Radiotherapy has been a mainstay of cancer treatment for more than a century. Over the years it has evolved from blasting a tumour and the surrounding tissue with poorly targeted X-ray beams, to a precision strike against the disease. Advances in imaging technology, as well as the development of complex, moving machines that deliver radiotherapy, mean that today's doctors can use computer planning to precisely mould radiation beams to the exact shape of a tumour. This image shows a scan through the middle of the head of a patient with throat cancer, whose radiotherapy is being planned using a technique called flattening-filter-free beams, or FFF. The dark red shape in the centre highlights the tumour, which will get the highest dose of cancer-killing radiation. Other colours show regions receiving lower doses, helping to spare important areas in the head and neck, such as the salivary glands, from any damage.
Written by Kat Arney
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.