Surgical Aspects of H/N Oncology Flashcards
Epidemiological facts/figures for Oral cancer:
90% oral/OP cancer is squamous cell carcinoma
6% of cancers overall
5 year survival for oral cancer is 46%
What are the risk factors for oral cancer?
- Alcohol and cigarettes (synergistic as alcohol acts as a solvent)
- Betel use
- Poor OH
- HIV
- EBV
- HPV
- Diet
- Genetics
- Previous SCC
What sites on the oro-pharnyx are commonly affected by cancer?
Contains lymphoid tissue (affected by HPV driven disease)
- Base of tongue
- Tonsil
- Soft palate (lateral aspect)
What are the common sites for oral cancer?
- Buccal mucosa
- Retromolar trigone
- Alveolus
- Hard palate
- Ant 2/3 tongue
- FoM
- Lip mucosa (wet vermillion backwards)
What stain can be used to detect dysplasia?
Lugol’s iodine
-> non-staining areas- dysplastic field change
What other cancers are common in oral cavity?
SCC
Lymphoma
ACC
What is the management/treatment plan for patient with head and neck cancer based on?
- Best options for patient
- Degree of fitness of patient
- Co-morbidities
What is the difference between curative and palliative?
Curative- degree of cure over 5 year period
Pallaitive- unlikely to be cured but aim to control disease for sustained period
Chemo, radio, immunological, surgical
May choose to manage symptoms with analgesia and other adjuncts
What are the treatment options for oral cancer?
Surgery alone- low volume disease
Radiotherapy- OPC
Chemotherapy
Dual/triple modality treatment (may include immunotherapy)
What are the surgical options for treatment of oral cancer?
Resection and pack- remove tumour and pack (WHV, bismuth and iodiform paste, ribbon gauze)
Resection and primary closure
-> Wedge resection of tongue tumour
Resection and reconstruction
What are the flap options for reconstruction in oral cancer patients?
Local flap- rotation flap within mouth
-> Palatal
Pedicled flap- FAM
-> Facial artery myomucosal flap
Free flap- tissue from elsewhere and reimplant into blood supply of new area
-> Should withstand radiotherapy
What are the options for managing the neck?
- No staging
- Imaging- ultrasound and CT for lymphadenopathy
- Staging- sentinel node procedure (t99 with gamma camera to look for certain nodes)
- Selective neck dissection- levels 1-3/1-4
- Comprehensive neck dissection- obvious nodal disease clinically and on scanning
What can CT be used for when planning resection?
Can outline tumour in red- volumetric analysis
-> 1cm around this area we put green line to give idea of structures that may need to be removed in resection
-> If unable to get a margin- consider not doing a resection
-> Idea of surgery is to achieve clear margin
Can look at arteries, nerves etc to avoid
What are the benefits of 3D planning for reconstruction on CT?
- Model/mirror imaging to model affected side the same as other side if sizable defect likely after surgery
- Cutting guides and templates to help with resection and reconstruction if bony
Why is reconstruction of mandible necessary?
- Airway would be comprimsied if not
- Poorer swallowing- issues with hyoid
- Tracheostomy device dependent
- Aesthetic issues
How is blood supply plumbed in a free flap?
Anastomose flap to vessels in the neck (end to side or end to end)
What type of flaps can be used for tongue?
- Fasciocutaneous (arm)
- Musculocutaneous
What can tongue flapped be shaped to control?
Movement
Tethering
Why is an adequate amount of bulk required for tongue flap?
For palatal contact required to initiate swallowing in total/subtotal glossectomy
What flap is used for a total glossectomy?
Cathedral triptych- comes from leg
Produces neotongue
Skin on surface with flap underneath
What kind of flap is used for FoM?
Radial Forearm flap
What are the aims for flaps in FoM?
- Try to preserve keratinised mucosa overlying the alveolar ridge where possible (allows implants)
- Avoid entraining non-attached/NK mucosa
- Try to maintain sulcus depth where possible
What can be done for hair growing on the flap?
Lasered off
Will stop with radiotherapy
What flap is used for the buccal space?
Radial forearm
What are the aims/considerations for buccal space flaps?
- Maintain sulcus depth
- Beware of involvement of commissure- need to weigh up oral stoma/aperture size vs oral competence (issue if not small enough)
What are the options for flap in buccal region if it is through and through (external cheek skin is removed)?
2 fasciocutaneous flaps
Chimeric flap
-> difficult to avoid tight vertical blind which creates issues with space/retention of protheses
Cervicofacial- better aesthetics and skin match (not good for function)
What can be done to flap at the commissure if it is not correct thickness?
Reduce it down over time
What flaps are used for mandible?
Soft tissue quality is important:
- DCIA (hip) with int oblique- keratinises well but difficult sulcus zone
- Scapula with various skin paddles (NK)
- Fibula with skin (difficult to adapt to sulcus)
How long does bone stock from flap last after radiotherapy?
3-5 years
When is the optimum time to place implants in flap for mandible?
While the source is still in situ as normal
-> on leg etc
What flaps are used for maxilla?
- Low level maxilla require soft tissue only reconstruction
- Use of Zip flaps- zygomatic implants
- Composite flap (if bigger disease) depends on contour/bone stock
- Soft tissue DCIA with internal oblique is best
- Scapula (difficult to retain implants) with various options next then fibula with skin
What must be done for flap in maxilla to create space for prostheses?
It must be hitched up
