BIO 302 - Exam 2 - Cancer Diagnosis & Assessment PowerPoint pt.1 Flashcards
(32 cards)
What is a diagnosis?
Identification of the illness through a process of evaluation.
Assessment of a person with symptoms (or an abnormality found on screening).
Prognosis is a ______ ______ whereas a diagnosis is a ______ _____ (_____________).
future prediction / present fact (identification of a condition).
What is a differential diagnosis?
A working list of diseases with similar signs and symptoms.
For ______ diagnosis of cancer, ___ or ____ ______ examination is the gold standard.
definitive / histo- or cyto-pathological
What are the 6 fundamental questions of evaluation of a symptomatic patient who may have cancer?
1: Do the symptoms and risk factors raise the possibility of cancer?
#2: Is there a mass present?
#3: Is the mass cancer or not?
#4: If cancer, what type?
#5: How aggressive is it?
#6: How much cancer is present in the body?; How far has it spread??
Signs and Symptoms may point to the source of the problem but many are nonspecific
Slide 5 and 6
Cancer site implies survival differences.
Green: Nonmelanoma skin, prostate, testes
Red: Lung, esophagus, liver, pancreas
Actions in the Cancer “work-up”
Ionizing radiation
Light bulb, sun, x-ray machine, and radioactive elements
UV, X-ray and gamma rays
What is Ionizing radiation?
Any type of particle or electromagnetic wave that can transmit enough energy toionizeor knock electrons out of outer shells atoms.
Examples of ionizing radiation used in diagnosis:
______ (SFF;______;______).
______ ______from radioactive decay (______;______).
Examples used in diagnosis:
X-rays (standard flat films; CT scans; mammography)
Gammaradiationfrom radioactive decay (nuclear imaging; PET scans)
When used for Diagnosis, radiation dose is ______ and exposure ______, but there is NO exposure to ionizing radiation that is totally safe.
low / limited
What is the primary method of assessing tumor stage?
Imaging
What information do we get from imaging?
(1) Where is the tumor?
(2) How big is it?
(3) What is the 3-dimensional configuration?
(4) What are the critical adjacencies?
* Is it resectable (able to be removed by surgery)?
(5) Are metastases present?
* If so, where are they? What are their sizes?
(6) Can a biopsy be acquired?
In a Radiological assessment, how are masses detected?
C
D
I
L
N
S
S
V
Calcification
Density / stroma
Involvement of adjacent structures
Location
Number and distribution
Shape (e.g., smooth vs. irregular borders)
Size
Vascularity
What are the techniques using Ionizing radiation?
(1) Mammography (low energy x-rays)
(2) X-ray (“flat films” – 2-dimensional)
* High-energy, very short wave length (between UV and gamma rays) electromagnetic radiation passes through materials opaque to light
* Energy is differentially absorbed or blocked as it passes through
* Air is black; bone is white; soft tissues are shades of gray
(3) Computed tomography (CT scan – 3-dimensional)
* Series of x-rays taken from many different angles that are reconstructed by computer to create cross-sectional images
* “Serial sectioning” through body
What is the difference between primary and metastatic lung cancer?
Primary: Single mass & Unilateral
Metastatic: Multiple Nodules & Bilateral
What are the techniques using radioactive isotopes?
Nuclear medicine scans: Based on tissue chemistry (metabolism) and uptake of radiopharmaceutical tracers to form “hot spots”
Positron Emission Tomography (PET) scans
Medical radiation : exposures with risk for patient
CT abdomen or body
X-ray lower GI tract
X-ray upper GI tract
Mammography
Chest X-ray
Extremity X-ray
CT abdomen or body - 3 years
X-ray lower GI tract - 1.3 years
X-ray upper GI tract - 8 months
Mammography - 3 months
Chest X-ray - 10 days
Extremity X-ray - <1 day
Positron emission tomography (Pet scan)
A form of nuclear scanning with “functional imaging” capacity
Uses a positron-emitting isotope (radiotracer) with a shortdecay time, like fluorine-18, which is made in a cyclotron
For cancer: fluorine-18 isotope is attached to glucose (fluorodeoxyglucose / FDG) and used for FDG-PET imaging
Glucose is taken up by cancers with high metabolic activity
Gamma rays (ionizing high-energy photons) are emitted by positrons from the decaying radioactiveisotope and are detected by sensors that encircle the body
When combined with CT or MRI (“co-registration” of images) metabolic and anatomic information is provided
Techniques without ionizing radiation: magnetic resonance imaging (MRI)
Uses rotating magnetic fields and radio waves to create detailed images.
NO ionizing agents are used – does not cause cancer.
MRI advantages
Produces high resolution contrast among different soft tissues (CT can’t)
NO IONIZING RADIATION is involved!
No long-term side effects
MRI disadvantages
More complicated and costly instrumentation
Scan takes much longer
Very noisy (rapid on-off of gradient magnets)
Claustrophobia-inducing
Expensive (average scan = $2,611; CT is half that)
Incompatible with metallic objects in body (e.g., pacemaker, drug pumps, aneurysm clips, cochlear implants)
Ultrasound - (sonogram) - superficial penetration
Oscillating high frequency sound waves with a frequency greater than the upper limit of the human hearing range reflect off body tissues and are picked up by a handheld transducer.
