Adapting radiotherapy for safer and more effective tumour control

Background

Radiotherapy is an important part of cancer treatment. Australian research indicates almost half of all cancer patients should have external beam radiotherapy at least once during their treatment.

External beam radiotherapy uses a radiation machine to direct radiation beams at the cancer. The machines are incredibly precise, but their targets are always moving. Even when we lie perfectly still, our bodies are always in motion – we breathe, our hearts beat, our muscles twitch, we swallow and we digest. This means that a cancer tumour is also never perfectly still. To overcome natural movement, standard radiotherapy treatments use a larger radiation beam than is needed to treat the whole tumour. This approach results in healthy tissue also being exposed to radiation.

To tackle this problem, Professor Keall and his team invented a system that adjusts the position of radiation beams in real-time. Called ’beam adaptation’, the system adjusts the radiation beams to target the tumour continuously; essentially following the tumour as it makes even the slightest of movements without damaging healthy tissue.

A limitation of beam adaptation is that it can currently only be used to treat a single tumour. This means that if a person has developed two or more tumours, standard radiotherapy is the only option.

The research

In this project, Professor Keall and his team at the University of Sydney and the Royal North Shore Hospital will take adaptive radiotherapy to the next level, enhancing the system to target and move with multiple tumours.

The researchers will focus on developing adaptive radiotherapy for locally advanced lung, prostate and oligometastatic cancer (multiple tumours that have spread beyond the primary site). They’ll use simulated treatment scenarios to refine the system, before testing in a phase one clinical trial.