My name is Julianna Sienna. I'm a fourth-year radiation oncology resident
at McMaster University.
On January 31st we went to visit Dr. Sienna at the Juravinski Cancer Centre in Hamilton Ontario Canada.
Upon arriving, she gave us a tour of one of the several radiation units that are located in the basement
of the hospital. Walking through what they called the maze you are greeted
with pleasant pictures as you approach the linear accelerator that administers
the radiation. Now let's see what doctor Sienna has to say about radiation oncology.
Radiation can be used as part of
treating cancer. The cancer journey might involve a medical oncologist, a surgical
oncologist, as well as a radiation oncologist and radiation might be used
at different parts of the cancer journey. Sometimes we use radiation in a what we
call neoadjuvant sense that means before something like surgery. It can
also be used in what we call an adjuvant setting so typically that's after a
surgical intervention. Additionally radiation can also be used
as the main modality to cure cancer and it is sometimes used when we are
palliating cancer patients in other words when we're trying to address
symptoms that arise as a result of cancer radiation treatment can also be
used to treat non-malignant conditions but typically here the majority of the
work that we do is using radiation to treat cancer patients.
Radiation is delivered typically Monday
to Friday not on weekends or usually not on holidays. The reason that we treat in
this way is to take advantage of the properties of tumor tissue versus normal
tissue so we want to allow the damage caused by radiation to build up in the
tumor to optimize the killing of tumor cells but we also want to allow time for
the normal tissue to repair itself
When a patient comes for treatment they'll come to the Cancer Center
typically they'd get changed into a dressing gown and then they would be set
up on the treatment machine there's going to be a very specific position and
in fact when they originally were seen for their simulation scan they would
have received small tattoos and those tattoos are used to help line the
patient up. It's very important because we've created a very precise plan for
that patient and having them lined up in the correct position ensures that we
know when we turn the radiation machine on we're actually treating where we're
intending to treat so we position the patient and then the machines, everyone
else leaves the room, and the machines are turned on and the machines move
around the patient. They won't see anything or hear anything and in fact
they just sort of lay there it may take anywhere from a few seconds to the most
complicated treatments can take up to 45 minutes and typically that depends on
exactly how a radiation plan was designed. Sometimes the radiation plan
can be as simple as one beam moving right through a patient and other times
it involves multiple different beams at different angles that are all converging
within the patient in the target tissue together
For a patient, the experience is similar to
having a chest x-ray in that they don't feel anything except that the photons we
use are higher energy.
One question we hear a lot is, is there a limit to how much radiation that I can
get and yes there is a limit we have information from historical events such
as the nuclear bomb in Hiroshima and the explosion at Chernobyl that have told us
how radiation can affect humans who don't have cancer and then we have lots
of studies that have told us how radiation effects in animals and in
humans both tumor tissues and normal tissues. Using these we have an idea of
how much radiation each organ in the body can tolerate and in fact every
organ has a different tolerance level and so this is really important when
we're when we were making a plan we have to ensure that any of the
normal tissues that are around the area that we're trying to treat are not
getting more than what we feel is a safe amount. Sometimes patients will say if
I've had radiation in one area does that mean I can never have it again in that
area and as a rule in general if you've had radiation in one area there may not
be an ability to go back and treat that area again so that's why we take good we
take great caution to ensure that we're giving the best plan the first
opportunity because we may not have an opportunity to come back and treat that
area again. Sometimes my patients will ask if they're having radiation, am I
radioactive and it's a very reasonable question but in fact in most cases no
patients will not be radioactive the photons which deliver the radiation will
pass through the body and while they're still having an effect in the tissues of
the body the radiation itself is not still there
so patients are not radioactive and it can continue on with their daily life
with no changes the one exception to this is with a particular type of
radiation treatment an implanted treatment called brachytherapy where a
radioactive source is actually implanted into the patient this is an entirely
separate branch of radiation oncology and in those patients they may have some
degree of radioactivity and it would be discussed with the physician at the time
of a consultation about what a patient might expect from this.
Thanks for watching! To learn more about radiation oncology please visit the Juravinski
Cancer Center website page on radiation therapy or listen to our podcast on
radio isotopes in medicine.