Prostate Brachytherapy 2017-06-14T10:00:34+00:00

Prostate Brachytherapy

What shall I know about prostate brachytherapy?

Prostate brachytherapy is a very sophisticated therapy for prostate cancer. During this treatment, radioactive seeds of iodine-125 (I125) are placed permanently in the prostate gland. The term «brachytherapy» was chosen on purpose, as in ancient Greek «brachy» means «short», which indicates that the radioactivity is administered directly to the cancerous tissue, in contrast with traditional external beam radiation, where the radioactivity unavoidably passes through healthy tissue before reaching the prostate. Brachytherapy delivers higher and more localized radiation to the prostate, while minimizing the effect on the neighboring organs such as the bladder and rectum. 

Prostate brachytherapy is a very sophisticated therapy for prostate cancer. During this treatment, radioactive seeds of iodine-125 (I125) are placed permanently in the prostate gland. The term «brachytherapy» was chosen on purpose, as in ancient Greek «brachy» means «short», which indicates that the radioactivity is administered directly to the cancerous tissue, in contrast with traditional external beam radiation, where the radioactivity unavoidably passes through healthy tissue before reaching the prostate. Brachytherapy delivers higher and more localized radiation to the prostate, while minimizing the effect on the neighboring organs such as the bladder and rectum. 

What are these radioactive seeds?

The radioactive seeds are small «cartridges» of titanium, 4.5mm long by 0.8mm diameter, containing the radioactive isotope iodine-125. The half-life time, that means the time required for the radioactivity to be reduced by half, is about 60 days, which means that most of the radioactivity is released into the prostate during the first three months. The granules remain biologically active for a total of approximately 9 months, while after this, they become virtually inactive.

How is this procedure developing?

Brachytherapy for prostate cancer takes part in two stages. Stage one involves a transrectal ultrasound examination of the prostate, while Stage two involves the implantation of the radioactive seeds and can either be done at once, using the «Real-time» technique, or about four weeks later, as called the «Seattle technique».

Prostate Examination

This is a detailed ultrasound examination, typically performed as a day case -no hospitalization needed, under general or local anesthesia, while the patient is going home shortly afterwards. As preparation, the patient will receive a laxative beforehand, in order for the bowels to be as empty as possible, to allow a reliable sonographic image to be viewed. During the examination, a volume catheter will be inserted into the urethra, which will help to clearly distinguish the urethra during the study. The catheter will be removed immediately after the procedure.

The volume of the prostate and the position of the urethra and rectum are recorded in the prostate examination.

Then, the specialized brachytherapy software creates a 3D model of the prostate and produces a plan for the dosage. This plan is unique to each patient and determines the location and number of radioactive seeds required -these seeds are then ordered.

In some cases, when the volume of the prostate is large, between 50-80cc, treatment with the seeds may need to be preceded by three months’ worth of hormonal therapy to reduce the size of the prostate and thus allow the implantation of radioactive seeds.

Implantation of seeds

Patients are usually admitted to hospital the day of the treatment. Adequate bowel preparation is necessary here.

The surgery is performed under general anesthesia. The implantation of radioactive seeds is done under ultrasound guidance adjusted using a special needle inserted through the perineum. Each needle helps to introduce 2-6 seeds and usually 20-30 needles are used to introduce 80-120 seeds. The granules are attached to an absorbable thread, which ensures that they remain at the site of implantation. The seeds remain at the point of implantation permanently. A urethral catheter is inserted, as in Stage 1 – the only difference being that the patient now remains in hospital until the next morning.

Which patients are suitable for this treatment?

Patients suitable for brachytherapy are those whose cancer still has a high chance of being confined within the prostate, without spreading to the near or distant organs. In some cases, when there are indications that the cancer has spread to a small area in surrounding tissues, the patient may need to receive a treatment of five weeks of external beam radiation therapy prior to brachytherapy. This combination treats a more extensive tissue area around the prostate.

The brachytherapy specialized team of Urologists will advise you whether or not you are a suitable candidate for brachytherapy.

Patients suitable for brachytherapy typically have the following characteristics:

  • The PSA (Prostate Specific Antigen) should ideally be less than 20ng/ml at diagnosis.
  • The cancer should be at stage T1 or T2 in the digital rectal examination, suggesting limited cancer within the prostate.
  • The malignancy Grade should ideally be Gleason Score 7 / 10 or less.
  • Patients should not suffer from significant urological symptoms such as decreased range of urination or difficulty emptying the bladder.
  • Ideally the prostate should be relatively small – less than 50cc. If the prostate gland is very large, some areas of the gland may be «hidden» behind the pelvis, making it impossible to achieve a satisfactory implant.

Is brachytherapy effective?

Long-term results from U.S. patients who underwent brachytherapy more than 15 years ago, show that it is a very effective form of treatment for patients with localized prostate cancer.

Brachytherapy compared with other treatments, as radical prostatectomy, external radiation, seems equally effective, but has fewer side effects and complications.

However, brachytherapy is not of course the only effective form of treatment for prostate cancer and some patients may have evidence for another form of therapy.