Brachytherapy - radioactive seed implants 

Home Treatments Lifestyle Symptoms Cancers

Who is eligible
Advantages and disadvantages
The volume study
The implant procedure
Post implant
Radiation safety

Side effects
Diet and bowel preparation 

Internal Radiation Therapy is available in some cases using tiny pellets containing radioactive medications, such as Iodine-125 Seeds, which are permanently implanted directly in the middle of the cancer where they can give off low-level radiation continuously for approximately one year. 

Patients are treated as an outpatient or at the most have one night in hospital. The majority of patients are back to work within one week, incontinence is rare and sexual potency is preserved in 93%.

Using transrectal ultrasound guidance, these seeds can be positioned so that radiation is distributed throughout the prostate gland. Since only a small volume is irradiated by each seed, relatively little radiation reaches the adjacent normal organs - the colon, which is directly under the prostate gland, or the bladder, lying on top of the gland.

 The implant procedure does not require a surgical incision. Instead, the seeds - smaller than grains of rice - are contained in thin needles which are passed into the prostate gland through the skin between the scrotum and rectum. As the needles penetrate through the prostate, they are seen on the screen of the ultrasound machine and can be accurately guided to their final position. While the needles are being inserted the ultrasound probe is in the rectum. When each needle is in its correct position in the prostate, the needle is slowly withdrawn and the individual seeds are injected into the prostate gland. The ultrasound probe and the needles are removed when the procedure has been completed. The number of needles and seeds required varies from patient to patient depending on the size of the prostate gland.

Who is eligible

Advantages and disadvantages

Advantages:   The most recent clinical data, based on 451 patients followed for up to six years, shows a higher percentage if implant patients remaining disease free than with either radical prostatectomy or external beam therapy.

Seed implantation is normally done as an outpatient procedure taking about one hour to perform. The patient usually leaves the hospital the same day as the implant procedure and resumes normal activities within several days.

Because the seeds are placed directly into the prostate, they can deliver two to three times more concentrated radiation to the prostate gland than external beam therapy.

Incontinence occurs in less than 5% of patients who have not had prior prostate surgery. 1,2.

Impotence occurs in 20-30% of patients under the age of 60. For patients over the age of 60, impotence occurs more often.

This procedure is better tolerated than surgery or external radiation and is well suited to older patients because it is much easier to withstand than surgery or external radiation.

 Disadvantages: The long term results are unknown at this time. The current clinical data show good results up to eleven years.

It is very common to experience problems with urination for several months after seed implantation. These symptoms will, however, gradually ease and eventually disappear.

Although the seeds remain radioactive for several months, the energy and activity of the seeds is so low that there is negligible risk of exposure to others and only simple precautions are necessary for the first 2-3 months.

The volume study

About 3 to 8 weeks before the implant a volume study of the prostate gland will usually be performed. The volume study is an examination to determine the exact size and position of the prostate gland. This examination is performed in theatre and requires a short anaesthetic. It will take about thirty minutes.

Using a TRUS (transrectal ultrasound) unit several ultrasound images will be taken of your prostate gland. These images provide a three dimensional model of the prostate gland which is then used to determine the number of iodine seeds needed to treat the prostate and exactly where they should be placed.

Before the implant, you may have blood tests done and possibly an electrocardiogram (ECG) and chest x-ray. Your doctor will determine which tests are necessary. The test results are used to inform the anaesthetist of your ability to tolerate anaesthesia.

One to two days before the implant, you will be given specific instructions regarding diet and bowel preparation. The bowel preparation will involve an enema. This removes faecal material from your lower bowel and rectum so that the ultrasound image of your prostate will be clear.

The implant procedure

The implant procedure is performed in theatre and lasts one to two hours. You may receive a general anaesthetic or local spinal anaesthesia. An ultrasound probe will be inserted into the rectum to image the prostate on a television monitor. The seeds, usually about 80 to 100, are then inserted into the prostate with needles. The needles are inserted through the skin between the scrotum and the anus and, with the TRUS (transrectal ultrasound) device, are guided with pin-point accuracy directly into the prostate. At the end of the procedure, a urinary catheter is temporarily placed in your bladder to drain urine.

Post implant

After the implant you will go to a recovery room for about two hours. While in the recovery room you may have an ice bag placed between your legs to help reduce swelling of the implant area. It is at this stage that the urinary catheter is usually removed. Occasionally, the catheter is left in overnight.

Antibiotics are given after the implant to prevent infection. You should take them as prescribed until you have used them all.

Most patients go home the day after the procedure but some leave hospital as soon as they have recovered from the anaesthetic and are able to pass urine freely. Because you may feel a little weak, it is recommended that you do not drive for at least 12 hours.

You  may resume eating and have visitors as soon as you wish, but you should avoid heavy lifting or strenuous physical activity for the first two days you are at home. After that you will probably  be rady to return to your normal activity level.

