NCCN Guidelines for Patients
Esophageal Cancer, Version 1.2016
Preparing for treatment
Before the scan, you may need to stop taking some
medicines, stop eating and drinking for a few hours,
and remove metal objects from your body. During
the scan, you will need to lie face up on a table that
moves through the machine.
See Figure 6
As the machine takes pictures, you may hear
buzzing, clicking, or whirring sounds. You will be
alone, but a technician will operate the machine in a
nearby room. He or she will be able to see, hear, and
speak with you at all times. One scan is completed in
about 30 seconds.
You will likely be able to resume your activities right
away unless you took a sedative. You may not learn
of the results for a few days since a radiologist needs
to see the pictures. A radiologist is a doctor who’s an
expert in reading the images.
Sometimes CT is combined with another imaging test
called PET (
used to together, they are called a PET/CT scan.
PET/CT is advised when there may be metastases
but a CT scan didn’t detect any.
PET/CT may be done with one or two machines
depending on the cancer center. Before PET, you
must fast for 4 hours or more. There may be other
limits to your diet. About an hour before the scan, you
will be injected with a sugar radiotracer.
The radiotracer emits a small amount of energy that
is detected by the imaging machine. Cancer appears
brighter in the pictures because cancer cells use
sugar more quickly than normal cells. PET can show
even small amounts of cancer because the images
are based on the cells’ use of sugar (cell metabolism).
Pictures of the insides of your body
can be made with an imaging test.
No devices will be inserted into
your body. However, you may be
injected with and have to drink a
contrast dye. During the test, you
will lie on a table that will move into
the tunnel of the imaging machine.
The pictures will be viewed by a
doctor who will look for signs of