You may have heard recent media reports raising concerns about
the fact that people with certain types of cancer and other
diseases are "radioactive" (meaning that they emit radiation from
their bodies) for up to a week after being treated for their
illness with radioactive materials. This raises some disconcerting
questions -- for instance, is it dangerous to share a bedroom or a
bathroom with people who have had radiation therapy? To stand next
to them at choir rehearsal? Is it safe to sit near such folks on a
train or plane?
There’s no question that radioactive materials used to treat
cancer and certain other diseases stay in the body and, for a
period of time, are theoretically powerful enough to be dangerous
to other people. But how dangerous... and when? To get some
perspective on this, I called Henry Duval Royal, MD, professor of
radiology at Washington University School of Medicine, who had some
helpful advice to offer.
WHY ARE WE WORRIED?
This issue grabbed headlines in recent months when it became
the focus of a congressional report. While the federal Nuclear
Regulatory Commission (NRC) once required hospitals to quarantine
radioactive patients after treatment, that requirement was dropped
in 1997. However, some legislators have reason to believe that
stricter measures should be in place -- which is what led to the
new report. Concerns were raised when patients treated with
radioactive materials caused alarms to go off in public
transportation systems and on bridges and in tunnels in New Jersey.
Alarms also were triggered in landfills in Maryland and
Massachusetts by household waste from patients being treated with
radiation.
The congressional report found that more than 10% of
outpatients being treated with radioactive materials aren’t being
appropriately educated about what they should do to avoid exposing
family members to radiation. On the other hand, 7% choose to
minimize the danger to family members and others with whom they
interact daily by staying in hotels for several days, a move Dr.
Royal calls "unnecessarily conservative."
How dangerous is this? After the NRC rescinded
its patient release regulation, researchers conducted a study
measuring the radioactivity of patients receiving outpatient
radioactive iodine therapy for thyroid cancer. Thirty patients and
65 family members (and their 17 pets) agreed to be monitored
continuously for 10 days. For two days after radiation treatment,
the patients were instructed to sleep alone and avoid prolonged
close personal contact with others -- after that they could resume
normal activities. The researchers learned that while family
members were indeed exposed to radioactivity from the iodine, the
amount was well below the limit of 5 millisieverts (mSv) per
exposure determined to be safe by the NRC. The study was reported
in the Journal of the American Medical
Association in May 2000. Note: Though
the study is now more than 10 years old, Dr. Royal said the
radiation treatments have remained the same, so the findings are
still valid.
It sounds frightening, but according to Dr. Royal, the risk
posed by being within a few feet of someone who has recently had
radioactive iodine treatment actually is quite small -- especially
when you take pains to avoid prolonged contact. Dr. Royal
emphasized that risk is measured by the strength of each radiation
dose, not by whether radiation sets off an alarm, and he added that
it is important to realize that radiation detectors are designed to
be very, very sensitive.
PROTECT YOUR LOVED ONES
Nonetheless, Dr. Royal agreed that it makes sense to do what
you can to minimize exposure to radiation. To err well on the side
of safety, Dr. Royal said that patients should sleep in a separate
bed for two weeks, which he said is "the absolute longest amount of
time that there is any reason for concern."
Other measures patients can take to protect their loved ones
include...
- Keep physical contact
brief. Don’t hug or cuddle kids or pets for prolonged
periods for the first two days following treatment, though it is
fine to be in the same room with them.
- Be a bit
standoffish. Keep a distance of three to six feet
from others while seated at the table or on a couch... avoid
letting anyone come in contact with your bodily fluids... don’t
share plates, eating utensils or cups... and don’t kiss. If you
want to be extra careful, he said, you may want to use a separate
toilet and flush multiple times and wash clothing
separately.
Put most succinctly, Dr. Royal said his advice is to "pretend
that you have a cold, and you’ll do all the right things."