Definition & Overview

An interstitial radioelement application is a procedure that is used to treat cancer. It involves exposing cancer cells (tumour) to radioactive substances with the expectation that the abnormal cells will be destroyed in a given period. The procedure is also referred to as brachytherapy.

Brachytherapy was developed over a century ago. In the early years, it did not yield successful results mainly due to the scarcity of radioactive material radium. Because of this, inadequate amounts of the substance were being used, rendering the procedure less effective. However, the discovery of more radium deposits made it possible to utilise the correct quantities of radioactive material for the procedure.

Brachytherapy is not the only form of radiation therapy used to treat cancer. Another form is external beam radiation therapy (EBRT). This method involves applying radioactive beam directly above the tumour. However, studies have shown that internal radiation therapy (brachytherapy) is more effective as the method allows the use of stronger radiation for shorter periods.

There are two basic types of brachytherapy procedures: temporary and permanent. The temporary method involves inserting the radioactive material through a catheter and directing it near or inside the tumour. After a specified period, the material is removed and the session completed. However, additional sessions may be required in the future. The radioactive substance can then be provided in low or high doses.

In a permanent brachytherapy procedure, the radioactive material (seeds), which is the size of a small pellet, is implanted into or near the tumour permanently. The radioactivity of the material will dissipate within a few months, thus causing no further harm to the surrounding area. The patient will not be aware of the presence of the seed, but it can be picked up by metal detectors.

Who Should Undergo & Expected Results

Brachytherapy is used as a treatment method for a wide variety of cancers, which include:

However, it is important to note that the procedure is only recommended if certain conditions are met. For example, if used in the treatment of breast cancer, the patient must be at least 50 years old and the tumour is less than 3cm.

Prior to undergoing the procedure, the patient needs to undergo a physical exam and the cancer must be studied carefully to assess the type of procedure required and the chances of success. The expected results of the procedure differ according to the type performed. Patients who undergo temporary brachytherapy will not need to be concerned about radioactivity after the procedure. This is because the radioactive material is removed from the body and doctors will ensure that the patient shows no signs of being radioactive before leaving the hospital.

Patients who undergo permanent brachytherapy have a different dilemma. Although the amount of radiation they will emit is considered small, it can still be a concern for pregnant women. Moreover, the radioactivity can be detected by machines at airports or other areas. In any case, this will only be for a limited time as the effects of the radioactive material are expected to dissipate within a few weeks or months.

How Does the Procedure Work?

Prior to the procedure, the patient will need to undergo several tests. These can include an electrocardiogram, x-rays, blood tests, and imaging tests.

Interstitial radioelement application, as the name suggests, is the use of radioactive materials passed through a small gap. In some cases, the material can be inserted through an available opening, such as the vagina. In others, doctors will need to inject the material using a catheter that is introduced into the body through a small puncture wound.

Once the catheter is in place, the surgeon will direct it to the location of the tumour. A wire that contains the radioactive element at the end is passed through the catheter and inserted into the tumour or near it.

During a temporary brachytherapy, the radioactive material is retrieved once the session is complete. In a permanent brachytherapy, the material is implanted into the area, but the wire and catheter will be retrieved.

After the procedure, the patient is given home-care instructions. Such instructions may include what to avoid during home treatment, such as going near pregnant women if a permanent radioactive material was implanted. In such cases, the doctor may also provide a letter detailing the patient’s condition and therapy in case radioactivity is detected by authorities.

Possible Risks and Complications

Although a highly effective form of cancer treatment, brachytherapy does have side effects. These may differ according to the type and location of the cancer being treated. Some of the most common are:

  • Fatigue
  • Swelling
  • Bruising
  • Abnormal bleeding
  • Pain or discomfort
  • Abnormal vaginal discharge
  • Urinary pain
  • Urinary incontinence
  • Diarrhoea
  • Rectal bleeding

There is also a possibility of long-term complications, such as erectile dysfunction and infertility. Moreover, there is a chance that the implanted pellet (seeds) may in time pass through the urinary system.


  • Lanna Cheuk DO; “Brachytherapy (Radioactive seed implantation therapy) in Prostate cancer”;

  • Website; “Brachytherapy”; Website Cancer Treatment Centers of America; “What is Brachytherapy”;

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