[en] Using molecules to safely carry radioactive materials inside the human body is helping physicians get more accurate images of tumours and more effectively eliminate cancer cells. This method of combining therapeutic and diagnostic uses of radiopharmaceuticals is called theranostics. It’s one of the latest advances in cancer care and one of several methods the IAEA is helping to bring to patients in countries worldwide through technology transfer and capacity building. “Theranostics has the potential to change the idea of cancer treatment,” said Mohamad Haidar, Associate Professor of Clinical Radiology in the Department of Radiology at the American University of Beirut Medical Center in Lebanon. “It is a very efficient approach that allows you to see what you treat and treat what you see. The result is a better quality of life, improved life expectancy and minimal side effects compared to other treatments, like chemotherapy.” While it has been used for more than 70 years for a few specific diseases, such as thyroid cancer, theranostics has only started to take off in the last few decades; advances in medicine and technology have led to the development of new radiopharmaceuticals and medical equipment, opening the door for theranostics to be used for fighting cancers of the prostate, liver, gastrointestinal system and nervous system, among others. This includes treatment of neuroendocrine tumours using a radiopharmaceutical called lutetium-177 (Lu-177)-DOTATATE).