Brachytherapy entails the insertion of radioactive seeds into the prostate gland. The specific manner of placement creates a radiation "cloud" or dose around and within the prostate gland in order to irradiate cancerous cells. This is fast becoming the treatment of choice for prostate cancer.
The procedure is done by a multi-disciplinary team, namely a Urologist, Radiation Oncologist, Anaesthetist and Medical Physicist. The particular procedure done at our Brachytherapy unit is termed intra-operative, real-time interactive, brachytherapy. This involves the creation and execution of an individualised radiation plan in real time, in the theatre. Doses are adjusted as the implant takes place to ensure maximum efficacy while controlling the dose to sensitive structures, being the urethra and rectum. As a result of this new technology, the side-effects of the treatment can be kept to a minimum.
Radiation safety is a concern of many patients. Radioactive Iodine (I-125) is a low energy radioactive material that will lose its radiation quickly. The low energy of the seeds means that the radioactivity cannot travel far and is thus mostly contained within the prostate gland. A small amount of radiation will be given off to the rectum and bladder. A very small amount of radiation will escape from your body. Therefore you should take precautions to ensure that people within proximity are protected from radiation. Objects that one touches will not become radioactive. Very occasionally a seed can migrate from the prostate in the bladder - you will then pass this seed when you urinate. The lost seed will not affect anybody or the result of the treatment.
TRANSRECTAL VOLUME ULTRASOUND STUDY (TRUS)
TRUS is an excellent method of imaging the prostate gland and the surrounding tissues. Because each man's prostate is unique, the TRUS is required to assess the size and shape of the prostate gland. This information is critical in determining how many seeds will be needed to be implanted into the prostate gland.
An image of the prostate, by means of an electronic probe, is recorded on paper as well as digitally. This information is then downloaded. Using this information, the Radiation Oncologist calculates your dose requirements using a technologically-advanced computer program. The radioactive seeds are then ordered to arrive on the day of procedure.
If you have not been put onto hormonal therapy for three months prior to the procedure, a second TRUS will be scheduled because the prostate gland actually shrinks when a patient goes onto hormone therapy. A smaller gland means less seeds need to be ordered. This is important for your medical aid, as the seeds are the most costly component of the brachytherapy procedure.
Some patients require hormonal therapy for three months prior to their Brachytherapy procedure. This is known as neo-adjuvant therapy. Firstly, in patients with very large prostate glands, the hormonal therapy will shrink the gland to a more manageable size. The larger the gland, the longer and more expensive the Brachytherapy procedure will be. Secondly, patients are stratified into low, intermediate and high-risk groups for disease reoccurrence after treatment. Patients in the high-risk group and some patients in the intermediate-risk group will be prescribed hormonal therapy.
The treatment comes as an injectable depot preparation called Zoladex, Superfact or Lucrin. The effect lasts for three months. The treatment should be looked upon as the first stage of your cancer treatment.
The usual side-effects include hot and cold flushes, loss of sexual libido, and some mild fatigue. These effects will cease when the medication wears off. If you experience any other symptoms, it is very important to advise the Urologist immediately.
Medical aids often require motivation for this therapy. You should be patient whilst your the medical aid goes through their standard process of assessment.
Is brachytherapy more effective than surgery or external beam radiation?
None of the three options have proven to be more effective than the others in controlling the disease. However, Brachytherapy carries a dramatically low side-effect profile compared to the other options, provided it is done by competent professionals.
How long will the seeds be radioactive?
The half-life of radioactive Iodine (125-I) is about two months. After 10 - 11 months the seeds have virtually no activity left.
What long-term effect will the seeds have if left in my body?
None. It is absolutely safe.
If I experience impotency, is there anything that can be done?
There is a penile rehabilitation plan that will be of some use to certain patients. It includes the use of certain drugs to enhance erection. You should speak to your urologist or oncologist.
How long will I be in hospital?
Most patients will be discharged the same day after emptying their bladder without a catheter; but this is up to the discretion of the Urologist or Oncologist.
How long does the implant take in theatre?
Approximately two hours.
What equipment is required for the procedure?
Highly sophisticated equipment is required for visualisation and determination of needle placement. A laptop with the necessary software is connected to this and the plan is worked out in real-time by the oncologist and physicist. The seeds are placed accordingly once the plan is completed.
How many seeds will be placed?
This depends on the size of the prostate. The number of seeds will range between 60 and 100 and 18 to 24 needles will be used to insert the seeds.
What are the seeds, what strength are they and what is the size of the seeds?
The seeds are radioactive Iodine in a sold state (metal) that have an activity of 0.35 mCi. They are approximately 4 mm in length.