at the royal marsden hospital, a study is under way to develop an algorithm that can determine the differencethe side effects of cancer treatment on a scan. these are things that are often very difficult for the human eye to determine. ok, so this is a patient with coronavirus, covid—19. essentially, we have some ct scans of the chest, taken a few weeks apart. doctor richard lee is a consultant in respiratory medicine and a champion of early cancer diagnosis at the hospital. so on the left side here, you can see the patient has the two lungs which are usually black in colour. and we have this fluffy, greyer kind of almost ground glass appearance at the bottom of the lung. one of the things we see in covid—19 is the ground glass change — it suggests infection or inflammation — but the same things can be seen in the context of how the cancer is behaving, and particularly important is how the treatment itself can cause a very similar change when there is toxicity. a large archive of anonymized clinical images is being used, with approval from the hospital's ethics board. this data can be studied