Nasopharynx Flashcards
what is the lining made up of
ciliated columnar epithelium
what level is it at
soft palate level
what connects the naso to the middle ear
estachian tube which equalizes pressure between the inner and outer ear, maintaining balance
what is the nasopharynx role
equalizes pressure between the inner and outer ear, enabling balance, warms and humidifies air
what are the pharyngeal tonsils
they are lymphoid tissue which has a immune response role, once these are removed people are more prone to infection
what is the epidemiology
40-60
3:1 [m:f]
high incidence in SE asia
aetiology
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
pathology
salivary adenocarcinomas
melanoma
adenoid cystic carcinoma
SCC [rapid growth, invasive]
sarcomas
lymphomas - adenoids + pharyngeal tonsils
spread types
direct and lymphatic
direct spread
surrounding bony anatomy + soft tissue
orbit, NC, PNS, cribiform plate, auditory tube, base of skull, upper C vertebrae
what is the lymphatic spread
retropharyngeal + cervical nodes
[70% have occult or overt lymph involvement]
what differentiation do they tend to be
well differentiated or anaplastic
what is N1
unilateral mets in cervical LN and/or unilateral/bilateral met in retropharyngeal < 6cms above caudal border of the cricoid cartilage
what is N2
bilat LN < 6cm above caudal border of cricoid cartilage
what is N3
any LN> 6cm and/or extension below caudal border of cricoid cartilage
what is the role of surgery
remove residual LN
limited role
biopsy
salvage therapy for recurrent disease [debulk]
what are the investigations
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
what is important to identify weight changes
SSD
what are the OARS
eye and bilateral lens
temporal lobe
brainstem
cochlea
optic nerve
optic chiasm
pituitary gland
parotid
spinal cord
what pathology is RT for
SCC and lymphomas
what is the GTV
the tumour itself [high dose], with a margin of 5mm
what differs from the standard position
the head rest differs allows for neck extension to avoid OARs
state the CTVs
CTV = includes areas of spread
CTV 1 = primary + involved nodes
CTV 2 = any potential spread
CTV 3 = may be required
what is IGRT
real time imaging, uses IMRT
checks patient position
