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