9 - Cancer and Reconstruction Flashcards
1
Q
Diagnostics aids in dysplastic lesions
A
- Chemical
- Lugols iodine
- Sugar attached to iodine
- Metabolically active areas will use up sugar and appear white
- Toluidine blue
- Stains acidic tissue components
- Affinity for tissues rich in DNA and RNA
- Poor PPV
- Lugols iodine
- Light based detection
- Vizilite (Chemiluminescence)
- Acetic acid mouthwash - to remove glycoprotein barrier
- Blue light
- Normal tissue - Blue colour
- Abnormal tissue with high nucleus to cytoplasmic ratio - Reflects light back and appears white
- Immunofluorescence
- Velscope
- Blue light shown into the mouth
- Normal tissue and excites the tissue causing it to fluoresce
- Abnormal tissue appear black
- Tissue fluorescence spectroscopy
- Small optical fibre produces various excitation wavelengths and maps out area of dysplasia
- Limited to small lesions
- Velscope
- Vizilite (Chemiluminescence)
2
Q
Free Flaps
A
3
Q
Indications for pre radiotherapy extractions
A
- Ben David 2007
- Teeth with unrestorable caries
- Caries extending to gingival margins
- Large compromised restorations with pocketing >5mm
- Periodontal disease
- Mobile teeth
- Significant pocketing
- Advanced recession or furcation involvement
- Severe erosion or abrasion
- Non functional teeth
- Primary closure and alveoloplasty
4
Q
Melanoma Dermatoscopy
A
- Dermatoscopy Clinical Findings
- Irregular borders
- Pseudopods
- Radial streaming
- Scar like depigmentation
- Heterogeneity in colour
- Irregular vascularity
5
Q
Melanoma Management
A
- Sentinel lymph node biopsy
- MSLT II Trial
- Most patients only have one small positive node (~80%)
- No difference between SLB and Completion neck dissection
- CND slightly improves 3 yr Disease free survival but not Melanoma specific survival
- If melanoma has metastasized to more than one node - Prognosis is not changed by doing a neck dissection
- AJCC - Recommends ND in up to Stage III disease
- MSLT II Trial
6
Q
Melanoma Pathophysiology
A
- Radial Growth Phase
- Lower risk phase
- Nodular melanoma does not have this phase
- Vertical Growth Phase
- Risk based phase
- Based on Breslow Depth
- Mutations
- BRAF
- cKIT - Mucosal melanoma
7
Q
Melanoma Risk Factors
A
- Risk Factors
- Epidemiology
- Male
- Age > 50
- History
- Family Hx
- Personal Hx of melanoma or other skin cancer
- Immunosuppression
- Genetics
- Fitzpatrick I or II
- CDKN2A mutation - Involved in Rb
- Syndromes
- Dysplastic naevus syndrome
- Basal cell naevus syndrome
- Xeroderma pigmentosum
- Epidemiology
8
Q
Melanoma Staging
A
- Breslow Depth
Used by AJCC as a prognostic factor in staging melanoma
Measurement of the depth of invasion of melanoma- Stage I - <1mm
- Stage II - 1-2mm
- Stage III - 2.1 - 4mm
- Stage IV - >4mm
- Clarks Level
Describes the depth of the melanoma based on anatomical regions- Level I - Epidermis
- Level II - Papillary dermis
- Level III - Papillary and Reticular dermis interface
- Level IV - Reticular dermis
- Level V - Subcut fat
9
Q
Melanoma Types
A
- Melanoma Types
- Superficial spreading
- Most common - 70%
- Irregular pigmented macule
- Grows radially then vertically
- Nodular - 15%
- Aggressive tumor
- Invasive vertical growth pattern
- 50% hypomelanotic
- Acral lentiginous 5%
- Palms, sole, nail beds
- Tends to occur in dark skinned people
- Desmoplastic
- Rare
- Appears like a scar
- Mucosal melanoma
- Very rare
- Aggressive with poor prognosis
- Superficial spreading
10
Q
Melanoma Workup and Staging
A
- Workup
- Biopsy
- Excisional biopsy with a 2-3mm
- Incisonal biopsy if anatomically challenging or large size
- Incisional biopsy where there is a low index of suspicion
- Immunohistochemistry staining
- HMB45
- S-100
- Melan-A
- Biopsy
- Staging
- Cutaneous
- T1-4 based on Breslow depth
- b - Ulceration
- T1-4 based on Breslow depth
- Mucosal
- T3 - Starting point for mucosal melanoma
- T4 - Invasion into adjacent tissue
- Cutaneous
11
Q
Multistage Carcinogenesis Steps
A
- Initiation
- Promotion
- Conversion
- Progression
- Initiation
- Initial damage to DNA by a carcinogen
- Causes either the activation of a Proto-oncogene or inactivation of a Tumor-suppressor gene
- Promotion
- Selective clonal expansion of “initiated” cell
- Tumor promotors are generally not mutagenic or carcinogenic. They act by reducing the latency period between mitosis
Agents capacble of both tumor initiation and promotion are known as complete carcinogens
- Conversion
- Transformation of a pre-neoplastic cell into one that expresses the malignant phenotype.
