> Learn
about Internal Radiation Therapy.
Intensity
Modulated Radiation Therapy (IMRT)
What is IMRT?
IMRT is an advanced, precise method of external beam
radiation therapy that delivers high doses of radiation
directly to the tumor while sparing surrounding healthy
tissue. IMRT allows doctors to customize the radiation
dose by modulating, or varying, the amount of radiation
given to different parts of the treatment area. This
modulation is done in highly accurate, three-dimensional
detail, according to the shape, size and location of
the tumor.
How does IMRT work?
First, doctors will create a detailed digital image
of your body using a CT (computed tomography) scan,
PET (positron emission tomography) scan, or MRI (magnetic
resonance imaging). This digital image will be loaded
onto a powerful computer and used to plan beam arrangements
that will best target your tumor. This technology allows
your treatment team to focus higher doses of cancer-killing
energy on tumors while preserving healthy tissue. Clinical
studies show that IMRT allows doctors to deliver high
doses of radiation directly to the tumor, increasing
treatment success and reducing side effects.
When do you use IMRT?
IMRT is an excellent choice for cancer of the prostate,
brain, gastrointestinal tract (esophagus, stomach, pancreas,
rectum and anus), and head and neck (nasopharynx, orapharynx,
hypopharynx, larynx and oral cavity).
Respiratory
Gating
What is respiratory gating?
Respiratory gating is the process of turning the radiation
beam on and off based on your breathing cycle. Some
aggressive cancers such as lung tumors may require higher
radiation doses for better control. Higher radiation
doses can only be delivered if the dose to normal tissues
can be kept to safe levels. Respiratory gating can be
used in combination with stereotactic body radiosurgery
or radiation therapy.
How does respiratory gating
work?
When you breathe, your internal organs move by as much
as several centimeters, causing cancer cells to move
in and out of the radiation treatment field. Computer-guided
imaging, simulation and planning allow your physician
to pinpoint the tumor, establish treatment objectives
and review many treatment options to determine the optimal
arrangement and dose of radiation beams. Using respiratory
gating, your radiation treatment is synchronized to
your individual breathing pattern, targeting the tumor
only when it is in the optimum range. This provides
the security of protecting healthy structures while
targeting the tumor with significantly higher doses
of radiation. High doses of radiation ensure the best
outcomes: greater control, tumor reduction, and potential
cure.
When do you use respiratory
gating?
Respiratory gating is used to treat lung, liver, pancreatic
and stomach cancers.
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| 1. 3-D planning targets
radiation beams to the contours of the tumor.
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2. Respiratory Gating synchronizes
the radiation to the patient’s breathing.
|
3. Radiation is administered
directly to the tumor with pin-point accuracy. |
Stereotactic
Radiosurgery (Radiation Therapy)
What is stereotactic radiosurgery?
Stereotactic radiosurgery, also called stereotactic
radiation therapy, does not involve actual surgery.
The procedure uses a large dose of radiation to destroy
tumor tissue. There are two types of stereotactic radiosurgery
- intracranial and extracranial.
Intracranial stereotactic radiosurgery
Intracranial stereotactic radiosurgery uses multiple
beams of radiation to deliver large doses of radiation
to tumors in the brain. The patient's head is placed
in a special frame, which is attached to his or her
skull. The frame is used to aim high-dose radiation
beams directly at the tumor inside the patient's head.
The dose and area receiving the radiation are coordinated
very precisely. Nearby normal brain tissues are not
damaged by this procedure. Treatment is performed as
an outpatient with only one treatment that takes about
45 minutes.
Extracranial stereotactic radiosurgery
Extracranial stereotactic radiosurgery or stereotactic
body radiosurgery uses multiple beams of radiation to
deliver large doses of radiation to cancerous cells
in the body, such as tumors in the lungs, liver and
upper abdomen.
How does stereotactic body
radiosurgery work?
First, you will receive a CT, MRI or PET scan, which
your doctor will use to pinpoint the tumor, establish
treatment objectives and review many treatment options
to determine the optimal arrangement and dose of the
radiation beams. Using respiratory gating, your radiation
treatment is synchronized to your individual breathing
pattern, targeting the tumor only when it is in the
optimum range. This provides the security of protecting
healthy structures while targeting the tumor with significantly
higher doses of radiation. High doses of radiation ensure
the best outcomes: greater control, tumor reduction,
and potential cure. This outpatient treatment consists
of five treatments given three times a week for two
weeks.
CT-based
Conformal Radiation Therapy
What is CT-based conformal radiation
therapy?
CT-based conformal radiation therapy uses computerized
tomography (CT) scans to create a three-dimentional
(3D) image of the body, which helps doctors better target
the tumor and minimize damage to healthy tissue.
When do you use CT-based conformal
radiation therapy?
CT-based conformal radiation therapy is used on all
patients who undergo radiation therapy.
