Head and Neck Cancer

1
Head and Neck Cancer
Contouring Session
2
We knew how to treat head and cancers in the 2D
era
3
What changed in the world of 3D

• Now we can see the tumor and involved nodes
• The isodoses especially with IMRT will follow
  what weve drawn
• The responsibly of the Radiation Oncologist
  increases tremendously
• No hiding behind the standard field recipes

4
Two basic approaches

• Strict following of ICRU concepts
• GTV
• CTV
• PTV
• Im a doctor - I know best
• Go straight for PTV

5
The case for this session

• 52 year old man, teacher, non smoker
• Presents with Lt sided neck mass 3cm in size
• FNA - squamous cell carcinoma
• ENT examination
• tumour on the Lt base of tongue - post 1/3 only
• extending
• close but not over the midline
• on the lat pharyngeal wall
• onto the tonsillar fossa
• biopsy - SCC

6
The case for this session - 2

• MRI and head and neck
• Lesion on the posterior tongue
• Involving the deep tongue muscles
• Extending on the tonsil, lat pharyng. wall
• 3 lymph nodes involved on the neck (level 2 and
  3)
• For combined modality treatment
  chemotherapy/radiotherapy

7
GTV

• What you see or know about the primary and nodes
• Tumour
• base of tongue
• tonsillar fossa
• lateral pharyngeal wall
• Involved nodes
• Lt side of the neck - level 2 3
• No need for any margins
• Dose aim 66-70Gy in 30-35 fractions

8
GTV
9
CTV

• All areas potentially involved by the tumour
• around primary
• nodal areas
• There is element of judgement
• exactly the opposite is true for GTV
• The risk of involvement is not the same for the
  different areas

10
High risk CTV

• Immediate vicinity of the primary tumour 1-2cm
• The nodal areas on the involved side of the neck
• Dose aim 60Gy in 30 fractions

11
High risk CVT
CTV
12
Low risk CTV

• Nodal groups on the contralateral side of the
  neck
• If bilateral neck nodes are present the
  contralateral neck is considered high risk CTV
• Zone around the primary further away from the
  actual GTV
• Usual prescribed dose 50-56Gy in 25-28
• The retrostyloid space on the contralateral side
  is usually outside of the low risk CTV

13
(No Transcript)
14
The parapharyngeal space and constrictor muscles

• Damage of constrictor muscles is related to
  swallowing problems
• Frequent reason for hypopharynx stenosis or
  dysfunction

15
Parapharyngeal nodes
Lateral Paraphryngeal Node
Tumor
Medial Paraphryngeal Node
16
Retrostyloid space

• Anatomically area on the neck above the level
  where the digastric muscle crosses the jugular
  vein
• Radiologically above the transverse processus of
  C1
• Not including it in volume allows excellent
  sparing of the parotid
• Only feasible if the neck nodes are not involved
  on that side

17
Retrostyloid space