Oropharynx

Question 1

What is the 3y OS for stage III/IV p16 positive and negative disease?

Answer 1

P16 +. 82%

P16 -ve 57%

Question 2

What are the first echelon nodes draining the oropharynx?

Answer 2

Level 2

Question 3

What percentage present with involved nodes?

Answer 3

60-80%

Question 4

What is the difference in T staging between p16 positive and negative oropharyngeal cancers?

Answer 4

T1-3 the same;

T1 <=2cm
T2 2-4cm
T3 >4cm or spread to lingual surface of epiglottis

T4 is split into a&b for p16 negative and all one group for p16 positive.

T4. Spread to nearby structures (larynx, mandible, extrinsic structures)

T4a. Invades; larynx, extrinsic muscles of tongue (except palatoglossus), medial pterygoid muscle, hard palate, mandible

T4b invades lateral pterygoid muscle, pterygoid plates, lateral nasopharyngeal, base of skull, carotid arteries

Question 5

What is the nodal staging for p16+ disease?

Answer 5

N1 ipsilateral LNs <=6cm

N2 contralateral or bilateral LNs <=6cm

N3 LN >6cm

Question 6

Describe the stage groups (TNM)

Answer 6

Stage I. T0-T2 N0-1 M0
Stage II T0-2 N2 M0 or T3 N0-2 M0
Stage III T0-4 N3 M0 or T4 N0-3 M0
Stage IV M1 disease

Question 7

How would you treat stage 1 or 2 disease?

Answer 7

Single modality.

Transoral surgery and neck dissection or XRT have comparable outcomes but XRT preferred for organ preservation

Question 8

How would you treat stage III/IV?

Answer 8

Chemoradiotherapy

66Gy in 30# over 6 weeks with cisplatin 100mg/m2 week 1&4

Question 9

What nodal levels would you treat in a node negative patient?

Answer 9

II - IVa

Ipsilateral if well lateralised (tumour confined to tonsillitis fossa or extending into soft palate or adjacent tongue base by <1cm

Bilateral if >1cm or midline structure

Question 10

What nodal levels would you treat in a node positive patient?

Answer 10

1b-Vb,
ipsilateral VIIa if posterior pharyngeal wall involved
VIIb if level II involved
SCF if level IVa or Vb

Ipsilateral if well lateralised
Bilateral if not

Question 11

Why has there been a rise in the incidence of oropharyngeal cancers?

Answer 11

Due to rising HPV infections

Question 12

How would you investigate a patient presenting with sore throat and otalgia?

Answer 12

Flexible direct endoscopy of upper aerodigestive tract
If oropharyngeal
MRI with contrast
CT neck and chest & upper abdomen
Possible PET if difficult staging
Biopsy under local or general anaesthetic

Question 13

What imaging is recommended after chemo radiotherapy?

Answer 13

PET scan at 3 months post treatment

Question 14

What is the rate of gastrostomy tube 2 years post chemoradiotherapy?

Answer 14

14%

Question 15

What did the PET Neck trial show with regards to management for pts with N2 or 3 disease?

Answer 15

Neck dissection only carried out post chemoradiotherapy if residual abnormal or equivocal nodes on PET 10-12 weeks after the end of chemoradiotherapy.

Question 16

When is post operative chemoradiotherapy indicated over PORT alone?

Answer 16

Patients aged <70y who have involved (<1mm) margins or extracapsular extension.

Question 17

What dose is given to the high risk areas and what dose to the elective areas (XRT)?

Answer 17

66Gy/30#

54Gy/30#

Question 18

What should be done pre-treatment?

Answer 18

Dietician, SALT, smoking cessation, dental referrals

NMGFR & audiometry if cisplatin

Question 19

What chemotherapy is given in CRT?

Answer 19

Cisplatin 100mg/m2 week 1&4

gFR >60

Question 20

What is the benefit of adding chemotherapy to XRT in T3/4 or N+ disease?

Answer 20

6.5% OS benefit at 5y

Question 21

Describe GTV/CTV margins

Answer 21

HDCTV = GTV + 5mm
Elective CTV = GTV +1cm and
Nodal levels 2-4 in N0, 1b-5 & 7a in N+

Question 22

Describe your XRT set up

Answer 22

Supine in 5 point shell, IV contrast CT.
VMAT
If skin involvement on nodes use bolus