FREQUENTLY ASKED
QUESTIONS
How does Radiation Therapy Work?
Cancer cells grow and divide more rapidly than
many of the normal cells around them. High doses of radiation can kill cells or
keep them from growing and dividing, and it has proven to be particularly
effective in killing cancer cells and shrinking tumors. Although some normal
cells are affected by radiation, most normal cells recover more fully from the
effects of radiation than do cancer cells. Receiving external radiation
treatments is painless, just like having an X-ray taken.
Does radiation therapy expose people to radioactive substances?
Many people, when they hear the word “radiation,” think immediately of
radioactive substances. However, no radioactive substances are involved in the
creation of X-rays or electrons by a medical
linear accelerator. When a linear accelerator is switched to “on,”
radiation is produced and aimed directly at cancer cells. Then, like a
flashlight, when the machine is switched off, there is no more radiation – none
is “stored” or “transported.”
What kind of radiation is used?
Photons (X-rays) and Electrons are used to deliver radiation. The radiation is
generated by a machine called a
linear accelerator. This machine stands approximately nine feet tall,
is nearly 15 feet long and can be rotated around the patient with great
precision. Operationally, microwave energy, similar to that used in a satellite
television transmission, is used to accelerate electrons to nearly the speed of
light. As they reach maximum speed, they collide with a tungsten target, which
in turn releases photons, or x-rays.
Very small beams with varying intensities can
be aimed at a tumor from various angles to attack the target in a complete
three-dimensional manner.
Varian’s SmartBeam IMRT can be delivered with beams the size of a 2.5
x 5 millimeter pixels – the size of a pencil tip – each with varying intensity.
The idea is to deliver the lowest dose possible to the healthy surrounding
tissue, reducing the chance of causing a radiation side effect, while still
delivering the maximum dose to the tumor.
How does a Medical Linear Accelerator work?
As radiation strikes human tissue it produces (largely from naturally occurring
water in the body) highly energized ions which are lethal to both normal and
malignant cells. While both good and bad cells suffer from radiation, healthy
cells can adapt over successive regenerative cycles. Malignant cells do not
possess this adaptation mechanism and thus do not survive; this is why patients
are scheduled to come into the Welch Cancer Center for daily treatments rather
than a single treatment.
What
are the side effects of treatment?
Side effects vary from patient to patient. Side effects of radiation are
directly related to the area of the body being treated. Most patients do not
experience any serious difficulties and most patients will be able to continue
with their normal daily activity during their treatment.
Who gives the treatment?
A doctor who has had special training in using radiation to treat disease - - a
Radiation Oncologist - - prescribes the type and amount of treatment
that best suits a particular patient’s needs. The Radiation Oncologist works
with the patient’s referring physician and also heads a highly trained
Health Care Team. This team often includes: 1) a
Radiation Physicist who participates in the planning process and
ensures that the machines deliver the right dose of radiation, 2) a
Dosimetrist, who plans the treatment with the Oncologist and the
Physicist, 3) a
Radiation Therapist, who sets the patient up for treatment and runs
the equipment that delivers the radiation and, 4) a
Radiation Oncology Nurse, who provides nursing care and helps
patients learn about treatment and how to manage any side effects.
How long is a course of treatment?
Radiation Therapy is usually given five days a week for six to eight weeks. When
radiation is used for palliative care, the course of treatment lasts for two to
three weeks. For each radiation therapy session, the patient is in the treatment
room for about 15 minutes. These types of schedules, which use small amounts of
daily radiation, rather that a few larger doses, help protect normal body
tissues in the treatment area. Weekend rest breaks allow normal cells to
recover. The total dose of radiation and the number of treatments a patient
needs depend on the size and location of the cancer, the type of tumor, the
patient’s general health, and other factors.
Is radiation therapy expensive?
Treatment of cancer with radiation can be costly. It requires very complex
equipment and the services of many health care professionals. The exact cost of
radiation therapy will depend on the type of treatment approach and the
number of treatments the patient needs.
In addition to Medicare, most health insurance
policies cover charges for radiation therapy including
IMRT. If you have any questions you should talk with your insurer or the
business office at Sheridan Memorial Hospital about your policy and how expected
costs will be paid.
