Page 1 of 4
Radioactive Seed Localization for Breast Surgery
What is radioactive seed localization?
This is an alternate procedure to having breast wire localization.
The seed can be placed several days prior to surgery. It will not move out of place. Having this
placed in advance will decrease the time spent at the hospital on the day of surgery.
A radioactive seed is a tiny metal piece about the size of a
sesame seed or point of a pencil. It contains radioactive
material that is sealed inside the seed. It will stay inside
the seed so that items you touch, people you talk to, and
the clothes you wear do not become radioactive.
The figure to the left shows the size of the radioactive
seed compared to a dime.
During wire localization, a wire is placed in the
breast to mark the location of the cancer on the
day of surgery.
A patient must arrive early on the day of surgery
for this procedure.
Page 2 of 4
Like wire localization, the radioactive seed is placed by a radiologist and is done in the breast
This may allow the surgeon to be more precise in locating the area of the breast to be removed.
Use of the seed instead of a wire may result in the surgeon being able to remove less tissue from
What to expect during seed localization
During the Procedure:
You will begin by having an ultrasound or mammogram of your breast. The breast imaging
technologist will locate the area of concern.
1. The technologist will clean your breast with an antiseptic solution.
2. The doctor will inject the numbing medicine (Lidocaine®) into your breast. You will feel a
stinging during this injection, but it will numb your breast quickly.
3. The doctor will place small needle into your breast at the site of concern. You may feel
pressure during the procedure. If you feel pain, please let the staff know so additional numbing
medicine can be given.
4. When the needle placement is confirmed, the radiologist will remove the needle leaving a
radioactive seed in place. Because the seed is so small, you will not be able to feel it.
5. After the procedure is complete two or more mammography pictures are taken to confirm the
seed placement. Your surgeon will refer to these during the surgery.
6. A small strip of tape called a steri-strip will be placed over the site.
Care After the Seed Localization.
You will meet with a nurse after the seed placement. The nurse will assess the insertion site for
any bleeding and place a protective bandage over the site. You can remove the bandage the next
day; however, keep the steri-strips in place.
If you are not having surgery the same day, avoid vigorous arm movements and heavy lifting
(more than 10 pounds) for the next 24 hours. You may return to work and most activities the
You may apply ice to the insertion site. This may help to reduce swelling and pain. Do not place
ice directly on the skin.
It is recommended you wear a comfortable supportive bra to minimize breast movement. A
sports bra works best.
Page 3 of 4
You may shower the next day and allow water to run over the insertion site. Pat this area dry. Do
not soak in a tub or pool for 48 hours.
You may have some mild discomfort and bruising. If you need something for discomfort,
Tylenol will often manage this pain. Take as directed.
Monitor for any signs of infection such as a temperature over 100.4°F, significant swelling,
firmness or warmth, increased redness or drainage around the site that is pus-like.
Please call the Breast Center if you are having heavy bleeding from the insertion site (bleeding
that soaks the bandage or that is flowing from the site). Hold firm pressure to the site if this
occurs. It is normal to have a small amount of blood (dime to quarter size) show through on the
Will I or those around me be exposed to harmful radiation if I have a radioactive seed
The radiation in the seed is not dangerous. It gives off only enough radiation to act as a marker
for the surgeon. Those who are in close contact with you may be exposed to very small amounts
of radiation. While there is no evidence that this causes harm, there are ways to reduce exposure
o The amount of radiation coming from your body is very small. It decreases a
great deal at one foot and is almost zero at three feet.
o Radiation exposure to others depends on how long you remain in close contact
with them. You cannot harm anyone by shaking hands, hugging or kissing. You
can sleep with a spouse or partner in the same bed. You can continue with most
o You should avoid placing an infant, child, or young animal on your chest for
longer than 30 minutes per day while the seed is in place.
o Once the seed is removed, the radiation is gone. The seed is disposed of
according to strict guidelines developed by UW Hospital.
ξ Radiation amount
o The amount of radiation a person will receive over a one hour period of being
within one foot of the radioactive seed is five times less than the radiation
exposure you would receive with a dental x-ray.
o The limit for workers that handle radioactive materials is 50 units per year. A
worker could be within 1 foot of a seed for an entire year straight and only be
exposed 9 units of radiation, less than one-fifth of the workers limit.
Page 4 of 4
Day of Surgery
On the day of surgery, the surgeon will make an incision into your breast and use a special tool
to remove the seed and the tissue around it. After the tissue is removed, it is x-rayed to assure
that the tissue contains the seed and the same area of concern that was seen on breast imaging.
The tissue is sent to our lab where a pathologist will look under a microscope to see what types
of cells are present in the tissue removed. You will be given the results in 3-5 working days.
Your surgeon will contact you to discuss results.
Seed removal and disposal
It is important you return for your scheduled surgery to have the seed removed. UW Hospital
and Clinics is required to assure proper disposal of every seed placed.
If there is any event that would keep you from having the radioactive seed removed on the
scheduled surgery date, please call the UW Hospital Breast Center immediately to inform
your breast surgeon. If you are unable to call, be sure that someone on your behalf contacts the
If you have questions or concerns or are not able to keep your surgery date, please call:
UW Health Breast Center Triage Nurse Line (608) 262-1368, this line is checked frequently. Or
call the UW Health Breast Center (608) 266-6400 and ask to speak to a nurse. Hours are
Monday through Friday, 8:00 a.m. to 5:00 p.m.
For medical emergencies, call 911.
After hours and weekends, call (608) 262-2122. This will give you the paging operator. Ask to
speak to the blue surgery resident on call. Give the operator your name and phone number with
the area code. The doctor will call you back.
If you live out of the area you may also call toll free at 1-800-323-8942.
Your health care team may have given you this information as part of your care. If so, please use it and call if you
have any questions. If this information was not given to you as part of your care, please check with your doctor. This
is not medical advice. This is not to be used for diagnosis or treatment of any medical condition. Because each
person’s health needs are different, you should talk with your doctor or 3/2015. University of Wisconsin Hospitals and
Clinics Authority. All rights reserved. Produced by the Department of Nursing. HF#7732.