- Transformation of a pre-neoplastic cell into one that expresses the malignant phenotype.
- Progression
- Expression of malignant phenotype and invading into adjacent tissue and metastasising
12
Q
OPSCC Epidemiology, Risk Factors & Pathophysiology
A
- Epidemiology
- M:F - 3:1
- Younger median age at diagnosis
- HPV responsibility for ~70% of OPSCC
- Risk Factors
- Male
- High SES
- Caucasians > Blacks
- Increased sexual partners
- <60 yrs of age
- Pathophysiology
- Preference for Oro pharynx theories
- Tonsillar crypts trap saliva - more time for HPV to access basement cells
- Transitional epithelium like cervix
- HPV exerts its actions via inactivation of:
- E6 Protein - downregulates p53
- As a result of p53 being downregulated
p16 is upregulated - p16 is used as a surrogate marker of HPV infection
- As a result of p53 being downregulated
- E7 Protein - downregulates Rb
- E6 Protein - downregulates p53
- Preference for Oro pharynx theories
13
Q
OPSCC Prognosis and Management
A
- Prognosis
p16 +ve OPSCC tends to have a better prognosis compared to p16-ve SCC- HPV +ve tumours habour fewer or different genetic mutations
- More sensitive to radiation
- Likely due to intact apoptotic response
- Absence of field cancerisation
- Immunologic response may play a role due to recognition of viral antigens
- Younger age group
- Better performance status
- Fewer comorbidities
- Management
- (T1 or T2) + N0
- Single modality - Radiotherapy or Surgery
Surgery preferred due to morbidity- Indications
- NCCN 2016 guidelines
- Preferred over XRT alone in localised resectable disease
- Fat plane present between tumour and pharynx
- Bulky disease
- Better disease control and lower locoregional recurrence rate
- Less morbidity especially swallowing
- Neck dissection provides prognostic information that directs adjuvant treatment
- NCCN 2016 guidelines
- Surgical modalities
- CO2 laser with direct laryngoscopy
- Tumor randomly cut out to reduce bulk
- TORS (Transoral robotic surgery)
- Limited to T1 and T2 tumors
- Tumor resected systematically
- Lip split mandibulotomy
- Open surgery
- CO2 laser with direct laryngoscopy
- Indications
- Single modality - Radiotherapy or Surgery
- More advanced stage
- Multi-modal therapy
- Chemoradiotherapy
- consideration of a neck dissection
- Multi-modal therapy
- (T1 or T2) + N0
- Survival
- Stage I - 90%
- Stage II - 70%
- Stage III - 50%
14
Q
Alberta Reconstructive Technique
A
Alberta Reconstructive Technique
- Surgical Technique
Two stage surgical procedure- Stage I
- VSP planned
- Fibula exposed
- Implants inserted into fibula with guides prior to osteotomy
- Occlusal template used intra-orally to ensure fibula segments are aligned properly prior to fixation onto plate
- Skin paddle used to cover implants
- Buried for 6 months
- Stage II
- Exposure of implants and soft tissue augmentation
- Exposure of implants and soft tissue augmentation
- Stage I
- Differences betwen ART and Rohner
- ART - does not have keratinised epithelium
- ART can be considered a one stage procedure
- ART has shorter time between VSP planning and resection of tumor
- Outcomes
- Cheaper than standard technique
Money saved on multiple review appt and pros cost due to improper placement of implants - 96% of implants utilized in ART
83% of implants utilized in Standard Technique - Shorter time to dental rehab with ART
- Cheaper than standard technique
15
Q
Rohner Technique
A
Rohner 2003
- Surgical Technique
Two surgical stage procedure- Stage I
- Implants inserted into fibula
- Impressions taken at this stage
- STSG onto periosteum with Goretex membrane over STSG
- 4-6 week healing prior to free flap harvest
