Principles of oncologic surgery Flashcards
What is the dominant therapy option for local tumour control?
surgical excision
complete surgical excision of a localised tumour cures more ptx than any other tx modality
What are the different roles of of oncologic surgery?
biopsy: diagnosis
prophylactic: prevention
definitive excision: cure
cytoreductive therapy (dirty surgical margins): “comprehensive” therapy, combined with RT/Chemo
palliative therapy: remove/relieve CS
always be clear about aims before Sx!
What are the advantages of oncological surgery?
immediate cure!
not carcinogenic
no toxic effects
not immunosuppressive
better for large masses
What are the disadvantages of oncological surgery?
local cure only (when too big or has potentially spread)
change in cosmesis
change in function (ex: amputation)
What do we need to know when planning oncological surgeries?
histological diagnosis!
extent of local dz
presence of local or distant mets
nutritional status of ptx
When is oncological surgery most successful?
if early in the course of the disease (smaller mass = easier clear margins)
first sx has best chance of success
adequate margins in 3 dimensions
Why is it important to have a successful surgery the first time?
untreated tumours have normal regional anatomy: facilitates removal
recurrent tumours may have seeded into previously non-involved tissue planes: can’t predict where tumour cells will extend so wider resection needed
most active/invasive parts of tumour at the periphery: incomplete excision leave only the most aggressive parts behind
there is less normal tissue after previous Sx: closure is more difficult
When should we biopsy?
If results would change the type or extent of the treatment plan
if results could change the owner’s mind about deciding to treat (tumour type, stage, prognosis, etc.)
if the lesion is in a “difficult area”: head and neck, distal limb
When should we not biopsy?
If results wouldn’t change the treatment plan
if results wouldn’t change the owner’s willingness to treat
if the biopsy is difficult (cns mass lesion, thyroid tumour, small intestine tumours)
What are the biopsy techniques to consider?
needle biopsy: FNA or core/tru-cut
incisional biopsy: surgical, grab or punch
excisional biopsy
What is important to consider/do during the tumour biopsy?
plan biopsy site carefully
avoid spreading tumour cells
avoid using diathermy directly on tissue
preserve in 10% formalin at a volume ratio of 10:1 (formalin:tumour)
How can we reduce contamination during oncologic surgery?
avoid entering pseudocapsule
manipulate tumour gently
isolate tumour from body cavity with laparotomy sponges
resect adhesions between tumour and normal tissue
lavage surgery site to remove blood, necrotic tissue, foreign material
change gloves and instrument to avoid seeding surgical wound
How do we manage the vessels in oncologic surgeyr?
reduction in blood flow reduces tumour embolic spread
control veins first: prevents venous emboli (could still spread via lymphatics)
control arteries first: prevents haemorrhage spread and organ congestion, reduced arterial supply = reduced venous flow
When should we remove the regional LN?
- positive for tumour and not fixed
- grossly abnormal at sx
- intimately attached to excised tissue
- if associated with therapeutic benefit
When should we not remove the regional LN?
- fixed to “critical adjacent tissue” (biopsy)
- if uncertain whether positive for tumour (biopsy)
What is a pseudocapsule?
zone of compressed tissue around the tumour
zone contains viable tumour cells
What is the technique for local/marginal excision?
tumour removed through natural capsule or immediate boundaries
What are the indications and contraindications of local/marginal excision?
indications: benign tumour and no local invasion
contraindications: local invasions, malignancy
What is the technique for wide local excision?
tumour removed with susbtancial margin of normal tissue
1cm: SCC, benign oral tumour
2-3cm: MCT, ST sarcomas
What are the indications and contraindications for wide local excision?
indications: benign tumours/local invasion, malignancy/limited local invasion
contraindications: more invasive malignancies, higher grade tumours
What is the technique of a radical excision?
margins extend into fascial planes undisturbed by tumour growth
What are the indications for radical excision?
malignancy and local invasion
What is the technique for radical local excision?
tumour removed with extensice margins of tissue including 1 or 2 fascial planes beyond gross tumour
What are the indications for radical local excision?
invasive sarcomas of the abdominal/chest wall
invasive carcinoma of the nasal planum
invasive tumours involving eyelids
invasive orbital/periorbital tumours
What is the technique for compartmental excision?
tumour removed in an intact anatomic compartment
What are the indications for compartmental excisions?
invasive tumours
What is the technique of radical amputation?
tumour removed with the entire limb
What are the indications for radical amputations?
large tumours and no other method possible
if radical excision impairs function
management of recurrences: disturbed fascial planes
