Principles of Oncologic Surgery Flashcards
1
Q
describe biopsies
A
- help plan treatment, give tumor type and grade
- not obtaining a diagnosis with your biopsy sample is considered a surgical failure
-obtain multiple samples for histopathology to maximize chances of getting a diagnosis
2
Q
describe biopsy planning
A
- consider definitive resection before making biopsy incision
- biopsy incision must be removed at time of definitive resection because now contaminated with tumor
-rib tumor = biopsy parallel to rib
-oral tumor = biopsy directly over tumor (not through lip) - biopsy at periphery of lesion where actively dividing cells are = best chance of getting an answer
-only exception: bone tumors - lines of tension: incise parallel to these lines
-few exceptions - limbs: longitudinal incisions
- if near abdominal midline: biopsy parallel to midline
3
Q
describe biopsy types
A
- needle core biopsy (tru-cut
-smallest sample size (14-18G)
-percutaneous application - punch biopsy:
-limited to superficial lesions - incisonal:
-ideal
-large tissue samples
-sample at edge of tumor: tumor most viable at leading edge, center often necrotic (bone tumors = only exception)
-requires planning of incision site: preparation for definitive resection - excisional:
-not ideal!
–lack of pre-op planning
–histopathology results may change surgical plan
-likely lead to: incomplete excision, local recurrence, need to additional therapy - bone biopsy:
-for suspected bone tumors: submit for culture if suspect infection
-biopsy at center of lesion: periphery of lesion is reactive and nondiagnostic
-jamshidi needle-core biopsy
-michele trephine
4
Q
describe the process of a bone biopsy (6)
A
- stab incision through skin/SQ/muscle
- insert needle with stylet in place
- remove stylet
- advance needle by twisting
- break sample by rocking back and forth
- remove needle and obtain sample
5
Q
how do you determine if surgery is an option?
A
- major patient factors:
-age is not a disease!
-general health of patient
-comorbidities: osteoarthritis, CDK/CHF factors for anesthesia, paraneoplastic conditions (hypercalcemia, hypoglycemia) - surgery is not always appropriate treatment:
-ex. lymphoma - must consider if other treatment options would be better
-should they be performed before (neoadjuvant) or after surgery (adjuvant)?
-neoadjuvant therapies can shrink the tumor but may alter wound healing
-adjuvant therapies can clean up cells left behind
6
Q
how do surgery and chemotherapy affect each other?
A
- chemotherapy impedes wound healing
- typically start chemotherapy 10-14d post op (at suture removal)
- metronomic chemotherapy is of particular concern
-targets angiogenesis which is required for wound healing
7
Q
how do surgery and radiation therapy affect to each other?
A
- preoperative RT
-damages normal tissues: stem cells, blood vessels, lymphatics, resulting in decreased wound healing
-surgery can be done when acute effects have resolved (3-4 weeks later) - post-operative radiation therapy:
-typically wait until suture removal (10-14d) to start RT
8
Q
describe surgery for cancer
A
- cytoreductive:
-resection within the tumor
-goal of microscopic disease:
–intralesional
–marginal - curative intent:
-removal of tumor with margins:
–wide
–radical
9
Q
describe cytoreductive surgery
A
- incomplete removal of a tumor (debulking)
-goal is to obtain microscopic disease
-if you remove 99.9% of a 1cm volume tumor, you leave 1 million cells behind - why?
-if margins not achievable without high morbidity
-goal to enhance efficacy of other treatments (most often RT) - if planning postop RT
-radiation oncologist must know the margins of the tumor/surgical field
-the entire area touched/contaminated with surgery must be treated!!
-incision must be oriented so that RT will be possible (flat, so don’t curve over the back)
10
Q
describe the goals of curative intent surgery
A
- every effort made to get a complete excision the FIRST time
-preop biopsy is IMPERATIVE for planning - remove with adequate margins
-en bloc excision: remove abnormal and normal as one block of tissue - reconstruct: have several options in place for larger resections
- confirm diagnosis and extent of excision (histopathology)
11
Q
what MUST you know prior to curative intent surgery?
A
- histologic type, stage, and grade of the tumor
-surgery without biopsy = HIGH risk of incomplete resection
-local and systemic effects of the tumor
-is surgery appropriate/is a cure possible? - cosmetics and function after surgery
- alternative or combination treatments
-chemo or RT
12
Q
why does the first surgery have the best chance of a cure?
A
- recurrence allows seeding of previously uninvolved tissue planes
-everything you touched in surgery is then contaminated - requires wider resection the second time
- loss of normal anatomic landmarks
- less normal tissue for closure
13
Q
describe imaging and curative intent surgery
A
- imaging can be helpful!
-ID extent of tumor
-plan surgery: CT most commonly used - if distant metastasis is found, curative intent surgery is not appropriate
14
Q
describe the doses of surgery
A
- intralesional/debulking: shaving off within the tumor
-ex. oral melanoma where cannot do more - marginal: just outside the tumor, but not enough to be confident you’re getting everything
-use when cannot get margins (odd location)
-beware the sneaky pseudocapsule!
–composed of compressed normal cells and contains viable tumor cells
–not a true capsule to is NOT a barrier to tumor cells, fingerlike projections of tumor can extend beyond this pseudocapsule - wide: the goal
-MCT and soft tissue sarcoma: aim for 2-3cm laterally and 1 fascial plane deep due to local recurrence
-feline injection site sarcoma: 5 cm laterally, 2 fascial planes deep (should be referred to a specialist) - radical: amputation or remove an entire muscle belly
15
Q
describe the surgical goals of palliative surgery
A
- goal is to improve QUALITY of life
-tumor type may not be amenable to curative intent
-owner not open to amputation/radical surgery
-sometimes palliative treatment may be radical! (amputation can be palliative) - limit the morbidity of the procedure
-goal is rapid return to function
-do not want the surgery to add to the patient’s suffering
16
Q
describe histopathology
A
- if it’s important enough to remove, it’s important enough to submit!
-histopath should not be optional
-give pathologist as much info as possible! - even if mass was previously biopsied, resubmit it
-diagnosis can change with large amount of tissue to evaluate - mark margins with ink or suture for evaluation
-margin assessment for further treatment: clean margin may not require any further
-dirty margin may need more
17
Q
how to address dirty margins?
A
- second surgery:
-scar revision
-2-3cm margins around scar
-fascial plane deep
-often more difficult to achieve margins the 2nd time - adjuvant therapies: RT most common
- active surveillance:
-palpate area regularly
-monitor for recurrence
-NOT benign neglect
18
Q
describe surgeries used to stage disease
A
- abdominal masses: exploratory surgery:
-remove if resectable
-if not, biopsy: can help plan other therapies - OHE:
-prevents mammary tumors if done before first heat
-prevent ovarian and uterine tumors - removal of retained testicles:
-13x increased risk of testicular tumors of cryptorchid - mastectomy
- large mass removal
- mandibulectomy
- maxillectomy
- ear surgery:
-total ear canal ablation
-pinnectomy - amputation
-hemipelvectomy: amputation with removal of part of pelvis - limb sparing surgery: alternative to amputation
-tumor must meet specific criteria
-four options: cortical allograft, metal rod connected to plate, replace with ulna (living graft), grow new bone - total orbitectomy
- nasal planectomy
- chest wall resection
- lung lobectomy
- abdominal mass excision
creative thinking but just because it CAN be done doesn’t mean it should!
