Call to arms: need for radiobiology in molecular radionuclide therapy

Dear Sir, Now is an extraordinarily exciting time for the multidisciplinary field of molecular radionuclide therapy (MRT) [1, 2, 3]. More patients than ever before are being treated with radiolabelled compounds, and an increasing number of pharmaceutical companies incorporate radiopharmaceuticals into their portfolios. MRT allows specific irradiation of localised and disseminated disease, with potentially fewer side effects than external beam radiotherapy (EBRT). However, aside from obvious improvements in radiochemistry, radiopharmacy, and dosimetry of MRT agents, a better understanding of the radiobiology, i.e. of the biological effects of ionising radiation of MRT agents, is needed. Radiobiology has been key in establishing optimal treatment regimens for EBRT whilst protecting healthy tissues. The paradigm of radiobiology is that tumour control probability and side effects are proportional to absorbed radiation dose; radiobiology is thus deeply connected with dosimetry. However,...