Existing data do not support that the public is at risk due to outpatient thyroid treatment.
In late October, The Endocrine Society, American Thyroid Association,
Society of Nuclear Medicine and American Association of Clinical
Endocrinologists released a joint statement backing current procedures for the
release of outpatients having undergone treatment with radioiodine, or
131I, stating that the current outpatient procedure, based on
scientific evidence, is safe for patients, their families and the public when
radiation safety instructions are followed. However, the associations
qualified their statement, adding that should data emerge that indicate there
is a safety concern, the issue should be re-examined.
The release of this statement was prompted by a meeting of the Nuclear
Regulatory Commission (NRC) that was scheduled to examine the use of medical
isotopes, such as radioiodine, and other medical issues later that month.
Before the meeting, Edward J. Markey, congressman and chairman of the
Energy and Environment Subcommittee of the House Committee on Energy and
Commerce, wrote a letter to the chairman of the NRC expressing concern over
public exposure to radiation due to patients being treated with radioiodine on
an outpatient basis. Markey claimed that the public has been unwittingly
exposed to radiation from patients who are discharged after being treated with
radioisotopes, and blamed weak NRC regulations for the exposure.
There is no good evidence of the public being harmed by exposure
to people who were treated with radioiodine, Richard T. Kloos, MD,
professor at Ohio State University, divisions of endocrinology and nuclear
medicine, said in an interview. That being said, while we dont have
any evidence of harm, we should still try to keep any risk that may exist as
low as is achievable.
Radioiodine has been used for more than 50 years to treat a variety of
thyroid diseases, including thyroid cancer, and has been found to have
relatively few undesirable effects, according to AACE. Typically, patients with
thyroid cancer undergo surgery followed by treatment with radioiodine. Patients
receive the treatment by mouth and during the first few days after the
outpatient procedure the radioiodine will leave the body through saliva, sweat,
urine, tears, vaginal secretions, semen and feces.
Although originally an inpatient procedure, in 1997, the NRC revised its
recommendations about patient release after radioiodine treatment, allowing
patients to be released provided the dose to any other individual exposed to
the patient did not exceed 5 mSv. This resulted in most patients undergoing
radioiodine treatment in an outpatient setting, an approach that, according to
the joint statement, enhances patient satisfaction and is the current
standard of medical practice.
Physicians are supposed to educate patients about appropriate behavior
after treatment and issue recommendations about interacting with others to
minimize risk (see sidebar).
A study by Grigsby and colleagues published in 2000 in the Journal
of the American Medical Association supported this recommendation.
Results indicated that for household members of 30 patients who underwent
radioiodine treatment, the dose of radiation exposure to any member was
well below the 5 mSv limit recommended by the NRC.
When people are sent home, they fill out a large group of papers
that explain all of the things that they need to avoid, said Ernest
Mazzaferri, MD, professor of medicine in the division of endocrinology,
diabetes and metabolism at the University of Florida, Gainesville.
Close and prolonged contact with others and exposure to bodily fluids
are the biggest concerns.
We dont want people kissing or sharing a drink, said
Kloos, who is also secretary and chief operating officer of the ATA.
People should stay at least an arms length away for a few days or
up to a week.
The greatest precautions are taken to protect children and young
teenagers who physicians theorize may be at the highest risk for harm due to
exposure, Kloos said. However, even that risk is theoretical, with little to no
data to support it, he added.
The problem is, of course, that you can give people advice, but
not everyone follows it, Mazzaferri said. We are all beginning to
recognize that may be a bigger problem than we thought.
However, Kloos did not classify radiation exposure due to radioiodine as
a public health concern.
I wouldnt put it in the top list of major problems facing
our population, he said. Radiation is a scary word that grabs
In addition, returning to the days of inpatient radioiodine treatment
would come with a larger set of issues, Kloos said. Among them are increases in
health care costs and increased waiting times for treatment due to a shortage
of hospital rooms equipped with the proper precautions, such as lead lining.
However, there is enough of an issue here that the various major
organizations are, as we speak, trying to put together something that would put
more safety features in place, Mazzaferri said.
The ATA recently assembled a document to help make recommendations for
outpatient treatment with radioiodine more uniform across hospitals and
eliminate any confusion that may exist, according to Kloos.
I found in the media coverage of this issue that people felt they
were not adequately informed or told the correct way to handle this
situation, Kloos said. I find that sad.
However, he added, in most cases, when competent health care providers
who provide this treatment know and instruct on published recommendations, most
people are willing and able to follow them.
If we make people think that treatment with radioiodine is so bad
that nobody wants to take it, the primary treatment for thyroid cancer will be
surgery alone, Mazzaferri said. Unfortunately, you need surgery and
radioiodine to get full destruction of this disease.
Exposure may be found to be a problem, but it is not so great a
problem that we should quit using this effective treatment, he said.
by Leah Lawrence
For more information:
- AACE. 2004. Radioiodine Therapy: Information for
- Grigsby PW. JAMA. 2000;283:2272-2274.
- Joint statement on radioactive precautions following radioactive
iodine therapy. Oct. 20, 1010.