diagnostic aids in oral cancer

DIAGNOSTIC AIDS IN ORAL CANCER

From where diagnosis starts..???

Diagnosis starts from the proper clinical examination.. clinician should able to predict the

diagnosis at the end of clinical examination.

Confirmatory diagnosis made from various diagnostic aids done in laboratory.

Clinical diagnostic aids

Vital tissue staining

TOLUIDINE BLUE STAINING

LUGOL’S IODINE

ACETIC ACID STAINING

BIOPSY ORAL BRUSH BIOPSY

FNAC

INCISIONAL BIOPSY

EXCISIONAL BIOPSY

EXFOLIATIVE BIOPSY

COLPOSCOPY ORAL DIRECT MICROSCOPY

LABARATORY DIAGNOSTIC AIDS

COMPUTED TOMOGRAPHY

POSITRON EMISSION TOMOGRAPHY

ULTRASOUNDS

MAGNETIC RESONANCE IMAGING

NUCLEAR IMAGING

RECENT ADVANCES

AUTO FLUORESCENCE

VELSCOPE

CHEMILUMINESCENCE

VIZILITE MICROLUX DL

NUCLEAR MEDICINE (BONE SCAN)

BASIC MEASURES OF ACCURACY OF DIAGNOSTIC TEST

SENSITIVITY

SPECIFICITY

POSITIVE PREDICTIVE VALUE(PPV)

NEGATIVE PREDICTIVE VALUE(NPV)

SENSITIVITY - The probability that someone who has the target disease will

generate a positive result.

SPECIFICITY - The probability that someone who does not have the target disease will generate a negative test

finding.

POSITIVE PREDICTIVE VALUE(PPV)- The probability that a person with positive test results actually has a the target disease.

NEGATIVE PREDICTIVE VALUE(NPV)- The probability that a person with negative test results doesn’t have the disease.

CLINICAL EXAMINATION

It’s has long been the standard method for oral cancer screening

INSPECTION

PALPATION

VITAL TISSUE STAINING

TOLUIDINE BLUE STAININGToluidine blue (tolonium chloride) is a

vital METACHROMATIC DYE that stains nucleic acids and abnormal tissues.

It has been used for decades as an aid to the identification of mucosal abnormalities of the oral cavity.

It demarcates the extent of lesion prior to excision.

RINSE ORAL

CAVITY WITH

WATER

METHOD

RINSE WITH 1./.

TOLUDINE BLUE OR DIRECT APPLN

RINSE AGAIN WITH

WATER RINSE WITH 1./. ACETIC ACID or DIRECT APPLN

OBSER FOR

DARKLY STAINED AREAS

Toluidine blue staining

ADVANTAGES• Helps to determine the extend of

biopsy site.• Easy to perform.• Non invasive.• Inexpensive.• Helps to monitor treated cancer

patients for recurrence.• Sensitivity of 72-100%• Specificity of 45-93%

DISADVANTAGES• Not recommended for patients with physical

or mental disability.

• Acetic acid may irritate the mucosa.

• Equivocal dye retention.

• Variable mode of application.

• 30% false positive results noted.

LUGOL’S IODINE Lugol’s iodine consists of iodine , potassium

iodide and distilled water in contrast to TB.

Lugol’s iodine is retained in normal squamous epithelial cells but not in dysplastic or malignant epithelial cells of the cervix.

Lugol’s iodine solution produces a brown black stain by reaction of the iodine with glycogen.

Normal mucosa contains higher amount of glycogen than abnormal mucosa and produces brown black stain.

Lugols iodine staining in buccal mucosa.

ACETIC ACID STAININGClinical application of 5% acetic acid:

A piece of gauze soaked with 5% acetic acid is applied to cleaned and dried lesion

for 60 seconds.

After the gauze was removed , the lesion was photographed again.

The investigator noted the characteristic of any changes.

A positive finding was designated as a lesion that changed colour to opaque white,

while a negative finding was a lesion that showed no change or changed to

transparent white as found in leukoedema

Acetic acid staining in later border of tongue

ORAL BRUSH BIOPSY In this technique ,oral cells can be obtained

by different physical systems of scraping the surface of mucosa , by rinsing the oral cavity or even by taking a sample of saliva from the patients.

Oral brush biopsy kit consists of OBB instrument , pre-coded glass slide , matching test, requisition form, alcohol/poly ethylene glycol fixative pouch in a pre – addressed container in which to submit the contents.

The coded test requisition form including demographic data such as patient’s age, sex and history of tobacco and alcohol use as well as the location , clinical description and category (class I or class II )of oral lesions.

Oral brush biopsy

All oral CDA slides were stained in accordance with a modified papanicolau method.

Stained slides then were scanned by the OralCDX computer system which consists of a neural- network based image processing system specifically designed to detect oral epithelial pre-cancerous and cancerous cells.

ADVANTAGES It has been shown that a brush is an adequate instrument due to its ease in sampling and to the quality

of oral cytologic sample.

Brush biopsy is a simple ,relatively inexpensive ,highly sensitive ,risk

free method of screening for cancer

LIMITATIONS• The existence of false

positives have been pointed out showing high sensitivity

(90%) and low specificity (3%).

