sentences:  She and her team have also estimated the absolute size of the benefit of radiotherapy to breast cancer patients and their work is enabling comparison of the likely absolute benefit of radiotherapy with its likely absolute risk for individual patients.Therefore, it is now becoming possible to assess which patients can receive standard radiotherapy, which should be considered for advanced techniques, and which should avoid radiotherapy altogether.Other topics that Darby has worked on include estimating the risk of lung cancer from residential radon, the risk of invasive breast cancer after a diagnosis of ductal carcinoma "in situ", and the risk of cancer after computerised tomography (CT) scans in young people.