About Your Placement of Fiducial Markers or Beacon Transponders (Calypso)

This information will help you prepare for the placement of your fiducial markers or beacon transponders (Calypso®) at Memorial Sloan Kettering (MSK).

The prostate is a walnut-shaped gland that is located below your bladder and sits directly in front of your rectum. It surrounds your urethra, which drains urine from your bladder. The gland also adds fluid to your semen.

Markers will be inserted into your prostate so that your healthcare providers can have a better view of your prostate during radiation therapy. There are 2 types of markers: fiducial markers or beacon transponders (Calypso®). Your radiation oncologist will determine which marker is best for you.

You have been scheduled to have markers placed on:

___________________________ (date) with  _______________________ (healthcare provider).

Your procedure will take place at the following MSK location:

Sidney Kimmel Center for Prostate and Urologic Cancers
353 East 68th Street (between First and Second Avenues)
Concourse Level

New York, NY 10065

Before Your Procedure

Tell your healthcare provider if you:

  • Take medication to thin your blood (anticoagulants) such as:
    • Aspirin
    • Clopidogrel (Plavix®)
    • Dalteparin (Fragmin®)
    • Heparin
    • Warfarin (Coumadin®)
    • Enoxaparin sodium (Lovenox®)
    • Rivaroxaban (Xarelto®)
  • Take steroids such as prednisone.
  • Take any other medications such as herbs, vitamins, dietary supplements, or natural or home remedies.
  • Have taken any antibiotics in the past 3 months.
  • Have any heart condition.
  • Have implanted devices such as knee or hip replacements.
  • Are allergic to the antibiotic ciprofloxacin (Cipro®) or any other medications.
  • Are allergic to latex.
  • Had a urinary tract infection (UTI) in the last month.
  • Had an infection or were ever hospitalized after a prostate biopsy.
  • Have a history of Achilles tendon injuries or tendonitis.
  • Have difficulty hearing.
  • Work in a hospital or nursing home.

3 days before your procedure

You may need to stop taking certain medications, including:

  • Aspirin
  • Products that contain aspirin
  • Vitamin E
  • Nonsteroidal anti-inflammatory drugs (NSAIDs) such as:
    • Ibuprofen (Advil® or Motrin®)
    • Naproxen (Aleve®)

If you take aspirin because you’ve had a problem with your heart or you’ve had a stroke, be sure to talk with your doctor before you stop taking it. For more information, review the resource Common Medications Containing Aspirin and Other Nonsteroidal Anti-inflammatory Drugs (NSAIDS).  It includes important information about medications you’ll need to avoid before your procedure and what medications you can take instead.

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The Day of Your Procedure

  • Eat your regular breakfast the morning of the procedure.
  • Do a Fleet® enema the morning of your procedure. You can purchase it at your local pharmacy without a prescription. Follow the instructions on the box.


You will need to take an antibiotic to prevent infection from the biopsy. Your healthcare provider will tell you which antibiotic you will take and give you a prescription. You will take one of the antibiotics listed below. 

Oral antibiotics

  • Ciprofloxacin 500 mg (2 tablets)
    • Take the first tablet 2 hours before your procedure.
    • Take the second tablet 12 hours later.
  • Cefixime (Suprax) 400 mg (1 tablet)
    • Take 1 tablet 2 hours before your procedure.
  • Cefuroxime (Ceftin) 500 mg (2 tablets)
    • ​Take the first tablet 2 hours before your procedure.
    • Take the second tablet 12 hours later.

Intravenous antibiotics

Your healthcare provider may decide that you need intravenous (IV) antibiotics instead of oral antibiotics. In that case, you will get the IV medication through a vein in your arm 1 hour before your procedure.

  • Ceftriaxone
  • ​Meropenem
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During Your Procedure

Your healthcare provider will use a local anesthetic to numb the area around your prostate. It will be similar to what you get at a dentist’s office. A probe will be placed into your rectum. Three markers will then be placed within your prostate through a needle.

This procedure will take 15 minutes. Before you are discharged, your healthcare provider will tell you how to care for yourself at home.

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After Your Procedure

Temporary effects on your stool, urine, and semen

  • You may see blood in your stool. You may also have a small amount of bleeding coming from your rectum. These can occur right after your procedure or for the next few days when you move your bowels.
  • Blood may be in your urine for 7 to 14 days after your procedure. This bleeding may come and go.
    • Increase how much liquids you drink for 3 days after your procedure. Try to drink double the amount of liquids that you usually drink. This will help to flush out your bladder, prevent infection, and minimize the amount of blood in your urine.
  • Your semen may appear “rusty” for up to 12 weeks after your procedure. This is because small amounts of blood may be in it. 


  • Do not engage in any sexual activity for 3 days after your procedure.
  • For the next 5 days after your procedure, do not do any sports, work out in a gym, ride a bicycle, or lift any objects heavier than 10 pounds.
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Call Your Healthcare Provider if You Develop:

  • Bright red blood or large clots in your urine
  • Heavy or continued bleeding out of your rectum
  • An inability to urinate
  • A temperature of 101° F (38.3°C) or higher
  • Shaking chills
  • Dizziness

The information in this resource is selective and does not cover all possible side effects; others may occur. Please report any problems to your healthcare provider.

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