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Flashcards in 9 - Cancer and Reconstruction Deck (21)
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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
  • 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
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
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
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
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
  • Staging
    • Cutaneous
      • T1-4 based on Breslow depth
        • b - Ulceration
    • Mucosal
      • T3 - Starting point for mucosal melanoma
      • T4 - Invasion into adjacent tissue
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.
  • 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
      • E7 Protein - downregulates Rb
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
        • 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
    • More advanced stage
      • Multi-modal therapy
        • Chemoradiotherapy
        • consideration of a neck dissection
  • 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
  • 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
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
16
Q

SM-ART Technique

A

Sydney Modified - 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
      • Custom recon plate used
      • STSG taken. Silicone sheet used to cover STSG
      • Skin paddle used to cover implants
      • Buried for 6 months
    • Stage II
      • Exposure of implants and soft tissue augmentation
      • Skin paddle divided in the middle
        Sutured onto the edges of the integrated STSG to form a new buccal and lingual sulcus
  • Difference between SMART and ART
    • STSG taken
      Keratinised epithelium over implant
    • Custom recon plate used
17
Q

Zygomatic implant perforated flap

A

Zygomatic implant perforated flap
One stage procedure

  • Surgical Technique
    • Resection of tumor
    • Quad zygomas placed free hand
    • Impressions taken immediately post implant placement
    • Zygomatic implants perforate the soft tissue flap
      • Clear plastic placed under healing abutments
18
Q

Oral premalignant disorders

A
  • WHO 2017
    • Leukoplakia
    • Proliferative verrucous leukoplakia
    • Erythroleukoplakia
    • Erythroplakia
    • Smokers keratosis
    • Submucous fibrosis
    • Chronic hyperplastic candidiasis
    • Syphillitic glossitis
    • Acitnic cheilitis
    • Discoid lupus erythematosis
    • Genetic
      • Fanconic syndrome
      • Dyskeratosis congentia
      • Xeroderma pigmentosum
      • Plummer Vinson syndrome
      • Epidemolysis bullosa
      • Graft vs Host disease
19
Q

Bone Graft - Non vascularized vs Vascularized

A
  • Pogrel 1997
    • Vascularized vs Non-vascularized bone grafts
    • Non vascularized bone graft
      • <6cm : 17% failure rate
      • >12cm : 75% failure rate
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
    • 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
  • 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
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
    • Neurological
      • IA - Inferior Alveolar
      • L - Lingual
      • H - Hypoglossal
      • F - Facial
  • 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