Canadian Cancer Statistics 2013. Cancer in Canada.
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Transcript of Canadian Cancer Statistics 2013. Cancer in Canada.
Canadian Cancer Statistics 2013
Canadian Cancer Statistics 2013
Canadian Cancer Statistics 2013
Canadian Cancer Statistics 2013
Cancer in Canada
MONITORING ORGANS: Cancer
Why Use Imaging?• non-invasive way of:– Screening for cancer
• ex. mammograms for breast cancer– Diagnosing/staging
• ex. location in the body, spread, guiding a biopsy– Guiding cancer treatments
• ex. focus on the tumors and minimize damage to surrounding tissue
– Determining if a treatment is working
– Monitoring for cancer recurrence
1. Ultrasounds
• Use of sound above human hearing range to image body structures, including soft tissues
• Sounds waves are reflected (echo) off of different density tissues differently
2. X-Rays• Oldest form of imaging
• Found by German physicist Wilhelm Rontgen, 1895
• High-energy electromagnetic waves that pass through soft tissue (ex. muscle) but are absorbed by dense tissue (ex. bone)
• Can also be used to see soft tissues with the help of stains (ex. bismuth)
Most popular use:
• Dental x-rays
An aside...
Electromagnetic radiation- Forms of energy, some on the visible spectrum
(light)
• Some can be damaging to our DNA, in particular high-energy high-frequency waves (above colour spectrum)
3. CAT Scans: computerized axial tomography scan
• An X-ray machine rotates around the patient taking hundreds of individual pictures form many angles
• More sensitive than an X-ray alone
• Computer re-assembles the picture into a 3-D image, allowing for organs to be viewed section-by-section
• Full body scans are still not routinely done due to high incidence of “incidentalomas”, not real issues that show up as issues on the scan
• Known to increase chances of cancer in children…
4. MRI (Magnetic Resonance Imaging)• uses radio waves and a strong magnet
• different tissues (including tumors) emit a more or less intense signal based on their chemical makeup
• produces a three-dimensional images of sections of the body
• MRI is sometimes more sensitive than CT scans for distinguishing soft tissues.
• can use radioisotopes (unstable atoms) that are injected into the target organ for imaging
5. PET (Positron Emission Tomography)
• used to locate a tumor
• the patient is given an injection of regular sugar and a small amount of radioactively labeled sugar
• because cancer cells take up sugar more than other tissues in the body the tumor is easier to find
• large amounts of radiolabelled sugar collect at site of damage “lighting” it up
• PET scans are beginning to be used to check if a treatment is working - if tumor cells are dying they use less sugar