A new radiotherapy treatment has dramatically reduced side effects for prostate cancer patients.
Volumetric Arc Therapy is able to more accurately focus radiation in three dimensions, allowing more radiation to be delivered to the tumour with less hitting nearby organs.
It can also be modulated as it goes, allowing each treatment to be completed in minutes.
Radiation oncologist Dr Doug Iupati said Wellington Hospital was the first in New Zealand to adopt the technology.
In the past, radiation treatment consisted of pointing a beam at the patient guided by relatively primitive, two dimensional CT (Computer Axial Tomography) scanning.
“You basically pointed a beam and shifted it around the patient,” Iupati said.
The prostate is in the middle of the body and varying the radiation intensity to it was a crude and slow process.
“You could do the modulating before the beam is moving; one direction – shoot – stop – move – beam on – beam off …. that takes a while.”
The new technology allows the beam to move around and be adjusted as it goes.
“That modulation is pretty much what we think eliminated bowel toxicity – diarrhoea, bleeding from the bowel and pain,” he said.
When Iupati was trained, 15 years ago, bowel damage was expected in every patient.
“We had to prescribe a steroid enema. We don’t do that any more.”
Collateral damage to the bowel was the limiting factor for radiotherapy, so oncologists can now apply more radiation intensity to the tumour.
“Increasing the dose to the prostate has been shown to increase the cure rate,” Iupati said.
Warwick Gibson of Kāpiti began a seven-week course of prostate cancer treatment in November, 2014.
He said the treatment was very quick.
“I was only in there for 10 – 15 minutes and then I was on my way back to work again. It’s all very well geared up. The staff and nurses were excellent and I didn’t have any side effects. All in all everything was very smooth.”
Iupati said the reduced treatment time also improved its effectiveness.
“The less time you are on the bench the less time you have to wriggle and move, and the more reliable it is.”
Get your prostate checked
Not only have prostate cancer treatments far more bearable, but men are less likely to need treatment and, if they do, it is likely to be much later.
Dr Doug Iupati said that, although prostate cancer was relatively common and one of the major killers, most tumours are classified as low risk.
In those cases the most likely treatment is “active surveillance” rather than surgery, radiotherapy or chemotherapy.
“Two thirds of patients can avoid having any treatment,” he said.
However, Iupati still urged me over 55 to get regular checks.
The cancer itself often has little or no symptoms for many years but treatments can have severe side-effects, including urinary and bowel problems, erectile dysfunction and loss of fertility, as well as all the usual effects of hormone therapy, radio-therapy and chemotherapy, such as pain, nausea and hair loss.
Survival outcomes have been very good and the period for follow-up treatment had risen to 10 years.
However, active surveillance was effectively a new treatment regime that had never been compared to a standard in the normal randomised trials.
Although most low-risk patients did well on it, not all did.
“The one third that progress on it tends to do worse,” he said.