Nuclear Medicine Patient Issues

Dose and risk from diagnostic and therapeutic nuclear medicine procedures. If you've had a nuclear medicine procedure and are concerned, select this category. Concerns and risks regarding pregnancy or effects on embryo/fetus can be found here.

What's My Risk?

The risks of health effects from radiation doses received during nuclear medicine procedures are either too small to be observed or are nonexistent. The benefits from properly performed clinically indicated nuclear medicine procedures far outweigh any hypothetical cancer risk. Diagnostic nuclear medicine procedures provide a medical benefit to you even if they do not appear to reveal anything and are of less risk than their alternatives, such as exploratory surgery.

Even if the result of the imaging exam was negative, the physicians were provided information they could use to determine the next course of action. Refusing medical imaging procedures may result in real and substantial risk by not receiving the clinical benefits of the procedures.

Because the Health Physics Society recommends against quantitative estimates of health risks for radiation doses below 100 mSv, we will not calculate hypothetical risks for diagnostic imaging procedures. The Society's position statement "Radiation Risk in Perspective" explains in more detail why it is inappropriate to estimate health risks at these doses. Some risk information is available from

What's My Dose?

If you want to know the specific dose you or a family member may have received for a particular exam you underwent, you need to contact your health care provider and ask for the effective dose due to the procedures. Typical doses from many diagnostic imaging procedures are posted on our website.

FAQs Developed by the HPS

The following FAQs have been developed by our topic editors for this category:

  HPS FAQ   Nuclear Medicine—Diagnostic Procedures
  HPS FAQ   Therapy—Nuclear Medicine

Relevant HPS Web Pages

The following HPS Web pages also address this category:

  HTML page   Benefits of Medical Radiation Exposures
  HTML page   Doses from Medical Radiation Sources
  PDF   Radiation Exposure from Medical Exams and Procedures

Questions Answered by HPS Experts

The following health physics questions have been answered by an expert and approved by our editors for inclusion in our "Ask the Experts" feature. Click on the question to see the answer.

