Brachytherapy for Prostate Cancer
Brachytherapy is a form of radiation therapy where radiation oncologists put a radioactive source inside the prostate.
This source delivers very high doses of radiation right to the tumour while limiting radiation to healthy body parts.
Radiation oncologists use 2 types of brachytherapy to treat prostate cancer:
Low dose rate (LDR) or seed brachytherapy
How does it work?
In LDR brachytherapy, radiation oncologists place small seeds of radioactive Iodine into the prostate.
Each seed is 5mm long and 1mm wide and doctors use 80 to 120 seeds. These seeds deliver radiation over a long time at a low dose rate.
As the seeds are right in the prostate, damage to healthy organs is reduced. LDR brachytherapy has a high cure rate for people who are suitable for this treatment.
Who is suitable?
LDR brachytherapy is suitable for people with lower risk, localised prostate cancers. The radiation oncologist will talk to you about whether it is the right option for you.
What are the benefits and side effects?
The main benefit of LDR brachytherapy is that it reduces side effects. There is still a small risk of urethral scarring and long-term changes in bladder habits. Like other prostate cancer treatments, there is a chance of developing erectile dysfunction. However, this risk is lowest for men treated with LDR brachytherapy.
This treatment is very convenient and usually only takes 2-3 hospital visits and one overnight stay.
What is the procedure for treatment?
The first visit is when the radiation oncology team plans where the seeds will go. Most men have a general anaesthetic for this procedure and doctors also do a rectal ultrasound.
Following this, medical physicists and radiation therapists make a treatment plan. The radiation oncologist checks the safety and effectiveness of this plan. The plan is a 3D model of where the treating team needs to put the seeds to deliver the right dose to the cancer. Once this is done, the treating team orders the seeds and preloads them into needles, ready to insert a few weeks later.
The insertion process takes around 90 minutes and requires another anaesthetic. During the process, radiation oncologists put the radioactive seeds into the prostate through the perineum, which is the skin between the scrotum and anus, using 20-30 thin needles.
Most men can go home on the same day they are treated. After a few weeks the treating team does a CT scan or MRI to ensure the seeds are in the right place to treat the prostate effectively.
Results of LDR brachytherapy
LDR brachytherapy is well established as a treatment for prostate cancer and large studies show the outcomes are at least as effective as external beam radiotherapy and surgery.
For more information watch the video.
In March 2016, Donald Patterson was the 400th man to be treated with LDR brachytherapy in Australia. View his experience.
High dose rate (HDR) brachytherapy
How it works
HDR brachytherapy uses a single radioactive source to deliver a high dose of radiation to the prostate over a short time. Radiation oncologists nearly always use it with external beam radiotherapy as a boost, enabling a higher dose to be given to the prostate cancer.
Who is suitable?
Radiation oncologists can use this treatment for men with higher risk (more locally advanced) prostate cancers.
What are the benefits and side effects?
The main benefit of HDR brachytherapy is that it gives a higher dose of radiation to the prostate than can be done with external beam radiation therapy alone.
The side effects include temporary bladder irritation and bruising from the needles. In the long term the risks are like external beam radiotherapy. There is a slightly higher risk of urethral scarring and bladder irritation.
What is the procedure for treatment?
Radiation oncologists do HDR brachytherapy using a machine called a remote after loader which contains a small, highly radioactive source.
During treatment, doctors insert thin hollow needles into the prostate for the time needed to deliver the treatment. The radioactive source is pushed through each needle, pausing on the way to give a dose of radiation to the tumour. Treatment only takes a few minutes and may be repeated over a few sessions (usually 1-4). Once the treatments are finished the needles are removed.
Men having HDR brachytherapy must have a spinal or general anaesthetic for the operation and spend up to 24 hours in hospital without getting out of bed.
Results of HDR brachytherapy
HDR brachytherapy offers results that are at least as good as external beam radiation therapy or surgery to take out the prostate.
Useful Resources
What is brachytherapy and how effective is it for prostate cancer? Interview with A/Prof Jeremy Millar, Director, Radiation Oncology, Alfred Health.
