Low Dose-Rate Brachytherapy

Low dose-rate brachytherapy, unlike external beam radiotherapy, treats the cancer by permanently inserting tiny radio-active seeds of Iodine-125 directly into the prostate with the aim of destroying the cancer.

What is involved?

The process is done in three visits:

  1. An outpatient appointment will assess your suitability for the treatment, and will consist of some simple tests, which would typically include a DRE examination and a trans-rectal ultrasound examination.
  2. The first stage of the treatment will be done as a day case in order to identify the exact size and shape of the prostate by computer imaging, and to plan the radiation dosage required.
  3. The second stage of the treatment consists of the actual implantation of the seeds under general anaesthetic by a series of 20–30 needles, each implanting between 2 and 6 seeds. X-rays may be taken during the procedure. You will wake with a catheter in place, which is removed before you leave hospital. A CT scan (see Further Tests for Prostate Cancer) is done following the treatment in order to check that the right dose has been delivered. Patients are sent home the next day with antibiotics and other medicines.

Is the radiation dosage dangerous?

The major portion of the radiation is released from the seeds into the prostate over the first three months. Thereafter the radiation decreases so that it is negligible after nine months. While the seeds are radio-active, you are not. No special precautions are generally considered necessary, but it is suggested that you avoid near contact with pregnant women, and young children should not sit on your lap for the first two months after the treatment. When having intercourse, you may be advised to use condoms for the first two occasions.

Side effects

About 5–10% of patients may experience temporary urinary retention. Some may experience frequency and urgency, which are again generally temporary. Bowel problems, (constipation or frequency) can occur 3–6 months after the treatment. Erectile problems can occur in 20–30% of men. These risks are claimed to be lower than with surgery or external beam radiotherapy and it has been shown that these have significantly improved with greater experience. There is evidence of a small risk of pelvic cancers after brachytherapy.

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Advantages and disadvantages

  • It allows a higher dose of radiation to be delivered directly to the prostate when compared with external beam radiotherapy.
  • There is only a short stay in hospital and in most cases no catheter after the treatment.
  • Incontinence is rare (less than 1%) and around 70-80% of patients retain their potency.

  • Only a few days off work are needed.

But:

  • The result of the treatment will not be known for several months.
  • There may be temporary worsening of urinary symptoms for about three months after treatment.
  • There is a risk of a narrowing of the urethra after treatment.
  • Brachytherapy is not possible after external beam radiotherapy.
  • Surgery is more difficult, though rarely needed, after brachytherapy and may lead to pourer outcomes.

 

 

4D Brachytherapy

A newer method becoming more common in many hospitals is 4D brachytherapy. It only requires two visits – an initial outpatient assessment, followed by the seed implantation, during which the planning is performed, known as real-time planning. 4D brachytherapy uses two different types of seed which come ready prepared in the correct implantation order. The whole procedure can be done more efficiently and accurately in under an hour, with a quicker recovery time and with fewer side effects for the patient.