Background:Hyperinsulinaemic hypoglycaemia (HH) is a potentially lethal disease caused by over functioning beta cells derived from the pancreatic islets of Langerhans. Lethal HH and brain damage is a problem especially in infants with congenital HH. Current therapeutic approaches are associated with severe side effects/morbidity (diabetes, exocrine pancreas insufficiency etc.) considered acceptable in relation to the lethal outcome of HH although massively reducing quality of life and also life expectancy.Aims and objectives:In order to significantly improve therapy of this awful disorder, we propose to develop a simultaneous imaging/therapy platform allowing diagnostic imaging as well as image guided surgical, photodynamic or radiopeptide therapy to selectively resect/destroy diseased beta cells. This platform will enable delivery of patient-individual tailored therapy, increasing cure rate while significantly reducing or even avoiding side effects. The platform will integrate information from pre-clinical imaging for optimal therapy planning with intra-operative imaging for image guided surgery. By implementation of extended field optical coherence tomography, information on a histopathological level will allow increased precision of therapy. Highly innovative photodynamic therapy will enable selective (endoscopic) destruction of diseased beta cells without resection of pancreatic tissue.Outcome:Our highly-innovative integrated imaging/therapy (“theranostic”) platform will allow diagnosis and monitoring of disease, support and guide therapeutic intervention, predict outcome of intervention and individual prognosis. This technology will massively improve therapy, especially in infants, by improving cure rates while significantly reducing morbidity for improved quality of life and increased life expectancy. We will contribute to the goals of the International Rare Diseases Research Consortium (IRDiRC): 200 new therapies.