This page discusses permanent brachytherapy (also known as low dose-rate brachytherapy) which is the most common brachytherapy approach used in New Zealand. As these names imply, the radioactive seeds remain inside the man’s prostate permanently, initially delivering a targeted low radiation dose and then gradually losing their radioactivity.
The radioactive seeds are small — less than the size of a grain of rice — and are implanted directly into the prostate gland. The seeds contain either radioactive iodine-125 or radioactive palladium-103. The total number of seeds required will vary according to the size of the prostate gland. It is possible to implant over 100 seeds if required. The seeds remain in place permanently but gradually lose their radioactivity while treating the cancer over a period of approximately six months.
The procedure is performed by a specialist radiation oncologist (cancer specialist) and a specialist urologist (urinary system specialist). The implanted seeds deliver about twice the dose of radiation to the prostate gland that external beam radiotherapy does. However, because the radiation is concentrated in a localised area, damage to healthy adjacent tissue is minimised and side effects are potentially less than those of the external beam radiotherapy procedure. A possible exception is the urethra, which is partially surrounded by the prostate, and can receive high doses of radiation leading to complications such as difficulty urinating.
Brachytherapy has a distinct advantage over external beam radiotherapy in that only a short visit to a hospital is required, rather than several visits to a radiotherapy clinic. However, brachytherapy is not appropriate for many men because of their type of cancer, the size of their prostate, or because they have had prior surgical treatments such as transurethral resection of the prostate (TURP), a common surgical treatment for enlarged prostate.
Before the procedure it is necessary to assess the size and shape of the prostate gland. This enables the implant procedure to be accurately planned and for the number of seeds required to be determined. During the assessment, a CT scan (computerised tomography) or MRI (magnetic resonance imaging) and a transrectal ultrasound scan will be performed.
Blood tests to measure the PSA (prostate specific antigen) and an ECG (a tracing of the heart’s electrical activity) will also be required. Bowel preparation, including a clear liquid diet and the administration of enemas, will be necessary on the day prior to the procedure to ensure that the lower bowel is clear.
The procedure is performed in an operating theatre using a spinal or general anaesthetic. A transrectal ultrasound probe is inserted into the rectum in order to locate the prostate gland and enable it to be seen on a monitor.
The seeds are placed into the prostate gland using needles inserted through the perineum (the area of skin between the scrotum and the anus). The transrectal ultrasound scan and x-rays are used to guide the needles and to assess the positioning of the seeds.
At the completion of the procedure a catheter (drainage tube) is inserted into the bladder to drain the urine. This is usually removed after a few hours.
Most people are able to be discharged from hospital within 24 hours of the procedure and a return to normal activity can usually be achieved within two to three days.
Side effects and complications
Common side effects of prostate brachytherapy include:
- Blood in the urine: This is normal and should resolve within a few days
- Bruising and tenderness of the perineum
- A burning sensation when urinating: Drinking plenty of fluids will help to minimise this and will help prevent urinary infection
- Difficulty passing urine, or an urge to pass urine quickly or more often
- A temporary increase in the frequency of bowel motions
- Pain or burning with ejaculation
- Discolouration of the semen
- Fatigue: This is common to all types of radiation treatment
These side effects are at their most troublesome four to six weeks after the procedure. However, for most patients they will subside completely over a period of a few months. More serious side effects can occur:
- Urinary incontinence (10-35% in the first few months, but few patients have leakage after one year)
- Rectal bleeding, usually just a few spots of blood (<5%)
- Ulceration of the rectum (<1%)
- Impotence (2.5 - 25%): This risk of impotence increases over the age of 60.
The risks and side effects of brachytherapy should be discussed with the specialist(s) prior to treatment and should be a consideration when deciding whether or not to opt for this treatment. More detailed information about the treatment and radiation safety guidelines will be given by the specialist(s) performing the procedure.
Follow up careIn order to check the position of the seeds a CT scan will be conducted about one month after the seeds have been implanted. Follow-up examinations are usually recommended every three months for the first year, then every six months after that. Rectal examinations and blood tests to measure the PSA levels are usually conducted in order to monitor the effectiveness of the implanted seeds in treating the prostate cancer.
Support and information
Cancer Society of New Zealand Information Service
Freephone Helpline: 0800 CANCER or 0800 226 237
Prostate Cancer Foundation Of New Zealand
Freephone Helpline: 0800 4 PROSTATE or 0800 477 678
Brightside Brachytherapy, Epsom, Auckland.
Australian Prostate Cancer Coalition (2010). Localised prostate cancer: a guide for men and their families (PDF). Sydney: Cancer Council Australia. www.andrologyaustralia.org/wp-content/uploads/BL-Localised-Prostate-Guide-2010-web-version.pdf
Matthews, J. (1999) Trans perineal permanent implantation of radioactive seeds into the prostate for prostate cancer. Auckland: Dr John Matthews
Zorn, K. C., Gautam, G. (1996-2013) Prostate cancer. Foothill Ranch: MedicineNet. Inc www.medicinenet.com/Script/Main/Art.asp?li=MNI&d=295&f=456&ArticleKey=456
O’Toole M.T. (Ed.) (2013) Mosby’s Dictionary of Medicine, Nursing & Health Professionals (9th ed.) St. Louis: Elsevier Mosby.
Theodorescu D. (2012) Brachytherapy (radioactive seed implantation therapy) in prostate cancer. Medscape Reference: Drugs, Diseases & Procedures. WebMD LLC. http://emedicine.medscape.com/article/453349
Last Reviewed - 30 April 2013