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Nuclear medicine patients at security checkpoints (NM specific)


Patients are informed about potential delays when crossing international borders after having a nuclear medicine procedure


+ Activation of radiation detectors

  • Patients receiving diagnostic and therapeutic doses of radiopharmaceuticals have the potential to activate radiation detectors.1          

    • These patients are a potential cause of false alarms where sensitive radiation detectors are in use (e.g., border crossings, airports, traffic tunnels)


  • The duration of time during which patients may trigger radiation alarms varies according to the radiopharmaceutical and dose, the sensitivity of detectors and the patient’s elimination rate and/or disease burden: 1





  • As part of their preparation for the procedure, patients are educated about the risk of setting off radiation detectors and the potential for delay and inconvenience if travelling.2

+ Documentation for the patient

  • Institutions can assist patients and security personnel by providing patients with a letter that documents the procedure and provides contact information for the security agents to use.
    • The letter will not prevent a patient from setting off a detector or from subsequent questioning, but will provide an explanation as to why the detector was activated3
    • Feedback from certain land border crossings shows that patients may experience a delay of about 20-30 minutes before being allowed entrance into other countries3


  • A letter should document the following:3
    • Patient name
    • Name and date of nuclear medicine procedure
    • Name of radiopharmaceutical and administered activity
    • Half-life of the radiopharmaceutical
    • 24-hour contact information of the institution where the patient underwent the procedure


  • The letter should be provided on institutional letter-head
  • Patients are advised to carry the provided letter at all times when travelling and retain the letter for the time they have the potential to activate radiation detectors.3 (See "Activation of radiation detectors" tab above)
  • If a border or airport security personnel require a copy for retention, patients are advised to ask that a photocopy of the letter be made rather than relinquishing the original

+ References

  1. Gangopadhyay KK. Triggering radiation alarms after radioiodine treatment. BMJ 2006;333:293.
  2. Dauer LT, Williamson MJ, St. Germain J, Strauss HW. Tl-201 stress tests and homeland security. J Nucl Cardiol 2007;14(4):582-588.
  3. Niagara Health System. Nuclear medicine – Post-procedure instructions. Available at: Accessed February 21, 2013.



April 18, 2013


Canadian Association of Medical Radiation Technologists
85 Albert St, Suite 1000, Ottawa, ON, K1P 6A4
phone: 613 234-0012 / 800 463-9729
fax: 613 234-1097