Massachusetts General Hospital (MGH) is considered to be one of the leading hospitals in the US – in terms of both patient care and its cutting-edge medical research. In this short film, Physics World visits the MGH to meet the chief of the hospital's physics division, Thomas Bortfeld, who describes the hospital's pioneering cancer treatments at its proton-therapy centre. Bortfeld also shares his thoughts on what it is like to move from an academic research setting to the dynamic environment of a working hospital.