Questions in this Category Are in the Following Subcategories:
  •  Diagnostic Nuclear Medicine
  •  Therapeutic Nuclear Medicine
  •  Positron Emission Tomography (PET)
  •  Questions Concerning Domestic Animals
  •  Miscellaneous
Diagnostic Nuclear Medicine
Q6940   –   Long-term effects from heart stress test
Q7133   –   Shielding in a nuclear stress laboratory
Q7171   –   Concerned about multiple x rays and nuclear medicine studies
Q7185   –   Pregnant when nuclear medicine study performed
Q7187   –   Has nuclear medicine exam affected woman's fertility?
Q7244   –   What is the risk to my toddler from DMSA scan?
Q7251   –   Radiation exposure and risk from a cardiac stress test
Q7272   –   Current and future risks from a Myoview stress test
Q7314   –   Low-dose iodine-131 therapy concerns
Q7376   –   Dose for a gastric emptying procedure
Q7485   –   Radiation exposure at work from nuclear medicine patients
Q7523   –   Is there a risk from a thyroid scan?
Q7645   –   Heart scan with sestamibi
Q7673   –   Will a stress test affect my family?
Q7888   –   Could a stress test injection affect blood pressure?
Q7917   –   Concern about exposure from too many exams
Q8034   –   Use of gamma camera data to calculate dose
Q8060   –   How long does a heart stress test expose family members?
Q8077   –   What is my dose from my bone scan?
Q8125   –   Can nuclear medical technicians administer iodine-131 for diagnostic studies?
Q8131   –   Can I be around my baby after my bone scan?
Q8520   –   Can radioactive thallium from stress test give me a headache?
Q8644   –   When can we conceive after husband has a heart scan?
Q8847   –   Will my baby have birth defects if I got pregnant after a scan with radioiodine?
Q8879   –   Restrictions for children after an adult nuclear medicine study
Q8924   –   Are there any precautions with children after a stress test with thallium?
Q9031   –   Precautions after an iodine-123 uptake scan
Q9143   –   Exams after a nuclear medicine study
Q9351   –   Did exposure during lymphoscintigraphy affect my fetus?
Q9412   –   What happens to the technetium-99 in your body?
Q9484   –   Will an iodine-123 scan affect fertility?
Q9489   –   Are cardiac patients at higher risk for cancer from their imaging and treatment procedures?
Q9534   –   Short- and long-term effects of nuclear medicine study
Q10030   –   How long must a person wait between bone scans?
Q10056   –   Dose effects from thallium-201 stress test
Q10271   –   Food and drinks in nuclear cardiology suite
Q10393   –   Dialysis patient and staff issues with cardiac imaging studies
Q10524   –   Underactive thyroid and pregnancy
Q10682   –   Dose from carbon-14 breath test for H. pylori
Q10752   –   Nuclear stress test doses
Q10773   –   Played with son after injection—any risks?
Q10802   –   Since technetium-99m decays to technetium-99, am I radioactive forever?
Q10815   –   Pregnant nurses who care for patients after diagnostic studies
Q10870   –   A nuclear medicine test to tell if there is fluid in the lungs
Q10927   –   Compare radiation doses from nuclear medicine and radiology exams
Q10988   –   Cancer risk from stress tests
Q11017   –   No hazard from technetium-99
Q11023   –   Can a nuclear medicine exam make your hair fall out?
Q11080   –   Incontinent nuclear medicine patient
Q11298   –   Nursing advice regarding nuclear medicine patients
Q11384   –   Renal scintigraphy for children
Q11465   –   Does caring for nuclear medicine patients affect breast milk?
Q11469   –   Carrying radioactive urine in a backpack
Q11537   –   Mothers can hold children who have an injection of a radiotracer
Q11560   –   Should I cancel my stress test?
Q11600   –   Intimacy after Iodine-123 scan
Q11650   –   Nurse's exposure to cardiac patients
Q11759   –   Radiation dose to child near an adult administered radioactive material for a nuclear medicine exam
Q11816   –   Cancer risk for 18FDG PET/CT studies
Q11976   –   Radiation risk from lymphoscintigraphy
Q12387   –   Does the timing of scans matter?
Q12423   –   Radiation risk from stress test and thyroid scan
Q12431   –   Are there protective garments against radiation from nuclear medicine patients
Q12442   –   Using a Geiger counter to measure radioactivity in my body
Q12521   –   Radiation risk from multiple studies
Q12552   –   How much radiation does a nuclear medicine patient emit?
Q12669   –   Breast-feeding after having a HIDA scan
Q12776   –   Could a nuclear scan affect my daughter's health?
Q13046   –   Recommendations for family members after NM myocardial perfusion study or stress test
Q13751   –   Does a nuclear stress test affect the thyroid?
Therapeutic Nuclear Medicine
Q7138   –   Mother questions when to resume activities with children post-therapy
Q7143   –   Patient release criteria using RG 8.39 and NCRP 155
Q7179   –   Fluid intake will reduce the dose to the bladder
Q7184   –   Mother of small child questions isolation
Q7767   –   Is it okay to go to a hotel after iodine-131 therapy?
Q7785   –   Is there a risk having diagnostic exams after iodine-131 therapy?
Q7840   –   Did I expose my family to unnecessary radiation?
Q8053   –   Stand-alone nuclear medicine clinics
Q8224   –   Calculating doses for patient release after 131-iodine therapy
Q8271   –   Will my house retain radioactivity after a therapy dose?
Q8293   –   Fetal risks after iodine-131 therapy
Q8500   –   Post-therapy guidelines for family members seem contradictory
Q8549   –   Treatment of the liver with iodine-131 Lipiodol
Q8596   –   Will iodine-131 affect my septic tank?
Q8606   –   How many times can you treat with iodine-131?
Q8654   –   Precautions when husband gets therapy and wife is pregnant
Q8690   –   How do I keep the exposure to my children low after radioiodine therapy?
Q9026   –   Concerns after treatment with radioactive iodine
Q9091   –   How much radioiodine comes out in sweat?
Q9425   –   How do I protect my baby after iodine-131 therapy?
Q9684   –   Is there a maximum lifetime dose for iodine-131 therapy?
Q9894   –   Septic tank change-out after iodine-131 therapy
Q9970   –   How long should I stay away from children after therapy with iodine-131.
Q10054   –   Did I expose my family to too much radiation after my radioiodine therapy?
Q10362   –   Patients receiving nuclear medicine treatment
Q10420   –   Is low-dose iodine-131 therapy dose safe?
Q10447   –   How long can a whole-body scan be performed after dose administration?
Q10522   –   Differences between low-dose and high-dose therapies
Q10680   –   No breast-feeding after radioiodine therapy for thyroid cancer
Q10868   –   Calculate a total body dose from my therapeutic administration of iodine-131
Q10877   –   Issues when dialyzing after iodine-131 therapy
Q10980   –   Exposed to a radioiodine therapy patient
Q11106   –   Therapy patients going to hotels
Q11199   –   Cautions around children after radiodine therapy
Q11222   –   Home contamination after radioiodine therapy
Q11441   –   More than one radioiodine therapy patient in a room
Q11616   –   Radioactive iodine therapy and contamination
Q11860   –   Activities with family after radioiodine therapy
Q11954   –   Do I need radioiodine after my thyroidectomy?
Q12265   –   Work considerations when the therapy patient is a hairstylist
Q12425   –   Effects from radiation exposure to child from sleeping with mother
Q12930   –   Family and home safety after radioiodine therapy
Q13058   –   Everything to know after radioiodine treatment
Q13658   –   Common complications following high-dose radioiodine iodine-131therapy
Q14337   –   Does the radiation from radioactive iodine therapy have any negative effect on hearing aids?
Q14995   –   Patient internal exposure from Radium-224 leaked from brachytherapy seeds
Positron Emission Tomography (PET)
Q8372   –   Visitor's PET scan and my child
Q8936   –   Is the PET bathroom at a hospital a hazard?
Q9308   –   Dose to a caregiver from a PET scan
Q10332   –   Breast-feeding after scan
Q12540   –   PET/CT at 21 years old
Questions Concerning Domestic Animals
Q7392   –   Protecting cats from radioiodine
Q7631   –   Exposure to pets
Q8917   –   Will my radioiodine dose affect my cats?
Q12386   –   Any concern for my cat after a nuclear stress test?
Q12592   –   Cat in my apartment after treatment with radioiodine
Q12768   –   Protecting myself after my cat's radioiodine treatment
Q12959   –   Pet safety after my radioiodine therapy
Q13550   –   Protecting my cats after my HIDA procedure
Q7991   –   MRIs and CT scans do not involve the use of radioactive drugs
Q8244   –   What is the risk of other cancers after thyroid cancer?
Q8409   –   When is the best time to perform a thyroid bioassay?
Q9698   –   Is it safe to be a nuclear medicine technologist?
Q10639   –   Dosimeter use when the patient works in the medical field
Q11974   –   Dose to infant's thyroid from iodine-131 in mother's milk

Other Useful Websites

The following websites may also be useful:

  External website   About Nuclear Medicine and Molecular Imaging – The Society of Nuclear Medicine and Molecular Imaging
  External website   Nuclear Medicine – Health Physics Society "Radiation Answers"