Particle therapy is an advanced form of radiation therapy that can be advantageous in specific cases. The most common form is called proton therapy and at this stage, Australian patients must travel overseas to access this treatment. Individuals who are most likely to benefit from proton therapy include those who have tumours that are near vital organs (such as base of skull tumours adjacent to the brainstem and nerves responsible for vision) and young patients where long term effects of treatment can potentially be minimised (such as hormonal imbalances, intellectual development delay and secondary cancers).
Protons are heavy charged particles and have a unique way of depositing their energy. Rather than causing damage through their whole path, they deposit most of their energy at a distinct depth before stopping completely. This effect is referred to as the Bragg Peak and allows the largest dose to be delivered in the tumour. Modern proton machines have intensity modulated proton therapy technology which utilise pencil beam scanning, allowing the radiation oncologist to prescribe treatment which ‘paints’ across the tumour volume, whilst sparing healthy tissues and organs.
Access to proton therapy is limited and strict criteria have been established to determine cases appropriate for Federal Government support via the Medical Treatment Overseas Program. As part of this application, the patient’s treating team will be asked to provide supporting documentation and evidence of benefit compared to conventional (photon) radiation therapy that is specific for the individual case.
In 2017, the Federal Government announced funding for the establishment of a proton therapy centre in Adelaide, with commencement of operations expected in 2020.
Watch the TEDx Talk- The Mighty Proton by Dr Anita Mahajan, Radiation Oncologist and Medical Director of the Proton Therapy Center at MD Anderson Cancer Center in Houston Texas, one of the largest cancer treatment centers in the world.