A Peter Mac led study has confirmed secondary cancers in the lungs can be safely treated with a once-off, high-dose burst of targeted radiotherapy.

Patients receiving radiotherapy usually visit hospital multiple times over successive days and weeks.

But Associate Professor Shankar Siva’s trial studied a high-dose and precision form of radiotherapy - stereotactic ablative radiotherapy or SABR – as either a single treatment or the same dose in four treatments.

Associate Professor Siva said there had been a major focus – especially during the COVID-19 pandemic – of finding a way to treat patients without the need for repeat visits to hospital.

“I think the future of radiation oncology could be these ultra-short treatments,” Associate Professor Siva said.

“Our results indicate that SABR can be a safe and effective treatment for patients whose cancer has spread to their lungs, even when it’s delivered in a single session.”

Patients in the SAFRON II trial typically had colorectal cancer that had spread to the lungs.

The 90 patients in this trial were randomised into two groups – half received a single dose of SABR, and the other had an equivalent dose of SABR but accumulated over four visits.

When followed up one year later, there was a little difference in side effects and outcomes.

Cancers were controlled for 93% for patients who received a single SABR treatment, compared to 95% for those who received four treatments. Overall survival was 95% compared to 93% and disease-free survival was 59% and 60%.

Patients in the trial will be followed for a total of three years to check on their outcomes.

The primary analysis of this Phase II trial was presented at the ASTRO (American Society for Radiation Oncology) 2020 Annual Meeting, held 25 to 28 October and online only this year due to COVID-19.

It was selected alongside eight other of the best abstracts from the meeting for the prestigious ASTRO press program.

The study was conducted over 13 medical centres in Australia and New Zealand with support from TROG Cancer Research.