- Anticoagulation given between the two procedures
- Prosthesis constructed prior to the second procedure
- Stage II
- Cutting guide used to osteotomize fibula into predetermined segments
- Prosthesis used as guide for stabilisation of fibula segments
Prosthesis placed onto implants and secured in IMF
- 95% Success rate of implants
- Stage I
20
Q
Defects - Maxilla Classification
A
- Classification can be broken down into defect based classification and rehabilitation based classification
- Defect based classification
- Browns 2010
- Vertical/Esthetic
- I - Alveolus
- II - Alveolus + Infrastructure maxilla
- III - Alveolus + Orbital floor
- IV - Alveolus + Orbital floor + Orbital contents
- V - Orbitomaxillary defect
- VI - Nasomaxillary defect
- Horizontal/Functional
- A - Palatal defect only
- B - Less than 1/2 unilateral
- C - Anterior defect, less than 1/2
- D - Greater than 1/2
- Vertical/Esthetic
- Cordeiro 2000
Based on the maxilla having 6 walls- I - Limited maxillectomy - 1 or 2 walls resected
- II - Subtotal maxillectomy - Resection of the lower 5 walls maxillary arch, palate, ant and lateral walls with preservation of orbital floor
- III - Total maxillectomy - Resection of all 6 walls of the maxilla
- a - Preservation of orbital contents
- b - Exenteration of orbital contents
- IV - Orbitomaxillecomy - Resection of the upper 5 walls with preservation of the palate
- Browns 2010
- Rehabilitation Classifications
Based on whether obturator is able to be supported- Okay Classification
- Ia - Defects that involve hard palatel but not the tooth-bearing alveolus
- Ib - Defects that involve any part of the maxillary alveolus and dentition posterior to the canines or involving the pre-maxilla
- II - Defects that involve any portion of the tooth-bearing alveolus but include only 1 canine
Anterior palatectomy that involved less than one half of the palate - III - Defects that involved any portion of tooth-bearing maxillary alveolus and includes both canines, total palatectomy and anterior transverse palatectomy that involve >50% of the palate surface
- Subclass
- f - Defects including inferior orbital rim
- z - Defects involving the zygoma
- Ohngren’s Line
- Line that connects from the ipsilateral medial canthus to the ipsilateral angle of the mandible
- Suprastructure - Above Ohngren’s line
Lesions arising from above this line carry a worse prognosis - Infrastructure - Below Ohngren’s line
Lesions below this line can be obturated
- Suprastructure - Above Ohngren’s line
- Line that connects from the ipsilateral medial canthus to the ipsilateral angle of the mandible
- Okay Classification
21
Q
Defects - Mandible Classification
A
- Browns Classification
- I - Lateral not including canine or condyle
- II - Hemimandibulectomy - Including ipsilateral canine
- III - Anterior defect - Bilateral canines but not angles
- IV - Extensive anterior defect - Bilateral canines and bilateral angles
- c - Denotes the resection of a condyle
- Urken’s Classification
Different permutations used to describe defect- Bone
- C - Condyle
- R - Ramus & Angle
- B - Body
- S - Symphysis
- SH - Hemi-symphysis
- Soft Tissue
- Mucosa
- L - Labial
- B - Buccal
- SP - Soft Palate
- FOM - Floor of Mouth
- T - Tongue
- C - Cutaneous
- Mucosa
- Neurological
- IA - Inferior Alveolar
- L - Lingual
- H - Hypoglossal
- F - Facial
- Bone
- Jewer’s Classification
Different permutations of HCL is used to described the defect- H - Hemi - Lateral defect including the condyle but not including canines
- L - Lateral - Lateral defect not including condyle or canine
- C - Central - Central defect including bilateral canines
