[Oncological theranostics in nuclear medicine].

The theranostic principle describes the diagnostic and therapeutic use of radioactive nuclides linked to biochemically active ligands. The oldest and most prominent field of application of theranostics in oncology is differentiated thyroid cancer treated by radioiodine therapy, which allows imaging of the iodine uptake and thus tumor manifestations by gamma (γ) radiation of radioiodine. Other areas of application include neuroendocrine tumors, castration-resistant prostate cancer and, in the context of individual therapeutic approaches, fibroblastic tumors. Imaging with beta-plus (β+) emitters is mainly performed using so-called hybrid imaging: positron emission tomography (PET) in combination with computed tomography or magnetic resonance imaging (PET/CT or PET/MRI). Beta-minus (β-) emitters are predominantly used in therapy, but the use of alpha (α) emitters is also increasing, thus, enabling targeted cancer treatment with mostly low-grade side effects.