottis media = fibrosis of the auditory tube (dizziness, temporary hearing loss)
dry mouth

Question 28

chemo

Answer 28

cisplatin
neo, con, adj
IIB-IV = concurrent chemo
3 induction cycles followed by RT, weekly or three weekly
bleomycin = pulmonary toxic + cardio toxic
epiribucin = hair loss
cetuximab = toxic

Question 29

prognosis

Answer 29

dependent on LN level
T1 = 65-100
T4 = 5-40
better in women and younger people