Imaging in cancer

Question 1

when is a barium swallow imaging technique used? AND EXAMPLE

Answer 1

only if patient can’t undergo endoscopy i.e esophageal cancer
-rarely used in real practice

Question 2

Barium info

Answer 2

doesn’t react with the body
is excreted safely
xray beams can’t pass through Barium atoms due to high atomic number
appears white in standard xray
but in other scans it can appear black or white
can do barium swallow or barium enema

Question 3

How does barium show a tumour

Answer 3

barium outlines the cancer in a scan

Question 4

single contrast

Answer 4

barium outlines the lumen- can’t see a tumour however

Question 5

double contrast

Answer 5

in addition to outlining the lumen it outlines the tumour so both are visible

Question 6

CT colonography

Answer 6

CO2 gas inserted to open the colon up as much as possible
may have to swallow contrast dye prior
CT examination of the lumen
-fecal tagging due to dye
-tumour wouldn’t retain contrast
- improves the differentiation of residual feces from polyps and thereby false-positives can be avoided.

Question 7

What does the diagnosing colonic tumours?

Answer 7

colonoscopy (endoscopy)

Question 8

what is the best technique to see colon polyps if they can’t undergo colonoscopy?

Answer 8

CT colonography

Question 9

cross section imaging

Answer 9

body in slices

includes CT, MRI & PET

Question 10

Uses of cross section imaging

Answer 10

• initial diagnosis and staging of disease
• monitor response to treatment
• evaluating residual mass after treatment
• recognition of complications of treatment
• when there is concern for disease relapse

Question 11

CT xray

Answer 11

body absorbs photons released by x-rays

-various angles around the body to get a 360 degree image

Question 12

Voxel is how thick? and why

Answer 12

1 cm- reduces noise ie in radiological terms- produces a less grainy image (improves quality)

Question 13

What is used to outline the GI tract?

Answer 13

gastrografin- dilute iodine based contrast

- not used routinely nowadays

Question 14

IV CT contrast agent?

Answer 14

iodine based contrast

omnipaque- injected into the veins demonstrate blood vessels or the vascularity of different tissues

Question 15

Risks of IV contrast use

Answer 15

allergic and anaphylactic reactions

Question 16

diagnosis and staging system

Answer 16

T, N, M

Question 17

T staging

Answer 17

TUMOURS

• very specific to particular organ
• can’t compare between structures
• shows depth or position of tumour

Question 18

N staging

Answer 18

involves lymph nodes N= nodes

Question 19

M staging

Answer 19

presence of distant metastases- spreading of cancer elsewhere in body
ie is there no metastasis or distant metastasis present

Question 20

Brain scanning

Answer 20

CT, MRI

PET can’t be used- as brain is highly metabolic

Question 21

which scan type is used to see the spinal cord

Answer 21

v intricate

MRI is only morality that can see detail

Question 22

which scan type can’t be used to examine the Lungs

Answer 22

don’t have H+ protons and MRI depends on these so it can’t be used

Question 23

which scan type can’t be used to examine the Esophagus

Answer 23

MRI cannot be used

Question 24

what scan can’t be used to examine the liver

Answer 24

highly metabolic- PET can’t be used

Question 25

which cancers can be diagnosed by CT imaging

Answer 25

``` lung tumour pancreatic tumour renal tumour adrenal tumour retroperitoneal tumour brain tumour ```

Question 26

CT and staging of cancer

Answer 26

Assess local spread e.g lymph nodes, adjacent organs assess distant spread e.g liver, lung, bone or brain metastases

Question 27

CT and staging of cancer

Answer 27

Assess local spread e.g lymph nodes, adjacent organs assess distant spread e.g liver, lung, bone or brain metastases

Question 28

ALARA principle

Answer 28

as low as reasonably achievable- make sure examination is really necessary- avoid repeat

Question 29

MRI

Answer 29

powerful magnet better quality/resolution of image

Question 30

radio frequency reciever

Answer 30

receives

Question 31

water molecule in MRI scan

Answer 31

a very light molecule- takes longer to get back

Question 32

fat molecule in MRI scan

Answer 32

takes less time to be received

Question 33

disadvantages of MRI

Answer 33

noisy claustrophobic can't image patients with pacemakers, aneurysm clips image is motion dependent- need ot stay still!

Question 34

screening importance

Answer 34

- diagnose disease at an earlier stage - cancer is easier to treat and most likely to be curable - NHS screening programme- breast, bowel and cervix no standardised screening for prostate- patient dependent

Question 35

WHO principles of screening

Answer 35

condition should be an important health population- breast, cervix and colon cancer v common in western population (japan- stomach) nee to have high uptake there should be a latent stage of the disease- lung cancer doesn't have latent stage- only 6 month max 2 years really. Should be visible in imaging before it becomes a cancer should be a test or examination for the condition- breast mamogram etc colon- fecal stool test test should be acceptable to the population- something people will accept to go through there should be a treatment for the condition- cancer shouldn't be lethal, low morality for the cancer so patients may recover facilites for diagnosis and treatment should be available

Question 36

Cancer staging- what does 'stage' refer to?

Answer 36

stage refers to the extent of your cancer, such as how large the tumor is, and if it has spread.

Question 37

TNM Staging System

Answer 37

T refers to the size and extent of the main tumor. The main tumor is usually called the primary tumor N refers to the the number of nearby lymph nodes that have cancer M refers to whether the cancer has metastasised. This means that the cancer has spread from the primary tumor to other parts of the body

Question 38

What stages are there?

Answer 38

5 stages: stage 0, I, II, III, IV Stage 0= Abnormal cells are present but have not spread to nearby tissue. Stage I, Stage II, and Stage III= Cancer is present. The higher the number, the larger the cancer tumor and the more it has spread into nearby tissues (in situ) Stage IV= The cancer has spread to distant parts of the body.

Question 39

'Localised'

Answer 39

Cancer is limited to the place where it started, with no sign that it has spread.

Question 40

genetic changes and cancer

Answer 40

Cancer is caused by certain changes to genes that control the way our cells function, especially how they grow and divide Genes carry the instructions to make proteins, which do much of the work in our cells. Certain gene changes can cause cells to evade normal growth controls and become cancer.

Question 41

Source of genetic changes that can cause cancer?

Answer 41

inherited from our parents if the changes are present in germ cells (reproductive cells of the body) result of errors that occur as cells divide or from exposure to carcinogenic substances that damage DNA, such as certain chemicals in tobacco smoke, and radiation, such as ultraviolet rays from the sun

Question 42

modalities of cancer therapy

Answer 42

``` surgery Radiation Therapy Chemotherapy Immunotherapy Targeted Therapy (targets the changes in cancer cells that help them grow, divide, and spread) Hormone therapy Stem Cell Transplant (restore blood-forming stem cells in cancer patients who have had theirs destroyed by very high doses of chemotherapy or radiation therapy) Precision Medicine ```

Question 43

TNM staging list

Answer 43

Tumour T1-4 Nodes N0-2 Metastasis M0-1

Question 44

barium enema

Answer 44

enema is injected into rectum examines colon colon x-ray Used in Chron's disease

Question 45

are CT and PET scans combined?

Answer 45

yes they are often combined to detect cancerous tumours

Question 46

SPECT- what is it?

Answer 46

Single-photon emission computed tomography | gamma cameras rotate around area of interest

Question 47

What does PET use?

Answer 47

radionucleides that decay by positron emission