Nuclear medicine patients: No-alarm holiday travel tips

SNM asks medical community to make patients aware of potential security tie-ups after treatment or imaging study

RESTON, Va. -- Traveling during the holidays--especially for the nearly 60,000 individuals who daily undergo a nuclear medicine treatment or test in this country--will go smoother if medical professionals advise their patients to follow some simple tips from SNM, the leading international molecular imaging and nuclear medicine society.

"Due to heightened concerns about terrorism, sensitive radiation detectors are used in some major cities and in public transportation facilities," explained SNM President Martin P. Sandler. "Occasionally, a patient who has had a nuclear medicine procedure may be stopped by security personnel because he or she may trigger the alarm on a radiation detector. On rare occasions, this could cause long delays, interrogation and body searches," added Sandler, who speaks for 16,000 physician, technologist and scientist members of the international scientific and professional society.

Nuclear medicine, which is broadening its scope to include molecular imaging, involves using tiny amounts of radioactive materials in patients to examine molecular processes in the body. These procedures can be used to detect and evaluate heart disease, cancer, brain disorders and stress fractures. Commonly performed procedures include positron emission tomography (PET) scans to diagnose and monitor treatment in cancer, cardiac stress tests to analyze heart function, bone scans to detect orthopedic injuries and lung scans blood clots.

Although the material used for these procedures is minute and soon loses its radioactivity, it may take time before a patient stops emitting detectable levels of radiation. The sensing devices used today at security screening points are extremely sensitive. "Residual radiation from medical treatments may cause travel delays due to increased security scanning at places such as airport boarding areas, rail stations, ports, international border crossings, bridges, tunnels and large public gatherings," noted Henry D. Royal, former SNM president and an expert in radiation safety. A patient's travel could be delayed while security officers evaluate the situation, he said.

"The nuclear medicine community has been working for years with representatives from both the Department of Homeland Security and the Department of Transportation to help them understand how patients can set off the detectors after treatment and to make recommendations about how to deal with that situation," said Royal. When it comes to nuclear medicine and stress-free travel, SNM says the public should keep in mind the following advice.

  • Preplan. To avoid any difficulties, patients should choose to schedule travel after nuclear medicine procedures, based on the specific radioisotope received and the length of time it remains detectable.
  • Know what radioisotope has been used in the treatment or study. Commonly used radioisotopes that could set off radiation monitors, each with its own "half-life" or period of continuing radioactivity, include technetium-99m (Tc-99m), fluorine-18 (FDG) and thallium-201 (Tl-201). Most recent problems with radiation monitors have been with the use of iodine-131 (I-131), which is used to treat hyperthyroidism, thyroid cancer and lymphoma.

Most nuclear medicine studies are performed with Tc-99m, which should not be detectable by sensitive radiation monitors three or four days after a test.

FDG is the most common radioisotope used with PET imaging, and it should be undetectable one day after a test.

Myocardial perfusion (blood flow) imaging can be performed with TC-99m or Tl-201 or a combination of both. Be sure to confirm which radioisotope has been used in your study. Tl-201 may remain detectable for 30 days.

A majority of security incidents with radiation monitors have involved treatment doses of I-131. This radioisotope may be detectable for as long as three months after treatment.

  • Patients and health care providers should discuss how long patients may emit detectable radiation following treatment.
  • Patients should obtain a letter from their doctors that contains the following information: the patient's name, contact information for the testing facility, the name of nuclear medicine procedure, the date of the treatment or test, the radionuclide that was used, its half-life, its administered activity and 24-hour contact information.
  • Patients should let their doctors know if security personnel stop them after triggering radiation devices. SNM asks that doctors report such incidents so the society may be able to identify and help educate specific authorities.

More Americans are receiving nuclear medicine treatments and tests. Every major hospital in this country has a nuclear medicine department, and last year, 19.7 million nuclear medicine procedures were performed on 17.2 million women, men and children in more than 7,200 medical sites in the United States--a 15 percent increase from four years ago. For more information about nuclear medicine, please visit SNM's Web site at


About SNM--Advancing Molecular Imaging and Therapy
SNM is an international scientific and professional organization of more than 16,000 members dedicated to promoting the science, technology and practical applications of molecular and nuclear imaging to diagnose, manage and treat diseases in women, men and children. Founded more than 50 years ago, SNM continues to provide essential resources for health care practitioners and patients; publish the most prominent peer-reviewed journal in the field (the Journal of Nuclear Medicine); host the premier annual meeting for medical imaging; sponsor research grants, fellowships and awards; and train physicians, technologists, scientists, physicists, chemists and radiopharmacists in state-of-the-art imaging procedures and advances. SNM members have introduced--and continue to explore--biological and technological innovations in medicine that noninvasively investigate the molecular basis of diseases, benefiting countless generations of patients. SNM is based in Reston, Va.; additional information can be found online at

Last reviewed: By John M. Grohol, Psy.D. on 30 Apr 2016
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