Many cancer patients in New Zealand and Australia are missing out on radiation therapy which could help in their treatment

Data presented to a radiology conference held in Auckland today shows fewer than a third of New Zealand patients will actually receive radiation therapy, despite half being likely to benefit.

In Australia, a study found similar numbers.

Carol Johnson from the Australian and New Zealand College of Radiologists says many patients offered the treatment were not doing it, and their distance from the radiology services was a factor.

In some of the regions such as Northland, Te Rawhiti, West Coast, intervention rates may be as low as 28 percent.

In bigger centres it's generally up around 40 percent.

Dr Johnson also stressed radiation technology has come a long way, and it's far less invasive than it used to be.