Evaluation of Diagnostic Aids Flashcards
Historically, oral cancer detection has been based on _______ _______ ______.
conventional oral examination (COE)
-visual and tactile
Nearly all cases of ______ arise from precursor epithelial changes.
OSCC
What do most cases of OSCC arise from?
precursor epithelial changes (oral epithelial dysplasia)
What is oral epithelial dysplasia?
maturational disturbances of epithelial cells
-histopathological marker of premalignancy
What proportion of the epithelium stains dark (dysplastic) in a sample of normal tissue? Mild Dysplasia? Severe dysplasia? Carcinoma in-situ?
Normal: 1/3
Mild: 1/2
Severe: 3/4
In-situ: entire thickness
True or False: Overall, COE has a good sensitivity and specificity.
True
What is the sensitivity percentage for COE? the specificity for COE?
sensitivity: 85%
specificity: 97%
True or False: Trained auxiliaries are as accurate as dental practitioners in detecting oral cancer.
True
What are three limitations of COE?
- Many common mimics of cancerous and precancerous lesions
- Cannot determine which lesions will progress to cancer
- Precancerous lesions have been found in normal mucosa
What is a “screening test?”
test used on people apparently free of disease in order to detect the disease in early stages
A ______ test is used to analyze abnormal clinical findings or symptomatic patient in order to establish or suggest dianosis.
case-finding test
Of the discussed diagnostic aids, which one is a case-finding test?
Brush Test Oral CDx (previously “brush biopsy”)
What is the indication for the Brush Test Oral CDx?
“to test the common, small, harmless-appearing white or red tissue spots” that are found on clinical examination.
True or False: The Brush Test provides a diagnosis based on cell culture.
False, does NOT provide a diagnosis. Only 1 of 4 “results”
What are the four results that are provided by Brush Test?
Incomplete Specimen (not enough cells)
Negative (no precancerous cells)
Atypical (abnormal cells)
Positive (dysplastic cells)
P.A.I.N…as in, this stuff is a pain to study
The Brush Test has recorded several false _____ results.
negative
Which of the Diagnostic Aids are “screening” tests?
- ViziLite Plus
- VELscope
- Identafi
- OralID
What are the three components of ViziLite Plus?
- 1% acetic acid (dries tissue)
- Disposable light stick
- Toluidine Blue Dye
ViZi uses “T”
True or False: TBlue Dye is very specific to dysplastic cells.
False, stains any surface abnormality (false positives)
**ViziLite is unable to discriminate normal tissue from premalignancy*
ViziLite uses ______ which is the emission of light as the result of a chemical reaction.
Chemiluminescence
What is the proposed mechanism of detection associated with chemiluminescence?
abnormal cells will have altered reflective properties. Normal cells will appear dark, Abnormal = acetowhite
_______ is a diagnostic aid that is based on the concept of tissue fluorescence.
VELscope
The VELscope emits _____light at 400-460nm and allows for direct visualization through a narrow-band filter. What color will “normal tissue” appear? What color will “abnormal tissue” appear?
blue
pale green = normal
dark = abnormal
_____ are molecules that emit energy in the form of fluorescence when excited by light. What are some examples?
Fluorophores
ex: collagen, elastin, NADH, FAD
Through the ViziLite, abnormal tissue appears ______. Through the VELscope, abnormal tissue appears ______.
ViziLite = white (lite...white) VELscope = dark
Minimal data supports the role of ViziLite as a screening tool due to its false ____.
false + (90%)
and
false - (15 cases)
In what other way might VELscope be beneficial?
allows for detection of cancer or precancer borders beyond conventional examination alone (visualizing the extend of margins for biopsy)
shows us the “scope” of the lesion
Identafi is a diagnostic aid based on ____-_____ fluorescence and reflectance _________.
multi-spectral
spectroscopy
True or False: Identafi is hand-held and cordless.
True
How many “color wavelengths” does Identafi use?
Three: white, violet, amber
Which color is used for the conventional oral exam (Identafi)?
white
What is the violet color used for (Identafi)?
for observing tissue fluorescence (abnormal mucosa appears dark)
When is the amber color used (Identafi)?
when suspected abnormalities are detected
-amber light shows reflectance and vasculature
Why is the amber light detection of vascularity questionable?
there is no magnification included (how could details possibly be seen)
True or False: The clinical application of Identifi has not been proven.
True
______ incorporates fluorescence technology with liquid-based cytology.
Oral ID
True or False: Oral ID has comparable performance to VELscope and BrushTest.
True
____% of oral cancer is diagnosed in Stage III-IV
63
What are the high risk sites for oral cancer and dysplasia?
ventro-lateral tongue
floor of mouth
lateral soft palate (anterior tonsillar pilars)
The “High Risk Zone” for oral cancer accounts for ___% of total oral surface, but ____% of cancerous lesions occur in this area.
20% of area
80% of lesions
What are the suspicious physical features that we must watch for?
- crisply defined red, white, or mixed-red-white lesions
- persistent ulceration (despite treatment)
- induration
What are the two best ways to defend against oral cancer?
- Patient education to raise awareness of oral cancer and the importance of oral examination
- careful visual and tactile examination with good judgement
