Smart radiation for prostate cancer saves more intimate functions
Jill MargoHealth editor
Updated Mar 1, 2016 – 12.23pm, first published at 11.20am
A smarter form of radiation treatment for prostate cancer will be given to an Australian patient for the first time on Wednesday.
It represents a new generation of standard brachytherapy which has been in use for 20 years and which delivers radiation via seeds implanted in the prostate.
Called 4D brachytherapy, this new version is much faster to perform and is said to provide higher survival rates with lower risks of incontinence and impotence than the standard form.
Targeted: 4D brachytherapy - smart radiation for prostate cancer.
As it is an accurate, highly targeted form of radiotherapy, it is suitable for men whose cancer has not spread outside the prostate.
The new technique uses scans and computer algorithms to tailor treatment to each patient and determine how many seeds should be used and where they should be placed.
The seeds, which are capsules the size of small grains of rice, are loaded with radiation. Fine needles are used to pass them through the perineum and position them directly into the prostate gland.
To limit the risk of the seeds migrating, stranded seeds are placed around the outside of the prostate and loose seeds are placed at the centre of the tumour.
This targeted treatment means higher doses can be used than in traditional radiotherapy with less chance of surrounding structures being damaged.
About 75 seeds are used in an average procedure. They remain in place for life, although their radiation gradually diminishes over six months.
The team behind the innovation is from St Luke's Cancer Centre in Guilford, England, where more than 500 men with early prostate cancer are treated annually.
Stephen Langley, professor of urology at St Luke's, says 4D combines the two stages of a standard brachytherapy into one short procedure.
Shorter procedure time
It can be completed in 45 minutes rather than the usual two to three hours. For efficiency, seeds are preloaded before the operation and a planning computer then identifies where every seed is implanted to ensure the radiation dose is correctly built up.
The 45-minute anaesthetic means a quicker recovery than robotic surgery which requires a four-hour anaesthetic. Langley performs both procedures and while they offer similar levels of success eliminating cancer he strongly encourages patients to weigh the long-term side effects of each.
Compared with surgery, Langley says urinary incontinence is rare after brachytherapy.
Issues such as frequency, a slow stream, getting up at night and urgency appear to be improved with 4D compared to standard brachytherapy because sensitive tissues such as urethra and the bladder are spared from radiation.
Men also tend to have very few bowel symptoms with 4D.
While ejaculate is usually saved, its volume and consistency often reduces. He notes, however, that three men have fathered children four years after treatment.
A main side effect is the potential swelling of the prostate to swell which can aggravate pre-existing urinary difficulties. Some men with a large prostate may be better treated with surgery.
So what happens if the seeds fail? Robert Laing, a radiation oncologist and the clinical director of St Luke's, says failure is identified through a rising PSA.
"We work up these patients very carefully with MRI, Pet CT scans and multiple biopsies. If the only site of disease is in the prostate we will offer them a radical prostatectomy."
He says of 3200 men treated with brachytherapy, about a half a per cent went on to have radical surgery.
Following brachytherapy there is bruising. While some men feel they are sitting on a golf ball, Laing says others have no local symptoms.
He says many want the procedure on a Thursday so they can be back at their desk on Monday, particularly if they don't want to disclose their cancer in the workplace.
Australians eligible for standard brachytherapy under Medicare are also eligible for 4D brachytherapy.
Langley and Laing will oversee Wednesday's Australian 4D operation in Hobart.
Jill Margo is the health editor, based in the Sydney office. Jill has won multiple prizes, including two Walkley Awards and is an adjunct associate professor at School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Australia. Connect with Jill on Twitter. Email Jill at jmargo@afr.com
Latest In Health & wellness
Most Viewed In Life and luxury