People may be able to stay at home following radioactive iodine treatment. However, they must take certain precautions to protect others from radiation exposure.

People will need to avoid close contact with others for the first few days or weeks after treatment.

During this time, the person must take extra care to avoid contact with young children or pregnant people.

This article looks at what to expect with radioactive iodine treatment and precautions to take following the procedure.

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Radioactive iodine (RAI) is a treatment method for hyperthyroidism and thyroid cancer. RAI is a form of radioactive nuclear medication that permanently destroys thyroid tissue.

People may take RAI orally, in the form of capsules or a drink, or through intravenous injections.

After receiving RAI treatment, the body will emit radiation for a period of time, which means people will need to take certain precautions to prevent the radiation from reaching other people.

People may need to stay in a specialized isolation room in the hospital following treatment, or they may be able to return home. If at home, people will need to take certain steps to protect others around them.

Low levels of radiation may remain in the body for months following treatment. People may be able to resume most normal activities within 5–7 days following treatment.

Small amounts of radiation may remain in the body for up to 3 months after treatment, which can be enough to trigger radiation monitors in places such as airports.

Why do people need to isolate?

People need to isolate themselves after RAI treatment to prevent others from radiation exposure.

It is particularly important to avoid contact with children and pregnant people, as it is especially harmful to developing children.

According to the American Thyroid Association, isolation time may vary depending on the RAI dosage. However, it may be as follows.

Activity Recommendations
returning to workplace remain off work for 1–5 days
spending time in public placesminimize time in public places for 1–3 days
remain 6 ft from others for 2–3 days
traveling avoid public transport or airplane travel for 1–3 days
avoid traveling with others in a car for 2–3 days
spending time with family remain 6 ft from others for 2–3 days
stay 6 ft from children and pregnant people for 1–5 days
sharing a bed sleep in a separate bed from another adult for 1–11 days
sleep in a separate bed from a child or pregnant person for 6–23 days
sharing utensils do not share utensils with others for 2–3 days
preparing food do not prepare food for others for 2–3 days
using the toiletsit down to urinate and flush 2–3 times after use for 2–3 days

However, these are only general recommendations. People must follow exact instructions from a healthcare professional on how to isolate after RAI.

The Society of Nuclear Medicine & Molecular Imaging (SNMMI) offers the following guidelines:

For the first 8 hours, a person should:

  • remain at least 3 feet from other people
  • avoid public transport and if in a vehicle with another person, aim to keep as much distance from them as possible
  • drink one glass of water per hour and use the toilet as soon as possible when needing to urinate

For the first 7 days, a person should:

  • remain in hospital isolation if they have infants or small children, or make arrangements for infants and young children to stay away from home
  • sleep in a separate bed from anyone else
  • avoid physical contact, such as kissing or hugging, with anyone
  • remain at least 3 feet away from pregnant people and anyone under the age of 18
  • avoid any public spaces or activities where people may be close to each other for more than 5 minutes

If people have infants or children at home, they must avoid close contact with them for several days following treatment.

People will need to arrange care for infants and young children for the first 2–5 days of treatment or possibly longer.

If people work with infants or children, they will not be able to resume work for several days following treatment.

The body absorbs RAI and excretes the rest through bodily fluids. Most of the excess RAI leaves the body through urine in the first 2 days. RAI can also be present in saliva, sweat, tears, feces, and vaginal secretions.

To protect others from radiation exposure, people can make sure to:

  • use a private toilet if possible
  • flush the toilet at least twice after using
  • sit on the toilet to avoid splashing and wipe the seat with a tissue after
  • wash hands after using the toilet and then rinse the sink
  • bathe each day
  • wash hands frequently
  • wash any eating utensils after using, washing them separately from others, or use disposable utensils
  • sleep alone and avoid prolonged close contact for 3–4 days, or as long as a doctor instructs
  • wash clothes, bedding, and towels daily and keep separate from other’s washing
  • avoid sharing personal items, such as toothbrushes, towels, and washcloths
  • avoid handling food for others with bare hands

People may find the following tips helpful for coping with isolation:

  • use texts, video calls, or emails to stay connected to friends and family
  • pass the time with enjoyable activities, such as reading, watching television, or listening to music
  • connect with others online who have gone through similar experiences
  • understand that it is normal to find the process challenging, and know that it is a temporary experience

After midnight on the day of treatment, a person will need to avoid eating and drinking until after the procedure.

People will usually be able to return home after having RAI treatment. They must avoid close contact with people for several days following treatment.

People must avoid any activities at work or home that put them in close contact with young children or pregnant people. They will need to avoid these activities for several days.

Before

People must stop taking anti-thyroid medications 3 days or longer before treatment.

People must also follow a low-iodine diet for around 2 weeks before treatment. People will need to avoid:

During

People may experience some thyroid pain during the procedure, which may feel similar to having a sore throat.

People can ask a healthcare professional about taking over-the-counter pain relief to help with this.

After

People may need to stay on a low-iodine diet for 48 hours after treatment.

RAI treatment destroys most or all of the thyroid gland. This means that people will need to take lifelong thyroid hormone replacement medication following RAI treatment.

The risk of cancer from RAI treatment is very low.

People will need to attend regular check-ups following RAI treatment and may need thyroid function tests every 4-6 weeks for 6 months after treatment.

If a person still has hyperthyroidism 6 months after treatment, they may need repeat RAI treatment.

RAI treatment usually results in hypothyroidism, which people will need to treat with thyroid hormone replacement. RAI is generally a safe and effective treatment for hyperthyroidism and thyroid cancer.

This section answers some frequently asked questions about where to stay after radioactive iodine treatment.

Can you stay in a hotel after radioactive iodine treatment?

Experts do not recommend that people stay in a hotel after RAI treatment.

This is because there is the potential for staff to come into contact with bodily fluids that contain RAI.

How long do you have to stay isolated after radioactive iodine?

For the first 8 hours after RAI treatment, people must remain at least 3 feet from other people.

For the first 7 days after treatment, people will need to:

  • sleep alone
  • avoid any physical contact with other people
  • remain at least 3 feet away from anyone who is pregnant or under 18
  • avoid any gatherings or activities where people will be close to others for more than 5 minutes

People will need to follow any instructions from their doctor as durations may vary depending on the dosage of RAI.

How do you clean your house after radioactive iodine?

People will need to wash their bedding, towels, and clothes each day, separately from other people’s items. People do not need to clean the washing machine between washes.

People will need to wash items after using them for eating and drinking. People will need to flush the toilet twice and rinse the sink after use.

Items with heavy staining from bodily fluids, such as sweat, saliva, or blood, may trigger radiation monitors at waste disposal sites.

People can talk with a healthcare professional about safely getting rid of these items.

People will usually be able to return home after RAI treatment. People will need to avoid staying in hotels or public lodgings.

People must avoid close contact with others, particularly with young children and pregnant people.

People will need to follow instructions from a healthcare professional, and they may need to take precautions for up to 1 week after treatment.