Urologist Dr Peter Aslan is one of the investigators on a world-first trial which may pave the way for an alternative to surgery or conventional radiation treatment for kidney cancer.
The targeted treatment, known as SIRT (Selective International Radiation Therapy) involves sending radioactive material directly to the tumour via its blood supply.
Tiny microspheres of radio-active material are injected, via a catheter, into the arteries that supply the tumour.
Whereas conventional radiotherapy can only be applied to limited areas of the body and can adversely affect nearby tissues, SIRT is a highly targeted treatment that investigators hope will only impact the tumour.
Kidney cancers had been considered difficult to treat with radiation as the dose required to shrink the tumour might cause significant damage to the surrounding tissues or could render the remainder of the kidney unviable.
However, with the completion of animal studies using the SIRT method which successfully isolated the impact of the radiation to the tumour only, the first human trials are underway and are already showing promising results.
“We are pleased, and even surprised, by the results so far,” says Dr Aslan.
“There has been some minor shrinkage of the tumour in two of three patients to date at fairly low radiation doses, and we anticipate the use of higher doses may produce even better shrinkage of tumours. However, the study is not designed to show that and the aim is to ensure the safety of the procedure. ”
The trial is being conducted at four radiation dose levels to evaluate feasibility and toxicity of the treatment procedure, and to determine the maximum tolerated dose.
“While surgery is the “gold standard” for treating kidney cancers, this is a non-aggressive treatment, which has the potential to be particularly suited for older or frailer patients for whom surgery may be a less desirable option,” says Dr Peter Aslan.
“As the average age of renal cancer patients increases, it makes the potential of this treatment even more relevant.”
“The other potential advantage, for other groups of patients, is that it may be helpful in shrinking larger tumours to a stage where they could be treated by cryotherapy or partial nephrectomy, which removes the tumour while maintaining kidney function,” says Dr Aslan.
In Australia kidney cancer (or renal cell carcinoma) is the eighth most common form of cancer and the numbers of cases continue to grow as the population ages and as more cases are detected incidentally during routine scans.
Renal cell carcinoma is where the cancers begin to grow in the tubules of one or both kidneys. Without treatment it can spread to other parts of the body.
The SIRT treatment, which has been developed by Australian medical device company, Sirtex, has already been used successfully, worldwide, to treat liver cancer.
Between 15 and 24 patients are required to complete this trial, and if the results are successful, there would be a follow-up study to definitely assess the effectiveness of the treatment.
Eligible patients are those with renal cancer not suitable for surgery, local ablation or other conventional treatments.