 In the 20 million strong metropolis of modern Mumbai, life is a constant world of activity. But despite the crowds and commotion outside, in this room, everything is calm, precise and controlled, allowing doctors to target cancer tumours with millimetre accuracy. Cereotactic radiation is known to be as precise and effective as a surgical knife in many types of cancer. And right now, we are testing its performance for inoperable liver cancer. This advanced form of radiation therapy is possible because of improvements in medical imaging, which allow a doctor to map out the exact contours of a tumour and use this 3D outline to shape radiation beams. During therapy, the patient lies on a custom-made body mould and uses sensors to monitor and control their breathing to minimise any movement during treatment. This immobilisation, combined with precise targeting, means the beams are less likely to damage surrounding tissue, so the doctors can deliver much higher doses of radiation. This makes treatment faster and more effective, with less side effects and in some cases, can buy even an advanced cancer patient valuable time.