Neutron capture therapy (NCT) is a binary form of radiotherapy that utilizes the high cross section of some nonradioactive elements, in particular boron-10 and gadolinium-157, for thermal neutron capture. The energetic charged particles (electrons and alpha particles) released in the capture reaction cause a high localized deposition. For almost a century, NCT has been regarded as the holy grail of targeted radiotherapy, but its superiority over other available treatments has not been demonstrated so far. Limitations included amongst others a poor and non-selective biodistribution of Boron carrier molecules, the limited availability of suitable neutron sources, a lack of tools for patient selection and individualized dosimetry, and a shortage of properly conducted clinical trials.