Nuclear medicine diagnostics, therapy and theranostics in the context of modern oncology Abstract. Nuclear medicine deals with imaging, therapy and theranostics using radioactive elements bound to targeted carrier molecules, so-called radiotracers. Modern oncology in particular benefits from the increasing diagnostic possibilities, for example in the context of increasingly precise tumour spread diagnostics or the early measurement of tumour response under targeted therapies. Modern nuclear medicine also offers new and innovative methods for the treatment of special types of tumours. For example, new therapies are available to treat metastatic prostate cancer, while other methods, such as breast and lung cancer or pancreatic cancer, are currently being tested in clinical trials. Nuclear medicine is complemented by theranostics, which combines therapeutic and diagnostic methods. Particularly in modern, personalized oncology with all its targeted therapies, these methods benefit from predicting therapy and high response rates.