Radiation
therapy uses radiation to destroy cancer cells within your body.
There are several forms of radiation available. We use both x-ray
and electron radiation. The type of radiation used will be selected
by the radiation oncologist and will be the best choice for your
specific type of cancer, the extent of your disease and its location.
With careful planning, radiation can be sculpted so it is directed
to the cancer and away from healthy tissue.
It
has been estimated that 50 to 60 percent of all cancer patients
will benefit from radiation therapy in their lifetime. Radiation
therapy may also be useful in treating some non-cancerous diseases.

During your consultation, you (and anyone you wish to bring) will
meet with the radiation oncologist to determine if radiation therapy
will be recommended to treat your disease.
First,
the registered nurse will go over some information forms with you.
(You may receive a phone call prior to your consultation and be
given the option of reviewing your forms over the phone.) If you
have brought any records or films from another facility, the nurse
will collect them at this time for the radiation oncologist to review.
The radiation oncologist will answer any questions, discuss the
benefits and risks that may be associated with the radiation therapy
and will explain the simulation and treatment process.
Once
you consent to radiation therapy, you will be given a packet of
materials pertaining to your treatment including information on
your specific disease, nutrition, skin care and general guidelines.
The nurse will go over each portion of the packet with you to answer
any questions. When you are ready to proceed, the nurse will schedule
an appointment for your simulation.

The radiation oncologist works with a radiation therapist and a
dosimetrist to obtain a three-dimensional view of the area to be
treated. Using a computed tomography (CT) simulator, the area on
your body is marked for reference.
Generally,
simulations are scheduled for one hour, but may take more or less
time depending on the complexity of the treatment setup. You may
be asked to drink a liquid contrast prior to the scan or be given
an intravenous (IV) contrast during the scan. The contrast will
aid the radiation oncologist in pinpointing the target on your scan.
There
are several steps that occur during the simulation:
Patient
Positioning - The radiation therapist will find the most
comfortable position to allow the treatment to be performed daily.
This process may include making patient-specific body molds that
help the patient maintain the same position for daily treatment
and improve the accuracy of the radiation delivery.
CT
Scan - This scan is very similar to a diagnostic CT scan;
however, once the scan is performed, special software is used to
help the radiation oncologist determine the “target volume.”
The target volume is the area of the tumor plus a defined volume
around it that may be involved. It may also include surrounding
structures next to the target volume or lymph nodes that may be
at risk.
Defining
the Isocenter - The simulation software determines the
center of the target volume called the “isocenter.”
All further treatment planning is based on this reference point.
The CT simulator has special positioning lasers that allow the radiation
therapist to mark on your body once the isocenter has been determined.
These lasers correlate to lasers located in the treatment room.
Marking
the Treatment Field - Marks will be made on your body to
assist the therapist in your treatment setup. They consist of isocenter
marks as well as positioning marks and may be located in several
places on your body. You will be asked to keep the marks on during
the duration of your treatments. Special clear tape, called Tegaderm,
will be placed over the marks to help maintain them. These marks
will be used by the therapists each day during your treatment to
assist in pinpointing the target volume. If they should fade during
the treatment, the therapist will replace them during your treatment
session. If a patient positioning device is used, marks will be
made on it as well to ensure proper alignment. The positioning devices
will also be used during your daily treatment.
Documentation
of the Treatment Setup - Once the marks are made, the therapist
will take photos of your treatment setup marks and positioning setup
to assist in your daily treatment setup. They are considered a part
of your treatment record and are confidential.
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Documentation
of the Treatment Setup -
Following the simulation process, the treatment planning begins.
During this phase, the information from the simulation is transferred
to a treatment planning system. This system allows the radiation
oncologist to work with a dosimetrist and physicist to plan the
precise angles and parameters of your treatment. Radiation doses
to the target volume are calculated and critical structures that
may be near the target volume will be accommodated. Different organs
and tissues in the body have different tolerances to radiation.
If there are organs included in the treatment field, their doses
will be calculated and tracked as well. This process may take from
several hours to several days depending on the complexity of the
treatment plan. Each patient’s treatment plan is designed
specifically for his diagnosis and status.
During
treatment planning, the radiation oncologist is able to shape and
sculpt the radiation beams to increase the accuracy of the treatment
and to decrease side effects. The radiation oncologist is able to
see what the dose results will be to all designated areas for the
full course of the radiation treatment.

Your daily treatments will be performed by a registered radiation
therapist using a Linear Accelerator or “linac.” Most
patients are required to come daily for treatment; however, treatment
is customized to meet each patient’s needs. Your radiation
oncologist will visit with you weekly to evaluate your progress
and to answer questions.
Treatments
are scheduled every fifteen minutes; however, depending on the complexity
of your treatment plan, your treatment may be scheduled longer.
The radiation therapist will work with you to find a treatment time
to fit your schedule.
During
your treatment, the overhead lights may be turned off to help the
therapist position you correctly and view the positioning lasers
on your body. You may see a light field coming from a portion of
the linac called the gantry. This light field correlates to the
actual treatment field. A special device called a multileaf collimator
(MLC) helps shape the radiation field. You may see the light field
change shapes and sizes as each treatment field is customized for
your treatment.
Once
you have been positioned correctly, the actual treatment will take
place. The radiation therapists are required to leave the room during
the treatment but will be viewing you on two camera monitors and
have voice contact with you at all times. It is important during
the setup and treatment that you remain still and breathe normally.
The therapists may come into the treatment room during different
phases of your treatment to adjust equipment. You should continue
to remain still during this process. The therapists will communicate
to you every time they leave the
treatment room.
Prior
to the start of your treatment, you may hear the linac make some
clicking and hissing noises. This is the therapist programming if
for your treatment. If you are being treated by more than one field
of radiation, the gantry may move around you - but it will not touch
you. Once the linac has been programmed, the therapist will begin
the treatment. The linac makes a buzzing noise during this process.
You will not feel the radiation while it is being delivered. The
length of the radiation time may vary for each field and may vary
day-to-day, as your treatment is dose dependent and not time -dependent.
If any time you have a question, please ask the therapist, who will
be glad to assist you.

You will be scheduled for follow-up appointments so that the radiation
oncologist can assess your progress. Your radiation oncologist will
then refer you to your primary physician. You may call our clinic
at any time if you have additional questions or concerns about your
radiation therapy.
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