This episode of the Physics World Weekly podcast features Ileana Silvestre Patallo, a medical physicist at the UK’s National Physical Laboratory, and Ruth McLauchlan, consultant radiotherapy physicist at Imperial College Healthcare NHS Trust.

In a wide-ranging conversation with Physics World’s Tami Freeman, Patallo and McLauchlan explain how ionizing radiation such as X-rays and proton beams interact with our bodies and how radiation is being used to treat diseases including cancer.

• This episode was created in collaboration with IPEM, the Institute of Physics and Engineering in Medicine. IPEM owns the journal Physics in Medicine & Biology.