Side effects

Immediately after the implant you may experience some of the following

These side effects are temporary and are caused by the needles used to place the seeds. The seeds themselves, the catheter and other instruments used during the procedure can also contribute to these side effects.

If you do feel discomfort, your doctor can provide you with pain medication.

You may notice a slight trace of blood in your urine for several days after  the implant. This is quite normal so don't be alarmed. If the bleeding becomes severe or there are large blood clots, call your oncologist or contact the ward from which you were discharged. Drinking plenty of water helps prevent blood clots and flushes the bladder.

15% of patients may get acute retention of urine and require a catheter.

Later on, you may also experience frequent or uncomfortable urination, a sense of urgency and a weaker urinary stream, This is generally due to the radiation from the seeds in the prostate. These symptoms will gradually decrease as the seeds lose their strength. This may be up to 6 to 12 months after the implant and can often be helped by dedication. Drinking plenty of fluids and avoiding caffeine may help to relieve these symptoms.

As with all medical procedures, there is a small chance that there can be long term, or even permanent, side effects. Your specialist doctor will discuss these risks with you.

Radiation safety

Many patients are concerned about whether an implant poses any potential dangers of radiation exposure to their family and friends.

Although the seeds are radioactive, you are not. One advantage of radioactive iodine-125 seeds is that essentially all radiation is absorbed within the prostate. Patients are not considered to be radioactive following discharge from the hospital. There are no restrictions on travel or physical contact with other adults. However, special precautions should be taken when the patient is in contact with small children and pregnant women in the first two months after treatment.

Special precautions

Women who are (or may be) pregnant should not sit very close to you, on the same settee for example. Apart from this there is no need for you to treat them any differently to how you would have done before the implant. You may greet them as you normally would and they may stay in the same room as you for as long as you wish.

The seeds are permanently imbedded in the prostate gland but there is a remote chance of a single seed being passed during sexual activity. Patients are therefore advised to use a condom for the first few weeks after the implant. During this time your semen may be discoloured brown or black. This is normal and is a result of bleeding that may have occurred during the operation and is now being released into the ejaculate. Condoms should be disposed of by double wrapping and placing in the dustbin.

From a practical standpoint, iodine-125 seeds produce radiation for about one year. After the radiation disappears, the seeds remain in the prostate gland, causing no problems.

Suggested Follow-up Schedule

After a seed implant you will see your urologist and radiation oncologist on a regular basis. Both specialist doctors will work together to provide you with the best care possible. The follow-up schedule starts six weeks after the implant and usually includes a visit every three to six months for the first five years, to check treatment progress. You may have a physical examination or blood tests during these visits.

About six weeks after the implant you will have a routine CT scan. This scan allows us to monitor the quality of our implants, to ensure they remain at a high standard.

The scan does not monitor the effectiveness of the treatment therefore you will not receive any results.

The effectiveness of treatment will be assessed by the follow up schedule mentioned above.

Diet and bowel preparation (Citramag)

Citramag (bowel laxative) will be given to you on the ward, it will give you diarrhoea and clear your bowels for the procedure. You will need to stay close to a lavatory afterwards. A little Vaseline around the back passage will prevent soreness. You should continue all medications as prescribed by your doctor with the exception of iron preparations. After taking your Citramag it is necessary to commence a clear liquid diet.

The following clear liquids are allowed:

Fruit juices:    apple, cranberry, grape, strained orange juice

Desserts:        jellies, fruit ices

Beverages:     coffee, tea lemon/orange drinks

Soups:           any strained soups

NO ALCOHOL PLEASE
Remember to drink as much fluid as possible.
Prior to your examination, the nursing staff will administer an enema on the ward.

To make Citramag pour 200mls or 8floz of hot water into a wide mouth measuring jug. Open 1 sachet of Citramag and empty contents into water. Stir thoroughly to dissolve and allow to cool. When cool pour solution into a suitable glass and drink.


Further general information Your doctors and specialist nurses are in an ideal position to give you relevant information on your disease and treatment as they know your individual circumstances. Cancerbackup has a help line (0808 800 1234) and a prize winning video available in English, Italian, Urdu, Bengali, Gujarati & Hindi explaining Radiotherapy & Chemotherapy. Cancernet.co.uk has over 500 pages describing cancer, its management, practical tips and tool which patients, their carers and their doctors have found helpful during the cancer journey.


Home | Cancer management | Cancer treatments - Chemotherapy Radiotherapy  Hormones  Biologicals | Complementary | Lifestyle - Exercise  Diet  Smoking  Sun | Tests for cancer | Books | Videos | Travel | Insurance | Symptoms | Side effects | Clinical trials | Glossary | Support groups & links | About cancer | About us | Disclaimer