APPLICATIONS• Detection of innocuous appearing but

persisting mucosal lesions .

• Alternate for assessing lesions in patients who refuse scalpel biopsy.

• Oral candidiasis, epithelial infections due to Epstein-bar virus and herpes virus.

COMPUTED TOMOGRAPHY

• CT or CAT ( Co-axial Tomography) can provide images of great diagnostic quality and usefulness.

• It could be described as a series of X-rays ,each one a view of 3mm section of the area being scanned.

• It is only able to detect the actual masses and still a biopsy is required to verify whether that mass is malignant.

HOW IS CT USED IN CANCER?

• To detect abnormal growth

• To help diagnose the presence of tumour.

• To provide information about the stage of cancer.

• To determine whether a cancer is responding to treatment.

• To detect recurrence of tumour.

• To help plan external-beam therapy or surgery

Combination of PET and CT

• To detect structure and function simultaneously.

• Greater detail with high level of accuracy; because both scans are performed at one time without the patient having to change positions, there is less room for error.

• Greater convenience for the patient who undergoes two exams (CT & PET )at one sitting.

Magnetic resonance imaging

PET• POSITRON EMISSION TOMOGRAPHY

{PET} is a nuclear medical imaging technique which produces three dimensional image of functional

processes in the body.

• It measures the metabolic activity of cells in the human body.

MAGNETIC RESONANCE IMAGING• MRI provides accurate view of the affected

area.• It is a procedure in which pictures are

created using magnetic and radio frequencies linked to a computer imaging system.

• The hydrogen atoms in the body reacts to the magnetic field and emits signals that are analysed by a computer to produce detailed images of organs and structures in the body.

• Occasionally a dye is injected into the blood stream during scanning to bring greater detail to the soft tissue areas of the scan.

• Again this procedure is only able to detect the actual presence of masses, and it still requires a biopsy for confirmation.

HOW DOES IT WORK..???

• A short lived radioactive tracer isotope , is injected into living subject (usually in to blood circulation). The tracer is chemically incorporated into a biologically active molecule.

• There is a waiting period while the active molecule becomes in concentrated in tissues of interest.

• As the radioisotope undergoes positron emission decay, It emits a positron .an antiparticle of electron with opposite charge.

• After travelling up to a few millimetres the positron encounter an electron.

• The encounter annihilates them both producing a pair of (gamma) photon moving in opposite directions.

• These are detected when they reach scintillator in the scanning device creating a burst of light which is detected by photomultiplier tubes.

• The technician can then create an image of the parts of your overactive.

ORAL SQUAMOUS CELL CARCINOMA

OSCC METASTASIS IN LUNGS

USES• TO DETECT CANCER.

• TO DETERMINE METASTASIS.

• TO DETERMINE PROGNOSIS OF CANCER TREATMENT.

• TO DETERMINE BLOOD FLOW TO THE HEART MUSCLE.

• EVALUVATE BRAIN ABNORMALITIES SUCH AS TUMOUR,MEOMERY DISORDER,SEIZURES…

• IN NEUROLGICAL DISORDERS.

• ALZHEIMER’S DISEASE.

TRACER USED IN PET

• Radioisotopes used in PET scans are isotopes of carbon, nitrogen, oxygen, gallium and 18F used as a substitute of hydrogen.

• Only radioactive forms of natural elements that will pass safely through your body and be detected by scanner.

BENEFITS OF PET SCAN• The information provided by the nuclear

medicine examinations is unique and unattainable using other imaging procedures.

• Nuclear medicine is less expensive and may yield more precise information than explanatory surgery.

• By identifying the changes in the body at cellular level ,PET imaging may detect early onset of disease before it is evident on other tests such as CT or MRI.

LIMITATIONS IN PET

Time consuming.

The Resolution of structures of the body with nuclear medicine may not be as clear as with other imaging techniques such as

CT or MRI.

PET scan give false results if chemical balance within the body are not normal.

VELSCOPE• Velscope is a portable device that allows for

direct visualization of oral cavity.

• It is being marketed for use in oral cancer screening.

• It follows the principles of fluorescence imaging.

• This technology stimulates epithelial cells and stroma by a blue light (400 – 460 nm).

• It is a self fluorescence of the tissues that allows detection of changes in morphology and composition of tissues in a non-evasive manner.

• It does not diagnose oral cancer, its just an adjunct to oral examination.

VIZILITE• Vizilite is not a diagnostic tool.

• It is a screening device that allows the clinician to more easily visualize suspicious lesions.

• Vizilite kit contains chemiluminescent device,30 ml acetic acid and light stick holder/retractor.

PROCEDURESTEPS :

Patient rinses with 1 % acetic acid for 1 minute.

Activate device by bending outer capsule to break inner vial.

Shake capsule to mix contents. Insert capsule into retractor unit.

Dim room lighting. Visually inspect oral cavity using

device. Discard materials.

HOW IT WORKS ?

Normal epithelium absorbs the light and appears dark.Abnormal tissues reflects light and appears bright white.`

Thank you