A pioneering radiation treatment has been used to treat kidney cancer for the first time in New Zealand by a team at
Waikato Hospital, opening new possibilities for some patients.
The stereotactic ablative radiotherapy (SABR) technique is a non-invasive, effective and accurate way to treat small
tumours, using high doses of radiation designed to kill cancer cells and spare healthy tissue. While it is currently
used on other parts of the body including the lungs, brain and bones, this is the first time the procedure has been
carried out on the kidney in New Zealand.
The patient was a woman in her 80s, referred to the Radiation Oncology Service where a cancer in her kidney was
identified through scans. The woman was ruled out as a candidate for surgery due to her other medical conditions and age
which put her at too much risk.
Radiation Oncologist Dr Roger Huang says because the cancer was localised to the kidney and had not spread, the decision
was made to attempt a more radical treatment approach.
"That's where SABR comes in. The difference between the conventional radiation therapy and SABR is that we deliver a
much higher dose and with millimetre precision."
He says the procedure has so far shown to be a safe and effective way of treating kidney cancer. It is also convenient
for patients because it cuts down the number of treatment sessions to either one or three.
Because SABR is non-invasive, the person is treated as an outpatient and does not require a stay in hospital or any
post-operative recovery. It also allows for the possibility to retain some organ function, compared to surgery.
Dr Huang says recent major advancements in medical technology, such as image-guided radiation treatment, have opened up
new frontiers in the treatment of cancer.
For the treatment to be a success, a lot of meticulous planning needs to be done to make sure the radiation hits exactly
where it needs to. This includes taking into account the movement of the organ while the patient is breathing.
"If we are a few millimetres out, we can potentially damage the surrounding organs with a very high dose of radiation."
He says there will be cases where SABR can't be done because of the risk to other major organs.
An initial scan about a month after treatment showed positive signs with the tumour reacting to the radiation as
expected. It's hoped a follow-up scan in the coming months will show the tumour starting to shrink, meaning the cancer
cells have either stopped dividing or have died.
Since the treatment, bleeding from the patient's kidney has stopped, her kidney function has been maintained and she is
no longer anaemic. She has also reported no major side-effects aside from fatigue, which was expected to improve over
time.
The treatment done at Waikato Hospital was based on an Australian study which showed promising results in controlling
local disease. Dr John Chin developed Waikato Hospital's treatment protocol.
Dr Huang says the procedure can offer an alternative for some cancer patients considered inoperable. Where previously
radiation treatment would have been considered to manage symptoms and maintain a quality of life, SABR allows it to be
taken a step further.
"Not only did we manage the symptoms, but we've given her a chance of cure."
The Radiation Therapy team is now developing SABR techniques to treat other cancer sites including in the prostate,
pancreas and liver.
Dr Huang believes the process could cut the length of treatment for prostate cancer from the current four weeks to one,
and it could improve outcomes for pancreatic cancer which can be difficult to treat using conventional radiation
therapy.
Dr Huang says Waikato Hospital has the opportunity to become a leader in developing and providing the SABR treatment in
New Zealand as the technique becomes more readily available.